U.S. patent application number 09/200054 was filed with the patent office on 2001-12-06 for machine for manufacturing thermoplastic tubes.
This patent application is currently assigned to THATCHER TUBES LLC. Invention is credited to KIERAS, RONALD E., RHOADES, JOHN J..
Application Number | 20010048953 09/200054 |
Document ID | / |
Family ID | 22740129 |
Filed Date | 2001-12-06 |
United States Patent
Application |
20010048953 |
Kind Code |
A1 |
KIERAS, RONALD E. ; et
al. |
December 6, 2001 |
MACHINE FOR MANUFACTURING THERMOPLASTIC TUBES
Abstract
The machine of the present invention is a means for
manufacturing thermoplastic tubes from hollow thermoplastic sleeves
by a variety of different manufacturing processes. The machine is a
single apparatus having an indexing table with a plurality of
mandrels for holding hollow thermoplastic sleeves for the purpose
of transporting the same around a closed manufacturing path. The
manufacturing path of the machine of the present invention is a
series of stations which are mechanical devices for carrying out
the manufacturing steps necessary to produce tubes from
thermoplastic blank sleeves. The stations of the manufacturing path
are modular so that they may be removed, added or rearranged; may
be optionally connected to a process logic controller and may
optionally have sensors for information feedback to the PLC
device.
Inventors: |
KIERAS, RONALD E.;
(WOODSTOCK, IL) ; RHOADES, JOHN J.; (POPLAR GROVE,
IL) |
Correspondence
Address: |
ARMSTRONG, WESTERMAN, HATTORI,
MCLELAND & NAUGHTON LLP
LAW & FINANCE BUILDING
429 FOURTH AVE, SUITE 707
PITTSBURGH
PA
15222
US
|
Assignee: |
THATCHER TUBES LLC
WOODSTOCK
IL
60098
|
Family ID: |
22740129 |
Appl. No.: |
09/200054 |
Filed: |
November 25, 1998 |
Current U.S.
Class: |
425/392 |
Current CPC
Class: |
B29C 66/91411 20130101;
B29C 66/91313 20130101; B29L 2031/712 20130101; B29C 43/08
20130101; B29C 66/91315 20130101; B29C 66/9141 20130101; B29D 23/20
20130101; B29C 66/73711 20130101; B29C 66/9121 20130101; B29C
66/73712 20130101; B29C 2043/3283 20130101; B29C 2043/5833
20130101; B29C 43/42 20130101; B29C 2043/3678 20130101; B29C
66/91421 20130101; B29C 66/71 20130101; B29C 66/72341 20130101;
B29C 2949/0829 20220501; B29K 2105/258 20130101; B29C 66/91216
20130101; B29C 33/20 20130101; B29C 65/7882 20130101; B29C 66/961
20130101; B29C 66/91645 20130101; B29C 66/91221 20130101; B29L
2023/20 20130101; B29C 2043/3623 20130101; B29C 2949/082 20220501;
B29C 66/71 20130101; B29K 2023/06 20130101; B29C 66/71 20130101;
B29K 2023/0633 20130101; B29C 66/71 20130101; B29K 2023/065
20130101; B29C 66/71 20130101; B29K 2067/00 20130101; B29C 66/71
20130101; B29K 2067/003 20130101; B29C 66/71 20130101; B29K 2069/00
20130101; B29C 66/71 20130101; B29K 2077/00 20130101 |
Class at
Publication: |
425/392 |
International
Class: |
B28B 021/00 |
Claims
What is claimed is:
1. An apparatus for converting thermoplastic sleeves into
thermoplastic tubes, comprising: an indexing device rotatable about
a shaft; means for supporting sleeves mounted on said indexing
device for advancement along a closed path in response to relative
rotation of said indexing device in a predetermined direction; a
frame for mounting said indexing device and a plurality of
manufacturing stations, said plurality of manufacturing stations
further comprising: means for loading said sleeves onto said
supporting means in a first location of said closed path; means for
forming a head on said sleeves to form tubes in a second location
of said closed path downstream of said first location; and means
for unloading said tubes from said supporting means in a third
location of said closed path downstream of said second location
positioned between said second and first locations.
2. The apparatus according to claim 1 wherein, said means for
loading sleeves onto said supporting means is a member selected
from the group consisting of a push rod driven by an air cylinder;
a push rod driven by a cam driver; an advancing and retracting
linear actuator; a crank motion device and a servo-motor driven
push rod.
3. The apparatus according to claim 1 wherein, said means for
forming a head on said sleeve is a member selected from the group
consisting of a heater and a mold die; a sonic welder and a heat
welder.
4. The apparatus according to claim 1 wherein, said means for
unloading said tubes from said supporting means is a member
selected from the group consisting of a stripper driven by an air
cylinder; a stripper driven by a cam driver; an advancing and
retracting linear actuator; an air blower; a crank motion stripper
and a servo-motor driven stripper.
5. The apparatus according to claim 1 wherein, said apparatus
further comprises a PLC device connected to said indexing device,
said loading means, said head forming means and said unloading
means.
6. The apparatus according to claim 1, wherein said indexing device
is a member selected from the group consisting of an indexing table
and an indexing drum.
7. An apparatus for converting thermoplastic sleeves into
thermoplastic tubes, comprising: an indexing device rotatable about
a shaft; means for supporting sleeves mounted on said indexing
device for advancement along a closed path in response to relative
rotation of said indexing device in a predetermined direction; a
frame for mounting said indexing device and a plurality of
manufacturing stations; said plurality of manufacturing stations
further comprising: means for loading said sleeves onto said
supporting means in a first location of said closed path; means for
forming a head on said sleeves to form tubes in a second location
of said closed path downstream of said first location; means for
decorating said tubes in a third location of said closed path
downstream of said second location; and means for unloading said
tubes from said supporting means in a fourth location of said
closed path downstream said third location positioned between said
third and first locations.
8. The apparatus according to claim 7 wherein, said means for
loading sleeves onto said supporting means is a member selected
from the group consisting of a push rod driven by an air cylinder;
a push rod driven by a cam driver; an advancing and retracting
linear actuator; a crank motion device and a servo-motor driven
push rod.
9. The apparatus according to claim 7 wherein, said means for
forming a head on said sleeve is a member selected from the group
consisting of a heater and a mold die; a sonic welder and a heat
welder.
10. The apparatus according to claim 7, wherein said means for
decorating is at least one member selected from the group
consisting of labeler; offset printer; inkjet printer; screen
printer; letter printer; computer printer; coater; embosser and
etcher.
11. The apparatus according to claim 7 wherein, said means for
unloading said tubes from said supporting means is a member
selected from the group consisting of a stripper driven by an air
cylinder; a stripper driven by a cam driver; an advancing and
retracting linear actuator; a crank motion stripper and a
servo-motor driven stripper.
12. The apparatus according to claim 7 wherein, said apparatus
further comprises a PLC device connected to said indexing device,
said loading means, said head forming means, said decorating means
and said unloading means.
13. The apparatus according to claim 7, wherein said indexing
device is a member selected from the group consisting of an
indexing table and an indexing drum.
14. An apparatus for converting thermoplastic sleeves into
thermoplastic tubes, comprising: an indexing device rotatable about
a shaft; means for supporting sleeves mounted on said indexing
device for advancement along a closed path in response to relative
rotation of said indexing device in a predetermined direction; a
frame for mounting said indexing device and a plurality of
manufacturing stations; said plurality of manufacturing stations
further comprising: means for loading said sleeves onto said
supporting means in a first location of said closed path; means for
forming a head on said sleeves to form tubes in a second location
of said closed path downstream of said first location; means for
decorating said tubes in a third location of said closed path
downstream of said second location; means for finishing said tubes
in a fourth location of said closed path downstream of said third
location; and means for unloading said tubes from said supporting
means in a fifth location of said closed path downstream said
fourth location positioned between said fourth and first
locations.
15. The apparatus according to claim 14, wherein said means for
finishing said tubes is a member selected from the group consisting
of a tab sealer; a capping device; a torquing device and an
inspecting device.
16. The apparatus according to claim 14, wherein said indexing
device is a member selected from the group consisting of an
indexing table and an indexing drum.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is related to three co-pending
applications: "Method for Manufacturing Thermoplastic Tubes" filed
even date herewith in the names of Ronald E. Kieras and John J.
Rhoades; "Process Control Method for a Machine for Manufacturing
Thermoplastic Tubes" filed even date herewith in the names of
Ronald E. Kieras, John J. Rhoades and Thomas A. Frazier; and "Plant
for Manufacturing and Packing Thermoplastic Tubes" filed even date
herewith in the names of Ronald E. Kieras and John J. Rhoades which
applications are assigned to the assignee of the present
application and incorporated by reference herein.
FIELD OF THE INVENTION
[0002] The present invention is a machine for manufacturing
thermoplastic tubes from thermoplastic sleeves.
BACKGROUND OF THE INVENTION
[0003] The machinery commonly used today for making finished,
headed thermoplastic tubes from 2 to 10 inches in length and from
1/2 inch to 3 inches in diameter comprises a series of machines
arranged linearly and having a total process line length of about
80 to 100 feet and a total height of about 20 to 30 feet. Process
lines of such dimensions are housed in factories often having
several acres of floor space.
[0004] A conventional process line for producing a single type of
thermoplastic tube in today's manufacturing plants includes
machines for heating raw polymer material into molten plastic;
extruding the molten plastic through a die to form an extruded,
stretched hollow body; cooling and then cutting the hollow body
into sleeves of equal lengths; transporting the sleeves to a
machine for molding a head on one end of the sleeves to form headed
tubes; transporting the headed tubes to another machine for
decorating or applying a graphic to the headed tubes; transporting
the printed tubes to yet another machine for applying a coating;
transporting the printed tubes to a different machine for applying
a cap to the headed end of the tubes and transporting the capped
tubes to a final machine for unloading the tubes from the process
line. The removed tubes are then packed for inventory or shipment.
Such a process line requires at least four workers during
operation, with one worker at the extrusion machine, at least two
workers along the line to monitor the tube conveyors and other
various machines and a final worker to pack the finished tubes at
the end of the line.
[0005] Increasing size has dominated production equipment design in
an effort to take advantage of economies associated with large
size. A conventional process line can simultaneously handle several
hundred tubes in different stages of production. While some
production advantages can be achieved by large size, many
limitations exist, even in view of the giant size of the
machinery.
[0006] Conventional process lines have inherent manufacturing
inefficiencies dictated by several factors such as those associated
with the line machinery itself namely: large scale, mechanical
operation, and process limitations as well as other inefficiencies
like unit cost limitations. Manufacturing inefficiencies, like
those described below, are serious barriers which ultimately can
limit the varieties of tubes available in the market.
[0007] Large scale processing machines have land, capital, and
labor requirements, the costs of which are high. Additionally,
large scale equipment is complex and as a result it requires more
labor and higher skilled labor to operate and maintain. Most
importantly, large scale design does not necessarily improve total
efficiency. While production capacity may be increased, it may be
done at the cost of efficiency. Complex machines require a
significant amount of capital, time and labor input which can mean
low overall efficiency when compared to the output.
[0008] The mechanical operation of conventional line machinery can
add inefficiency to the manufacturing process. Process line
down-time is inevitable because of the mechanical constraints of
current machinery. For example, about 70% to 80% of line down-time
is attributable to the tube and sleeve conveyor systems. One
process line will have several transport systems, each system
typically being a long chain with tube holding mandrels spaced
every couple of inches, wrapped around many drive gears. These
chain systems easily become jammed, frequently deliver improperly
positioned articles to the process machinery and often need to be
stopped for adjustment and resetting. As a result of stopping one
transport system, the entire manufacturing line must be shut
down.
[0009] Line down-time results in production loss. If one of the
processing machines on the line malfunctions on the night shift,
for example, when an engineer is not available to correct the
problem, the entire line will be stopped and it will remain idle
until morning. This loss is inefficient and costly to a
manufacturer.
[0010] The inflexibility of the production equipment creates
inherent constraints on the manufacturing process. Line equipment
cannot easily be rearranged to effectuate different manufacturing
processes because the individual machines weigh several thousands
of pounds and are not readily mobile. Furthermore, large scale
machines are built for a single purpose and are limited to that
purpose. For example, offset printing machines are limited to
printing articles by the offset printing method. Thus the
arrangement of production equipment limits the number of processing
methods available to a manufacturer.
[0011] Process control for monitoring and controlling the quality
of each individual tube product is not commercially available for
adaption to current machinery. For example, there is no known
practical way to identify, monitor and track defective products
during the manufacturing process. Defective products are removed
only at the end of the line. When a defect occurs on a tube at the
beginning of the line, continued processing of that tube is
inefficient since the tube will eventually be discarded.
[0012] Because an 80 to 100 foot tube production line requires at
least four laborers per shift, has a predictable defect rate,
requires time to retool for each job and costs money even to remain
idle, it creates a high manufacturing cost that can only be lowered
by large production jobs. It is a waste of resources to manufacture
small numbers of tubes on such large machinery because the
manufacturing cost per tube is too high. Conventional process lines
can be limited to certain size manufacturing jobs in order to
recapture manufacturing costs.
[0013] While the output of a single machine of the present
invention does not compare to the production capacity achieved by
one conventional 80 to 100 foot processing line, if the output of
one simple efficient machine is multiplied by the use of a series
of such machines, then the total output of the series of machines
can rival the conventional process lines. Thus, where efficiency is
maximized and multiplied, a great number of thermoplastic tubes may
be produced.
OBJECTS OF THE INVENTION
[0014] It is the principle object of the invention to provide a
machine for manufacturing thermoplastic tubes that more efficiently
uses land, labor and capital, as compared to conventional
manufacturing machines.
[0015] It is an object of the present invention to provide a
flexible machine for manufacturing thermoplastic tubes to
accommodate different manufacturing process methods.
[0016] It is a another object of the present invention to provide a
machine for manufacturing thermoplastic tubes which can mark,
identify, index and track every thermoplastic article being
handled.
[0017] It is still another object of the present invention to
provide a machine for manufacturing thermoplastic tubes which can
be associated with other similar machines of the present
invention.
[0018] It is yet another object of the present invention to provide
a machine that provides an operating environment substantially free
of contaminants, such as dirt and dust, for manufacturing
thermoplastic tubes suitable for the pharmaceutical industry.
[0019] It is a further object of the present invention to provide a
machine for manufacturing thermoplastic tubes of improved
quality.
[0020] It is yet a further object of the present invention to
provide a machine for manufacturing thermoplastic tubes which can
manufacture large numbers of tubes as well as small numbers of
tubes at similar operational costs.
[0021] It is still a further object of the present invention to
provide a machine for manufacturing thermoplastic tubes which can
be operably associated with a programmable logic controller.
[0022] It is a specific object of the present invention to provide
a machine for manufacturing thermoplastic tubes which can monitor
and confirm the integrity of each manufacturing process step.
[0023] It is another specific object of the invention to provide a
single machine for the production of thermoplastic tubes which can
fit into a 4.times.4 foot area.
[0024] Other objects, features and advantages of the present
invention will become apparent from the following detailed
description taken in conjunction with the accompanying
drawings.
SUMMARY OF THE INVENTION
[0025] The machine of the present invention manufactures
thermoplastic tubes from thermoplastic sleeves by a variety of
different process methods. The machine has an indexing device with
a plurality of mandrels for holding thermoplastic sleeves for the
purpose of transporting the same around a closed manufacturing
path. The manufacturing path of the machine of the present
invention comprises a series of manufacturing stations which have
mechanical devices for carrying out the manufacturing steps
necessary to produce tubes from blank sleeves.
[0026] The manufacturing stations of the manufacturing path are
modular so that they may be removed, added or rearranged; the
stations may be optionally connected to a programmable logic
controller (PLC) and may optionally have sensors for information
feedback to the PLC device. The flexibility to add, remove or
rearrange manufacturing stations gives the machine of the present
invention the capacity to carry out a variety of different
manufacturing process methods for making thermoplastic tubes.
Further, with the addition of at least one PLC device, the machine
can be operated by feedback control and can be associated with
other similar machines.
[0027] The machine of the present invention overcomes the
aforementioned disadvantages of the conventional process lines for
manufacturing thermoplastic tubes. The machine is itself more
mechanically efficient than a conventional process line. For
example, it utilizes a single indexing device, a few feet in
diameter at its maximum, which serves the same purpose as the 100
foot or longer transportation system of conventional process lines.
The machine has modular manufacturing stations which can be added,
removed or rearranged to create a variety of different
manufacturing processes and the stations are simplistic in design
which lowers the necessary capital and labor inputs. Furthermore,
accurate process control may be added to the machines which creates
labor savings, improves efficiency and reduces product waste.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] FIG. 1 is a schematic view of a machine of the present
invention of a first embodiment having a PLC device;
[0029] FIG. 2 is a schematic view of a single prior art process
line for manufacturing thermoplastic tubes;
[0030] FIG. 3 is a schematic view of an arrangement of three
manufacturing machines of the present invention for manufacturing
thermoplastic tubes;
[0031] FIG. 4 is a schematic view of the machine of the first
embodiment without the PLC device, shown only with an indexing
table, holding mandrels, and a mounting ring for mounting
manufacturing stations;
[0032] FIG. 5 is a schematic view from the rear of the machine of
FIG. 4.
[0033] FIG. 6 is a schematic view of a housing for seating a
holding mandrel in an indexing table;
[0034] FIG. 7 is a schematic view of a machine of the first
embodiment without the PLC device shown with supply and removal
means;
[0035] FIG. 8 is a schematic view of the machine of the first
embodiment without the PLC device shown from a lower
perspective;
[0036] FIG. 9 is a schematic view of the machine of the first
embodiment shown from the front with various stations
identified;
[0037] FIG. 10 shows the relative locations of fourteen different
manufacturing stations located around the circumference of an
indexing table, comprising a second embodiment of the machine of
the present invention;
[0038] FIG. 11 is a schematic view of an indexing table and the
fourteen manufacturing stations of FIG. 10;
[0039] FIG. 12 is a schematic view of a load station;
[0040] FIG. 13 is a schematic view of a preheat station or heat
station;
[0041] FIG. 14 is a schematic view of a heating probe of the
preheat or heat stations shown in FIG. 13;
[0042] FIG. 15 is a schematic view of a mold station;
[0043] FIG. 16 is a cross-sectional view of a mold die used in the
mold station of FIG. 15;
[0044] FIG. 17 is a schematic view of a treat station;
[0045] FIG. 18 is a schematic view of a label station;
[0046] FIG. 19 is a schematic view of a print station;
[0047] FIG. 20 is a schematic view of a cure station;
[0048] FIG. 21 is a schematic view of a coat station;
[0049] FIG. 22 is a schematic view of a tab seal station;
[0050] FIG. 23 is a schematic view of a cap station;
[0051] FIG. 24 is a schematic view of a torque station;
[0052] FIG. 25 is a schematic view of an unload station;
[0053] FIG. 26 is a schematic view of a sonic welding station;
[0054] FIG. 27 shows the locations of twenty manufacturing stations
along the edge of an indexing table, with each manufacturing
station associated with a PLC device, which is a third embodiment
of the present invention;
[0055] FIG. 28 is a schematic view of the twenty manufacturing
stations of FIG. 27;
[0056] FIG. 29 is a schematic view of an inspection station;
[0057] FIG. 30 is a schematic view of a confirmation station;
[0058] FIG. 31 is a schematic view of a reject station;
[0059] FIG. 32 is a schematic view of the machine of a fourth
embodiment;
[0060] FIG. 33 is a schematic view from the front of the machine of
FIG. 32;
[0061] FIG. 34 is a schematic view of a machine of a fifth
embodiment;
[0062] FIG. 35 is a schematic view from the front of the machine of
FIG. 34;
[0063] FIG. 36 is a schematic view of a machine of a sixth
embodiment;
[0064] FIG. 37 is a schematic view from the front of the machine of
FIG. 36;
[0065] FIG. 38 is a schematic view of a machine of a seventh
embodiment;
[0066] FIG. 39 is a schematic view of a machine of an eighth
embodiment;
[0067] FIG. 40 is a schematic view of a machine of a ninth
embodiment;
[0068] FIG. 41 is a schematic view from the front of the machine of
FIG. 40;
[0069] FIG. 42 is a schematic view of a machine of a tenth
embodiment;
[0070] FIG. 43 is a schematic view from the front of the machine of
FIG. 42;
[0071] FIG. 44 is a schematic view of a machine of an eleventh
embodiment;
[0072] FIG. 45 is a schematic view from the front of the machine of
FIG. 44;
[0073] FIG. 46 is a schematic view of one embodiment of an indexing
drum; and
[0074] FIG. 47 is a schematic view of a machine of the present
invention with an indexing drum as the indexing device.
DETAILED DESCRIPTION
[0075] I. Organization
[0076] This specification is organized into the following
sections:
[0077] I. Organization
[0078] II. Introduction
[0079] 1) Conventional Manufacturing Machinery
[0080] 2) The Machine of the Present Invention
[0081] III. Manufacturing with a Machine of the Present
Invention
[0082] 1) Loading Thermoplastic Sleeves
[0083] 2) Forming a Head on Thermoplastic Sleeves
[0084] 3) Decorating Thermoplastic Tubes
[0085] 4) Finishing Thermoplastic Tubes
[0086] 5) Unloading Thermoplastic Tubes
[0087] 6) Additions and Alternatives
[0088] 7) Large Scale Manufacturing
[0089] IV. Manufacturing with a Programmable Logic Controller
[0090] V. Manufacturing Example
[0091] VI. Further Embodiments
[0092] The machine of the present invention, the method of
manufacturing with the machine and the process control of the
machine are summarized in the Introduction. Next the machine and
method of manufacturing are described in detail as the machine and
method would be utilized to manufacture thermoplastic tubes from
thermoplastic sleeves. Manufacturing with a programmable logic
controller is described followed by a manufacturing example and
further embodiments of the machine of the present invention.
[0093] II. Introduction
[0094] The machine of the present invention manufactures
thermoplastic tubes from thermoplastic sleeves by a variety of
different process methods. The machine is a single apparatus having
an indexing device transportation means, i.e) an indexing table or
indexing drum, with a plurality of mandrels for holding hollow
thermoplastic sleeves for the purpose of transporting the same
around a closed manufacturing path. The manufacturing path of the
machine of the present invention comprises a series of stations
which have mechanical devices for carrying out the manufacturing
steps necessary to produce thermoplastic tubes from thermoplastic
sleeves.
[0095] A tube, as the term is used herein, refers to any
thermoplastic sleeve having at least a head on one end. A sleeve,
as the term is used herein, is a hollow body of a discrete size of
any shape. A sleeve may be fabricated from a sheet, extruded in
sleeve form, or made by any other known means. The sleeves used in
the present invention are preferably cut from an elongated
longitudinally stretched and extruded thermoplastic hollow
cylinder.
[0096] The thermoplastic tubes produced according to the present
method can be formed from various thermoplastic materials. Such
thermoplastic materials include, but are not limited to, high
density polyethylene, low density polyethylene, polypropylene, a
polyester such as polyethylene terephthalate, polycarbonates,
polyvinyl chloride, and the like.
[0097] Thermoplastic tubes may also be formed from multi layers or
laminates of various plastic materials, such as a layer of an
oxygen-impermeable material comprising a polyamide such as nylon,
or ethylene polyvinyl alcohol, a polyvinylidene chloride or the
like sandwiched between two polyethylene outer layers. Also, five
layer composites comprising an outer layer and an inner layer of a
thermoplastic such as polyethylene, polypropylene, a polyester such
as polyethylene terephthalate, an intermediate layer of an
oxygen-impermeable material, and adhesive layers between the
oxygen-impermeable material and the outer and inner layers of
thermoplastic to bond the same, can be used to form thermoplastic
tubes according to the present method.
[0098] Thermoplastic tubes are formed from a flexible material and
are readily squeezable and collapsible to force the contents of the
tube out of an orifice formed in the end of the tube at the head
portion. They are generally of a size having a wall thickness of
the sleeve portion of between about 0.010 to 0.040 inch in
thickness, while a shoulder and a neck portion of the tube will be
thicker than the wall of the sleeve, generally between 0.035 to
0.045 inch thick. Since the tube is preferably formed from an
extruded sleeve, the wall thickness of the sleeve portion will be
very uniform, with a variance in wall thickness of the sleeve
portion being only about + or -10 percent.
[0099] Preferably the extruded sleeve from which the thermoplastic
tube is formed is a sleeve cut from an extrusion which has a wall
thickness in the molten state preferably two to three times the
wall thickness of the final cooled extruded thickness. The
extrusion from which the sleeve is cut can be of any shape.
Consequently, the sleeve cut from the extrusion can take the shape
of the extrusion like cylindrical, oval, elliptical, rectangular or
any other shape. The shape of the sleeve used in the presents
invention is typically cylindrical. Such a tubular extrusion, as is
known, is formed by extruding thermoplastic material from an
extrusion annulus in a molten state and stretching the hot tubular
form, in the direction of the longitudinal axis, into a tube or
sleeve having a wall thickness one-half (1/2), one-third (1/3), or
less, than the extrusion annulus. Such a stretch oriented extruded
sleeve, when heated above the glass transition temperature of the
thermoplastic material, due to the plastic memory of the
thermoplastic material, will increase in thickness to the thickness
of the molten material exiting the extrusion annulus, and shrink in
length, thus providing sufficient molten plastic mass to form a
head on the sleeve according to the present method. When using high
density polyethylene (HDPE) or low density polyethylene (LDPE), for
example, the annulus would extrude a tubular form of about 1.5 inch
in diameter having a wall thickness between about 0.040-0.046 inch,
which would be stretched into a stretch oriented extruded sleeve of
about 1.0 inch in diameter having a wall thickness between about
0.015-0.018 inch. The final thermoplastic sleeves used in the
present invention can be of any typical diameter such as {fraction
(1/2, 5/8, 3/4, 7/8)}, 1, 1 {fraction (3/16)}, 1 3/8, 1 1/2 and 2
inches.
[0100] In addition to forming a head on a thermoplastic sleeve,
there are many other manufacturing process steps that may be
performed on a thermoplastic sleeve such as decorating, securing a
cap to the headed end, marking articles with indicia, etc. All
manufacturing steps are performed by the manufacturing stations
located around the closed manufacturing path.
[0101] The stations of the manufacturing path of the present
machine are modular so that they may be removed, added or
rearranged; the stations may be optionally connected to a
programmable logic controller (PLC) and may optionally have sensors
for information feedback to the PLC device and feedback process
control. The flexibility to add, remove or rearrange manufacturing
stations gives the machine of the present invention the capacity to
carry out a variety of different manufacturing methods for making
thermoplastic tubes.
[0102] The configuration of the machine of the present invention
i.e.) the configuration of the indexing device, manufacturing path
and optional PLC device, depends on the desired tube to be
produced. If only a simple tube is desired than the machine may be
configured with the minimum stations necessary, namely a load
station; a station for forming a head; and an unload station. Such
a machine may also be appropriate if the sleeves are previously
decorated or preprinted and only the manufacturing of a head is
desired. If a decorated tube with a cap secured to the headed end
is desired then the machine can be arranged with additional
stations for decorating and securing a cap to the tube.
[0103] FIG. 1 illustrates a machine 1 of the present invention of a
first embodiment having a indexing table 3 rotatable in a
predetermined direction and housed in a frame 5 and mounted, by
mounting bolts 7, on a fixed shaft 61 (FIG. 5) associated with an
indexer 63 (FIG. 5). Indexing table 3 has a plurality of mandrels 9
mounted thereon for holding thermoplastic sleeves.
[0104] Adjacent each mandrel 9 on machine 1 is a manufacturing
station 11, mounted on a mounting ring 13, for performing a process
step on a sleeve mounted on each mandrel 9. The configuration of
manufacturing stations 11 on mounting ring 13 comprises the
manufacturing path. The manufacturing path is closed or endless
because the first station in the path is adjacent to the last
station in the path. All sleeves are transported around the
manufacturing path by the indexing table 3. All manufacturing
stations 11 of the manufacturing path may be connected to a PLC
device 15, as shown by the dashed lines. Indexing table 3 rotates
relative to the manufacturing stations 11. A base plate 17 with a
plurality of leveling legs 19 supports frame 5. In another
configuration, PLC device 15 may be housed on base plate 17.
[0105] The embodiments shown and described herein describe a
machine of the present invention, a method of manufacturing with
the machine and a process control of the machine. The embodiments
do not intend to encompass every possible variation, configuration
and combination of the machine, method of manufacturing, and
process control within the scope of the present invention. Other
embodiments will be apparent to those skilled in the art.
[0106] 1) Conventional Manufacturing Machinery
[0107] There is shown in FIGS. 2 and 3 a schematic view of the
relative lengths of a conventional process line (FIG. 2) which is
between 80 and 100 feet long and an arrangement of three machines
of the present invention, about 30 feet long in length associated
with a common conveyor (FIG. 3). Each arrangement in FIGS. 2 and 3
includes one machine for extruding a hollow thermoplastic body and
cutting the body into thermoplastic sleeves of equal lengths.
[0108] In the conventional manufacturing process, the thermoplastic
sleeves travel along a path 80 to 100 feet in length where the
sleeve is formed into a thermoplastic tube which can be decorated,
sealed with protective material and capped. Conversely, with only a
single machine used in a plant of the present invention, a
thermoplastic sleeve is loaded onto the machine whereby it travels
around a closed path only a few feet in length where the sleeve is
formed into a thermoplastic tube which may also be decorated,
protective sealed and capped on the same manufacturing path.
[0109] Referring to FIG. 2, the machine 21 for extruding, cooling
and cutting thermoplastic sleeves is followed by a loading machine
23 which loads thermoplastic sleeves onto a transportation belt 25
which transports the sleeves to a machine 27 for forming a head on
one end of the sleeves. The resulting headed thermoplastic sleeves,
which are now considered as thermoplastic tubes, are transported by
a system 29 to a printing machine 31 for decorating the exterior of
the thermoplastic tubes. The decorated thermoplastic tubes are then
transported by a conveyor 33 to a capping machine 35 where a cap is
snapped or screwed onto the headed end of the thermoplastic tubes.
Finally, the capped tube is unloaded from the process line by an
unloader 37 and transported by a conveyor 39 to a packing machine
41, where the tubes are packed for shipment.
[0110] By comparison, an arrangement of three machines 43, 45 and
47 is shown in FIG. 3. The arrangement includes a machine 49 for
extruding, cooling and cutting thermoplastic sleeves followed by a
loading machine 51 for loading thermoplastic sleeves onto a
conveyor system 53. The sleeves travel down conveyor system 53
where they are loaded onto one of the three machines 43, 45 and 47
by mechanical feeders 55, 57 and 59. Machines 43, 45 and 47
transport the sleeves around a closed path only a few feet in
length where the sleeves are transformed from blank sleeves into
finished thermoplastic tubes by the action of several manufacturing
stations located around the closed path.
[0111] The machine of the present invention uses significantly less
sleeve and tube handling transfers compared to conventional tube
manufacturing machines. This reduction, due in part to the
compactness of the manufacturing path on the machine, improves
efficiency and reduces the cost and time of the tube manufacturing
process. In fact, the total time of manufacturing from resin pellet
to finished tube is a few minutes as compared to at least a half an
hour on conventional machinery. The machine of the present
invention may be built to fit in a 4.times.4 foot area.
[0112] 2) The Machine of the Present Invention
[0113] FIGS. 4-9 illustrate, in greater detail, machine 1 of the
first embodiment that may be used as one of machines 43, 45 and 47
shown in arrangement in FIG. 3. FIG. 4 shows mandrels 9 of machine
1, shown without PLC device 15. Mandrels 9 are evenly spaced on
indexing table 3. Indexing table 3 is typically a circular plate.
While the preferred embodiment of indexing table 3 is an aluminum
plate, indexing table 3 may be substituted by any other means which
transports sleeves around a closed manufacturing path.
[0114] The manufacturing stations 11 of the closed manufacturing
path (FIG. 1) are mounted and arranged on a support, such as
mounting ring 13 (FIG. 4). Mounting ring 13 supports manufacturing
stations 11 in a position such that manufacturing stations may
perform a process step on a sleeve or tube on mandrel 9. In the
embodiment in FIG. 1, mounting ring 13 supports manufacturing
stations 11 so that they are adjacent to and in front of a
corresponding mandrel 9. Alternatively, stations 11 could be
mounted on a frame (not shown) in the same plane as indexing table
3 so that manufacturing stations are beside a corresponding mandrel
9.
[0115] FIG. 5 is a perspective view from the rear of machine 1 of
FIG. 4, showing indexing table 3 connected to a shaft 61 rotatably
mounted on an indexer 63. Indexer 63 may be conveniently mounted on
frame 5.
[0116] Indexer 63 is a means for rotating or advancing indexing
table 3 in a step-wise or incremental manner so that sleeves loaded
onto mandrels 9 stop at each manufacturing station of the closed
path for a time period long enough to effectuate a manufacturing
process step. Indexing table 3, of this embodiment, rotates
counterclockwise.
[0117] FIG. 6 illustrates a housing assembly 65 for mandrel 9 on
indexing table 3 of machine 1. Housing assembly 65 at the base of
mandrel 9 allows mandrel 9 to rotate smoothly at various speeds,
which is necessary for certain manufacturing steps. Inside housing
assembly 65 are two rings 67 and 69 of ball bearings separated by a
bearing spacer 71. A bearing clamp 73 is also added to housing
assembly 65 for support. At one end of mandrel 9 is mounted a
mandrel pulley 75 for improved weight distribution and a means to
rotate mandrel 9. The desirable housing assembly 65 materials are
durable materials, such as metal, because the components of housing
assembly 65 wear.
[0118] FIGS. 7 and 8 show perspective views of machine 1. FIG. 7
shows machine 1 with pickle sorter 77 which supplies sleeves
directly to load station 79. FIG. 7 also shows unload chute 81
which transports tubes from machine 1 that have been removed by
unload station 83 from indexing table 3. FIG. 8 shows, in greater
detail, the relative locations of load station 79, unload station
83 and the remaining manufacturing stations.
[0119] To make machine 1 operable, machine 1 must be connected to a
power source and other additional input sources as necessary, such
as compressed air, water, electricity, steam, heated air, etc. In
additional to supplying sleeves to machine 1, other raw materials
such as caps, formed heads, etc. may be necessary for the
manufacturing process.
[0120] FIG. 9 schematically shows the configuration of the 12
manufacturing stations 11 of machine 1, all connected to PLC device
15. The manufacturing stations and corresponding manufacturing
process steps shown are: (A) load, (B) preheat, (C) heat, (D) mold,
(E) treat, (F) print, (G) cure, (H) coat, (I) cure, (J) cap, (K)
torque and (L) unload.
[0121] The minimum process steps necessary to form a tube from a
sleeve are: loading the sleeve on the machine, forming a head on
the sleeve, and unloading the headed sleeve. Besides the minimum
steps, many other finishing or intermediate steps may be performed
by additional manufacturing stations to produce a product of higher
complexity.
[0122] For example, machine 85 a second embodiment of a machine of
the present invention represented schematically in FIG. 10, has 14
stations located adjacent to each of 14 mandrels 87 mounted on
indexing table 89, which rotates counterclockwise via indexer 91
(FIG. 11) in this embodiment. The 14 different stations and
corresponding process steps are as follows: (A) load, (B) preheat,
(C) heat, (D) mold, (E) treat, (F) label, (G) print, (H) cure, (I)
coat, (J) cure, (K) tab seal, (L) cap, (M) torque and (N)
unload.
[0123] FIG. 11 is a perspective view of machine 85 of FIG. 10,
showing partial illustrations of manufacturing stations (A) through
(N). Machine 85 has three different decorating stations, (F) label,
(G) print and (I) coat. It is unlikely that a manufacturing process
would employ all three stations. Typically, only one or two of the
decorating stations would be operable. Non-operable stations may be
turned off manually or by a PLC device or they may be removed.
[0124] III. Manufacturing with a Machine of the Present
Invention
[0125] Again the configuration of the indexing device,
manufacturing path and optional PLC device, depends on the desired
tube to be produced. A decorated, sealed and capped tube will be
produced using machine 85, a second embodiment of a machine of the
present invention, illustrated in FIGS. 10 & 11 having 14
stations. All 14 manufacturing stations belonging to machine 85 are
described below.
[0126] Each manufacturing station comprises a device for performing
a manufacturing step and a means for mounting the device on a
support or frame, like mounting ring 13 of FIG. 1. The mounting
means may include a portion which is adjustable, like an X-Y
positioning table, so the relative location of the device to the
sleeve holding mandrel may be changed. The adjusting may be done
manually or optionally by PLC control. The manufacturing stations
operate continuously and may be coordinated with the rotation of
the indexing device.
[0127] The manufacturing stations of the second embodiment shown in
FIG. 11 may be grouped into five general process steps: 1) Loading,
2) Forming a Head, 3) Decorating, 4) Finishing and 5) Unloading. As
will be described below there are many ways to effectuate the
manufacturing process steps to create decorated, sealed and capped
tubes.
[0128] 1) Loading Thermoplastic Sleeves
[0129] After transporting sleeves to a machine of the present
invention each sleeve is loaded on a mandrel on the indexing device
at a load station. The load station comprises a loading device that
can load a sleeve onto a mandrel which is about 0.005 inch smaller
in diameter than the sleeve, to provide a snug fit and a means to
mount the loading device to the frame of the machine. Preferably,
the sleeve should be loaded and positioned so that one end of the
sleeve extends a predetermined distance over one end of the
mandrel.
[0130] The loading device may be conventional device: a pneumatic
push rod, a cam driven push rod, an advancing and retracting linear
actuator, a crank motion device or a servo-motor driven push rod.
The preferred loading station, a pneumatic push rod, is described
below as load station (A).
[0131] (A) Load Station
[0132] FIG. 12 illustrates the preferred embodiment of load station
(A), which loads and positions sleeves onto mandrel 87 on indexing
table 89. Load station (A) comprises a pneumatic loading device and
a means for mounting the loading device to a frame or a mounting
ring, like mounting ring 13 of FIG. 1. In this embodiment,
pneumatic loading device comprises a pneumatic push rod 93 which
pushes sleeves supplied to cradle loader 95, by pickle sorter 77 as
shown in FIG. 7, onto mandrel 87.
[0133] Pneumatic push rod 93 is driven back and forth along cradle
loader 95 by air cylinder 97, supplied with air by air lines 99,
positioned behind cradle loader 95 on a mounting bracket 101.
Mounting bracket 101 is further mounted on mounting plate 103 which
is attached to a mounting ring or equivalent, like ring 13 of FIG.
1.
[0134] Cradle loader 95 has a "V" shaped surface 105 for aligning
the center axis of a thermoplastic sleeve resting on V-shaped
surface 105 with the center axis of mandrel 87, so the sleeve may
be loaded onto mandrel 87, with a clearance as small as 0.005 inch,
without damage. Cradle loader 95 is secured on mounting plate
103.
[0135] Both cradle loader 95 and air cylinder 97 are mounted on a
portion of mounting plate 103 that is adjustable relative to the
location of mandrel 87, much like an X-Y positioning table. The
adjustment may be done manually by a X-axis adjustment rod 107 and
a Y-axis adjustment rod 109. Alternatively the adjustment could be
controlled by a PLC device.
[0136] Load station (A) operates as follows: A sleeve is supplied
to V-shaped surface 105 of cradle loader 95 from a supply means.
When the center axis of the sleeve is aligned with the center axis
of mandrel 87, push rod 93 pushes the sleeve along V-shaped surface
105 so that the sleeve loaded onto mandrel 87 and preferably
positioned with a portion extending over the end of mandrel 87 so
that an end is exposed.
[0137] The ideal cradle loader has a low coefficient of friction
and a surface that will not mark or scratch sleeves which rest on
the surface. Possible materials that have a non-marking surface
with a low coefficient of friction are Teflon and Delrin, a type of
lubricated nylon.
[0138] After sleeve is loaded onto mandrel 87, indexing table 89
advances or "indexes" one position and stops again so that the
loaded sleeve is adjacent to the next station downstream load
station (A) in the closed manufacturing path.
[0139] 2) Forming a Head on Thermoplastic Sleeves
[0140] In the preferred embodiment, a head is formed on the exposed
end of the loaded sleeve by first heating the exposed end above the
glass transition temperature so the thermoplastic is molten and
then forming the molten thermoplastic into a head with a mold die
or equivalent device.
[0141] In this embodiment, a single indexing device supports
sleeves and tubes in a variety of different stages of
manufacturing. The speed of rotation of the indexing device is
limited by the speed of the slowest manufacturing step. In this
embodiment time is conserved by dividing the heating step between
two stations, a preheat station and a heat station.
[0142] Machine 85, of the second embodiment, formes a head on a
thermoplastic sleeve by the separate steps of preheating, heating
and molding. Three manufacturing stations are used, preheat (B),
heat (C) and mold (D).
[0143] (B) Preheat Station
[0144] FIG. 13 illustrates preferred preheat station (B), located
downstream from load station (A). Preheat station (B) heats the
portion of a sleeve which extends beyond the end of mandrel 87
above the glass transition temperature to create a molten
thermoplastic mass for molding into a head. Preheat station (B) has
a heating device secured to a movable carriage and means to mount
the device and carriage to the frame of the machine of the present
invention, like mounting ring 13 of FIG. 1. The carriage brings the
heating device into proximity with the exposed portion of the
sleeve.
[0145] In FIG. 13 carriage 111 has a frame or housing 113 which
provides a top surface 115 for securing by brackets 117 a heating
device 119 behind a sleeve cooling bushing 121 and an interior
cavity 123, under top surface 115, for mounting or locating a means
to impart motion to carriage 111, like an air cylinder 125.
Carriage 111 is pneumatically driven by an air cylinder 125,
supplied with air by lines 127. Carriage 111 is slidably mounted on
rods 129 which are linear guide means. Each rod 129 is secured by a
bracket 131 at each end of rod 129 to mounting plate 133.
[0146] Preheat station (B) operates as follows: when a sleeve
loaded and positioned on mandrel 87 is aligned with the center axis
of cooling bushing 121 and heating device 119 of preheat station
(B), carriage 111 advances along rods 129 to bring heating device
119 in proximity to the sleeve. Carriage 111 may move by any
conventional method, namely a servo or indexing motor, a pneumatic,
hydraulic, electric or magnetic actuator.
[0147] As carriage 111 advances, the exposed portion of the sleeve
enters and passes through an orifice 135 in cooling bushing 121.
The exposed portion of the sleeve is partially inserted into
heating device 119. Heating probe 137 located in heating device 119
extends into the exposed portion of the sleeve. The interior
surface of the exposed portion is then heated by hot air exiting
small openings 139, shown in FIG. 14, at the end of heating probe
137. Air is supplied to heating device 119 by supply line 141.
Cooling bushing 121, which may be cooled by a water jacket (not
shown), substantially prevents the heat applied to the exposed end
of the sleeve from spreading to the remainder of the sleeve.
[0148] Carriage 111 retracts by the action of air cylinder 125 to
its original position, out of the path of motion of mandrel 87,
after a preselected period of time. The time of heating depends on
the material and the thickness of the thermoplastic to be heated.
After carriage 111 retracts, the preheating step is completed.
[0149] Any means for heating an air flow in heating device 119 is
satisfactory. Typically, heating device 119 is made of a metal
which has good electrical resistance. In this embodiment, heating
device 119 is itself heated so that air flowing through it is
raised to the desired temperature. The air flow rate, the
temperature of the heating element and time of heating can all be
controlled by a PLC device.
[0150] Preheat station (B) is made of light weight durable
materials. For example, cooling bushing 121 may be made of aluminum
and heating element 119 and heating probe 137 may be made of
stainless steel. Aluminum provides a durable and light weight
material for housing 113 of carriage 111. Rods 129 receive a lot of
wear so they need to be made of a durable and hard material.
Ideally, rods 129 can be made from cold rolled steel.
[0151] After the heating at preheat station (B), indexing table 89
advances one position so that the heated exposed end of the sleeve
is now adjacent heat station (C).
[0152] (C) Heat station
[0153] FIGS. 13 and 14 also illustrate the preferred heat station
(C) of this embodiment. Preferably heat station (C) is physically
the same as preheat station (B). Heat station (C) operates in the
same manner as preheat station (B) and heats the preheated exposed
portion of the sleeve above the glass transition temperature.
Depending on the heating time of preheat station (B), the carriage
111 of heat station (C) (FIG. 13) may move at the same rate or a
different rate than carriage 111 of preheat station (B).
[0154] As the inside surface of the sleeve is heated close to the
glass transition temperature, in this embodiment, the inside
surface melts faster than the outside surface. The heating of a
longitudinally stretched and extruded thermoplastic sleeve results
in die swelling. Die swelling is the shrinking and thickening of a
thermoplastic sleeve because the plastic memory of the sleeve wants
to return the sleeve to its original larger shape, the shape of the
die used in the extrusion process. The molten preform mass at the
heated end of the sleeve thickens and is ideal for molding a head
onto the end of the sleeve.
[0155] After the heating is completed carriage 111 of heat station
(C) retracts out of the path of mandrel 87. Indexing table 89
advances one position so that the hollow thermoplastic sleeve is
adjacent mold station (D) downstream from heat station (C).
[0156] (D) Mold station
[0157] FIGS. 15 and 16 illustrate preferred mold station (D),
located downstream from heat station (C). Mold station (D) forms a
head from the heated thermoplastic mass at the end of the sleeve
previously heated in preheat station (B) and heat station (C). Mold
station (D) has a mold die secured to a movable carriage and means
to mount the device and carriage to the frame of the machine of the
present invention, like mounting ring 13 of FIG. 1. The carriage
brings the mold die into contact with the exposed portion of the
sleeve.
[0158] In FIG. 15 carriage 143 has a frame or housing 145 which
provides a top surface 147 for securing a mold die 149 and an
interior cavity 151, under top surface 147, for mounting or
locating a means to impart motion to carriage 143, like an air
cylinder 153. Carriage 143 is pneumatically driven by an air
cylinder 153, supplied with air by lines 155. Carriage 143 is
slidably mounted on rods 157 which are linear guide means. Each rod
157 is secured by a bracket 159 at each end of rod 157 to mounting
plate 161.
[0159] In this embodiment, mold die 149, secured by brackets 163 to
top surface 147 of carriage 143 and preferably made of aluminum or
steel, has four components: a mold bushing 165, a mold bushing
plate 167, a thread insert plate 169 and an orifice pin bushing
171, as illustrated in cross-section in FIG. 16. Mold bushing 165
forms the entrance to mold die 149. Mold bushing 165 guides the
heated sleeve into mold die 149. The subsequent components, mold
bushing plate 167, thread insert plate 169 and orifice pin bushing
171 shape portions of a head on the end of the sleeve. A die with
four components, like mold die 149, allows a manufacturer to
selectively shape the head of a sleeve with specific members to
comprise mold die 149. Orifice pin bushing 171 contains a spike
(not shown) located in the center to form an orifice in the headed
end of the thermoplastic tube.
[0160] Alternatively the mold die may be a one-piece die which does
not open. Such a die would be useful for forming a simple head on a
sleeve. The die may take the form of a simple one-piece member with
a concave face to shape the sleeve end portion of the molten
thermoplastic into a closed end of a tube. But if threads or
undercuts are desired on the head, then at least a portion of the
mold die, for example, must open to allow the release of the tube
once the head has been formed. Simple open and close pneumatic
dies, like an air cylinder split die, are available for this
purpose.
[0161] The time and pressure of the molding step are important. The
time for molding should be limited to the time necessary to form a
head from the heated thermoplastic. If a head is not removed from a
die once formed, it may stick to the inner surface of the die. If
the mold pressure is too great, the thermoplastic may be pressed
out of the mold. If the mold pressure is weak, a head may be poorly
formed and uneven. The time of molding and pressure used will
depend on the thermoplastic and its thickness. Time and pressure
may be controlled by a PLC device.
[0162] After a head is formed, indexing table 89 indexes to the
next station located downstream, treat station (E).
[0163] 3) Decorating Thermoplastic Tubes
[0164] As previously mentioned there are a variety of ways to
decorate the outside surface of a thermoplastic sleeve or
thermoplastic tube if it has been so formed. The decoration step
may precede the head forming step. In this embodiment however,
decoration occurs after forming a head on the sleeve.
[0165] Decorating may occur by a variety of different means and
methods. For example, a label may be applied to a tube by a label
dispensing device. A tube may be marked with an indicia, including
an individual indicia or a printed graphic. Many printing methods
are know for printing indicia on tubes, such as offset printing,
screen printing, foil printing, inkjet printing, letter printing,
computer printing, etc. A tube may also be decorated by being
coated, heat embossed or etched.
[0166] The outside surface of a thermoplastic tube or sleeve is
typically treated prior to decorating by printing, coating or
labelling so that the outer surface is more receptive or adherent
to a printed graphic. The type of treatment step will depend on the
decoration step that follows.
[0167] The manufacturing stations used to decorate the
thermoplastic article on machine 85 of the second embodiment
include: treat station (E) for pretreating the thermoplastic
article, label station (F), print station (G), coat station (I) and
cure stations (H) and (J).
[0168] (E) Treat station
[0169] Often before a printed indicia or label may be applied to
thermoplastic polymer, the polymer must be treated to receive the
printed indicia or label. There are a variety of ways to surface
treat thermoplastic, such as, flame treatment, corona treatment,
ionic treatment, electrical treatment, heat treatment or chemical
treatment.
[0170] Corona treating is common and works as follows: A corona
treating system is like a capacitor. High voltage is applied to an
electrode. Between the electrode and a "ground" is a dielectric,
comprised of the thermoplastic tube and air. The voltage buildup on
the electrode ionizes the air in the electrode, creating the highly
energized corona. This excites the air molecules, reforming them
into a variety of free radicals, which then bombard the tube
surface, increasing its polarity by distributing free bond sites
across it. This makes the surface more receptive to printed
indicia.
[0171] Flame treatment is common for bottles, tubing, and
automotive parts. Like corona, it induces an ionized airstream,
which alters the surface as it impinges upon it. Flame treatment is
accomplished by burning an ultra-lean gas mixture, whose excess
oxygen is rendered reactive by high temperatures.
[0172] Treatment, specifically corona and flame treatment, alter a
polymer's surface chemistry. The presence of carbonyl and hydroxyl
groups, which are absent on an untreated surfaces, enhances
wetability, allowing inks, coatings, and adhesives to flow out and
coat uniformly.
[0173] FIG. 17 illustrates treat station (E). Treat station (E)
comprises treatment device 173, having supply line 175, which
provides the means for treating a thermoplastic tube located on
mandrel 87. In this embodiment, treatment device 173 is a corona
treater. Treatment device 173 is secured to mounting bracket 177
that is adjustable relative to the location of mandrel 87, much
like an X-Y positioning table. Mounting bracket 177 has a X-axis
adjustment rod 179 and a Y-axis adjustment rod 181. Mounting
bracket 177 is further mounted on the frame of the machine.
[0174] (F) Label Station
[0175] In this embodiment, the first decorating station downstream
treat station (E) is label station (F). Label station (F) has a
device for applying adhesive labels to the exterior surface of
thermoplastic tubes and a means to mount the device to the frame
(not shown) of the machine. A device suitable for applying labels
to thermoplastic tubes may be used in label station (F). The indigo
or zicon processes are preferable for labeling on thermoplastic
tubes.
[0176] FIG. 18 illustrates preferred label station (F). Label
station (F) has a label dispenser 183, which dispenses sheet 185,
having labels thereon, which travels through a series of
directional cylinders 187 a, b, c, d, e, and f, which are label
guides, to a final label intake roll 189. Sheet 185 exits
dispensing device 183, travels to directional cylinder 187e, which
is in close proximity with a tube on mandrel 87. When sheet 185
passes directional cylinder 187e, an individual label is pinched
off sheet 185 and pressed against a tube. The empty label sheet 185
is rewound on label intake roll 189.
[0177] It is important that the labels are applied to tubes and not
to mandrel 87. To avoid such error, a sensor can be included in
label station (F) to detect whether a tube is located on mandrel
87.
[0178] Label station (F) is a labeling device housed in a frame 191
which is mounted on a frame or mounting ring, like mounting ring 13
as shown in FIG. 1, of the machine of the present invention.
[0179] (G) Print station
[0180] Instead of applying an adhesive label to the exterior of the
thermoplastic tube, a printed indicia may be applied to the tube.
FIG. 19 illustrates a preferred inkjet printer of print station (G)
having four printer head cartridges 193 a, b, c and d disposed on a
bar 195 which is secured to mounting bracket 197, which is further
mounted to the frame (not shown) of the machine of the present
invention. Printer head cartridges 193 a, b, c and d are connected
to a plurality of ink supply and control lines 199.
[0181] The inkjet printer of print station (G) is preferably
controlled by a PLC device. A PLC device gives a manufacturer the
ability to mark each tube with an individual indicia or the same
printed graphic. A PLC device can control the ink flow and pattern
of printing from the printer head cartridges of an inkjet printer.
A PLC device may be programmed to print individual indicia, like a
unique serial number on each tube. Thus an inkjet printer is
advantageous because of the ability to quickly and automatically
alter, modify, and change printed indicia on thermoplastic
tubes.
[0182] After a printed indicia is applied to the tube, the printing
must be cured.
[0183] (H) Cure station
[0184] Cure station (H), located downstream from print station (G),
cures the printed indicia applied to the thermoplastic tube. FIG.
20 illustrates preferred cure station (H), having a curing unit 201
connected to a supply and control line 203. Curing unit 201 is
secured to mounting bracket 205 that is adjustable relative to the
location of mandrel 87. Adjustment may be done manually by a X-axis
adjustment rod 207 and a Y-axis adjustment rod 209. Alternatively
the adjustment could be controlled by a PLC device. Mounting
bracket 205 is secured to the mounting ring or equivalent of the
frame of the machine of the present invention.
[0185] Curing unit 201 may cure the printed graphic by any known
means such as heat, infrared light, hot air, or ultra violet light.
In the embodiment illustrated in FIG. 20, curing unit 201 is a hot
air curing unit where hot air is discharged from curing unit 201
onto the tube.
[0186] Curing unit 201 may be left on continuously. Or, like other
stations in the manufacturing process, it may be computer
controlled so that the curing process may be controlled with more
precision. Because curing unit 201 may be a UV light emitting unit,
safety shutters (not shown) may be provided to shield operators
from the exposure of UV light.
[0187] (I) Coat station
[0188] The third decorating station on machine 85 is coat station
(I) which is a station for applying a coat of material to a tube.
This may be an alternative to decorating via label station (F) or
print station (G). Coat station (I) may also be used in conjunction
with label station (F) and print station (G). FIG. 21 illustrates
preferred coat station (I). Coat station (I) has two coater rollers
211 a and b in front of a doctor blade 213, all of which are
supported on a mounting bracket 215 further mounted on the frame of
the machine of the present invention. The two coater rollers 211 a
and b contact a tube on mandrel 87 and apply a chemical coat
directly onto the tube. The chemical coat is applied to coater
rollers 211 a and b by doctor blade 213. Doctor blade is connected
to a chemical supply line (not shown). After a chemical is applied
on the tube the chemical coating is typically cured.
[0189] (J) Cure station
[0190] Final cure station (J) is the same as cure station (H)
illustrated in FIG. 20. Final cure station (J) is for the purpose
of curing coating or indicia on tubes and may cure by the same
means as cure station (H). In the present embodiment, final cure
station (J) is a heat cure station having a curing unit 201 which
is a hot air curing unit where hot air is discharged from curing
unit 201 onto the tube.
[0191] After decorating, the thermoplastic tube may advance through
a variety of different finishing stations for finishing the
decorated tube. The number, arrangement and variety of finishing
stations will depend on the desired tube to be produced.
[0192] 4) Finishing Thermoplastic Tubes
[0193] Besides forming a head on a thermoplastic sleeve and
decorating the same, there are many different process steps that
may be performed for finishing the thermoplastic tube. For example,
the orifice on the formed head may be sealed with a protective
foil, a closure means may be secured to the formed head and the
closure may be torqued automatically for proper tightness.
[0194] Machine 85 of FIG. 11 includes the following finishing
stations: tab seal (K), cap (L) and a torque station (M).
[0195] (K) Tab Seal Station
[0196] FIG. 22 illustrates a tab seal station of the preferred
embodiment. A tab sealer 217 is housed in a frame 219 comprising a
mounting bracket 221 on which tab sealer 217 rests connected to a
mounting plate 223 located on either side of the mounting bracket
221. This structure can support the remainder of the device as
necessary, to place a small protective seal, made of foil or other
material, over the orifice of headed thermoplastic tubes.
[0197] A protective tab seal is added to tubes by means of a
applicator device which, in the preferred embodiment is a tab seal
punch 225 which cuts and places appropriately sized tab seal
material 227 over the orifice of a thermoplastic tube.
[0198] As shown in FIG. 22 tab seal punch 225 is driven by an air
cylinder 229 supplied with air by air and control lines 231. The
tab seal punch 225 slidably moves, by the action of the air
cylinder 229 through a tab seal die 235 on a tab seal mounting
plate 237 and contacts tab seal material 227 on the other side of
the tab seal die 235. This tab seal material 227 is supplied from a
tab seal stock roller 239. Tab seal material 227 unwinds from stock
roller 239, passes tab seal punch 225 and is taken up by tab seal
foil intake roller 241.
[0199] By the pneumatic action of the tab seal punch rod 225
through the tab seal die 235, small portions of tab seal material
227 are cut from the ribbon of tab seal material 227 and brought
into contact with the headed end of a thermoplastic tube whereby
the tab seal foil is cut and secured.
[0200] The tab seal station (K) illustrated in FIG. 22, operates
continuously as long as it is supplied with tab seal foil stock. To
possibly accommodate longer continuous manufacturing periods, a tab
seal foil stock roller (not shown) may be mounted on top of the
frame of the machine such that tab seal foil stock ribbon is wound
from the foil stock roller down in front of the tab seal die to
supply foil stock to the tab seal station. This ribbon may be wound
under the die and back up to a larger intake roll (not shown)
mounted elsewhere on the manufacturing station. Therefore this
allows for the possibility of much larger stock and intake rolls to
accommodate larger manufacturing times.
[0201] (L) Cap Station
[0202] Cap station (L) is located downstream from tab seal station
(K). This station provides a means for adding a closure or cap,
typically made of plastic, to the headed end of a tube. The cap may
be either snapped onto the end of the thermoplastic tube or screwed
on if the head has screw threads.
[0203] Preferable capping station (L), as shown in FIG. 23,
comprises a cap applicator 243 and brackets 245 for mounting cap
applicator 243 to the frame of the machine, like mounting ring 13
of FIG. 1. Cap applicator 243 is a device which secures a cap or
closure to the headed end of tubes. Each cap is individually placed
on the headed thermoplastic tube by cap applicator 243. If the cap
must be screwed on to the head of the thermoplastic tube, then cap
applicator 243 has a screw type mechanism for rotating caps. Cap
applicator 243 is continuously supplied with caps by a supply line
(not shown). Cap applicator 243 is connected to power supply and
control line 247.
[0204] After a cap is applied to the headed thermoplastic tube, the
torque of the cap is typically adjusted.
[0205] (M) Torque Station
[0206] Torque station (M) is located downstream from cap station
(L). Torque station (M) is provided for adjusting the torque of the
closure applied to the head of the thermoplastic tube in cap
station (L).
[0207] As illustrated in FIG. 24, torque station (M) comprises a
cap torque chucking device 249 and brackets 251 for mounting torque
chucking device 249 to the frame of the machine, like mounting ring
13 of FIG. 1. Chucking device 249 adjusts the torque of each cap on
each tube. It can accomplish this device by a mechanical screw
means.
[0208] Torque station (M) is connected to power supply and control
line 253.
[0209] 5) Unloading Thermoplastic Tubes
[0210] Manufacturing on a machine of the present invention ends
with unloading tubes from mandrels 87. To unload thermoplastic
tubes off mandrels, the following devices, each comprising an
unload device or stripper, may be used: a pneumatic stripper, a
stripper driven by a cam driver, an advancing and retracting linear
actuator stripper, a crank motion stripper or a servo-motor driven
stripper. The preferred unloading device is a pull rod stripper
driven by an air cylinder which works similarly to push rod 93 of
load station (A).
[0211] (N) Unload Station
[0212] The final station of machine 85 is illustrated in FIG. 25 as
unload station (N). Unload station (N) is downstream torque station
(M) and next to the first station in the manufacturing path load
station (A).
[0213] Pneumatic stripper 255, with stripper plate 257, is driven
back and forth along guide arm 259 by air cylinder 261, supplied
with air by air lines 263, positioned behind guide arm 259 on a
mounting bracket 265. Mounting bracket 265 is further mounted on a
mounting plate, like mounting plate 103 of FIG. 12, which is
attached to a mounting ring or equivalent, like ring 13 of FIG. 1.
Stripper 255 removes the finished thermoplastic tubes from mandrel
87 by stripper plate 257 attached to the end of stripper 255.
[0214] Unload station (N) operates as follows: a stripper plate 257
slides back and forth in contact with mandrel 87 unloading any tube
on mandrel 87. Once the thermoplastic tube has been removed,
stripper 255 and stripper plate 257 return to their original
position.
[0215] All of the 14 stations described above operate to form one
embodiment of a complete manufacturing process for decorated capped
and torqued thermoplastic tubes.
[0216] 6) Additions and Alternates
[0217] The machine of the present invention is intended to be
flexible to that manufacturing stations of various types, numbers
and arrangements may be configured on the machine so that a large
variety of tubes can be manufactured. In addition to the stations
and methods described above, many other manufacturing stations and
process steps are possible. Described below are other methods and
devices for the machine of the present invention, without intending
to be limiting.
[0218] Forming a head a sleeve, for example, may be done by a
variety of different methods. For example, a previously formed head
may be joined with a thermoplastic sleeve by heat welding or sonic
welding the sleeve and the head together. Or a head may be formed
from the end of the thermoplastic sleeve by the process disclosed
in U.S. Pat. No. 5,069,856, assigned to the assignee of the present
invention and the process of which is incorporated herein. Further
a head may be formed by injection blow molding or blow molding a
head directly onto a sleeve loaded onto a mandrel on the indexing
device.
[0219] Still further a head may be molded in a reusable closure
means or cap. An example of molding in a reusable closure means is
described co-pending application "Method of Forming a Headed
Thermoplastic Tube with a Reusable Closure" assigned to the
assignee of the present invention and incorporated by reference
herein. Therefore, depending on the finished product desired any
number of different methods may be used to form a head on the end
of thermoplastic sleeve.
[0220] An example of forming a head in a in a reusable closure
means is as follows: A method of forming a tube from an
thermoplastic extruded, stretched sleeve is provided by positioning
a sleeve over a forming mandrel with an exposed portion of the
sleeve extending beyond a head forming end of the mandrel. The
inner wall surface of the exposed portion of the thermoplastic
sleeve is heated to a temperature above the glass transition
temperature of the thermoplastic material to render the inner
surface area molten, while maintaining the outer surface of the
sleeve below the glass transition temperature so as to provide
support for the exposed portion of the sleeve and retain the
cylindrical shape thereof. The heated exposed portion is then
shaped into a conical shape, such as by directing hot air against
the outer surface thereof. Pressure is then applied to the conical
shaped exposed portion of the thermoplastic extruded sleeve by
contacting the exposed portion with a reusable closure means to
form a headed thermoplastic tube. The pressure applied to the
conical shaped exposed end portion forces the same into a reusable
closure means for the tube held in place by a holding or gripping
member.
[0221] The reusable closure means used in this method functions as
a mold for the neck or a mold for both the shoulder and neck when
forming a head on the thermoplastic sleeve and a reusable cap for
the finished thermoplastic tube. The reusable closure means is made
of a material incompatible with the thermoplastic sleeve material
such that when the molten end of the thermoplastic sleeve is
pressed into the reusable closure means, the reusable closure means
does not melt or stick to the molten preform.
[0222] Yet a further method for forming a head on a tube involves
rotating a sleeve while heating it. An example of this method is
described co-pending application "Method of Forming a Headed
Thermoplastic Tube" assigned to the assignee of the present
invention and incorporated by reference herein. A thermoplastic
extruded, longitudinally stretched sleeve is positioned over a
forming mandrel with an exposed portion of the sleeve extending
beyond a head forming end of the mandrel. The mandrel is then
rotated while the sleeve is heated. The rotation provides for even
heat distribution at the location where the heat is applied. The
rotation of the sleeve is stopped and pressure is then applied to
the conical-shaped, exposed portion of the thermoplastic, extruded
sleeve by contacting the exposed portion with a molding die to form
a headed thermoplastic tube.
[0223] An alternate way to form a head is to weld a preformed head
onto a sleeve by high frequency sound. Sonic weld station,
illustrated in FIG. 26, may be substituted for preheat (B), heat
(C) and mold (D) stations of machine 85 as an alternative station
for forming a head on a sleeve.
[0224] FIG. 26 illustrates a preferred sonic welding station for
welding by high frequency sound, a preformed head to a
thermoplastic sleeve. Sonic weld station has a sonic welder
attached to a movable carriage and means to mount the device and
carriage to the frame of the machine of the present invention, like
mounting ring 13 of FIG. 1. The carriage brings the sonic welder
into proximity with a sleeve.
[0225] In FIG. 26 carriage 267 has a frame or housing 269 which
provides a top surface 271 for securing sonic welder 273 and an
interior cavity 275, under top surface 271, for mounting or
locating a means to impart motion to carriage 267, like an air
cylinder 277. Carriage 267 is pneumatically driven by an air
cylinder 277, supplied with air by lines 279. Carriage 267 is
slidably mounted on rods 281 which are linear guide means. Each rod
281 is secured by a bracket 283 at each end to mounting plate
285.
[0226] The sonic weld station operates as follows: when a sleeve
loaded and positioned on mandrel 87 of machine 85, for example, is
aligned with sonic welder 273, carriage 267 advances along rods 281
to bring sonic welder 273 in proximity to the sleeve. As carriage
267 advances, an exposed portion of the sleeve enters and passes
into sonic welder 273 which welds a preformed head to the sleeve by
means of high frequency sound. Sonic welder 273 is connected to
supply and control line 287 which supplies the input necessary for
sonic welder 273 to operate.
[0227] Sonic welder 273 is mounted in housing 289 which is attached
to top surface 271 of carriage 267. Carriage 267 retracts by the
action of air cylinder 277 to its original position, out of the
path of motion of mandrel 87, after a preselected period of time.
The result of the manufacturing step is that a preformed head is
welded onto a sleeve to form a tube.
[0228] The machine of the present invention is also useful for
completing the manufacturing of tubes if, for example, the sleeves
have been partially processed at another location. Preprinted
sleeves may be loaded onto a machine of the present invention and
the manufacturing of tubes may be completed by forming a head on
the sleeves and performing any desired finishing step like, tab
sealing, capping or torquing.
[0229] 7) Large Scale Manufacturing
[0230] The machines of the present invention may be arranged into
small groups. When arranged into small groups or "production
cells," space, labor and raw material input can be saved. One
production cell typically contains six machines each of which can
manufacture headed, sealed, capped and decorated tubes from blank
thermoplastic sleeves. A single cell has a total output equivalent
to a single conventional process line.
[0231] A manufacturing and packing plant using machines of the of
the present invention is an efficient arrangement of a plurality of
production cells connected by a common transportation line. The
efficient arrangement of cells leads to further decreases in labor
necessary to operate a number of production cells. An example of
the preferred manufacturing plant is described in co-pending
application "Plant for Manufacturing and Packing Thermoplastic
Tubes" assigned to the assignee of the present application and
incorporated by reference herein.
[0232] IV. Manufacturing with a Programmable Logic Controller
[0233] A PLC device may be added to the machine of the present
invention for the purpose of controlling the entire machine
including the various manufacturing stations. In conventional
process lines some of the manufacturing equipment is PLC
controlled. However machine feedback control to control all aspects
of a manufacturing step, product quality control and product
feedback control and total mechanical control over sleeves and
tubes have not been feasible. Such PLC control is almost impossible
in conventional processing lines because large processing lines
handle several hundred thermoplastic articles at a time and there
is no systematic method for keeping track of individual articles
and controlling the same on the conventional machines.
[0234] FIG. 1 illustrates one embodiment of a machine of the
present invention, with each manufacturing station connected to a
PLC device, as indicated by the dashed lines. The PLC device can
perform a variety of functions: A PLC device may be employed to
control, by turning on or turning off, each manufacturing station
along a manufacturing path. A PLC device can control the inputs
needed for each manufacturing station. For example, a PLC device
can control the heating temperature of the preheat and heat
stations. The PLC can control the speed of each manufacturing
station and the speed of the entire manufacturing machine.
[0235] Process control for the machine of the present invention
involves controlling the operation of individual manufacturing
stations alone or in combination with other manufacturing stations
around the closed manufacturing path. The operation of the
manufacturing stations may be based on information gathered from
sensors obtaining information about the operation of each
manufacturing station itself, sensors obtaining information about
the quality of the thermoplastic tubes produced, or information
obtained from both the operation of each of the manufacturing
stations and the quality of the thermoplastic tubes produced.
Examples of the sensors that may used are listed below in Table
I:
1TABLE I SENSOR TYPE MEASUREMENT 1. Load sensor Electric Eye
Confirm Load 2. Preheater Air Flow Flow Meter Air Flow Rate 3.
Preheater Temperature Thermocouple Air Temperature 4. Sleeve
Temperature Infrared Sensor Sleeve Temperature 5. Heater Air Flow
Flow Meter Air Flow Rate 6. Heater Temperature Thermocouple Air
Temperature 7. Sleeve Temperature Infrared Sensor Sleeve
Temperature 8. Mold Temperature Thermocouple Cooling Water
Temperature 9. Mold Flowmeter Flow Meter Cooling Water Flow Rate
10. Treater Confirmation Electric Eye Confirm Corona Arc 11.
Treater Amperage Ammeter Treatment Level/ Pinhole Detection 12.
Label Sensor Labeler Confirm Label Application Controller 13.
Printer Print Controller Confirm Print Application 14. Cure Sensors
Voltmeter Cure Unit Voltage Ammeter Cure Unit Amperage Thermocouple
Cure Unit Temperature 15. Inspection System Vision System Confirm
Heading & Print (Camera) Quality 16. Coating Sensor Level
Sensor Confirm Coating Pretense 17. Cure Sensors Voltmeter Cure
Unit Voltage Ammeter Cure Unit Amperage Thermocouple Cure Unit
Temperature 18. Inspection System Vision System Confirm Heading,
Print, & (Camera) Coating Quality 19. Tab Seal Thermocouple
Punch Temperature Electric Eye Tab Seal Pretense 20. Inspection
System Vision System Confirm Heading, Print, (Camera) Coat, &
Tab Seal Quality 21. Capping Electric Eye Confirm Cap Pretense 22.
Torque Torque Meter Confirm Applied Torque 23. Inspection System
Vision System Confirm Heading, Print, (Camera) Coat, & Capping
Quality 24. Eject Electric Eye Confirm Tube Removal 25. Reject
Electric Eye Confirm Tube Removal 26. Confirmation Microswitch
Confirm Tube Removal
[0236] After gathering selected information from sensors in various
locations around the closed manufacturing path the process control
method would continue as follows: a signal would be generated
corresponding to the selected information gathered from each of the
manufacturing stations. The signals generated would be imputed into
a PLC device and with the use of the signals, the operation of
corresponding manufacturing stations would be controlled by the PLC
device.
[0237] In a typical example of the control system, the PLC device
will compute all of the "decisions" regarding the operation of the
manufacturing machine based on information received from sensors on
each manufacturing station. This provides the manufacturer with the
opportunity to monitor the activities that occur at each station
and identify any abnormalities in the product or process
immediately. Defective products can identified instantly and
downstream stations may be shut off to conserve process resources.
The defective products can then be segregated at a reject station
on the machine.
[0238] The PLC device in combination with the manufacturing
stations, sensors and indexing table can collect, on a continuous
basis, the type, degree and frequency of failures of the product or
process. This can provide a profile of effectiveness of equipment
and each process step. Reports can be generated about process and
quality of the product.
[0239] Further process control would include establishing setpoints
for controlling the operation of each manufacturing station and
with the use of the generated signals, as previously mentioned, the
operation of each manufacturing stations could be controlled within
the established setpoints. Setpoints,may be established
automatically after the machine invention has reached steady state.
The PLC device would automatically establish upper and lower
boundary setpoints based on the operation of the machine at steady
state over a period of time. Alternatively, the setpoints may be
predetermined and simply programmed into the PLC device.
[0240] The signals generated from the sensors located on the
manufacturing stations themselves or around the closed
manufacturing path may be mechanical, electronic, optical,
pneumatic, hydraulic or combinations thereof. Any type of signaling
means may be used to communicate among the sensors and the PLC
device.
[0241] Another method for controlling the thermoplastic tube
manufacturing machine is the following: marking each tube with
individual indicia; sensing selected information from tubes marked
with individual indicia; generating a signal corresponding to each
of manufacturing stations based on selected information; inputting
signals to the PLC device; and with use of signals, controlling the
operation of a corresponding manufacturing station with the PLC
device.
[0242] Each thermoplastic tube may be marked with an individual
indicia from a computer controlled printing device, like the inkjet
printer of FIG. 19, which has the capability of uniquely marking
each tube. Then select information may be gathered from the tubes
marked with an individual indicia by a sensing means. Further
signals may be generated based on the selected information
gathered. The signals may be input into a PLC device and with the
use of the signals, the operation of corresponding manufacturing
stations may be controlled. This type of process control is the use
of a feedback loop based on individually marked tubes to indicate
to a PLC device to make or stop producing certain types, kinds, or
varieties of tubes.
[0243] For example if 15,000 tubes of three different lots of 5,000
tubes per lot, all having the same diameter, are to be
manufactured, then a feedback loop based on marked indicia on each
tube would allow a manufacturer to manufacture the 15,000 tubes
continuously without stopping the machinery. After 5,000 tubes of
one type have been manufactured and an indicia on tube number 5,000
was identified by sensing means, like a vision camera, then a
signal could be generated based on this indicia, and sent to a PLC
device. With the use of this signal, the PLC device may then
control the operation of the machine, with a subsequent command
control signal, to change production, like changing the decoration
step or the finishing steps, to manufacture the second lot of 5,000
tubes. The process could be repeated for the third lot of 5,000
tubes. By this feedback control method based on marking each tube
with an individual indicia, a manufacturer may operate a machine of
the present invention with zero down time.
[0244] FIG. 27 is a schematic representation a machine 291 of a
third embodiment invention having indexing table 293, 20 mandrels
295 mounted thereon and 20 manufacturing stations labelled (A)
through (T), corresponding to each of 20 mandrels, all connected to
PLC device 297. Indexing table 293 rotates counterclockwise in this
embodiment in response to indexer 299 (FIG. 28). The 20 stations
and corresponding process steps of this embodiment are as follows:
(A) load, (B) preheat, (C) heat, (D) mold, (E) treatment, (F)
label, (G) print, (H) cure, (I) inspect, (J) coat, (K) cure, (L)
inspect, (M) tab seal, (N) inspect, (O) cap, (P) torque, (Q)
inspect, (R) unload, (S) reject and (T) confirmation. FIG. 28 is a
perspective view of FIG. 27, showing only the main components of
manufacturing stations (A) through (T). The manufacturing stations
of machine 291 which are common to machine 85 of the second
embodiment are physically the same as the manufacturing stations of
machine 85.
[0245] In addition to adding sensors to the stations of the
manufacturing path illustrated in FIGS. 27 & 28, additional
stations have been added. Four inspection stations (I), (L), (N)
and (Q) have been added at different locations along the closed
manufacturing path. Product inspection may be performed by any
known method. FIG. 29 illustrates any one of inspection stations
(I), (L), (N), and (Q). An inspection station is typically a vision
camera which has the ability to inspect product quality. The
inspection station in FIG. 29 is illustrated as having a vision
camera 301 receiving input and sending output signals to PLC device
297 (FIG. 27) through control and power line 303. Vision camera 301
is mounted on a bracket 305 which may be adjustable and mounted on
a frame or mounting ring of the machine, like mounting ring 13 of
machine 1 in FIG. 1. Inspection stations can identify and monitor
individual indicia on sleeves and tubes so marked.
[0246] Preferred rejection station (S) is illustrated in FIG. 31.
It is mechanically the same as unload station (N) of the embodiment
on FIG. 25. Pneumatic stripper 307, with stripper plate 309, is
driven back and forth along guide arm 311 by air cylinder 313,
supplied with air by air lines 315, positioned behind guide arm 311
on a mounting bracket 317. Mounting bracket 317 is further mounted
on a mounting plate, like mounting plate 103 of FIG. 12, which is
attached to a mounting ring or equivalent, like ring 13 of FIG. 1.
Stripper 307 removes defective tubes from machine 291 based on
command signals from PLC device 297.
[0247] Reject station (S) operates as follows: a stripper plate 309
slides back and forth in contact with mandrel 295 unloading any
tube on mandrel 295. Once the thermoplastic tube has been removed,
stripper 307 and stripper plate 309 return to their original
position.
[0248] Confirmation station (T), illustrated in FIG. 30, is for the
purpose of confirming that a tube has been removed by either unload
station (R) or rejection station (S) from mandrel 295. The
confirmation station (T) in FIG. 30 is shown as having a sensor arm
319 receiving input and sending output signals to a PLC device (not
shown) through control and power line 321. Sensor arm 319 is
mounted on a bracket 323 which may be adjustable (not shown).
Confirmation station (T) can alternatively be an electronic or
vision means for performing tube confirmation.
[0249] V. Manufacturing Example
[0250] A 10 mandrel machine having 7 manufacturing stations, in
order: load, heat, mold, treat, print, cure, and unload, was used
to manufacture headed and decorated thermoplastic tubes from
longitudinally stretched and extruded thermoplastic sleeves. Headed
tubes of high quality were produced at a rate of 13 tubes per
minute (tubes/min). The following process parameters were used to
achieve this output:
[0251] The machine used a 10 mandrel aluminum indexing table
approximately 16 inches in diameter set at a counterclockwise
rotation speed of 1.3 revolutions/min. The load station was a
pneumatic push-pull device which loaded thermoplastic sleeves from
a chain conveyor onto holding mandrels on the indexing table at a
rate of 13 sleeves/min. Each sleeve was loaded onto a mandrel so
that approximately 0.5 inch of sleeve extended beyond the end of
the mandrel. The sleeve was then transported downstream to the
second station in the manufacturing path, the heat station.
[0252] The heat station had a hot air heating probe mounted behind
a cooling bushing on a slidable pneumatic carriage. The portion of
the sleeve extending beyond the end of the mandrel was heated by
air flowing at a rate of 40 cubic cm/second (cc/s) at a temperature
of about 720.degree. F., for approximately 3 seconds. The carriage
was set at a speed of approximately 0.5 cycle/s.
[0253] Following the retraction of the carriage, the heated
thermoplastic sleeve was indexed one position downstream to the
mold station. The mold station was mounted adjacent the heat
station on the same slidable pneumatic carriage. The carriage
advanced to contact a mold die with the molten preform mass at the
end of the heated sleeve. The contact time was about 3 seconds and
the mold die temperature was room temperature.
[0254] The thermoplastic sleeve, now a thermoplastic tube, was next
transported to a corona treatment unit. The treatment of the
thermoplastic tube occurred for approximately 2 seconds. Following
surface treatment, the tube was indexed further downstream to a
coat station where a coating was applied to the tube surface. A
thin coating was applied around the tube by the application rollers
of the station. Following this, the thermoplastic tube was cured by
hot air at the cure station, at a temperature of 300.degree. F.
from an industrial blower.
[0255] After hot air curing the finished thermoplastic tube was
unloaded from the machine. The total processing time for one tube
was 4.6 seconds and the machine produced tubes at a rate of 13
tubes/min. The tubes produced were finished commercially viable
tubes of high quality and were later capped to produce headed
thermoplastic tubes which were decorated and capped.
[0256] Producing tubes which have an adhesive label on the
aforementioned machine was less complicated. Instead of treating
and coating on the machine, a label station was added to apply
labels to the thermoplastic tube. All of the parameters and
stations previously mentioned were the same except for the addition
of the label station. Labeled commercially viable tubes were
produced at a rate of 13 tubes/min.
[0257] VI. Further Embodiments
[0258] The machine of the present invention is flexible and may be
adapted to manufacture thermoplastic tubes of various lengths,
thicknesses, weights, diameters, shapes, and complexity. In order
adapt a machine to manufacture tubes of a specific diameter, the
indexing table is fitted with appropriately sized mandrels and the
manufacturing stations are adapted to work on the specific diameter
thermoplastic sleeves. Adaptations for the stations may include
adjusting the position of the station relative to the mandrel,
changing the size of a bushing orifice, or changing the size of a
component of a particular station. Additionally the machine of the
present invention may altered to accommodate different
transportation means--different indexing devices, like an indexing
drum.
[0259] The machine of the present invention is flexible to accept a
variety of manufacturing processes on the same machine. Different
manufacturing processes are created by the number, sequence and
variety of manufacturing stations around the closed manufacturing
path. The stations around the path may be changed in a number of
ways including: adding or removing manufacturing stations, turning
on or turning off stations and rearranging the order of the
stations.
[0260] The following figures will illustrate some of the possible
configurations of a machine of the present invention which result
in a variety of manufacturing methods.
[0261] FIG. 32 illustrates a machine 325, shown without a frame,
having an indexing table 327 which rotates counterclockwise in
response to indexer 329; 6 manufacturing stations: load (A),
preheat (B), heat (C), mold (D), label (E) and unload (F); 6
mandrels 331; and a manufacturing path capable of 6 process steps,
namely: loading, preheating, heating, molding, labeling and
unloading. FIG. 33 is a front view of the closed manufacturing
path.
[0262] Even in the embodiment of FIG. 32, the manufacturing path
may be rearranged so that labelling is performed prior to heating
and molding. To do this the label (E) station would be moved to a
mandrel upstream of the preheat (B) station. The advantage of a
machine with six manufacturing stations and six mandrels is that it
is compact, easy to operate, simple in design and consumes small
amounts of power, air, electricity and other inputs.
[0263] FIG. 34 illustrates a machine 333, shown without a frame,
having an indexing table 335 which rotates counterclockwise in
response to indexer 337; 6 manufacturing stations: load (A),
preheat (B), heat (C), mold (D), label (E) and unload (F); 10
mandrels 339; and a manufacturing path capable of 6 process steps,
namely: loading, preheating, heating, molding, labeling and
unloading. FIG. 35 is a front view of the closed manufacturing
path. Machine 333 has 4 expansion mandrels for the addition of
manufacturing stations in the future. Machine 333 has the potential
to accept more manufacturing process methods than machine 325 of
FIG. 32 because of the expansion mandrels.
[0264] FIG. 36 illustrates a machine 341, shown without a frame,
having an indexing table 343 which rotates counterclockwise in
response to indexer 345; 10 manufacturing stations: load (A),
preheat (B), heat (C), mold (D), label (E), inspect (F), inspect
(G), unload (H), reject (I) and confirm (J); 14 mandrels 347; and a
manufacturing path capable of 10 process steps, namely: loading,
preheating, heating, molding, labeling, first inspecting, second
inspecting, unloading, rejecting and confirming. FIG. 37 is a front
view of the closed manufacturing path. Four expansion mandrels
allow for the addition of other manufacturing stations as well as
the flexibility to rearrange the manufacturing path illustrated in
FIG. 36.
[0265] FIG. 38 illustrates a machine 349, shown without a frame and
shown with only partial views of the manufacturing stations, having
an indexing table 351 which rotates counterclockwise in response to
indexer 353; 6 manufacturing stations: load (A), preheat (B), heat
(C), mold (D), label (E) and unload (F); 20 mandrels 355; and a
manufacturing path capable of 6 process steps, namely: loading,
preheating, heating, molding, labeling and unloading. If space is
not a constraint, machines with larger indexing tables may be built
for the future potential of manufacturing expansion.
[0266] The machine 357 illustrated in FIG. 39 is similar to that of
FIG. 38, having five additional manufacturing stations: inspect
(F), inspect (G), unload (H), reject (I) and confirm (J)
stations.
[0267] FIG. 40 illustrates a machine 359, shown without a frame,
having an indexing table 361 which rotates counterclockwise in
response to indexer 363; 9 manufacturing stations: load (A),
preheat (B), heat (C), mold (D), label (E), tab seal (F), cap (G),
torque (H) and unload (I); 9 mandrels 365; and a manufacturing path
capable of 9 process steps, namely: loading, preheating, heating,
molding, labeling, tab sealing, capping, torquing, and unloading.
FIG. 41 is a front view of the closed manufacturing path. This
manufacturing machine is compact in size and has the ability to
manufacture headed, labelled, tab sealed, capped and torqued
thermoplastic tubes.
[0268] FIG. 42 shows a machine 371 of the present invention having
an indexing table 367 upon which is mounted a plurality of oval
forming mandrels 369, for holding oval thermoplastic sleeves to
form oval thermoplastic tubes. Oval thermoplastic tubes are formed
in a manufacturing path, schematically represented, having 9
manufacturing stations and corresponding process steps: load (A),
preheat (B), heat (C), mold (D), treat (E), print (F), cure (G),
cap (H) and unload (I). FIG. 43 is a front view of indexing table
367 with oval mandrels 369.
[0269] FIG. 44 illustrates a tooling change for a machine 373 of
the present invention capable of manufacturing twice as many
thermoplastic tubes. Pairs of mandrels 375 are positioned side by
side with only a small gap between them on indexing table 377 which
rotates in response to indexer 379 so that the manufacturing
stations can work on two thermoplastic articles simultaneously. The
manufacturing stations may need to be altered slightly to
accommodate two articles. FIG. 45 is a front view of machine
373.
[0270] Alternatively instead of an indexing table, an indexing drum
381 (FIG. 46) may be used as the indexing device in a machine 383
of the present invention, shown without complete frame (FIG. 47).
Indexing drum 381 is a drum with the cross-sectional shape of a
cylinder or polygon having a plurality of means for supporting
thermoplastic sleeves, i.e) mandrels 385 around the outside length
of the drum. Manufacturing stations for working on thermoplastic
sleeves loaded on mandrels 385 are oriented accordingly so they can
perform manufacturing steps on the thermoplastic sleeves (FIG.
47).
[0271] Machine 383 rotates clockwise in response to an indexer (not
shown) around the following 8 manufacturing stations and
corresponding manufacturing steps: load (A), heat (B), mold (C),
treat (D), print (E), cure (F), cap (G) and unload (H), similar to
like stations previously described for machine 85 of the second
embodiment of a machine of the present invention. The manufacturing
stations (A)-(H) are mounted on a mounting ring 387 which is
further mounted on a frame of the machine 383. For clarity, FIG. 47
shows only manufacturing stations (A)-(H) and mounting ring 387 for
the first set of mandrels 385 on indexing drum 381. In production,
mounting ring 387 would extend the length of indexing drum 381 and
all stations (A)-(H) would be repeated for the corresponding
mandrels 385. Sleeves would be supplied to all load stations by a
chute or transportation means (not shown).
[0272] One advantage of a indexing drum is that more thermoplastic
tubes may be produced in a compact space by simply extending the
indexing drum and adding more mandrels for supporting thermoplastic
sleeves and additional manufacturing stations mounted on a mounting
ring. The description of the process method and process control of
a machine of the present invention herein applies to a machine
having an indexing drum.
[0273] While there has been illustrated and described several
embodiments of the present invention, it will be apparent that
various changes and modifications thereof will occur to those
skilled in the art. It is intended in the appended claims to cover
all such changes and modifications that fall within the true spirit
and scope of the present invention.
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