U.S. patent application number 14/113041 was filed with the patent office on 2014-02-13 for apparatus and method for heat shrinking a film wrapping an object.
This patent application is currently assigned to FUJI SEAL INTERNATIONAL, INC.. The applicant listed for this patent is Ernst Christiaan Koolhaas, Martinus Hubertus Maria Van Der Linden. Invention is credited to Ernst Christiaan Koolhaas, Martinus Hubertus Maria Van Der Linden.
Application Number | 20140041341 14/113041 |
Document ID | / |
Family ID | 46197652 |
Filed Date | 2014-02-13 |
United States Patent
Application |
20140041341 |
Kind Code |
A1 |
Koolhaas; Ernst Christiaan ;
et al. |
February 13, 2014 |
APPARATUS AND METHOD FOR HEAT SHRINKING A FILM WRAPPING AN
OBJECT
Abstract
An apparatus for heat shrinking a film wrapping an object
includes a housing having a heat treatment chamber, a transport
device for supporting and moving the object through the heat
treatment chamber. Steam, supplied from at least one supply is led
to at least a first and a second fluid outlet device and directed
at the transported object using one or more outlets. The fluid
outlet devices are disposed on opposite sides of the transport
device. According to the invention the apparatus and method further
include generating a downward directed fluid flow in an area
extending between the fluid outlet devices having a lower
temperature than the steam supplied from the outlets. This results
in improved sleeving results and higher efficiency.
Inventors: |
Koolhaas; Ernst Christiaan;
(Nuenen, NL) ; Van Der Linden; Martinus Hubertus
Maria; (Veghel, NL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Koolhaas; Ernst Christiaan
Van Der Linden; Martinus Hubertus Maria |
Nuenen
Veghel |
|
NL
NL |
|
|
Assignee: |
FUJI SEAL INTERNATIONAL,
INC.
Osaka-shi, Osaka
JP
|
Family ID: |
46197652 |
Appl. No.: |
14/113041 |
Filed: |
May 10, 2012 |
PCT Filed: |
May 10, 2012 |
PCT NO: |
PCT/NL12/50316 |
371 Date: |
October 21, 2013 |
Current U.S.
Class: |
53/442 ;
53/557 |
Current CPC
Class: |
B29C 65/66 20130101;
B29L 2031/7158 20130101; B29K 2067/003 20130101; B29C 63/423
20130101; B29C 65/10 20130101; B29C 66/71 20130101; B29C 61/00
20130101; B29C 66/43121 20130101; B29L 2031/744 20130101; B29C
66/532 20130101; B65B 53/02 20130101; B65B 21/245 20130101; B29C
63/0069 20130101; B65B 53/063 20130101; B29K 2067/003 20130101;
B29C 66/71 20130101; B29C 35/049 20130101 |
Class at
Publication: |
53/442 ;
53/557 |
International
Class: |
B65B 53/02 20060101
B65B053/02 |
Foreign Application Data
Date |
Code |
Application Number |
May 10, 2011 |
NL |
2006752 |
Claims
1. A heat shrink oven for heat shrinking a film wrapping an object,
the heat shrink oven comprising: a housing having a heat treatment
chamber for containing steam and for arranging a steam flow
pattern, a transport device for supporting and moving the object
through the heat treatment chamber, at least one steam supply for
supplying steam to the heat treatment chamber, at least a primary
steam unit comprising a first and a second steam outlet device
comprising one or more outlets for steam, the steam outlet devices
connected to the steam supply, the first steam outlet device
disposed in the heat treatment chamber along a first side of the
transport device and the second steam outlet device disposed along
a second side of the transport device, opposite the first side, the
outlets directed towards the moving object, wherein the heat shrink
oven further comprises, a secondary steam system, arranged in the
heat treatment chamber, for generating a downward directed steam
flow in an area extending between the steam outlet devices, the
downward directed steam flow having a lower temperature than the
steam supplied from the steam outlet devices, wherein the secondary
steam system is arranged to be supplied with steam internal in the
heat treatment chamber.
2. The heat shrink oven according to claim 1, wherein the secondary
steam system is arranged to supply secondary steam having a
temperature of at least 4 degrees Celsius lower than the primary
steam flow entering the heat treatment chamber through the
outlets.
3. The heat shrink oven according to claim 1, wherein the secondary
steam system is arranged to supply secondary steam having a
temperature of less than 88 degrees Celsius.
4. The heat shrink oven according to claim 1, wherein the outlets
are positioned to supply the primary steam directed generally
horizontal.
5. The heat shrink oven according to claim 1, wherein the secondary
steam system for generating the downwardly directed steam flow is
also arranged to generate a generally upward directed steam flow in
the heat treatment chamber in an area outside the area between the
opposite fluid outlet devices.
6. The heat shrink oven according to claim 1, wherein the secondary
steam system for generating the downwardly directed steam flow
comprises a guide allowing the outward guiding of the steam
flow.
7. The heat shrink oven according to claim 5, wherein the apparatus
comprises a frame received in the heat treatment chamber for
mounting the steam outlet devices and wherein the secondary steam
system for generating the steam flow surrounds the steam outlet
devices mounted to the frame.
8. The heat shrink oven according to claim 1, wherein the secondary
steam system for generating the downwardly directed steam flow
further comprises steam flow device arranged to generate the
downward flow of steam.
9. The heat shrink oven according to claim 1, wherein multiple sets
of steam outlet devices are provided along the transport device and
wherein the secondary steam system is positioned at the most
upstream steam outlet devices or upstream from the most upstream
steam outlet devices.
10. The heat shrink oven according to claim 1, wherein the steam
outlet device comprises at least three or more outlets in a
straight line.
11. The heat shrink oven according to claim 1, wherein the
transport device is at least partially received in the heat
treatment chamber and the object is a generally cylindrical
container for a beverage and the film is a cylindrical
envelope.
12. The heat shrink oven according to claim 1, wherein the heat
treatment chamber is a closed housing containing the steam, the
heat treatment chamber having a tunnel-shaped space, the transport
device arranged to carry objects through the tunnel-shaped
space.
13. The heat shrink oven according to claim 1, wherein the heat
treatment chamber is arranged to allow circulation of the secondary
steam flow.
14. The heat shrink oven according to claim 13, wherein the heat
treatment chamber and secondary steam system are arranged to
maintain the flow of secondary steam continuously.
15. A method of shrinking a heat shrinkable film wrapping an
object, the method comprising in a heat treatment chamber of a heat
shrink oven: transporting the upright standing object wrapped with
heat shrinkable film through the heat treatment chamber, applying
primary steam onto a side of the film, and directing secondary
steam of lower temperature than the primary in a downward direction
onto the object, the heat treatment chamber containing the steam
and allowing circulation of secondary steam.
16. The method according to claim 15, wherein the method comprises
maintaining the flow of secondary steam continuously in the heat
treatment chamber.
17. The method according to claim 15, wherein the secondary steam
is directed onto the object upstream from the application of
primary steam.
18. The method according to claim 15, wherein the secondary steam
is directed onto the object during application of the primary
steam.
19. The method according to claim 15, wherein directing the steam
in the downward direction comprises generating a closed flow
pattern for steam in the heat treatment chamber, in the downward
direction onto the object, in an outwards direction, away from the
object, followed by an upward direction and inward direction.
20. The method according to claim 15, wherein applying the steam
for heat shrinking a first part of the film comprises applying the
steam to a bottom part of the object.
21. The method according to claim 15, wherein the method comprises
multiple stages of applying steam to the object being transported
through the heat treatment chamber.
22. The method according to claim 15, wherein steam is applied from
two opposite sides onto the object carried through the heat
treatment chamber.
Description
[0001] The invention relates to an apparatus and method for heat
shrinking a film wrapping an object.
[0002] Such an apparatus and method are known and disclosed in EP 2
103 527 A1 or US 2009/0188605.
[0003] U.S. Pat. No. 3,744,146 discloses a method and apparatus of
subsequent treatments of an object. Cooler air is provided as air
curtain near the tunnels ends of a shrink tunnel.
[0004] U.S. Pat. No. 5,031,298 discloses a tunnel for heat
shrinking sleeves around objects. A gaseous fluid is used as
heating medium. Nozzles on opposite sides of a conveyor can be
displaced towards or away from each other. A temperature sensor
determines the temperature, establishes a difference with a
predetermined/desired temperature and moves the heaters
accordingly. To improve uniform shrinking of the sleeve a gaseous
flow is directed down, e.g. using a blower creating a continuous
sheet of air onto the moving object to prior inflate each sleeve.
The temperature of the gaseous flow is adjusted to correspond with
the predetermined temperature.
[0005] An object, such as a PET bottle is filled with beverages
such as soft drinks and generally has a cylindrical shape. It is
positioned onto and carried by a transporter such as a conveyor.
The object will be moved through the heat treatment chamber.
[0006] A cylindrical label is often formed of a shrink film on
which a brand name, information on the contents of the container
and the like is printed. A label or film mounting system fits the
envelope of film over the object.
[0007] The exact position of the film can differ from object to
object. In order to allow shrinking the film, a current method and
apparatus for heat shrinking employs multiple stages of heat
shrinking. The speed of transport can be reduced to allow longer
interaction.
[0008] It is a goal of the current invention to provide a method
and apparatus allowing higher process speed or less stages of heat
shrinking in the apparatus/method. In general, a more efficient
method and apparatus are to be provided.
[0009] According to a first aspect an apparatus for heat shrinking
a film wrapping an object is provided, the apparatus comprising a
housing having a heat treatment chamber and a transport device for
supporting and moving the object through the heat treatment
chamber. The heat chamber is a closed housing that contains the
heated fluid/steam.
[0010] In an embodiment at least one supply for steam is provided
connected to at least two fluid outlet devices for the steam. A
first fluid outlet device of the at least two fluid outlet devices
is disposed in the heat treatment chamber along a first side of the
transport device and the second fluid outlet device is disposed
along a second side of the transport device, opposite the first
side. The outlets of each fluid outlet device are directed towards
the moving object, that is, to the object supported by the
transport device moving through the treatment chamber.
[0011] In an embodiment the apparatus further comprises a system
for generating a downwardly directed fluid flow in an area of the
moving object between the fluid outlet devices. The system is
arranged in or received in the heat treatment chamber. The system
provides an additional or secondary fluid flow subsidiary to the
primary steam supplied from the outlets.
[0012] In an embodiment the system is arranged for generating the
secondary downward steam flow having a temperature that is lower
that the primary steam supplied from the outlets. The secondary
system is arranged to use steam from the heat treatment chamber.
The secondary system has an internal steam as steam supply. As
internal steam is used, the temperature of the steam is lowered
with respect to the primary steam supplied from the nozzles.
[0013] The transport device moves the object at a substantial speed
into and through the heat treatment chamber, which results in
turbulence in the fluid present in that chamber. The downward fluid
flow can result in less turbulence of the fluid around the moving
objects as the downward flow provides a more homogeneous flow of
the fluid.
[0014] Further the generated secondary downward fluid flow can
carry the primary steam away after being applied to the object. The
secondary fluid flow carries the primary fluid away in a downward
direction. A result of this carrying away is that primary, heated,
fluid will not contact upward parts of the moving object. The
system in accordance with the invention will result in less
deformation, at that location, of upward parts of the film wrapping
the object.
[0015] Further the somewhat cooler (secondary) fluid flow in the
downward direction could result in some local temperature control
of the film. The secondary fluid flow preheats the film.
[0016] According to the invention the downwardly directed fluid
flow of somewhat lower temperature is provided together with and as
an additional flow to the supply of steam that will shrink the
film.
[0017] Further the auxiliary downward flow of fluid, even though
somewhat cooler, could result in heating or preheating the surface
of the object somewhat more as a result of increased heat capacity
due to the increased flow. This preheating of the surface will
allow better adherence of subsequently heat shrunk film.
[0018] The steam can be part of a fluid, preferably steam that can
be a mixture of air, steam or other heated gasses.
[0019] In an embodiment the temperature of the secondary fluid flow
is at least 4, preferably 12, degrees Celsius lower than the steam
flow entering the heat treatment chamber through the outlets. In an
embodiment the temperature of the secondary fluid flow is less than
88 degrees Celsius, preferably less than 85 degrees Celsius and
more preferably less than 82 degrees Celsius. Heat shrink ratios of
well known films at these temperatures are low, resulting in a
primary shrink only as a result of applied (primary) heat, making
the process more controllable.
[0020] As the heat shrinking of film is very sensitive to the
temperature of the fluid, providing a cooler fluid flow of some
degrees Celsius, e.g. 4 or more, or 6 or more degrees Celsius, will
lead to less, or preferably no, heat shrinking of the upward parts.
Heated (primary) fluid is provided via the outlets of the fluid
outlet devices and contacts the objects more or less directly after
entering the chamber. The secondary fluid, fluid present in the
chamber, can used for keeping the film at a temperature under the
shrinking temperature.
[0021] In an embodiment a cooling system is available providing
cooler fluid/air, preferably near the windows, as a further aid in
cooling the secondary fluid flow.
[0022] In an embodiment the system for generating the downwardly
directed fluid flow is free of auxiliary heating devices. Steam is
provided to the chamber only via the fluid outlet device(s).
Application of the supplied steam to the film wrapping the object
will provide a first temperature reduction of the fluid.
[0023] The apparatus will have a tunnel-shaped area extending
through the apparatus allowing passage of the object with film
through the heat treatment chamber. The tunnel-shaped area is
limited at an underside by the transport device supporting the
object. The fluid outlet devices are directed towards the
tunnel-shaped area, and could be positioned (partially) in the
tunnel-shaped area. The tunnel-shaped area extends between the
opposite disposed fluid outlet devices.
[0024] In an embodiment the heated (primary) fluid flow is supplied
in a sideward direction, generally perpendicular to the secondary
flow. In an embodiment steam is supplied to the heat treatment
chamber in a horizontal direction. To this end the outlets of the
fluid outlet device are directed generally horizontal direction.
The horizontal direction results in shrinking of a circumferential
part of the film, generally cylindrically, around a cylindrical
object.
[0025] In an embodiment the outlets are directed at a bottom end of
the moving object supported by the transport device. The bottom end
of the object is carried by the transport device. This will result
in heat shrinking the bottom end of the film wrapping the object.
If the bottom end is heat shrunk, a generally downward flow of
fluid will result in inflating the cylindrical film, resulting in
better or more predictable position of the film, allowing more
efficient subsequent heat shrinking.
[0026] In an embodiment the secondary steam system for generating
the downward steam flow is part of a system arranged in the heat
treatment chamber for arranging a flow pattern for steam in the
heat treatment chamber comprising the generally downward flow
between the steam outlet devices. The secondary steam system is an
heat chamber internal system.
[0027] In an embodiment the system for generating the downwardly
directed fluid flow is also arranged to generate a generally
upwardly directed fluid flow in the heat treatment chamber in an
area outside (not between) the fluid outlet devices. The upward and
downward fluid flows can be part of a pattern of flows in the heat
treatment chamber. The pattern will allow maintaining the flow of
secondary fluid continuously. The path of the steam from steam
outlets through the heat treatment chamber will lower the
temperature of the steam before the steam is (again) supplied as
secondary steam onto the objects.
[0028] In an embodiment the downward directed flow between the
fluid outlet devices is guided outwards and upwards through an area
not between/outside the opposed positioned first and second fluid
outlet devices. In particular the downward flow between the fluid
outlet devices is guided outwardly and afterward upwardly,
surrounding or encircling the fluid outlet device.
[0029] During its flow the fluid will cool and upon reaching the
area directly above the moving object and subsequently flowing
downward, it will have a lower temperature than the steam from the
outlets.
[0030] In an embodiment the system for generating the downwardly
directed fluid flow comprises a partition, preferably arranged as a
guide allowing the outward guiding of the fluid flow. The partition
will allow the outward flow of fluid in the treatment chamber. The
partition or guide is preferably positioned under the transport
device.
[0031] In an embodiment the apparatus comprises a frame received in
the heat treatment chamber for mounting the fluid outlet devices
and the system for generating the downwardly directed fluid flow
surrounds the fluid outlet devices mounted to the frame.
[0032] In an embodiment the system for generating the downwardly
directed fluid flow further comprises, received in the heat
treatment chamber, a fluid flow device, such as a vent, positioned
vertically above the transport device and directed to allow
downward fluid flow in the direction of the moving objects.
[0033] In an embodiment the apparatus comprises a human interface
allowing inputting a configuration of e.g. the fluid flow speed of
the fluid flow device/vent. This will allow control by the operator
of the downward flow and thereby of the advantageous effects
according to the invention.
[0034] In an embodiment the apparatus comprises multiple sets of
fluid outlet devices provided along the transport device and
wherein the system for generating the downwardly directed fluid
flow generates the downward flow (at least) between the fluid
outlet devices disposed most upstream.
[0035] In an embodiment the system for generating the downwardly
directed fluid flow further comprises an outlet connected to the
heat treatment chamber. This will allow to discharge some fluid
from the chamber. In an embodiment the outlet is provided in the
area not between the fluid outlet devices.
[0036] In an embodiment the downward flow is provided in along the
transport device over a length of at least the length of one fluid
outlet device. During the complete passage of the object along the
fluid outlet device it is subjected to the beneficial downward
fluid flow as provided according to the invention.
[0037] In an embodiment the fluid outlet device comprises at least
three or more outlets generally positioned in a straight line along
the transport device.
[0038] In an embodiment the outlet comprises a nozzle, a nozzle end
thereof positioned less than 8 cm sideways from the moving objects.
The operator is able to adapt the distance from nozzle end to
object. In an embodiment the nozzles are positioned above the
transport device.
[0039] In an embodiment fluid outlet devices disposed more
downstream the tunnel, are positioned at a vertically more remote
position from the transport device than the upstream fluid outlet
devices. This will allow to first (upstream) heat shrink the film
near a bottom end of the object and later (downstream) the upper
part of the film.
[0040] In an embodiment the fluid outlet device comprises a
manifold arranged to distribute the supplied steam from the supply
line to the outlets. This will allow an evenly distributed steam
onto the film wrapping the objects.
[0041] In an embodiment the transport device is at least partially
received in the heat treatment chamber. In an embodiment the object
is a generally cylindrical container for a beverage. In an
embodiment the film is a cylindrical envelope.
[0042] According to a further aspect of the invention a method is
provided for shrinking a heat shrinkable film wrapping an object.
The method comprises in a heat treatment chamber transporting the
upright standing object wrapped with heat shrinkable film through a
heat treatment chamber and applying steam onto a side of the film.
This method is known in the art. It is a goal to improve the method
so as to allow more efficient heat shrinking of the film.
[0043] In an embodiment the method further comprises directing
fluid of lower temperature than the steam in a downward direction
onto the object during application of the steam. This will allow to
locally, near the upward part of the object, cool the heat shrink
film, preventing (early) shrinking thereof. Further a homogeneous
flow of fluid is provided over the object. The downward flow will
carry steam downwardly, reducing turbulence in the upward area.
[0044] In an embodiment the steam is applied from two opposite
sides onto the object carried through the heat treatment
chamber.
[0045] In an embodiment the downward secondary fluid flow is
generate between fluid outlet devices positioned opposite one
another along the transport device for carrying the object and
films.
[0046] In an embodiment applying the steam for heat shrinking a
first part of the film comprises applying the steam to a bottom
part of the object. According to this embodiment the downward flow
can blow up the envelope wrapping the film after first heat
shrinking a bottom end thereof. This results in better and more
stable positioning of the film and allows quicker heat shrinking of
the complete film in subsequent (downstream) heat shrinking
steps.
[0047] In an embodiment of the method directing the fluid in the
downward direction comprises generating a circular fluid flow in
the heat treatment chamber, in the downward direction onto the
object, in an outwards direction, away from the object, followed by
an upward direction and inward direction. This circular fluid flow,
encircles the outlets for applying the steam to the objects/film.
During circulation, within the heat treatment chamber, the
temperature of the fluid can be reduced with 4 or more degrees
Celsius, which will allow obtaining the beneficial effects
according to the invention
[0048] In an embodiment the method comprises disposing fluid from
the heat treatment chamber. In an embodiment the fluid is disposed
from the circular flow in a direction aligned with that flow. The
discharge will not cause extra turbulence.
[0049] In an embodiment directing the fluid in the downward
direction comprises venting the fluid. Venting can be controlled or
configured allowing configuring the beneficial effects of the
invention.
[0050] In an embodiment the method comprises multiple stages of
applying steam to the object being transported through the heat
treatment chamber. A further (downstream) stage can follow the
stage comprising the application of steam in combination with the
downwardly directed fluid of lower temperature. In a further
downstream step a high power heat shrink step is possible as the
position of the envelope film is improved according to the
invention, allowing faster heat shrinking.
[0051] The invention will now be described referring to the drawing
wherein:
[0052] FIG. 1 shows a first view of an apparatus according to the
invention;
[0053] FIG. 2 shows a cross sectional view of the apparatus
according to FIG. 1;
[0054] FIG. 3 shows a cross sectional view along A-A in FIG. 2;
[0055] FIG. 4 shows a further cross section of the apparatus
according to the invention, and
[0056] FIG. 5 shows a cross section along C-C in FIG. 4.
[0057] For better understanding of the invention, similar parts
will have the same reference numbers in the following description
of the figures.
[0058] Apparatus 1, as schematically illustrated in FIG. 1, is an
apparatus for heat shrinking a heat shrink film 3 wrapping an
object 2.
[0059] The heat shrinking film 3 is made from shrinkable material
that will shrink at a certain minimum temperature that can be
reached by applying steam such as steam. Shrinking of the film will
result in closely wrapping the shape of the object formed by a
bottle or package. Reference is made to EP 2 103 527 A1 by the same
applicant, included by reference.
[0060] An apparatus 1 for heat shrinking, such as a heat shrink
oven, is known as such from prior art and has a housing 9. The
illustrated housing is of generally rectangular shape. Top sides
along the length of the housing are bevelled.
[0061] The housing 9 has heat treatment chamber 64. Inside the heat
treatment chamber a tunnel-shaped space 10 is formed, having an
entry side 10A and an exit side 10B. The apparatus comprises
transport device 11. The transport device 11 extends through the
heat treatment chamber 64. The transport device can carry an object
2 with film 3 through the tunnel-shaped space 10.
[0062] The housing 9 is provided with windows 25 allowing the
operator to look inside the heat treatment chamber inside the
housing 9. Several windows 25 allow the operator to watch several
steps (upstream near 10a or downstream near 10b) of the
process.
[0063] On the outside of housing 9 a human interface 62 from a
configuration device and is provided to allow the operator to
control the heat treatment process in the heat treatment chamber.
Specifically the operator is able to adjust or reconfigure
parameters of the supplied steam.
[0064] In this embodiment the human interface 62 comprises multiple
knobs 26. Each knob 26 can be used to control one or more
parameters of the heat shrinking process. The interface 62 can also
comprise shafts 72 connected to a control valve for controlling the
supply of steam. In an embodiment the pressure of the steam is
controlled allowing control of the temperature. As will be
discussed hereunder the configuration device can also adapt the
distance 80, see FIG. 4.
[0065] In order to shrink the film 3 wrapping the object 2 using
heat, the apparatus comprises a supply 12 for heated fluid. The
heated fluid can be steam. In this embodiment the steam is supplied
from an external source. In another embodiment the steam is heated
in the apparatus.
[0066] The supply will allow the steam to be supplied to the heat
treatment area 64 and in particular to the tunnel shaped area 10
receiving the object. The supply 12 can comprise a system of tubes
for transporting the steam, for clarity sakes not visible in the
figures.
[0067] Multiple fluid outlet devices 13a-13a'; . . . ; 13d-13d' are
connected to supply 12 (in FIG. 3 only one connection 90 is shown)
and disposed on either sides along transport device 11. Fluid
outlet device 13A is disposed on the right-hand of the transport
device 11. The fluid outlet device 13A' is positioned on the
left-hand side. The tunnel-shaped area 10, shown in FIG. 2 with
dotted lines, is positioned partially in between the fluid outlet
devices 13A-13A'.
[0068] In the embodiment shown, every fluid outlet device 13a-13a';
. . . ; 13d-13d' comprises multiple outlets 27, 60 arranged in
line. Outlets 27, shown in FIG. 4, are arranged for releasing the
steam. This fluid is at such operational temperature and has heat
to shrink film when the fluid comes into contact with film.
[0069] The outlets 27 are directed at objects supported and
conveyed by the transport device 11 through the tunnel-shaped area
10.
[0070] A detailed view of fluid outlet devices 13a-13a' and outlet
60 is shown in FIGS. 4 and 5. The outlets 60 are disposed on the
body 61. The outlets 27, 60 with body 61 form the fluid outlet
device 13a-13a'; . . . ; 13d-13d'. The outlets 27 are connected to
supply 12 for steam. The fluid outlet devices 13a-13a' etc.
comprise a manifold for distributing the supplied steam to the
different outlets 27, 60.
[0071] FIG. 3 shows the fluid outlet devices 13a-13a'; . . . ;
13d-13d' disposed on either side of the transport device 11 with
the outlets 27 directed at the tunnel-shaped area 10 or the area
through which the object 2 with film 3 are transported when carried
by the transport device 11.
[0072] Several fluid outlet devices 13a-13d are disposed along the
length 8 of the transport device 11 at different locations. An
object 2 supported and carried by the transport device 11 will pass
along the subsequent fluid outlet devices 13a-13d' when moved in
the transport direction 8.
[0073] An object 2 wrapped with film 3 is transported from the
inlet side 10a to the outlet side 10b and fluid outlet device 13a
is positioned more upstream than fluid outlet device 13d.
[0074] The fluid outlet devices 13a-13d' can be positioned at
different heights (indicated by arrow 63) or angles (indicated by
arrow 66) along the transport device 11 in order to, when an object
2 and films 3 wrapping the object are transported in the transport
direction, supply the steam onto the objects 2/films 3 moving
through the tunnel-shaped area 10 at different locations.
[0075] The different positions of the fluid outlet devices allow
obtaining a shrinking effect of the complete film 3 around object 2
with certain control in order for the film to closely wrap the
shape of the object 2. The positioning and configuration of the
fluid outlet devices along the transport device 11 allows control
of circumstances of shrinking. Good control reduces failure in
wrapping the object and will improve efficiency of the apparatus as
a whole. Further the size of the nozzle of the outlets can be
varied.
[0076] In order to control the circumstances of shrinking in the
tunnel-shaped area 10 even more, in accordance with the invention,
the heat treatment chamber 64 comprises a system for generating a
downward directed fluid flow 65 in the tunnel-shaped area, between
to two fluid outlet devices 13a-13a' disposed opposite on another
along the transport device 11.
[0077] The primary steam flow from the outlets 27 is directed at
the moving objects 3 and the steam will perform its shrinking
function by subsequently losing some of its heat. The system
according to the invention will subsequently direct the "used"
steam away from the object and away from the transport device. The
system will direct secondary steam away in a downward
direction.
[0078] The system in accordance to the invention provides an
additional flow pattern 5 on top of the steam released from the
fluid outlet device 13a-13d'. The system in accordance to this
embodiment will allow a circulation of secondary steam in a pattern
indicated with arrow 5 in FIG. 2.
[0079] The flow pattern for steam inside the heat treatment chamber
64 generated by the system of the invention generally extends in a
cross sectional plane of the machine, perpendicular to the
transport device 11.
[0080] The circulation pattern 5 comprises a generally downwardly
directed fluid flow part 65 in the area of the tunnel-shaped area
10, between the oppositely positioned fluid outlet devices 13a,
13a', continuing until substantially the height of the transport
device, thereafter bending in an outward direction towards the
sides of the heat treatment chamber 64, to subsequently curl
upwards along the side 66 of the heat treatment chamber 64 and
guided inward near a top of the heat treatment chamber 64.
[0081] In an embodiment, shown in FIGS. 2 and 3, a fluid flow
device 20, comprising one or more vents 21, is arranged vertically
above the transport device 11. In the shown embodiments multiple
vents 21 are disposed along the length of the transport device
11.
[0082] Every vent 21 is mounted to a propelling shaft 22' connected
to the driving unit 22. Driving unit 22 can be an electromotor.
[0083] In an embodiment the power unit 22 is physically positioned
in a chamber 68 separated from heat treatment chamber 64. Chamber
68 will contain less or no steam reducing the chance of malfunction
of the electrical part.
[0084] For configuring the supply of steam 5 shafts 72 can be used
connected to control valves positioned in the supply.
[0085] FIGS. 2 and 4 shows vents 21 of system 20 having an intake
side 21a for taking in secondary steam 5 present in the heat
treatment chamber, as well an outflow side 21b for returning to the
heat treatment chamber the secondary steam 5.
[0086] The secondary fluid flow from the fan is directed downwardly
towards the transport device and provides a generally homogeneous
flow in the tunnel-shaped area through which the objects 2 with
wrapping film 3 pass.
[0087] The system for generating a downward flow results in a more
homogeneous temperature in the tunnel-shaped area 10, resulting in
a more even heating of the film 3 during transport of the object
along the different fluid outlet devices 13a-13a'; . . . ;
13d-13d'. Shrinking the film 3 will be improved as a result of the
more efficient heat distribution and the shrinking process will be
more controlled.
[0088] The system for generating the downward flow results in
higher efficiency of the machine especially in the area surrounding
the most upstream fluid outlet device 13a, 13a'. If the first
shrinking step is performed successfully, further shrinking steps
by fluid outlet devices 13b-13d can follow along the transport
device and can be performed more rapid.
[0089] The system for generating downward fluid flow results in an
apparatus using the fluid in the heat treatment chamber in a more
efficient fashion and in general the use of the fluid in this
apparatus can be reduced. The reduction results in a higher energy
efficiency.
[0090] By better controlling the circumstances of the shrink
process in the tunnel-shaped area, the film 3 but also the object 2
will have a higher temperature which will result in a better
shrinking. By adding the additional downward flow more heat
conductance is initiated. Again, the higher control of shrinking
will result in shortening the length of the heat shrink oven
resulting in a smaller apparatus.
[0091] The fluid flow device 20 can allow adjustment of the speed
of the downward flow using a human interface.
[0092] Further, in combination with configuration means for
configuring the supply and/or the pressure of the steam to the heat
treatment chamber will allow control of shrinking the film wrapping
the object 2 passing through the tunnel-shaped area 10 over the
transport devices 11.
[0093] As a further result of the system for generating the
downward flow the fluid outlet devices can comprise more outlets
27,60 and can be positioned at a shorter distance from the object
to the tunnel-shaped area. In an embodiment fluid outlet devices
are disposed in the apparatus along the transport device having
about 40-90 outlets per meter.
[0094] FIG. 4 shows an exhaust 73 allowing the release of fluid
present in the heat treatment chamber 64. Exhaust 73 is arranged in
the area outside the fluid outlet devices 13a-13a'. In this area
the flow pattern has an upward direction. The outlet/exhaust is
positioned to allow the pattern to flow into the outlet, not
disturbing the fluid pattern.
[0095] The transport device 11 supports the object 2 and will as
such form a wall for the downward directed flow. It will also
function as a partition between fluid directed to the left hand
side and fluid directed to the right hand side. In an embodiment
the partition can be further embodied encompassing guides for the
outward directing of fluid.
[0096] Fluid flow device 24 has an outlet side 21b. in this
embodiment the inlet side 21a is positioned on the side of the
fluid flow device.
[0097] FIG. 5 shows the fluid outlet devices 13a positioned at
different heights and at different angles. FIG. 5 also shows parts
75, 76, 77 of the frame allowing the positioning of the fluid
outlet devices 13a.
[0098] The frame, not shown, allows the circulation pattern 5
around the fluid outlet devices 13a-13d.
[0099] During circulation, but already due to the fact that the
steam is directed at the film, the temperature of the fluid is
lower than the steam released from the outlets 27. During
circulation no heat is added and therefore the temperature of fluid
will be reduced further.
[0100] As it reaches the inlet side 21a of the vents 22,24 the
fluid will have a significant lower temperature than the fluid
supplied to the heat treatment chamber, e.g. at least 2 degrees,
but preferably 5, 12 or more degrees less. In an embodiment the
fluid temperature is lower than 90 degrees when it is directed
downward by the vents 22,24 and forms the downward directed flow
between the fluid outlet devices 13a-13d.
[0101] Fluid flow devices 24 are connected to a carrier 23 part of
the frame of the housing 9.
[0102] The distance 80 between the outlets 27 of fluid outlet
devices 27 can be varied. In the system of the invention the
distance 80 is preferably less than 8 cm.
[0103] Many different embodiments of the transport device are
possible within the scope of the invention.
[0104] The system for providing the downward directed flow between
the fluid outlet devices can be positioned partially inside and
partially outside the heat treatment chamber.
* * * * *