U.S. patent number 3,869,325 [Application Number 05/291,134] was granted by the patent office on 1975-03-04 for method of making a convolute tube.
This patent grant is currently assigned to Sonoco Products Company. Invention is credited to Werner Witzig.
United States Patent |
3,869,325 |
Witzig |
March 4, 1975 |
Method of making a convolute tube
Abstract
An elongate, convolutely wound, adhesively secured tube and
method for making same from elongate sheet material and being
characterized by eliminating the necessity of having a high
moisture content in the adhesive for holding the wound tube
together following winding, wherein the method includes applying
relatively slow acting, low moisture adhesive to a major portion of
a first surface of the sheet material, applying relatively fast
acting adhesive to a minor portion of the first surface
substantially adjacent a first longitudinal edge thereof into a
convolute tube with the first longitudinal edge forming an outside
trailing edge and the fast acting adhesive acting to immediately
secure the trailing edge to the outer surface of the convolute tube
to retain the convolute tube in the wound condition during
activation of the slow acting, low moisture adhesive.
Inventors: |
Witzig; Werner (Hartsville,
SC) |
Assignee: |
Sonoco Products Company
(Hartsville, SC)
|
Family
ID: |
26966594 |
Appl.
No.: |
05/291,134 |
Filed: |
September 21, 1972 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
|
835393 |
Jun 23, 1969 |
3704730 |
|
|
|
Current U.S.
Class: |
156/192; 156/289;
493/277; 156/218; 156/291; 493/304 |
Current CPC
Class: |
B31C
1/00 (20130101); F16L 9/16 (20130101); Y10T
156/1038 (20150115) |
Current International
Class: |
B31C
1/00 (20060101); F16L 9/00 (20060101); F16L
9/16 (20060101); B31c 001/00 () |
Field of
Search: |
;156/184,187,192,203,218,289,291 ;93/94R ;138/144,146
;117/68.5 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Drummond; Douglas J.
Assistant Examiner: Lewris; Basil J.
Attorney, Agent or Firm: McBride; C. Gordon
Parent Case Text
This application is a division of application Ser. No. 835,393,
filed June 23, 1969, now U.S. Pat. No. 3,704,730.
Claims
What is claimed is:
1. A method of making convolutely wound, adhesively secured tubes
of at least two plies from elongate sheet material having opposed
first and second surfaces and first and second longitudinal side
edges and being characterized by eliminating the necessity of
having a high moisture content in the adhesive for holding the
wound tube together immediately following winding and thereby
avoiding a subsequent drying step, said method comprising the steps
of,
applying relatively slow acting, low moisture adhesive to a major
portion of the first surface of the sheet material while leaving a
first longitudinally extending band free of slow acting, low
moisture adhesive in close proximity to the first longitudinal edge
but spaced slightly therefrom allowing the slow acting, low
moisture adhesive to be also positioned immediately along the first
longitudinal edge, and while leaving a second longitudinally
extending band free of slow acting, low moisture adhesive adjacent
the second longitudinal side edge of the sheet material,
applying relatively fast acting adhesive along the first
longitudinally extending band free of slow acting, low moisture
adhesive on the first surface of the sheet material,
applying a lubricant along the second longitudinally extending band
free of slow acting, low moisture adhesive on the first surface of
the sheet material,
applying relatively slow acting adhesive on the second surface of
the sheet material along a portion adjacent the second
longitudinally extending edge, and
convolutely winding a predetermined length of the elongate sheet
material transversely of the length into a convolute tube with the
second surface of the sheet material forming the outside surface of
the tube and with the second longitudinal edge having the lubricant
adjacent thereto on the first surface and the adhesive adjacent
thereto on the second surface forming the leading inside edge of
the tube and the first longitudinal edge having the relatively fast
acting adhesive adjacent thereto forming the outside trailing edge
of the tube for immediate adherence of the trailing edge portion to
the outside surface of the convolute tube to retain the convolute
tube in the wound condition during activation of the slow acting,
low moisture adhesive to bond the convolute tube in the wound
condition.
2. The method, as set forth in claim 1, wherein the second
longitudinal band free of slow acting, low moisture adhesive which
contains lubricant thereon is of a width substantially equal to the
circumference of the inside surface of the wound convolute
tube.
3. The method, as set forth in claim 1, wherein the fast acting
adhesive is a hot-melt adhesive and wherein the slow acting, low
moisture adhesive has a moisture content of substantially less than
65% by weight when applied avoiding the necessity of a subsequent
drying step after winding of the convolute tube.
4. A method of making convolutely wound, adhesively secured tubes
from elongate sheet material having opposed first and second
surfaces and first and second longitudinal side edges and being
characterized by eliminating the necessity of having a high
moisture content in the adhesive for holding the wound tube
together immediately following winding and thereby avoiding a
subsequent drying step, said method comprising the steps of,
applying relatively slow acting, low moisture adhesive to the first
surface of the sheet material while leaving at least one
longitudinally extending band free of slow acting, low moisture
adhesive substantially adjacent the first longitudinal edge,
applying relatively fast acting adhesive along the longitudinally
extending adhesive free band on the first surface of the sheet
material, and
convolutely winding a predetermined length of the elongate sheet
material transversely of the length into a convolute tube with the
second surface of the sheet material forming the outside surface of
the tube and with the first longitudinal edge having the relatively
fast acting adhesive adjacent thereto forming the outside trailing
edge of the tube for immediate adherence of the trailing edge
portion to the outer surface of the convolute tube to retain the
convolute tube in the wound condition during activation of the slow
acting, low moisture adhesive to bond the convolute tube in the
wound condition,
said step of applying relatively slow acting, low moisture adhesive
to the first surface of the sheet material including leaving a
second longitudinally extending band free of slow acting, low
moisture adhesive adjacent the second longitudinal side edge of the
sheet material,
said step of convolutely winding the elongate sheet material into a
convolute tube including forming the inside leading edge of the
tube from the second longitudinal side edge of the sheet
material,
applying a lubricant along the second longitudinally extending
adhesive free band on the first surface of the sheet material;
and
applying relatively slow acting adhesive along the second
longitudinally extending edge on the second surface of the sheet
material for adhering the leading inside edge of the sheet material
to the inside surface of the convolute tube when wound.
Description
This invention generally relates to elongate tubes made from
elongate sheet material such as paper and the like, but more
particularly to elongate convolutely wound tubes and an improved
method for making same.
Heretofore, methods for making convolutely wound tubes from
elongate sheet material such as paper and the like generally
included applying an adhesive to one surface of the sheet material
and convolutely winding a predetermined length of the elongate
sheet material transversely of the length thereof into a convolute
tube with the adhesive permanently bonding the convolute tube in
the wound condition. Typically, as when forming a convolute tube
from paper, an adhesive having a high moisture content (about
80-85% by weight) was employed which wet the sheet material and wet
fastened the convolute windings in overlying relation to hold the
tube in the wound condition immediately following winding and
during activation of the adhesive as by drying the wound tube in an
oven or the like.
It is readily apparent that the wetting of the paper by the
adhesive presents many problems in the manufacture of convolute
tubes. In particular, the additional drying step substantially
increases the cost of producing such convolute tubes and the
facilities for drying consume valuable space. In addition, the
wetting of the paper by the adhesive causes a loss of strength in
the paper which limits the rate at which the paper may be
convolutely wound and the manner in which the wound tube may be
handled until drying is complete. Furthermore, the convolute tube
produced is not completely satisfactory in that the adhesive is
dispersed throughout the thickness of the wall of the tube rather
than between convolute windings and in many cases on both the inner
and outer surface thereof.
With the aforementioned in mind, it is an object of this invention
to provide an improved convolutely wound tube and method for making
same from elongate sheet material such as paper and the like
wherein an initially low moisture adhesive may be used to
permanently bond the convolute tube in the wound condition, thus,
avoiding a drying step following winding.
Another object of the invention is to provide an improved
convolutely wound tube and method for making same from elongate
sheet material such as paper and the like wherein a means is
provided for holding the convolute tube in the wound condition
immediately following winding to allow the use of an initially low
moisture, slow acting adhesive to permanently bond the tube in the
wound condition.
By this invention, it has been found that the above objects may be
accomplished by providing a method of making convolutely wound,
adhesively secured tubes utilizing the steps of applying relatively
slow acting, low moisture adhesive to a major portion of the first
surface of the sheet material, applying relatively fast acting
adhesive to a minor portion of the first surface of the sheet
material substantially adjacent the first longitudinal edge
thereof, and convolutely winding a predetermined length of the
elongate sheet material transversely of the length into a convolute
tube with the second surface of the sheet material forming the
outside surface of the tube and with the first longitudinal edge
having the relatively fast acting adhesive adjacent thereto forming
the outside trailing edge of the tube for immediate adherence of
the trailing edge portion to the outer surface of the convolute
tube to retain the convolute tube in the wound condition during
activation of the slow acting, low moisture adhesive to permanently
bond the convolute tube in the wound condition.
The improved convolutely wound, adhesively secured tube formed by
the above method comprises a plurality of overlying convolute
windings of the sheet material and including inside and outside
edges formed by the longitudinal edges of the sheet material, a
fast acting adhesive bonding the last convolute winding to the next
underlying convolute winding, and a slow acting, initially low
moisture adhesive bonding the remainder of the convolute windings
in overlying relationship, the fast acting adhesive retaining the
convolute windings in overlying relationship during activation of
the slow acting, low moisture adhesive after winding of the
tube.
Some of the objects of the invention having been stated, other
objects will appear as the description proceeds, when taken in
connection with the accompanying drawings, in which:
FIG. 1 is a perspective view of a portion of an elongate
convolutely wound tube produced in accordance with the present
invention;
FIG. 2 is an enlarged sectional view taken substantially along the
line 2--2 of FIG. 1;
FIG. 3 is an enlarged view of area 3 of FIG. 2 illustrating the
bonding of the last convolute winding to the next underlying
convolute winding;
FIG. 4 is an enlarged view of area 4 of FIG. 2 illustrating the
bonding of the inside edge to the inside surface of the convolute
tube;
FIG. 5 is a somewhat schematic top plan view of a convolute winding
machine which may be used in making the convolutely wound tube of
the present invention;
FIG. 6 is a somewhat schematic perspective view of a method of
making elongate convolutely wound tubes with the convolute winding
machine of FIG. 5 in accordance with this invention; and
FIG. 7 is an enlarged sectional view taken substantially along the
line 7--7 of FIG. 6.
Referring now to the Figures wherein like reference characters are
used throughout to indicate like parts, there is shown in FIGS. 1-4
an elongate convolutely wound tube generally designated at 10 of
this invention and may be formed from any elongate sheet material,
such as paper, plastic and the like. However, the method of making
the convolutely wound tube 10 disclosed herein is particularly
adapted for paper in view of the shortcomings of the prior art
methods previously referred to wherein a high moisture adhesive is
used to hold the wound tube together immediately following
winding.
The elongate convolutely wound tube 10 of this invention, as
illustrated, comprises a plurality of overlying convolute windings
11 of the sheet material, and includes inside edge 12 and outside
edge 13 wherein the convolute windings 11 are adhesively secured in
overlying relation. More particularly, a fast acting adhesive 14,
preferably a hot melt adhesive which is a mixture of 100%
nonvolatile thermoplastic resin and/or resins and wax, such as
manufactured by Imperial Adhesives, Inc., 6315 Wiehe Road,
Cincinnati, Ohio, under the name "THERM-O-LOK Resin 5002," is
disposed substantially adjacent the outside edge 13 between the
last convolute winding and the next underlying convolute winding
and includes adhesive properties such as to retain the convolutely
wound tube 10 in the wound condition immediately following winding.
A slow acting adhesive 15, initially having a low moisture content
and preferably less than 65% by weight to prevent wetting of the
sheet material and which may be a dextrine adhesive of solution or
emulsion type, is disposed between a major portion of the convolute
windings 11 and permanently secures them in overlying relation. A
slow acting adhesive is chosen as the bonding adhesive for the
major portion of the convolute windings 11 because such adhesives
are characterized by their low viscosity prior to activation, the
ease with which they may be applied in controllable quantities and
their relatively low cost.
Thus, it can be seen that the combination of the fast acting
adhesive 14 and slow acting, low moisture adhesive 15 provides for
a convolutely wound tube 10 which does not require drying after
winding, which employs a relatively inexpensive adhesive that is
relatively easy to apply in controllable quantities to bond the
major portion of the convolute windings 11 in overlying relation,
and which tube is held in the wound condition immediately after
winding and during activation of the slow acting adhesive 15 by a
fast acting adhesive 14.
Furthermore, it will be noted that the relatively slow acting, low
moisture adhesive 15 is disposed immediately adjacent the outside
edge 13 between the last convolute winding and the next underlying
convolute winding to insure that there will be no free edges left
on the outside surface of the convolutely wound tube 10. Similarly,
the relatively slow acting, low moisture adhesive 15 is disposed
immediately adjacent the inside edge 12 between the first convolute
winding and the next outer convolute winding to insure that there
will be no free edges left on the inside surface of the convolutely
wound tube 10.
Referring now to FIGS. 5-7, it will be observed that in making the
elongate convolutely wound tube 10, paper or other sheet material
20 having first and second opposed surfaces 21, 22 and first and
second longitudinal side edges 23, 24 is drawn from a roll 30 or
other suitable source of supply over guide rolls 31, 32, through a
first slow acting, low moisture adhesive applying station generally
designated at 33 and over guide roll 34 by a pair of nip driving
rolls 35, 36 which are intermittently driven by any conventional
driving means (not shown) to pass a predetermined length of the
sheet material 20 to a conventional cutting station generally
designated at 37 where the sheet material 20 is cut into
predetermined lengths in accordance with the length of the tube to
be formed therefrom.
At adhesive applying station 33, a slow acting, low moisture
adhesive 15 initially having a low moisture content, preferably of
the above described type, is applied longitudinally of the sheet
material 20 to a major portion of the first surface 21 while
leaving a longitudinally extending band 40 free of adhesive in
close proximity to the first longitudinal edge 23 but spaced
slightly therefrom and while leaving a second longitudinally
extending band 41 free of adhesive immediately adjacent the second
longitudinal side edge 24.
In order to apply the slow acting, low moisture adhesive 15, there
is provided an applicator roll 42 in contact with the first surface
21 of the sheet material 20 transverse thereof and driven by the
movement of the sheet material 20 and a transfer roll 43 which dips
into a slow acting, low moisture adhesive bath 44 and transfers the
slow acting, low moisture adhesive 15 from the bath 44 to the
applicator roll 42 which applies the slow acting, low moisture
adhesive 15 to the first surface 21 of the sheet material 20. The
applicator roll 42 is substantially equal to the width of sheet
material 20 and has a pair of doctor blades 45, 46 cooperating
therewith which continuously remove the slow acting, low moisture
adhesive 15 from portions of the applicator roll 42 which causes
the applicator roll 42 to leave longitudinal bands 40 and 41 free
of adhesive on the first surface 21 of the sheet material 20.
It will be noted that immediately adjacent the first longitudinal
edge 23, the slow acting, low moisture adhesive 15 is applied to
the first surface 21 of the sheet material by the applicator roll
42. As is readily apparent, the width of the adhesive free bands
40, 41 may be varied by varying the width of the doctor blades 45,
46 and in accordance therewith, the width of the band 41 free of
adhesive immediately adjacent the second longitudinal edge 24 is
preferably made substantially equal to the circumference of the
inside surface of the convolute tube to be produced for reasons to
become apparent in convolute winding of the sheet material 20.
Beyond the cutting station 37, the sheet material 20 having been
cut into predetermined lengths is advanced on a platform formed
from a plurality of longitudinally extending and laterally spaced
wires 47 whose near ends are suitably connected to the frame of the
cutting station 37 (not shown) and whose far ends extend over a
transverse bar 48, by means of advancing pins (not shown)
operatively associated with the platform and carried by pressure
frame 49 (FIG. 5). This advancement of the cut lengths of the sheet
material 20 moves the second longitudinal edge 24 thereof into an
aligned longitudinally extending groove 51 of a mandrel 52 which
extends parallel with and longitudinally of the sheet material
20.
Disposed intermediate the cutting station 37 and mandrel 52 and
cooperating with the sheet material 20 as it is advanced to the
mandrel 52 is a fast acting adhesive applying station 53, a
lubricant applying station 54, and a second slow acting, low
moisture adhesive applying station 55.
The fast acting adhesive applying station 53 includes a container
56 having a fast acting adhesive 14 stored therein and a nozzle 57
extending therefrom and disposed directly above the longitudinal
band 40 free of adhesive substantially adjacent the first
longitudinal edge 23 of first surface 21 and is adapted to apply a
fast acting adhesive 14 in discrete quantities longitudinally of
band 40 during passing of the sheet material 20 thereunder.
The lubricant applying station 54 may be of any conventional design
and could include a housing 58 in which a block of wax 59 or other
type solid lubricant is placed with the bottom surface of the block
of wax 59 gravity loaded into wiping engagement with the
longitudinal band 41 free of adhesive immediately adjacent the
second longitudinal edge 24 of the sheet material 20. While there
is illustrated the application of a solid lubricant, liquid
lubricants or combinations of solid and liquid lubricants may be
employed and applied by depositing drops on the band 41.
The second slow acting, low moisture adhesive applying station 55
is disposed in cooperation with the second surface 22 of the sheet
material 20 immediately adjacent longitudinal edge 24 and includes
an applicator roll 61 which dips into a slow acting, low moisture
adhesive bath 62 and applies a slow acting, low moisture adhesive
15 on the second surface 22 of the sheet material 20 along a
portion immediately adjacent the second longitudinal edge 24 for
reasons to be later explained.
With the second longitudinal edge 24 of the sheet material 20 in
the groove 51 of mandrel 52, as shown in the right-hand portion of
FIG. 6 and in FIG. 7, the mandrel 52 is rotated by a driving
mechanism generally indicated at 64 to impart a predetermined
number of revolutions to mandrel 52 to convolutely wind the sheet
material 20 into the convolute tube 10 and is wound with the second
surface 22 of the sheet material 20 forming the outside surface of
the convolutely wound tube 10 and with the first longitudinal edge
23 having the fast acting adhesive 14 substantially adjacent
thereto forming the outside trailing edge 13 of the convolutely
wound tube 10 and immediately adhering the trailing edge portion to
the outer surface of the convolutely wound tube to retain the
convolutely wound tube in the wound condition immediately after
winding and during activation of the slow acting, low moisture
adhesive 15 which permanently bonds the major portion of the
convolute windings 11 in overlying relation. Therefore, immediately
after winding, the convolutely wound tube 10 may be stripped from
the mandrel 52 and the convolute winding machine made ready for the
winding of a subsequent tube.
It will be readily apparent that the longitudinal band 41 free of
adhesive immediately adjacent longitudinal edge 24 becomes the
inside surface of the convolute tube and is disposed directly
against the mandrel 52 during convolute winding and thus, the
lubricant 59 applied thereto facilitates in the stripping of the
convolutely wound tube 10 from the mandrel 52. Upon removal, it
will be noted that the second longitudinal edge 24 held in the
groove 51 of the mandrel 52 is not adhesively secured to the
convolute windings during winding but upon removal from the mandrel
52 will be secured to the next outer convolute winding by the slow
acting, low moisture adhesive 15 applied on the second surface 22
of the sheet material 20 immediately adjacent the longitudinal edge
24 and insure that there will be no free edges on the inside
surface of the convolutely wound tube 10.
From the foregoing description, it can be appreciated that this
invention has eliminated the necessity of having a high moisture
content in the adhesive for holding the convolutely wound tube in
the wound condition immediately following winding and thereby
avoiding a subsequent drying step.
In the drawings and specification, there has been set forth a
preferred embodiment of the invention, and although specific terms
are employed, they are used in a generic and descriptive sense only
and not for purposes of limitation.
* * * * *