U.S. patent application number 10/824552 was filed with the patent office on 2004-09-30 for laminated hook fastener.
This patent application is currently assigned to Velcro Industries B.V., a Netherlands corporation. Invention is credited to Kennedy, William J., Provost, George A., Rocha, Gerald F..
Application Number | 20040187275 10/824552 |
Document ID | / |
Family ID | 25676756 |
Filed Date | 2004-09-30 |
United States Patent
Application |
20040187275 |
Kind Code |
A1 |
Kennedy, William J. ; et
al. |
September 30, 2004 |
Laminated hook fastener
Abstract
An extruded hook fastener strip is created on a roll having hook
forming cavities in its surface by extruding plastic material into
the interface between the forming roll and a second strip carried
by a backing roll. The second strip is firmly bonded to the
fastener strip on that side opposite the formed hooks.
Inventors: |
Kennedy, William J.;
(Manchester, NH) ; Provost, George A.;
(Manchester, NH) ; Rocha, Gerald F.; (Bedford,
NH) |
Correspondence
Address: |
FISH & RICHARDSON PC
225 FRANKLIN ST
BOSTON
MA
02110
US
|
Assignee: |
Velcro Industries B.V., a
Netherlands corporation
|
Family ID: |
25676756 |
Appl. No.: |
10/824552 |
Filed: |
April 13, 2004 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
10824552 |
Apr 13, 2004 |
|
|
|
09737161 |
Dec 14, 2000 |
|
|
|
6737147 |
|
|
|
|
09737161 |
Dec 14, 2000 |
|
|
|
09162949 |
Sep 29, 1998 |
|
|
|
6248419 |
|
|
|
|
09162949 |
Sep 29, 1998 |
|
|
|
09046922 |
Mar 24, 1998 |
|
|
|
09046922 |
Mar 24, 1998 |
|
|
|
08651170 |
May 21, 1996 |
|
|
|
5744080 |
|
|
|
|
08651170 |
May 21, 1996 |
|
|
|
08319267 |
Oct 6, 1994 |
|
|
|
5518795 |
|
|
|
|
08319267 |
Oct 6, 1994 |
|
|
|
08080348 |
Jun 21, 1993 |
|
|
|
08080348 |
Jun 21, 1993 |
|
|
|
07747876 |
Aug 16, 1991 |
|
|
|
5260015 |
|
|
|
|
Current U.S.
Class: |
24/445 ; 264/167;
264/171.13 |
Current CPC
Class: |
Y10T 24/2733 20150115;
Y10T 24/2758 20150115; Y10T 24/27 20150115; A44B 18/0092 20130101;
Y10T 442/15 20150401; B29C 2043/465 20130101; A44B 18/0003
20130101; B29D 5/00 20130101; Y10T 442/155 20150401; Y10T 442/109
20150401; A44B 18/0084 20130101; B29C 2043/461 20130101; B29C
59/025 20130101; Y10T 24/2792 20150115; B29C 43/46 20130101; Y10T
442/184 20150401; Y10T 24/2775 20150115; Y10T 428/24008 20150115;
Y10T 442/164 20150401; Y10T 442/102 20150401; A44B 18/0049
20130101; B29C 43/222 20130101; Y10T 24/2708 20150115; Y10T 24/275
20150115; Y10T 428/249959 20150401; B29L 2031/729 20130101; Y10T
428/249958 20150401; A44B 18/0007 20130101; Y10T 428/24017
20150115; A44B 18/0073 20130101 |
Class at
Publication: |
024/445 ;
264/167; 264/171.13 |
International
Class: |
B32B 003/06 |
Claims
1-29. (Cancelled)
30. A product constructed to mount on material covered with
hook-engageable loops, the product comprising a field of
loop-engageable hooks having stems of molded plastic resin, the
stems protruding from one side of a base layer of plastic resin,
and a second layer joined to the opposite side of said base layer,
said second layer bearing printing, the printing being visible from
at least one side of the product.
31. The product of claim 30 in which said second layer is a
preformed layer laminated to said base layer.
32. The product of claim 30 in which said second layer is of
plastic resin.
33. The product of claim 32 in which said plastic resin of said
second layer is of the same general character as the plastic resin
of which the base layer is formed.
34. The product of claim 33 in which said plastic resin is
polyethylene.
35. The product of claim 30 in which said second layer is
paper.
36. The product of claim 30 in which the self-adhesive property of
the base layer serves to adhere said second layer to said base
layer.
37. The product of claim 30 in which said second layer comprises
preformed sheet material in an insitu laminated relationship with
said base layer.
38. The product of claim 37 in which said printing, in pre-applied
state on said second layer has been exposed to the conditions of
said insitu lamination.
39. The product of claim 38 in which the printing lies of the face
of said second layer joined to base layer.
40. A product comprising a field of loop-engageable hooks having
stems of molded plastic resin, the stems protruding from one side
of a base layer of plastic resin and a second layer joined to the
opposite side of said base layer, said second layer bearing
printing, the material of which the hook material and base layer is
formed being substantially transparent, and said printing being
visible from the side of said product having said hooks.
41. The product of claim 40 in which said second layer comprises a
preformed layer bearing printing on its side adjacent said plastic
resin base layer.
42. The product of claim 40 in which said second layer is plastic
film.
43. The product of claim 40 in which said second layer is
paper.
44. A product constructed to engage with material bearing
hook-engageable loops, the product comprising a field of
loop-engageable hooks having stems of molded plastic resin, the
stems protruding from one side of a base layer of plastic resin,
and a second layer joined to the opposite side of said base layer,
said second layer joined to said base layer by an infusion or
diffusion bond with the plastic resin of which said base layer is
formed.
45. The product of claim 44 in which said second layer comprises
preformed sheet of plastic resin.
46. The product of claim 44 in which said second layer comprises
preformed sheet of paper.
47. The product of claim 44 in the form of an insitu laminate, the
paper being adhered to the base layer.
48. A method of making a strip-form product having an array of
projections integrally molded with and extending from a side of the
product, the method comprising introducing molten resin into a
pressure nip defined in part by a surface of a rotating molding
roll, the molding roll defining an array of projection cavities
extending inward from the surface of the roll, such that the resin
is forced into the cavities to mold a corresponding array of
projections extending from a base layer of resin solidified on the
surface of the molding roll; introducing a preformed sheet material
into the nip with the molten resin, such that the sheet material is
permanently bonded to the resin in regions located directly beneath
at least some of said upstanding projections, by infusion or
diffusion of the molten resin under pressure into the preformed
sheet material; and solidifying the resin on the molding roll; and
stripping the solidified resin and sheet material from the molding
roll.
49. The method of claim 48 in which the projections overhang the
base layer of resin as molded.
50. The method of claim 48 in which the projections comprise
fastener elements.
51. The method of claim 50 wherein the fastener elements are
configured to releasably engage loops.
52. The method of claim 48 in which the preformed sheet material
comprises a non-woven fabric.
53. The method of claim 48 in which the base layer of resin forms a
continuous layer along the product.
54. The method of claim 53 in which the base layer of resin is
coextensive in width with the product.
55. The method of claim 48 in which the preformed sheet material is
coextensive in width with the product.
56. The method of claim 48 in which the preformed sheet material
forms a backing of the product.
57. The method of claim 56 in which the projections comprise
fastener elements and in which the preformed sheet material carries
engageable loops.
58. The method of claim 48 in which the preformed sheet material
comprises paper.
59. The method of claim 48 in which the preformed sheet material
comprises foam.
60. The method of claim 48 in which the resin base forms a broad
sheet underlying all of the projections.
Description
[0001] This invention relates to an improved fastener of the hook
and loop type and a method for producing the same using a combined
extrusion/roll forming process. The assignee of this application is
owner of U.S. Pat. No. 4,775,310 which describes an apparatus for
making a separable fastener and U.S. Pat. No. 4,872,243 which
describes the product produced by the apparatus of the former
patent. Striplike fasteners of the type described in the subject
patents comprise a great multiplicity of closely spaced upstanding
hooklike projections to releasably engage loops of a companion
fastener strip to form a cyclable or semipermanent closure sold in
the trade under the brand name Velcro.RTM.. Depending upon the
configuration of the multihook fastener, many different types of
material are adapted for coaction therewith to effect joining of
the structures to which the strip fasteners are themselves joined.
Such fastener devices are finding broad usage in such diverse
applications as securing automotive seat covers to foamed seat
buns, closures for food bags, the application of armor to military
vehicles and holding down floor coverings to floors.
[0002] Each of the recited applications and many more, well known
to those skilled in the art, require the fastener to be permanently
attached to a second article such as a piece of textile fabric, a
seat bun, a floor or the flap of a paper bag. Sewing, however, is
limited as to the nature of the material to which the fastener may
be attached. Adhesive systems have long been used as a principal
method of attaching fasteners to other objects as well. U.S. Pat.
No. 3,773,580 discloses a method of securing a fastener member to a
substrate by first applying a synthetic resin adhesive to one side
of the base of a fastener, opposite the side containing the
upstanding engaging elements, and then applying an adhesive to the
substrate. Thereafter the adhesive coating on the fastener is
activated. The two adhesive coated surfaces are brought together in
face to face relationship to firmly affix the fastener member to
the substrate. The subject patent teaches that "in order to
securely bond an adhesive to the tape member it is preferred that
the opposite surface of the tape member have a suitable base coat
which would provide for a secure bond between the tape member and
the adhesive". U.S. Pat. No. 3,726,752 instructs that in preparing
adhesive laminates, wherein synthetic resin based adhesive is
laminated to a web of polyamide polymer, it was found that strong
bonding between the polyamine substrate and the adhesive lamina
were difficult to achieve, and the prior art is "well-studded with
attempts to overcome this problem". This patent overcomes such
difficulties by treating the polyamide web with primer coating
consisting of a complex chemical mixture in a solvent medium to
render an improved bonding surface. Many patents, including U.S.
Pat. No. 2,349,290 and U.S. Pat. No. 3,060,070 and U.S. Pat. No.
3,111,448 and U.S. Pat. No. 2,766,164, describe methods for bonding
poly(amide) polymer to specific surfaces primarily natural or
synthetic rubber. All of these teachings rely upon chemical means
for enhancing the ability to bond to the surface of a sheet or
fibrous material.
[0003] Many plastic fastener tapes are produced from plastic
materials possessing the minimum strength and resiliency essential
to the proper functioning of the hooklike projections. Customarily
the side of the fastener tape opposite the upstanding hooks is a
smooth, flat, uniform and regular surface difficult to bond, as is
well documented in the prior art. Such difficulties present
particular problems for hook and loop fasteners. This class of
products are convenience products and if it is necessary to apply
complex chemical treatments to the tape prior to bonding the
convenience advantage is lost. It is known to apply pressure
sensitive adhesives to such fasteners by the application of corona
treatments in the manufacturing facilities where the fastener tapes
are manufactured but such treatments are not available for many
users and do not present a reasonable solution for creating a
fastener surface which is readily bondable to a wide variety of
surfaces using a wide range of adhesive types. U.S. Pat. No.
3,594,865 describes an apparatus for continuously forming a
flexible web with molded protuberances of plastic material
incorporated in a base web. The base of the web is either a porous
woven or nonwoven fabric, or an extruded film. The supporting
fabric is impregnated with molten plastic simultaneously as hooks
are formed. While U.S. Pat. No. 3,594,865 is sparse in detail
concerning the nature of the product formed from the apparatus it
does characterize the impregnation of the base fabric as complete,
stating in appropriate part, "a liquid moldable plastic material,
for example a molten plastic, is injected into the hook molding
recesses of the wire and also onto the surface and into the
interstices of the base fabric which lies on the surface of the
drum." The base fabric passes under a nozzle which impregnates it
with the same plastic used to inject the dies used to form the
plastic hooks with the clear implication the porous base web is
completely saturated with the plastic. This is considerably
different from the products of the present invention wherein the
process controls the distribution of plastic into the backing
material to a degree necessary to firmly hold the backing material
to the base of the hook sheet but does not encase the backing to
destroy it's aesthetic characteristics as a functioning backing
material to modify the back surface of the fastener. The backing of
U.S. Pat. No. 3,594,865 is primarily a support onto which hooks are
formed and does not modify the backing of the fastener to receive
adhesives or gluing agents nor is it possible to utilize loop
materials as the backing material to form back to back fasteners.
It is also known to use complex laminating methods to add a
bondable surface to many sheet materials but such methods are
expensive and often create a final product which has undesirable
characteristics such as bulk, stiffness, a tendency to delaminate,
operating temperature limitations or other properties making the
laminate undesirable.
[0004] A product using such techniques, well known in the art of
hook and loop fasteners, is the so called back to back fastener.
Such a product is created by taking a hook fastener and a loop
fastener and bonding the two together in a back to back
relationship such that the resulting laminate has hooks on one side
and loops on the other side. Such a combination finds wide use in
many strapping operations such as wire ties, plant ties and
fastener straps for holding splints and the like in place. The
limitation of such products in the past has focused on the method
used to laminate the two components together as described above.
The bulk created by the adhesive bonding of such laminates has
clearly limited its usefulness.
[0005] Therefore it is the object of the present invention to
produce a hook portion of a hook and loop fastener system which has
a surface opposite the surface containing the upstanding hooks
substantially modified in its characteristics from the customary
flat, smooth, even surface which has little compatibility for
bonding to other materials. A further objective of the invention is
to create a surface on the back of a base of a plastic hook and
loop fastener which will readily accept bonding agents such as
adhesives, glues, cements and the like without special treatment of
the surface. It is a further objective of the invention to create a
loop surface on the back portion of the base of a plastic hook
fastener which is capable of engaging into hooks on the front
surface thereof to form a back to back laminate with less bulk,
stiffness and thickness.
BRIEF SUMMARY OF THE PRESENT INVENTION
[0006] The process described in U.S. Pat. No. 4,794,028 for making
plastic hooks utilizes an apparatus described in U.S. Pat. No.
4,775,310 comprising "a first cooled unitary forming roller having
a plurality of hook forming cavities defined in the periphery
thereof and extending inwardly therefrom; a second pressure roller
positioned for coaction with said first forming roller; means for
concurrently rotating said first and second rollers in opposite
directions about their generally respective axis; means for forming
a striplike extrusion of molten plastic material adjacent said
first and second rollers to be directed therebetween at an
interface thereof such that said plastic material fills said hook
forming cavities and forms a striplike member having a base portion
and a great multiplicity of hooklike projections extending from one
surface of said base portion and integral therewith; means for
removing said striplike member from said first forming roller at a
position spaced from the interface of said first and second rollers
such that said hooklike projections are withdrawn from said hook
forming cavities without opening said cavities after being cooled
by the first forming roller to a desired temperature." I have found
it possible to introduce into the nip, formed by the two cylinders,
various sheet materials which will become an integral part of the
striplike material on the side opposite the hooks. Surprisingly,
introduction of such materials into the nip along with the molten
plastic does not interfere with the operation of the process and
while certain cautions and limitations are, of course, desirable,
the formation of such insitu laminates proceeds to great advantage.
I have found a very wide variety of materials, such as nonwoven
fabrics, woven and knitted textiles, reinforcing yams, scrims and
nettings, sheets of paper, plastic films, metallic window screening
and almost any material in filmlike or thin sheet form can be
handled in this manner. The formation of the striplike plastic
fastener sheet insitu with a porous foreign backing most often is
accomplished by infusion of the molten plastic into the structure
of the web material where there is an intimate intermingling of the
plastic within the pores of the web. In the case of nonporous
films, the films tend to melt on their surface forming an
intermolecular diffusion which forms a strong bond between the
sheets. The inclusion of such foreign materials provides a
substantial advantage over prior art methods of creating laminates.
Such striplike materials contain no foreign material; the bonds are
strong and a wide range of materials may be joined in this way.
Additionally, the process of adding the backing at the time of
creating the hooks offers economic advantages over the more
conventional processes of creating a laminate using adhesives or
other bonding agents in second stage processes.
DETAILED DESCRIPTION OF THE INVENTION
[0007] In order to more fully understand the invention, reference
should be had to the following detailed description taken in
conjunction with the attached drawings, wherein:
[0008] FIG. 1 is a schematic sectional view of the apparatus used
in the prior art for creating the plastic fastener hook tape of the
prior art.
[0009] FIG. 2 is a schematic sectional view of the apparatus of
FIG. 1 which is modified in accordance with the present
invention.
[0010] FIG. 3 is a schematic rear view of the forming roll
arrangement of FIG. 2.
[0011] FIG. 4 is a schematic cross-sectional view of the hook
fastener tape formed by the prior art process.
[0012] FIG. 5 is a schematic cross-sectional illustration of one
embodiment of the invention.
[0013] FIG. 5A is another schematic illustration of the product of
FIG. 5.
[0014] FIG. 6 is a schematic cross-sectional illustration of
another product of the invention.
[0015] FIG. 7 is a schematic cross-sectional illustration of yet
another form of the invention.
[0016] FIG. 8 is a schematic cross-sectional view wherein the
bottom layer of the product is a loop fastener.
[0017] FIG. 9 is a schematic cross-sectional view wherein the
product includes a layer of foam.
[0018] FIG. 9A shows how the foam layer of FIG. 9 can be
sheared.
[0019] FIG. 1 is a cross-sectional view of the apparatus used in
the prior art for creating the plastic fastener hook tape of the
prior art. Extruder barrel 1 melts and forces the molten plastic 3
through die 2 into the nip 6 between base roller 4 and cavity
roller 5 containing cavities to form the hooks of a strip fastener
of the well known hook and loop type. The strip fastener material
formed in the nip 6 travels around the periphery of the cavity
roller 5 and around stripping roller 7, which assists in pulling
the formed hook sheet 8 from the cavity roll, and thence to a
windup device, not shown.
[0020] While many methods of feeding sheet material to the forming
section of the hook forming device are possible FIG. 2 illustrates
a device particularly well adapted to that purpose. I have found
that by introducing a preformed sheet material 10 into the nip 6 at
the same time molten plastic 3 is forced into the nip 6 to create
the strip fastener tape, the sheet material will bond intimately
with the fastener to become an integral part of the structure of
the strip fastener. As in FIG. 1, extruder 1 forces molten plastic
3 through die 2 into nip 6 between rolls 4 and 5. However, I have
added at the edges and around the periphery of backing roller 4 a
set of pins which will carry the sheet material 10 into the nip 6
in a flat, unwrinkled state. It is important to maintain a smooth,
wrinkle free, properly tensioned sheet in order to form a smooth,
even laminate backing for the fastener. To assure proper tensioning
and alignment of the secondary sheet material, a roll of the
secondary material 10 is mounted on a let off device and threaded
around diversion roller 11 into a web straightening device 12, well
known in the art as typically sold by the Fife Manufacturing
Company which assures the edge of the web of sheet material is
centered as it is fed onto backing roller 4 around scroll roll 13,
composed of ribs of elastomeric material to firmly grip the sheet
and impinge it against the backing roller 4 and onto pins 14. Pins
14 and roller 4 deliver the web into nip 6 along with molten
plastic 3. As the molten plastic 3 is forced by the pressure
imposed upon it by the narrow space of the nip 6, it flows into
cavities in cavity roller 5 and also into any pores present in the
sheet material being carried by the backing roller 4. In this way
the web sheet 10 is intimately joined to the forming hook sheet 8
and becomes an integral part thereof to form a laminated sheet 9.
FIG. 3 is a rear view of the forming roll stack along line A,Al.
The backing roller 4 is supported on shaft 15 which is held by
bearing 16 in its proper place in side plates, not shown. Bearing
16 is connected to hydraulic lines 19 from a hydraulic pump located
remotely from the roll stack. The pins 14 are held by hub 18 which
is fitted to the shaft 15 holding the backing roller 4. It is
possible to incorporate the pins 14 directly into the backing
roller 4 but I prefer to utilize separate pin holding hubs which
afford some degree of flexibility in utilizing various size and
shape pins for differing sheet materials.
[0021] The customary procedure for operating the apparatus
described is to thread up the secondary backing 10 through the
machine, start the extruder 1 so that plastic 3 is flowing smoothly
through the die 2 and then move the lips of the die 2 into
proximity of the nip 6 between the two forming rollers 4 & 5.
The molten plastic is picked up by the backing roller 4 and
delivered into the nip 6 as pressure from the hydraulic cylinders
17 raises the backing roller 4 into position. As the gap 6 between
the backing roller 4 and the cavity roller 5 is reduced, the molten
plastic 3 flows into the nip 6 and is forced into the open cavities
in the forming roll 5. Molten plastic is also forced into the pores
of the backing material 22, penetration depending upon the
thickness of the backing, the pore structure of the backing, the
viscosity of the molten plastic and the pressure of the plastic in
the nip. The pressure in the nip 6 is a function of the hydraulic
pressure used to close the rollers 4 & 5 and the quantity of
material delivered into the nip 6 relative to the quantity consumed
in forming the backing and filling the cavities.
[0022] FIG. 4 is a cross-section of the hook fastener tape formed
by the prior art process. The hook tape consists of a base 20 and
hooks 21 projecting from the base. The plastic material forming the
tape is essentially uniform throughout. FIG. 5 is one embodiment of
a product of this invention created by introducing a nonwoven
fabric into the nip of the forming rolls as described above. Base
20 containing hooks 21 projecting therefrom is attached nonwoven
fabric 22. At the interface 23 between the two layers the plastic
from the fastener flows around and entraps some of the fibers of
the nonwoven 22 thereby bonding the nonwoven fabric to form a
laminate of the two layers. The nonwoven may be light or heavy,
thin or thick, dense or open. The properties of the nonwoven, the
pressure exerted and the viscosity of the plastic in the nip will
determine the degree to which the plastic flows into the fibrous
network, or put alternately, the degree to which the nonwoven will
imbed into the plastic. FIG. 5a is a schematic representation of
the laminate of FIG. 5 where the layer 23 represents the zone of
mixed fabric and plastic. It should be understood this layer is not
of uniform cross-section but rather there is a gradient
concentration across this layer ranging from no fibers at the
bottom of the plastic layer 20 to no plastic at the top of the
fiber layer 24. If, on the other hand, the nonwoven web is thick
and dense, the plastic will only marginally penetrate into the
nonwoven and the back side of the fastener will have the appearance
of the free standing fibrous nonwoven. By carefully selecting the
fibrous nonwoven web, the plastic for forming the fastener and the
operating conditions of the process; it is possible to generate a
wide range of products with different degrees of fibers projecting
from the surface of the plastic thus providing a wide variety of
products directed to many different applications.
[0023] FIG. 6 is a cross-section diagram of yet another product of
the present invention where an open, woven, textile reinforcing
scrim 25 has been added into the nip 6 of the calendar with a
slight overfeed to create an excess of the backing fabric. Because
of the open structure the plastic 20 has encapsulated large
sections of the fabric scrim 25 yet sections of the fabric come to
the surface 26 of the fastener. Such a combination can be used to
add strength to the plastic tape, but also provide substantial
modification of the plastic surface of the fastener.
[0024] FIG. 7 again shows the plastic hook fastener 20 with
upstanding hooks 21 laminated to a sheet of paper 27 containing on
the surface thereof an adhesive layer 28. The adhesive may be any
convenient type depending upon the intended use of the product. In
this way it is possible to apply reactivatable adhesives, pressure
sensitive adhesives or contact adhesives as the bottom layer of the
laminate. Depending upon the nature of the adhesive laminate being
applied, care must be taken to prevent the adhesive from being
squeezed or distorted by the action of the pressure of the nip.
[0025] FIG. 8 shows yet another embodiment of the technique of the
present invention wherein the backing layer 29 is the loop side of
a hook and loop fastener. Molten plastic 3 flows through die 2 and
is forced into the pores of the backing of the loop 29 at the
interface 27 encapsulating some of the yams of the loop backing
integrally holding the backing with the plastic sheet. In this way
is created a product which is well known when created by adhesive
bonding but in this embodiment the laminate is created without
foreign materials required to hold the layers together. Such back
to back products are useful for the manufacturer of so called
backstraps well known in the art of hook and loop materials.
[0026] FIG. 9 shows an embodiment of the invention wherein the
sheetlike material is a thin polyurethane foam 30. The thin foam 30
can be introduced into the nip of the calender as previously
described. The surface of the foam 30 is intimately bonded to the
plastic of the striplike fastener 20. FIG. 9a shows the same
arrangement as FIG. 9 with the foam 30 attached to the back of the
fastener 20 but also illustrates what happens when attempting to
remove the foam 30. The bond attaching the foam 30 to the plastic
fastener 20 member is greater than the cohesive strength of the
foam 30. When attempt is made to separate the foam from the back of
the fastener 20, the foam 30 splits or tears within the body of the
foam 31 leaving a substantial portion of the foam on the back of
the plastic strip fastener.
[0027] The following examples will aid in further understanding the
range and uniqueness of this invention.
EXAMPLE I
[0028] The apparatus described in U.S. Pat. No. 4,775,310 was set
up to produce a plastic hook product, designated as hook type
CFM-15 by the Velcro Group Corporation, using a nylon 12 resin,
identified as resin L-2121 sold by the Hules Chemical Corporation.
The melt temperature of the resin measured at the exit end of the
extruder was 454.degree. F. The die head temperature was
460.degree. F. Line speed was 30 feet per minute; tape width was 10
inches; calendering pressure was 2000# gage. The top roll
temperature was 31.degree. F.; the forming roll temperature was
55.degree. F.; and the bottom roll temperature was 37.degree. F. A
roll of nonwoven fabric, on 850 a nylon nonwoven fabric sold by the
Freudenberg Company, slit to a 10 inch width was introduced into
the calender at the nip formed between the bottom and forming
rolls. After a short initial start up period the fabric processed
smoothly through the forming section without difficulty. The
nonwoven fabric was intimately integrated into the plastic of the
hook sheet. The laminate thus formed could not be separated into
its constituents, one from the other, without destroying the fiber
layer. The back of the hook product manifested a smooth, soft
fibrous surface substantially different from the surface of the
product without the laminated layer.
EXAMPLE II
[0029] The apparatus described in U.S. Pat. No. 4,775,310 was set
up to produce a plastic hook product designated as hook type CEM-15
by the Velcro Group Corporation, using a co-polyester resin sold by
the DuPont Company, a Hytrel.RTM. 8238 with 10% of a master batch
fire retardant added to provide fire resistance to the final
product. The melt temperature of the polymer, at the end of the
extruder, was 475.degree. F. and the die temperature was
476.degree. F. The line speed was 30 feet per minute. A roll of
spunbonded nonwoven fabric, sold as Remay.RTM. 2016, weighing 1.35
ounces per square yard with a thickness of 0.009 inches was slit to
10 inches width and introduced into the nip formed by the bottom
and forming rolls of the device as described in Example I. The
bottom roll temperature was 50.degree. F., the forming roll
temperature was 50.degree. F. and the top roll temperature was
90.degree. F. A tension of 100 pounds was exerted against the spun
bonded fabric in order to prevent wrinkles from developing as the
sheet passed into the nip of the calender, and the bottom roller
was overdriven at 8% relative to the forming roller. The spunbonded
fabric showed minor wrinkling and folding. The tension on the
fabric was reduced to 35-40 pounds and the overfeed increased to
8.5% which reduced the wrinkles to an acceptable level.
[0030] The laminated product formed consisted of an integral bond
between the plastic base of the hook sheet and the upper layer of
the spunbonded fabric. The plastic forming the underside of the
base of the hook tape was intimately merged with the interstices of
the fabric. The spunbonded nonwoven layer could not be separated
from the plastic without being destroying. Even when tearing the
laminated sheet, the two layers would not separate. Because of the
heavy weight of the spunbond, fibers were apparent on the under
surface of the laminate and it was possible to disrupt and loosen
fibers from the surface by vigorous rubbing. Even after substantial
rubbing, however, a great quantity of fibers, primarily from the
upper surface of the spunbond remain attached to the surface of the
plastic.
EXAMPLE III
[0031] Exactly the same configuration as used in Example II was
utilized but the spunhonded nonwoven used was a lighter weight
version of Remay, designated as Remary.RTM. style 2006, weighing
0.6 ounces per square yard with a thickness of 0.006 inches. In
order to eliminate wrinkles and folds from the web, tension was
reduced to 25 pounds and the same overfeed was used on the bottom
roller. The product formed by this combination was similar to that
of Example II but the mingling of the polymer into the interstices
of the nonwoven was greater than in that example, but it was still
possible to raise fibers from the surface by vigorous rubbing, and
there were many fibers on the surface of the plastic projecting as
a very fine fuzz above the surface.
EXAMPLE IV
[0032] Exactly the same configuration as used in Examples II and
III were utilized but the spunbonded nonwoven used was even lighter
then in the previous examples. The version of Remay in this example
was designated as Remay.RTM. style 2250, weighing 0.5 ounces per
square yard with a thickness of 0.004 inches. In order to eliminate
wrinkles and folds from the web, tension was reduced to 20 pounds
and the overfeed was increased to 9% on the bottom roller. The
product formed by this combination was similar to those of Examples
II and III but the mingling of the polymer into the interstices of
the nonwoven was marginally greater than in Example III. This
mingling was enhanced to the extent it was difficult to raise
fibers from the surface by vigorous rubbing even when using a coin
to abrade the surface. Yet it was possible to clearly see the
fibers on the surface as an integral part of the surface and even
projecting as a very fine fuzz from the surface.
EXAMPLE V
[0033] The apparatus described in U.S. Pat. No. 4,775,310 was set
up to produce a plastic hook product, designated as hook type
CFM-15 by the Velcro Group Corporation, using a polyester copolymer
resin, Hytrel 8238, sold by the DuPont Company. The melt
temperature of the polymer at the end of the extruder was
475.degree. F. and the die temperature was 470.degree. F. The line
speed was 35 feet per minute and the tape width was 8-9 inches. The
bottom roll temperature of the calender was 85.degree. F., the
forming roll was 40.degree. F. and the top roll was 40.degree. F.
The calender pressure was 2500 pounds per lineal inch. A roll of
tricot knitted fabric, sold by Velcro USA as Loop 3200, was slit to
a width of 10 inches and fed into the calender at the nip formed by
the bottom and forming rolls. As the hook product was formed the
molten plastic backing flowed into the interstices of the knitted
fabric. The layers forming the laminate between the plastic hook
and the tricot fabric could not be separated without destroying the
material making up the layer. In spite of the fact that Loop 3200
is a very open structure and the plastic from the hook portion of
the laminate surrounded and encapsulated many of the ground yams of
the fabric, a sufficient number of loops remained extending upwards
from the back of the product to enable hooks from the face to
tightly engage when a tape of the product was turned such that the
hooks were made to face the loops on the reverse side of the
structure. In this manner was formed a product commonly known in
the trade of hook and loop fasteners as back to back closure.
EXAMPLE VI
[0034] A sample of the Loop 3200 described in Example V was
laminated to a 1/8 inch thick polyether urethane foam using flame
lamination techniques well known in the art. The foam laminate thus
formed was slit into a 10 inch wide roll of material which was fed
into the hook forming device described in Example V. In this
instance, however, the resin used was a polyethylene resin produced
by the EXXON Chemical Company sold as Escorene LL6301.57. The melt
temperature of the polymer at the end of the extruder was
420.degree. F. and the die temperature was also 420.degree. F. The
calender pressure was 1250 pounds per lineal inch and the bottom
roll temperature was 70.degree. F., the forming roll temperature
was 50.degree. F., and the top roll temperature was 90.degree. F.
The line speed was 30 feet per minute. The foam side of the foam
loop laminate was orientated to join with the plastic backing of
the hook portion of the product and the loop portion faced
outwardly from the bottom side of the product. A tenacious laminate
resulted. The layers of the laminate could be separated by tearing
the loop portion away from the plastic portion and the rupture
between the layers occurred along the foam interface leaving a thin
layer of foam on both the plastic and the loop. The force necessary
to separate the layers was approximately 2 pounds per inch of
width. The use of the foam as an intermediate layer yielded a
product with soft loop backing which readily engaged the hooks on
the face side of the product when turned in back to face
relationship. The degree of contamination of the loop structure as
occurred in Example II was essentially eliminated and the presence
of the foam layer provided a soft cushioning to assist in the hook
loop engagement.
EXAMPLE VII
[0035] Using the process configuration of Example VI a sample of a
different loop, Velcro loop style 3610, was introduced in place of
the loop used in Example V. Loop 3610 is a relatively heavy weight
loop fabric weighing in the range of 8.02 to 9.95 ounces per square
yard and having a nominal thickness range of 0.062 to 0.087 inches.
The loop passed through the nip without difficulty using a tension
of 100 pounds on the loop fabric, on overfeed on the bottom roll of
8% and a nip pressure of 1250 pounds per lineal inch. The plastic
from the forming hooks mingled and encapsulated many of the fibers
on the back side of the loop Fabric thus creating a substantial
bond holding the two layers together. Because Loop 3610 is such a
substantial product it was possible to work loose one corner of the
fabric from the plastic and by so doing test the bond strength of
the laminate. The peel separating force averages 6 pounds to
delaminate the two layers. The loop face of the Loop 3610 appeared
to be unaffected by the laminating process and when the laminate
was turned on itself such that the hooks engaged the loop in face
to face relationship substantial gripping was achieved. The
performance of the back to back closure thus formed was comparable
to the performance of an independently formed hook product formed
from the same polymer against Loop 3610.
EXAMPLE VIII
[0036] Using the process configuration of Example VI, a sample of a
different loop, Velcro loop, style 3003, was introduced in place of
the loop used in Example VII. Loop 3003 is a circular knit fabric
with a substantially high loop pile on one surface, a relatively
heavy weight of 9 ounces per square yard and a nominal thickness of
0.10 inches. The loop passed through the nip with some difficulty
due to its bulk but the sample formed provided an extremely high
degree of mingling of the plastic resin with the backing fibers of
the loop fabric. The bond was sufficiently strong. The two layers
could not be separated for testing with destroying one or both of
the layers. The mile fibers of the loop fabric did not appear to be
affected by the laminating process and the closure performance of
the back to back product thus formed was essentially the same as
the closure performance of a comparable hook product produced
independently tested against an independent loop of the same
style.
EXAMPLE IX
[0037] The extrusion configuration of Examples VI through VIII
using Escorene polyethylene was used to create yet another laminate
in which the web introduced into the nip between the bottom roll
and the forming roll was kraft paper. The paper bonded tightly to
the back of the hook tape and could not be separated from the
laminate without being destroyed. Penetration of the plastic into
the paper was limited as shown by the ability to delaminate the
paper from itself leaving a thin veil of paper fibers still
attached to the plastic.
EXAMPLE X
[0038] In place of the standard kraft paper of Example IX, a length
of kraft paper containing, on one surface, thereof, a water
activable adhesive was introduced into the nip between the bottom
roll and the forming roll with the adhesive side of the paper away
from the plastic of the hook tape. The paper bonded tightly to the
plastic of the hook, in a manner the same as described in Example
IX. The paper could be torn from the laminate leaving a veil of
fine paper fibers on the plastic surface. The interesting facet to
this laminate was the fact the adhesive layer on the back of the
hook tape could be activated by applying water to the adhesive and
the adhesive used to attach the hook laminate to other objects.
Small squares of the laminate so formed were activated as one would
activate a postage stamp, with the tongue, and the small square of
hook was easily attached to other objects. Appropriate loops
attached to other objects were in this way releasably attached to
each other.
EXAMPLE XI
[0039] The extrusion configuration of Examples VI through IX using
Escorene polyethylene without any additives was used to create yet
another laminate in which the web, introduced into the nip between
the bottom roll and the forming roll, was a printed high density
polyethylene film. The film bonded to the back of the hook tape but
could be peeled from the laminate with a relatively light force of
less than 0.5 pounds per inch of width. An especially interesting
aspect of this laminate was that the printing could be read clearly
through the slightly opaque face of the hook tape. The HD
polyethylene printed message was in no way distorted and was only
slightly less bright than the original printed message of the
film.
EXAMPLE XII
[0040] In place of the printed polyethylene film of Example XI a
page from a Rand-McNalley Road Atlas, made of paper with a road map
printed on each side, was introduced into the nip between the
bottom roller and the forming roller. The paper bonded tightly to
the 15 plastic polyethylene hook sheet that it could not be
separated from the plastic without destroying the paper. The fine
lines of the map were visible through the slightly opaque plastic
film forming the hook tape. The paper sheet was printed on both
sides and it was also possible to read the map on the back side of
the hook sheet. The assembly with the printed matter on its reverse
side could be attached to display boards with loop material covers.
The combination formed an interesting method for affixing display
material to other objects. Conversely, it is possible to make a
display surface with the hooks extending outward from the display
surface which can be read through the hook tape to which objects
can be attached. In this way, the design portrayed on the display
is read through the hooks and sections of the display can be
covered up by attaching loon material to the exposed hooks.
EXAMPLE XIII
[0041] The apparatus as described in previous examples was set up
to process polypropylene resin designated as Ferro HDPS 0250D, a
fire retardant polypropylene resin from Ferro Chemical Company. The
melt temperature was 400.degree. F. and the die temperature was
also 400 .degree. F. The line speed was 30 fpm and the nip pressure
was 1500 pounds per linier inch. After 30 the process was operating
and forming an appropriate hook product a length of ether type
polyurethane foam 0.065 inches thick, was introduced into the nip
formed between the bottom roll and the forming roll. The foam
bonded tenaciously to the plastic underside of the hook sheet and
could not be removed without destroying the foam layer. In the
process of being laminated, the foam was substantially compressed
but remained tightly bonded to the polypropylene and provided a
soft, resilient backing to the polypropylene hook tape which
substantially changes the aesthetic and tactile response to the
hook product.
* * * * *