U.S. patent application number 17/167333 was filed with the patent office on 2021-05-27 for thermally insulating sheet formed from a down core structure and method of fabrication.
The applicant listed for this patent is Ronie Reuben. Invention is credited to Ronie Reuben.
Application Number | 20210154698 17/167333 |
Document ID | / |
Family ID | 1000005381443 |
Filed Date | 2021-05-27 |
United States Patent
Application |
20210154698 |
Kind Code |
A1 |
Reuben; Ronie |
May 27, 2021 |
THERMALLY INSULATING SHEET FORMED FROM A DOWN CORE STRUCTURE AND
METHOD OF FABRICATION
Abstract
A thermally insulating sheet formed by a down core structure
which is comprised solely of down feather material mixed with
binding material which is heat fused together to form a homogeneous
sheet core. The method of fabricating the homogeneous thermally
insulating sheet to form the down core structure is described. This
novel method restrains the down clusters and binding material
during the process of mixing, depositing, conveying and heat fusing
to form a homogeneous down core sheet. The down core structure is
subjected to two separate heat treatments which produces a down
core sheet having at least some of its outer surfaces being of
higher bond density than the inside of the core.
Inventors: |
Reuben; Ronie; (Town of
Mount Royal, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Reuben; Ronie |
Town of Mount Royal, QC |
|
CA |
|
|
Family ID: |
1000005381443 |
Appl. No.: |
17/167333 |
Filed: |
February 4, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
15932579 |
Mar 19, 2018 |
10946412 |
|
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17167333 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
D04H 1/559 20130101;
B60R 13/0815 20130101; B68G 3/08 20130101; D04H 1/60 20130101; B05D
1/265 20130101; B32B 9/047 20130101; B05D 3/0426 20130101; B32B
5/028 20130101 |
International
Class: |
B05D 3/04 20060101
B05D003/04; B05D 1/26 20060101 B05D001/26; B32B 5/02 20060101
B32B005/02; B68G 3/08 20060101 B68G003/08; B32B 9/04 20060101
B32B009/04 |
Claims
1. A thermally insulating sheet formed by a down core structure
comprising down feathers mixed with binding material which when
subjected to heat is capable of bonding together and with said down
feathers to form a homogeneous core, said down feathers being down
clusters each having a central quill with fluffy tentacles
projecting therefrom in all directions creating a three dimensional
cluster structure which traps air, said clusters attaching to one
another by said tentacles and said binder material, said binding
material being comprised of glue particles and/or polymer fibers,
said polymer fibers having a low melting point in the range of from
about 80 degrees C. to 160 degrees C., said down core structure
having a top and bottom outer surface and opposed side surfaces and
wherein said outer surfaces are bonded at a higher density than the
internal portion of said core thereof.
2. The thermally insulating sheet as claimed in claim 1 wherein
said binding material is comprised solely of said polymer fibers,
there being from about 2% to 30% of said polymer fibers by weight
of said mixture and preferably 6% to 15% by weight of said polymer
mixture.
3. The thermally insulating sheet as claimed in claim 2 wherein
said binding material is comprised of a mixture of said polymer
fibers and said glue particles, there being from about 2% to 30% by
weight of said glue particles in said mixture, and preferably 6% to
15% by weight of said glue particles.
4. The thermally insulating sheet as claimed in claim 2 wherein at
least some of said polymer fibers are stretchable polyester fibers
capable of bonding together and to said down clusters when heat
treated whereby to form said homogeneous sheet which exhibits
elastic properties to permit said down core structure to stretch
with no or minimal fracture to said down core structure and capable
of recovering substantially its original relaxed form after
deformation and/or stretching.
5. The thermally insulating sheet as claimed in claim 4 wherein
said polyester fibers are one of or a mixture of polyurethane resin
fibers, styrene fibers, hollow bi-component fibers, styrene fibers,
twisted fibers and other similar fibers and wherein at least some
of said polymer fibers are capable of stretching.
6. The thermally insulating sheet as claimed in claim 1 wherein
said binding material is comprised solely of said polymer fibers,
there being 5% to 90% by weight of fibers mixed with said down
feathers, said down polymer fibers occupying preferably of from
about 10% to 25% by weight of said mixture with said down
feathers.
7. The thermally insulating sheet as claimed in claim 2 wherein
said binding material is comprised of a mix of said polymer fibers
and said glue particles in equal proportions or in a proportion of
30% polymer fibers and 70% glue particles or variations thereof,
said binding material occupying a volume of from about 6% to 15% by
weight with said down feathers.
8. (canceled)
9. The thermally insulating sheet as claimed in claim 1 wherein
said down core structure further comprises other components in the
form of chemical additives or fibers to provide fire retardants or
to improve the tensile strength of the core.
Description
CROSS-REFERENCE
[0001] This is a divisional application of application Ser. No.
15/932,579, filed on Mar. 19, 2018 which is a continuation-in-part
application of continuation-in-part application Ser. No. 14/999,493
filed on May 16, 2016, now U.S. Pat. No. 10,390,637 and application
Ser. No. 13/999,094, filed on Jan. 13, 2014, now U.S. Pat. No.
9,380,893.
TECHNICAL FIELD
[0002] The present invention relates to a thermally insulating
sheet formed from a down core structure and a method of fabrication
of the down core sheet.
BACKGROUND ART
[0003] In my U.S. Pat. No. 6,025,041 I describe a first generation
down feather sheet and wherein the down feathers are retained in a
homogeneous form by a chemical binder agent or rigid fibers and
further wherein the down feathers are exposed on all sides of the
sheet. A primary purpose of that down feather sheet was to provide
a sheet of down feathers for use by the apparel fabricating
industry as superior insulation in garments. Such a down feather
sheet provided a substantially constant distribution of the down
feathers and thus prevented the development of cold spots in the
insulation. Because the down feathers are exposed in all outer
surfaces of the down feather sheet extra care was necessary to
prevent the down feathers from detaching from the faces of the
sheet or patterns cut from the sheet.
[0004] There is a need to develop a down feather sheet for use in
many other applications to provide improved thermal insulation,
such as in the construction of vehicles where the passenger
enclosure which is climatically controlled during hot or cold
weather condition needs to be well insulated. Countless other
applications exist as one can imagine. However, for such commercial
use, as well as in the fabrication of articles of apparel, there is
a need to retain the down feathers captive in the sheets or
patterns and to make down feather sheet stretchable (elastic)
whereby it can be stretched during installation or use when the
need arises to do so.
[0005] Another problem with down insulating products, such as
articles of apparel is that when such articles are washed in a
washing machine, the down has a tendency to form clumps and the
minute down clusters can come out of the lining fabric. Ideally,
such products should be dry cleaned but still the down clusters,
being very small and unstable, can be drawn out of the lining
fabric. Such affects the insulating quality and the aesthetic
appearance of the garment.
[0006] More recently, such down feather sheets have been held
captive between sheets of non-woven fabrics adhered to opposed top
and bottom surfaces of the sheets and held thereto by a glue binder
present at the interface with the down sheet. Although, that
solution did prevent some escapement of the down feathers, it did
not provide for the use of such material in other industrial
manufacturing applications as the material, although flexible did
not provide for stretching of the sheet to attach it to flexible
and rigid shaped objects and in restricted spaces where it is
necessary for the sheet to stretch. Also, when used in garments in
areas where movement is required such as in underarm areas or knee
areas of clothing, rigid down insulating sheets when stretched
would tear to form clumps of insulation which would gather in
specific areas and become visible to the eye and form cold spots in
the garment. Therefore, that improvement did not overcome these
existing problems to extend the use of such down feather
sheets.
[0007] It is desirable to form a down feather sheet comprised of a
core mixture of down feather material with a binder as described in
my above mentioned patent. However, I have found that because the
down clusters are very unstable and difficult to manipulate, and
particularly so if conveyed in a thermal chamber or oven without a
scrim sheet on the top surface thereof, the air flow in the chamber
causes the down clusters to disperse from the surfaces of the sheet
of loose down feather making it impossible to produce a homogeneous
sheet solely of down feathers and a binder material mixture.
SUMMARY OF THE INVENTION
[0008] It is a feature of the present invention is to provide a
thermally insulating sheet formed solely by a down core structure
and a method of fabricating same
[0009] Another feature of the present invention is to provide a
method of fabricating a homogeneous thermally insulating sheet
comprised of a mixture of down feather material mixed with a
binding material in predetermined proportions and heat set together
while overcoming the above mentioned disadvantages of not using
scrim sheets to retain the mixture captive.
[0010] It is a further feature of the present invention to provide
a thermally insulating down sheet formed by a core structure which
is breathable, soft, lightweight, and without the use of scrim
sheets while substantially preventing the escape of down clusters
from the opposed surfaces and side surfaces of the down sheet.
[0011] Another feature of the present invention is to provide a
down sheet formed from down material bonded together by glue
particles and/or polymer fibers mixed in predetermined proportions
to form a down core sheet and wherein the top outer surface and
side surfaces of the down core sheet has a higher bond density than
the inner area of the core.
[0012] According to the above features, from a broad aspect of the
present invention, there is provided a thermally insulating sheet
formed by a down core structure comprised of down clusters mixed
with binding material which when subjected to heat is capable of
bonding together to form a homogeneous core sheet. The down cluster
each have a central quill with fluffy tentacles projecting
therefrom in all directions creating a three-dimensional cluster
structure which traps air. The clusters attach to one another by
their tentacles and the binder material. The binding material is
comprised of glue particles and/or polymer fibers, with the polymer
fibers having a low melting point in the range of from about 80
degrees C. to 160 degrees C., and wherein said down core has at
least some bonded outer surface of higher bond density than the
inner core.
[0013] According to another broad aspect, the present invention
provides a method of fabricating a homogeneous thermally insulating
sheet formed by a down core structure, the method comprising the
steps of:
i) Mixing in a mixing chamber down feather material with a binding
material in predetermined proportions. The binding material is
comprised of glue particles and/or polymer fibers having a low
melting point in the range of from about 80 degrees C. to 160
degrees C. ii) Displacing a conveyor belt having a non-stick
surface under an outlet opening of the mixing chamber. iii)
Releasing predetermined quantities of the mixture of down feather
material and binding material from the outlet opening onto the
non-stick surface of the conveyor belt when the conveyor belt is in
motion to form a sheet layer of the mixture. iv) Restraining the
sheet layer of said mixture as it is conveyed from the outlet
opening to a thermal chamber to subject the mixture to a
temperature sufficient to heat bond at least some of the surfaces
of the mixture, and v) Releasing the restrainment.
DESCRIPTION OF THE DRAWINGS
[0014] A preferred embodiment of the present invention will now be
described with reference to the accompanying drawings in which:
[0015] FIG. 1A is a fragmented perspective view of a thermally
insulating stretchable down sheet constructed in accordance with
the present invention and illustrating two types of elastomeric
outer sheets and different types of binding techniques;
[0016] FIG. 1B is an enlarged view of a section of the down core
and wherein the down cluster are trapped and bound together by
heat-fused glue particles and elastomeric binding strands and the
down tentacles of the clusters to form a stretchable down core;
[0017] FIG. 2 is a schematic illustration showing a method of
fabricating the thermally insulating stretchable down sheet using a
binder having multi-directional elastic properties when heat fused
and mixed with the down and held captive between opposed
elastomeric sheets having multi-directional stretchability;
[0018] FIG. 3 is a schematic illustration showing a modification of
FIG. 2 wherein a coating of a tackifier binder is applied between
the down core and the outer elastomeric multi-directional
stretchable sheets;
[0019] FIG. 4 is an enlarged and partly fragmented section view
illustrating an application of the thermally insulating stretchable
down sheet and wherein the sheet is stretched and secured to an
irregular shaped member;
[0020] FIG. 5 is a block diagram illustrating an embodiment of
another method of fabricating the homogeneous thermally insulating
sheet of the present invention formed by a down core structure
without the use of scrim sheets on opposed surfaces of the core
structure;
[0021] FIG. 6 is an enlarged view of the section of the side plates
extending into the inlet section of the thermal chamber and which
progressively exposes the side surfaces of the sheet mixture of the
down feather material with the binder material, and
[0022] FIG. 7 is a fragmented side view illustrating the thermally
insulating sheet formed solely by a down core structure.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0023] Referring now to the drawings, and particularly to FIG. 1A,
there is shown at 10 a thermally insulating stretchable down sheet.
It is comprised of a stretchable down core 11 sandwiched between
and bonded to a top and a bottom multi-directional stretchable
elastomeric sheet 12 and 13, respectively, made from woven or
non-woven fibers. The core 11 is comprised of down clusters 14
mixed with a stretchable binder 15, in predetermined proportions.
The binder 15 is a mixture of an elastic glue and stretchable
polyester fibers capable of bonding when heat treated whereby to
form a homogeneous thermally insulating down core which exhibits
elastic properties permitting it to stretch with the elastomeric
sheets with no or minimal fracture to the core.
[0024] The expression "elastomeric" as used herein is meant to have
the meaning of elastic or stretchable wherein the core formed of
down and the elastic binder is capable of recovering substantially
its original relaxed form after stretching or deformation. Also,
the elastomeric sheets may be woven or non-woven in the form of
films, nettings, and the like, and are basically isotropic,
exhibiting essentially the same properties in all directions of
their two dimensional plane. Such elastomeric goods as utilized
with the present invention are for example polyurethane resins
which are capable of fusing when subjected to heating whereby to
bond. Some elastic polymer filaments 15' are formed from styrene
strands and some may exhibit an elongation to break of at least
200%, and when released from stretching retreats to about 125% of
its original length. Many of such fibers or filaments and nonwovens
are currently available in the trade. Webs made thereof provide
excellent stretchable characteristics, breathability, softness,
lightweight and weathering resistance.
[0025] The elastomeric, multi-directional, stretchable sheets 12
and 13 may also be in the form of netting, as mentioned above and
as denoted by reference numeral 12' in FIG. 1A and comprised of
polymer filaments produced by extrusion streams to form a regular
array of weft and warp stretchable filaments bonded together at
their crossings to produce a net which exhibits multi-directional
stretching. For example, such netting may be fabricated from Nylon
6 and polypropylene. These nettings are all known in the art and
for example disclosed in U.S. Pat. No. 4,636,419, the disclosure of
which is herein incorporated by reference. U.S. Pat. No. 4,241,123
also discloses a non-woven netting formed by a first group of
melting monofilaments and a second group of monofilaments or a yarn
which is crossed, pressed and heat welded to form a fiber stand
netting capable of softening under heat treatment to bond to the
core 11 and has the capability to stretch in all directions.
[0026] FIG. 1B is an enlarged view illustrating the mixture of the
down clusters 14 with a binder which is constituted by a mixture of
the elastic glue particles 15 and the elastic polymer strands or
filaments 15'. Each cluster 14 has a central quill point 14' with
fluffy tentacles or filaments 14'' projecting from its central
quill point 14' in all directions creating a three dimensional
structure which traps air to give down insulating ability. The
clusters attach to one another by their tentacles 14'' when plucked
from the goose, duck or swan. As can be seen such as identified by
reference numeral 17, some of the glue particles 15 that are melted
bind to both the down clusters 14 and the elastic polymer filaments
15' and thus provide improved bonding of the elements in the
mixture and entrapment of the down clusters preventing the down
clusters from escaping from the side edges of the sheet 10. The
filaments 15' or fibers act as carriers for the glue particles. As
also denoted by reference numeral 18, the filaments 15' bind to
themselves at their crossings and to the down tentacles 14'. Also,
the tentacles 14' have a twisted shape and interconnect with the
tentacles of adjacent clusters. The interconnections of the
filaments, the stretchable glue and the tentacles of the down with
one another form a homogeneous stretchable core sandwiched between
the opposed multi-directional stretchable elastomeric sheets 12 and
13.
[0027] With reference now to FIG. 2 there is described a method of
fabricating a thermally insulating stretchable down sheet 10 of the
present invention. As herein shown, the machine 20 comprises a
conveyor 21 having an endless belt 22 fabricated from a non-stick
material and capable of withstanding heat up to at least 150
degrees C. The belt 22 extends through the machine length, as
herein shown, although the conveyor may be constituted by two or
more driven and aligned conveyor belt sections driven synchronized
to one another. The belt is driven by a motor 23 coupled to a drive
drum or sprocket 24, the speed of which is controlled by a
controller device 25 whereby to control the thickness or density of
the down core 11 deposited on the belt. The different operating
parameters of the machine are programmed in the controller device
and can be adjusted on the controller device or remote
therefrom.
[0028] At the inlet end of the conveyor 21 there is supported a
roll 26 containing a supply of the stretchable elastomeric sheet 13
which is dispensed on the top surface 22' of the conveyor belt at a
speed synchronized with the speed of the conveyor belt 22. An air
mixing chamber 27 is supported above the top run 22' of the
conveyor and is preferably, although not exclusively, constructed
of clear plastic whereby to view the operation therein of the air
turbulence mixing action of the down feathers 14 with the binder
glue particles and/or the stretchable fibers 15'. Air mixing
currents 28 are injected at an upward angle inside the mixing
chamber 27 by blowers 29, the air speed of which may be regulated
by the controller settings. The down clusters 14 are fed into the
mixing chamber 27 at a control rate via a feed chute 30. The dry
elastic glue particles 15 and/or elastic filaments 15' are also fed
to the mixing chamber 27 via a chute 31, there being from about 2%
to 30% of filaments by weight of the mixture. The elastic glue
particles are released in volume to comprise 2% to 30% by weight of
the mixture with the down and preferably 6% to 15% by weight.
Likewise, when the binder is a stretchable elastic filament 15', it
is fed to the mixing chamber 27 via a separate chute 32. The
stretchable elastic filaments may comprise 5% to 90% by weight of
the mixture with the down to form a mostly polyester insulating
sheet with reduced thermal insulating properties. Preferably, the
down mixture is from about 10% to 25% by weight to form the down
insulating sheet of the invention. The binder is preferably
constituted by a blend of the elastic glue particles 15 and the
stretchable or elastic filaments 15' in equal proportions or 30%
filaments and 70% glue particles or variations thereof depending on
the desired elastic properties. As an example, a 30 grams down
insulating sheet 10 contains between 3 grams to 7.5 grams of the
glue and filaments mixture, whereas a 100 grams down insulating
sheet may contain 10 grams to 25 grams of the glue and filaments
mixture. It is contemplated that to the mixture there may also be
added other components in the form of chemical additives or fibers
to provide fire retardants or to improve the tensile strength of
the core.
[0029] The elastic glue binder as herein contemplated has a
softening binding point above 80 degrees C. while the elastic
filaments which are low molecular weight polymers may have a
softening point slightly below 80 degrees C. As the down and binder
mix in the upper part of the mixing chamber, the mixture starts to
precipitate downwards to the lower part 27' of the chamber where a
dispensing rotor 33 is rotated to dispense the mixture through a
bottom depositing outlet opening 34 of the mixing chamber 27 at a
constant volume onto elastomeric sheet 13. By controlling the speed
of the conveyor belt, the thickness of the deposited mixture is
controlled and this is accomplished by the conveyor speed setting
in the controller 25.
[0030] Downstream of the mixing chamber there is supported a second
roll 35 containing a supply of the multi-directional stretchable
elastomeric sheet 12 which is applied on the top surface of the
down core sheet 11 exiting its passage from under the mixing
chamber 27. Optionally, a down core sheet restrainer device 36 may
be supported across the conveyor belt 22 to restrain the down and
bi-component stretchable mixture on opposed sides thereof by
adjustable guide side walls 37 supported above and close to the top
surface of the conveyor belt 22 to prevent the down mixture from
escaping from the side edges thereof. The elastomeric stretchable
sheet 12 restrains the top surface of the down mixture.
Additionally, a top compression plate 38 may span across the
conveyor belt above the down mixture to gradually compress the
mixture if desired prior to entry into a thermal chamber 39. If it
is desired to support the down and the binder mixture on the bottom
elastomeric sheet only, then the second roll 35 of the elastomeric
sheet is not necessary. However, to retain the down mixture in
place the top compression plate 38 would act as a covering over the
top surface of the down mixture with the binder. The down clusters
are very unstable and are easily releasable into the air when not
constrained. This is why the second roll 35 is positioned close to
the outlet 34 in order to restrain the down as soon as possible
after being deposited on the elastomeric sheet.
[0031] The thermal chamber 39 is of a predetermined length and
provided with heating devices 40 capable of generating controlled
heat in the thermal chamber in the range of from about 80 degrees
C. to 160 degrees C. to melt the elastic glue 15 mixed with the
elastic filaments 15'. At the outlet 41 of the thermal chamber
exits the thermally insulating stretchable down sheet 10 and it may
be conveyed along a cooling end section 42 of the conveyor 21 to
cool the sheet 10. Alternatively, cooling air blowers 43 may be
mounted above the exit end section 42 of the conveyor to provide
for rapid cooling of the sheet 10. A suitable slitter device 44 can
then sever the sheet into sections to form individual sheets or
slit the sheet to provide the end of a roll of the down sheet.
[0032] Referring now to FIG. 3 there is illustrated a further
modification of the machine 20. As herein shown a tackifier or
plasticizer applicator 50 and 50' may be positioned adjacent the
entry end and exit end respectively of the mixing chamber 27
whereby to release a small quantity of a tackifier on the top
surface 13' of the stretchable elastomeric sheet 13 and the top
surface of the down mixture for the addition of stretchable
adhesive. The tackifier may be constituted by the elastic glue
particles or the elastomeric binding filaments or a combination
thereof whereby to enhance the binding at the interfaces of the
multi-directional stretchable elastomeric sheets 12 and 13 with the
down feather core 11. This is particularly useful if the
elastomeric sheets are constituted by netting which improves
breathability and wherein the added tackifier further prevents the
down clusters from being released through the interstices of the
netting.
[0033] As shown in FIG. 4, because the thermally insulated down
sheet 10 of the present invention has multi-directional
stretchability it can be used in numerous insulating applications.
As herein shown, the sheet is secured to a rigid curved body 55 by
fasteners, one fastener 56 herein illustrated, and is stretched in
a curved area 57 of the body 55 where the sheet 10 is stretched
thereby stretching and compressing the core material 11 in the zone
identified by arrows 58 and without fracturing the sheet due to its
stretchability. Similarly, when the sheet 10 is sewn in articles of
apparel the same stretching occurs in certain areas of the apparel
where there is movement, stretching the insulation such as in arm
pit areas of jackets, the knee areas of the legs of insulating
pants, such as ski pants, etc. The breathability of the insulating
stretchable down feather sheet 10 also provides for the passage of
humidity and air flow when positioned in vent areas of certain
articles of apparel or any area where such breathable feature is
required. The thermally insulating stretchable down sheet can be
secured to various elements by many types of securement means, such
as glue, stitching, heat bonding, etc.
[0034] Referring now to FIGS. 5 to 7 there will be described the
method and the apparatus for the fabrication of a thermally
insulating sheet 60, as shown in FIG. 7 comprised solely of a down
feather mixture mixed with binder material. There are no scrim
sheets as above described to retain the down and binder material
mixture during the process and on the finish product. FIG. 5
illustrates the method of fabricating the homogeneous insulating
sheet 60 of FIG. 7, formed solely of a down core structure. The
method comprises a mixing chamber 61 in which down feather material
comprised mainly of down clusters 62 and tiny feathers mixed with a
binder agent or material in the form of binding fibers 63 and/or
glue particles 64 mixed in predetermined proportions. The mixing is
made by a mixing air flow 65 and mixing rolls 66 disposed above an
outlet opening 67 of said mixing chamber 61. The mixture is
discharged at the outlet opening 67 at a predetermined rate. A
conveyor belt 68 having a non-stick outer surface 69, such as a
TEFLON, registered trademark, coated surface, is displaced under
the outlet opening 67 at a predetermined speed to receive thereon
the down cluster and binding material mixture to form a sheet core
layer 70. The speed of travel of the conveyor belt 68 determines
the thickness of the deposit from the mixing chamber.
[0035] Mixture restraining means is provided in the immediate area
of the outlet opening 67 to restrain the mixture of unstable down
clusters 66 mixed with binding fibers 63 and/or glue particles 64.
This restraining means is constituted by a mixture restraining
endless belt assembly 71 driven at the same speed as the conveyor
belt 68 and trained about a drive pulley 72 and idle pulleys 73.
The restraining endless belt 68 also has a non-stick outer surface
74 and it is supported for engagement with a top surface 70' of the
sheet layer 70 deposited on the conveyor belt 68. As shown, the
restraining endless belt 68 has a forward guide pulley 73'
positioned close to the outlet opening 67 to immediately engage
with the top surface of the sheet layer 70 exiting the outlet
opening 67. It also has a long mixture restraining belt section 74'
to restrain the down feather and binder mixture sheet layer 70 has
it travels through a first heat treatment chamber 75. The
restraining endless belt 68 is also a perforated belt having tiny
holes therein to permit heat transfer from the heat treatment
chamber 75 to at least the top surface of the sheet layer mixture
70. The belt could also be heated instead of being perforated to
heat the top surface of the sheet layer mixture 70. The entire
mixture restraining belt assembly 71 is adjusted vertically
depending on the desired thickness of the sheet layer 70 required
at the outlet of the heat chamber 75.
[0036] The mixture restraining means also comprises a restraining
side wall structure 76 formed about the outlet opening 67. It has
an end wall 77 and opposed parallel side walls 78 which extends
along the conveyor 68 closely spaced to the outer surface 69 of the
conveyor to retain the sheet layer mixture 70 captive from the
sides. The end wall 77 may not be necessary but it prevents the
unstable down clusters in the mixture from escaping from under the
outlet opening 67. Accordingly, the deposited mixture, in the form
of a sheet layer, is held captive at the bottom by the conveyor
belt 68, at the side surfaces 70'' by the parallel side walls 78 of
the restraining side wall structure 76 and the top by the
restraining endless belt 71.
[0037] As shown in FIGS. 5 and 6, the side walls 78 extend within
the heat treatment chamber and terminate at an end 79 close to the
exit end 75'' of the thermal chamber 75. The side walls 78 are also
perforated with holes 80 from the inlet end 78' of the heat
treatment chamber 75 to the end 79 of the side walls. The holes 80
progressively increase in size from the inlet end to the outlet end
of the chamber, as illustrated, whereby the outer side surfaces of
the sheet layer mixture 70 is progressively exposed to the heat
from the heat treatment chamber to progressively expose the mixture
to the heat to prevent the small clusters from escaping through the
holes 80, for example if the holes where too large at the end 78'.
The perforated restraining endless belt 71 also causes the heat to
better penetrate to the top surface of the sheet layer mixture 70
to sufficiently bind the mixture at the top surface. Accordingly,
when the sheet layer 70 exits the heat treatment chamber 75 the
exposed outer surfaces of the sheet layer mixture 70 are
substantially heat fused to prevent the clusters, fibers and glue
particles to be released during its travel to the second section
75' of the heat treatment chamber or a further heat chamber where
the sheet layer mixture 70 is subject to sufficient heat treatment,
in the range of from about 80 degrees C. to 160 degrees C., to
cause the low melting point fibers to soften and bind together at
their crossing and to the down clusters to bind all of the mixture
material together inside the core to form a homogeneous core
mixture 70' which is then conveyed through a cooling chamber 85. It
is also conceivable that the temperature of the first thermal
section 75 be sufficiently high to quickly fuse the outer surfaces
of the mixture conveyed therethrough, say slightly above 160
degrees C.
[0038] Because the top surface 70' and the opposed side surfaces
70'' are subjected to two heat treatments, more bonding or fusing
will occur at those surfaces to produce a higher density bond than
the inside of the core. Such is very desirable to prevent the down
from escaping from the outer surfaces. With regards to the bottom
surface of the down core sheet it is contemplated that it could be
heated through the conveyor belt as it travels through the second
thermal chamber 75' from under the belt by a pressurized heat
chamber boiling hot air upwards to heat the conveyor belt and hence
the bottom surface of the sheet layer mixture 70. A scrim sheet can
also be bonded to the bottom surface of the down core as shown in
FIGS. 1A, 2 and 3.
[0039] Although FIG. 5 illustrates the heat treatment chamber being
formed in two sections 75 and 75', the thermal chamber can be a
single chamber and wherein the restraining endless belt 71 is
caused to exit the chamber through a slit formed in the top wall of
the thermal chamber. As also shown in FIG. 5, a belt surface
cleaning apparatus 83 is mounted along the bottom travel path 84 of
the conveyor belt 69 to brush off or scrape any residue material
that may be stuck to the outer non-stick surface 69 and to convey
such by vacuum to a collection reservoir.
[0040] The above description of the preferred embodiment is
intended to cover equivalent modifications of the specific examples
described herein provided such equivalent modifications fall within
the scope of the appended claims.
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