U.S. patent application number 10/653858 was filed with the patent office on 2004-04-22 for forming continuous fastener material.
This patent application is currently assigned to Velcro Industries B.V., a Netherland Antilles corporation. Invention is credited to Clune, William, Provost, George A..
Application Number | 20040076793 10/653858 |
Document ID | / |
Family ID | 29271001 |
Filed Date | 2004-04-22 |
United States Patent
Application |
20040076793 |
Kind Code |
A1 |
Clune, William ; et
al. |
April 22, 2004 |
Forming continuous fastener material
Abstract
A method of reorienting directional features associated with
manufacture of continuous fastener materials to produce products
having such reoriented features, produces fastener products having
an array of individual fastener elements extending from a
sheet-form base, the fastener elements adapted to engage mating
elements for releasable fastening. The method includes the steps of
forming a continuous pre-form product having a planar base defining
longitudinal edges and an array of fastener elements extending from
the base; joining the longitudinal edges of the pre-form product to
form a tube having a seam defined by the joined longitudinal edges;
and severing the tube across the seam to form the fastener product
with segments of seam extending between longitudinal edges of the
fastener product. Various techniques for performing the method and
various products taking unique advantage of these techniques are
disclosed for providing novel fastener products.
Inventors: |
Clune, William; (Concord,
NH) ; Provost, George A.; (Litchfield, NH) |
Correspondence
Address: |
FISH & RICHARDSON PC
225 FRANKLIN ST
BOSTON
MA
02110
US
|
Assignee: |
Velcro Industries B.V., a
Netherland Antilles corporation
|
Family ID: |
29271001 |
Appl. No.: |
10/653858 |
Filed: |
September 3, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10653858 |
Sep 3, 2003 |
|
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09711227 |
Nov 9, 2000 |
|
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6640348 |
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Current U.S.
Class: |
428/100 |
Current CPC
Class: |
B29L 2031/753 20130101;
B29C 48/0019 20190201; B29C 69/001 20130101; B29C 48/35 20190201;
A44B 18/0061 20130101; Y10T 24/2792 20150115; B29C 48/08 20190201;
B29C 2793/009 20130101; Y10T 156/1013 20150115; B29C 43/46
20130101; A61F 13/0273 20130101; Y10T 428/24017 20150115; A44B
18/0049 20130101; B29C 53/58 20130101; B29C 53/50 20130101; B29C
2043/465 20130101; Y10T 156/1038 20150115; B29L 2031/729 20130101;
Y10T 156/1087 20150115; B29C 53/48 20130101; Y10T 24/27 20150115;
B29C 2043/461 20130101; B29C 48/12 20190201; B29C 48/13 20190201;
B29C 43/222 20130101; A61F 13/622 20130101; Y10T 156/1084
20150115 |
Class at
Publication: |
428/100 |
International
Class: |
B32B 003/06 |
Claims
What is claimed is:
1. A method of forming a fastener product having an array of
individual fastener elements extending from a sheet-form base, the
fastener elements adapted to engage mating elements for releasable
fastening, the method comprising the steps of: forming a continuous
pre-form product having a planar base defining longitudinal edges
and an array of fastener elements extending from the base; joining
the longitudinal edges of the pre-form product to form a tube
having a seam defined by the joined longitudinal edges; and
severing the tube across said seam to form the fastener product
with segments of seam extending between longitudinal edges of the
fastener product.
2. The method of claim 1 wherein the step of forming the pre-form
product includes continuously extruding resin and continuously
molding the resin to form said array of fastener elements
integrally with a surface of the pre-form product.
3. The method of claim 2 wherein the fastener elements of the
pre-form product comprise molded fastener elements overhanging the
base to define an overhang direction, the overhang direction in the
fastener product extending at least obliquely toward one of the
longitudinal edges of the fastener product.
4. The method of claim 3 wherein the overhang direction of the
molded fastener elements in the fastener product extend
perpendicular to the longitudinal edges of the fastener
product.
5. The method of claim 1 wherein the base of the pre-form product
has a widthwise elastic region corresponding to a longitudinally
elastic region in the fastener product.
6. The method of claim 5 wherein said method of forming the
pre-form product includes introducing a sheet-form,
uni-directionally elastic material to a pressure gap defined
against a rotating mold roll, said uni-directionally elastic
material having widthwise elasticity and being longitudinally
inelastic to form the widthwise elastic region of the base of the
preform product corresponding to the longitudinally elastic region
in the fastener product.
7. The method of claim 6 wherein the uni-directionally elastic
material comprises at least one surface of exposed loop material
engageable by said fastener elements.
8. The method of claim 1 wherein the base of the fastener product
is resiliently elastic within its plane.
9. The method of claim 1 wherein the fastener elements are
hook-shaped.
10. The method of claim 1 wherein the step of severing comprises
severing the tube to form a sheet-form fastener product, then
slitting the sheet-form fastener product to form multiple
continuous strips of fastener product.
11. The method of claim 1 wherein the step of severing comprises
severing the tube along a helical path.
12. The method of claim 1 wherein the step of joining comprises
wrapping the pre-form product to form a tube with opposite
longitudinal edges of the pre-form product joined to form a helical
seam about the tube; the step of severing comprising severing the
tube along a longitudinal path to form said fastener product.
13. The method of claim 1 wherein the step of forming the pre-form
product further comprises shaping selvedge portions along the
longitudinal edges of the pre-form product to facilitate joining
the longitudinal edges to form the tube.
14. A method of forming a strip-form fastener product having an
array of individual fastener elements extending from a continuous
base, the fastener elements adapted to engage mating elements for
releasable fastening, the method comprising the steps of: molding a
continuous pre-form product having a planar base and an array of
fastener elements extending from the base, the fastener elements
overhanging the base to define an overhang direction; joining the
longitudinal edges of the pre-form product to form a tube; and
severing the tube to form the strip-form fastener product with the
overhang direction of the fastener elements extending toward a
longitudinal edge of the strip-form fastener product.
14. The method of claim 13 wherein the step of severing comprises
severing the tube along a helical path.
15. The method of claim 13 wherein the step of joining comprises
wrapping the pre-form product to form a tube with opposite
longitudinal edges of the pre-form product joined to form a helical
seam about the tube; the step of severing comprising severing the
tube along a longitudinal path to form said fastener product.
16. A continuous strip-form fastener product of finite width and
having two longitudinal edges, the product comprising a series of
joined pre-form tape segments, each having a planar base with
opposite machine direction edges extending between longitudinal
edges of the product, and an array of fastener elements extending
from the base and arranged in rows parallel to the machine
direction edges, adjacent tape segments permanently joined along
seams at their machine direction edges.
17. The continuous strip-form fastener product of claim 16 wherein
the array of fastener elements comprises rows of molded hooks, each
hook having a head overhanging the base in a direction parallel to
the machine direction edges of the pre-form tape segments and a
direction extending toward a longitudinal edge of the fastener
product.
18. The continuous strip-form fastener product of claim 16 wherein
the pre-form tape segments further comprise elastic zones having
resiliency in a direction transverse to the machine direction edges
of the pre-form tape, the elastic zones forming zones of increased
longitudinal elasticity in the strip-form fastener product.
19. The continuous strip-form fastener product of claim 18 wherein
at least one surface of said elastic zones comprises a loop
material engageable by said fastener elements.
Description
TECHNICAL FIELD
[0001] This invention relates to continuous fastener products and
methods and apparatus for forming them.
BACKGROUND
[0002] The use of so called "hook and loop" fasteners has become
exceedingly prevalent in consumer, industrial and medical
applications, and virtually any other situations in which fastening
is necessary. Such fastening materials are often advantageously
manufactured in continuous strip-form to gain various economies
inherent in continuous manufacturing techniques and for convenient
shipment and storage in roll form for later use. Methods of
continuous manufacture frequently result in continuous fastener
products having certain directional characteristics, i.e., features
associated with their direction of continuous manufacture ("machine
direction") which are distinct from features perpendicular to their
direction of continuous manufacture ("cross-machine
direction").
[0003] While the use of continuously manufactured fastener products
is desirable for numerous fastener applications, in some instances
the "as-manufactured" direction of the directional features
associated with the manufacturing process is less desirable than
other possible directional feature orientations. The ability to
transform the directional orientation of these directional features
to a more desirable direction during continuous manufacture of the
fastener product is highly advantageous.
[0004] The invention features a novel method of reorienting
directional characteristics of a continuously manufactured fastener
product to a more desirable direction. The invention also features
a novel continuously manufactured fastener product with reoriented
directional characteristics.
SUMMARY
[0005] In one aspect the invention provides a method of forming a
fastener product having an array of individual fastener elements
extending from a sheet-form base, the fastener elements adapted to
engage mating elements for releasable fastening. The method
includes the steps of forming a continuous pre-form product having
a planar base defining longitudinal edges and an array of fastener
elements extending from the base; joining the longitudinal edges of
the pre-form product to form a tube having a seam defined by the
joined longitudinal edges; and severing the tube across the seam to
form the fastener product with segments of seam extending between
longitudinal edges of the fastener product.
[0006] Variations of this aspect of the invention may include one
or more of the following additional features. The step of forming
the pre-form product includes continuously extruding resin and
continuously molding the resin to form the array of fastener
elements integrally with a surface of the pre-form product. The
fastener elements of the pre-form product are molded fastener
elements overhanging the base to define an overhang direction, the
overhang direction in the fastener product extending at least
obliquely toward one of the longitudinal edges of the fastener
product. The overhang direction of the molded fastener elements in
the fastener product extend perpendicular to the longitudinal edges
of the fastener product. The base of the pre-form product has a
widthwise elastic region corresponding to a longitudinally elastic
region in the fastener product. The step of forming the pre-form
product includes introducing a sheet-form, uni-directionally
elastic material to a pressure gap defined against a rotating mold
roll, the uni-directionally elastic material having widthwise
elasticity and being longitudinally inelastic to form the widthwise
elastic region of the base of the pre-form product corresponding to
the longitudinally elastic region in the fastener product. The
uni-directionally elastic material includes at least one surface of
exposed loop material engageable by the fastener elements. The base
of the fastener product is resiliently elastic within its plane.
The fastener elements are hook-shaped. The step of severing
comprises severing the tube to form a sheet-form fastener product,
then slitting the sheet-form fastener product to form multiple
continuous strips of fastener product. The step of severing
comprises severing the tube along a helical path. The step of
joining comprises wrapping the pre-form product to form a tube with
opposite longitudinal edges of the pre-form product joined to form
a helical seam about the tube; the step of severing including
severing the tube along a longitudinal path to form the fastener
product. The step of forming the pre-form product further includes
shaping selvedge portions along the longitudinal edges of the
pre-form product to facilitate joining the longitudinal edges to
form the tube.
[0007] In another aspect, the invention provides a method of
forming a strip-form fastener product having an array of individual
fastener elements extending from a continuous base with the
fastener elements being adapted to engage mating elements for
releasable fastening.
[0008] The method includes the steps of molding a continuous
pre-form product having a planar base and an array of fastener
elements extending from the base, the fastener elements overhanging
the base to define an overhang direction; joining the longitudinal
edges of the pre-form product to form a tube; and severing the tube
to form the strip-form fastener product with the overhang direction
of the fastener elements extending toward a longitudinal edge of
the strip-form fastener product.
[0009] Variations on this aspect of the invention may include one
or more of the following features. The step of severing includes
severing the tube along a helical path. The step of joining
includes wrapping the pre-form product to form a tube with opposite
longitudinal edges of the pre-form product joined to form a helical
seam about the tube; the step of severing comprising severing the
tube along a longitudinal path to form the fastener product.
[0010] In another aspect, the invention provides a continuous
strip-form fastener product of finite width and having two
longitudinal edges, the product including a series of joined
pre-form tape segments, each having a planar base with opposite
machine direction edges extending between longitudinal edges of the
product, and an array of fastener elements extending from the base
and arranged in rows parallel to the machine direction edges,
adjacent tape segments permanently joined along seams at their
machine direction edges.
[0011] Variations on this aspect of the invention may include one
or more of the following additional features. The array of fastener
elements includes rows of molded hooks, each hook having a head
overhanging the base in a direction parallel to the machine
direction edges of the pre-form tape segments and a direction
extending toward a longitudinal edge of the fastener product. The
pre-form tape segments further include elastic zones having
resiliency in a direction transverse to the machine direction edges
of the pre-form tape, the elastic zones forming zones of increased
longitudinal elasticity in the strip-form fastener product. At
least one surface of the elastic zones includes a loop material
engageable by the fastener elements.
[0012] The details of one or more embodiments of the invention are
set forth in the accompanying drawings and the description below.
Other features, objects, and advantages of the invention will be
apparent from the description and drawings, and from the
claims.
DESCRIPTION OF DRAWINGS
[0013] FIG. 1 illustrates a continuous strip of fastener product of
the invention.
[0014] FIG. 2 is an enlarged view of the area indicated by Circle 2
of FIG. 1.
[0015] FIG. 2A is a view similar to that of FIG. 2 illustrating an
alternative hook arrangement.
[0016] FIG. 3 is a diagrammatic illustration of a method and
apparatus for producing the fastener product of FIG. 1.
[0017] FIG. 4 is a view similar to that of FIG. 1 illustrating a
pre-form product for producing the fastener of FIG. 1.
[0018] FIG. 5 illustrates the pre-form product of FIG. 4 being
processed to form the fastener product of FIG. 1.
[0019] FIG. 6 is a view similar to that of FIG. 5 illustrating an
alternative method of forming the fastener product o FIG. 1 from
the fastener product of FIG. 4.
[0020] FIG. 7 illustrates an alternative embodiment of a continuous
strip of fastener product of the invention.
[0021] FIG. 7A illustrates the fastener product of FIG. 7 in a
stretched condition.
[0022] FIG. 8 illustrates an application of the fastener product of
FIG. 7.
[0023] FIG. 9 illustrates a pre-form product for producing the
fastener product of FIG. 7.
[0024] FIG. 9A is a view taken from the direction of line 9A--9A of
FIG. 9.
[0025] FIG. 9B illustrates marginal edge portions of a
cross-section of the pre-form product of FIG. 9 during processing
to form the fastener product of FIG. 7.
[0026] FIG. 10 illustrates a pre-form product for producing the
fastener product of FIG. 12.
[0027] FIG. 11 is a view taken along line 11--11 of FIG. 10.
[0028] FIG. 11A is a highly enlarged view of the area indicated by
circle 11 A of FIG. 11.
[0029] FIG. 12 illustrates an alternative continuous fastener
product of the invention.
[0030] FIG. 13 illustrates strips of the fastener product of FIG.
12 partially fastened to each other.
[0031] Like reference symbols in the various drawings indicate like
elements.
DETAILED DESCRIPTION
[0032] FIG. 1 illustrates a continuous strip of fastener product 10
having a flexible planar base 12 defining opposite longitudinal
edges 14, 15 along its width "w". A multitude of fastener
protrusions, e.g., hook-like elements 16, arranged in parallel rows
protrude from base 12 and equally spaced seams 18 traverse the
width of base 12 in a direction parallel that of the hook rows,
i.e., along line A. Hooks 16 are formed integrally from the same
material as plastic base strip 12 as described below.
[0033] Referring now also to FIG. 2, hooks 16 project from base 12
and are equipped with a crook 20 for engaging mating fastener
material, e.g., hook-engageable loop material. Each crook 20
projects out from a stem 22 to define an overhang direction (arrow
d in FIG. 2) relative to base 12, the direction of overhang being
parallel to the rows of hooks 16. A suitable shape for hooks 16 is,
for example, of CFM-29 designation, available from Velcro USA Inc.
of Manchester, N.H. The CFM-29 hooks are only 0.015 inch (0.38 mm)
in height h, with a width w.sub.h of 0.017 inch. The thickness of
the base material is 0.005. Alternative protrusion shapes, such as
mushrooms, palm trees, flat-topped hooks, or other loop-engageable
shapes are also suitable.
[0034] FIG. 2A illustrates an alternative, currently preferred,
arrangement of hooks 16 having hooks of alternate rows overhanging
base 12 in opposite, parallel directions (as indicated by arrows d,
d').
[0035] FIG. 3 illustrates a method and apparatus for producing the
above described fastener product. The method builds upon the
continuous extrusion/roll-forming method for molding fastener
elements on an integral, sheet-form base described by Fischer in
U.S. Pat. No. 4,794,028, the contents of which are hereby
incorporated by reference. The relative position and size of the
rolls and other components are not to scale. An extrusion head 30
supplies a continuous sheet of molten resin 32 to a nip 34 between
a rotating mold roll 36 and a counter-rotating pressure roll 38.
Mold roll 36 contains an array of miniature, fastener
element-shaped mold cavities extending inward from its periphery
for molding the fastener protrusions, e.g. hooks 16 (FIGS. 1, 2).
Pressure in nip 34 forces resin into the fastener element cavities
and shapes the resin to form the substrate (base 12 in FIG. 1). The
formed product is cooled on the mold roll until the solidified
fastener elements (e.g., hooks 16) are stripped from their fixed
cavities by a stripper roll 42.
[0036] Referring now also to FIG. 4, the product 50 that is
stripped from the mold roll 36 is the pre-form product for use in
making the above described fastener product 10 through processing
further described below. Pre-form product 50 includes both fastener
elements 16' and base 12' and is a seamless continuous strip of
fastener tape having parallel opposite longitudinal edges 52, 53
that are formed in a direction tangential to nip rolls 36, 38. This
tangential direction is also known as the machine direction of the
pre-form process. Crooks 22 of hooks 16 overhang base 12 in a
direction (arrow d in FIG. 2) parallel to the machine
direction.
[0037] Referring again to FIG. 3, pre-form product 50 proceeds from
stripper roll 42 to a stationary mandrel 60. Folding plate 56 wraps
pre-form product 50 in a width-wise manner about mandrel 60
bringing longitudinal edges 52, 53 to an overlapping or adjacent
position. Joining apparatus 58 then joins longitudinal edges 52,
53, e.g., by heat staking, adhesive, ultrasonic bonding, or any
other known method of bonding plastics, to form a tubular fastener
product 64 (see FIG. 5) having a seam 65 formed at the joined
longitudinal edges. Mandrel 60 typically has a circumference
slightly smaller than the width of pre-form product 50 so that
wrapping of pre-form product 50 about the mandrel allows some
overlap of longitudinal edges 52, 53. Alternatively, mandrel 60 has
a circumference slightly greater than the width of pre-form product
50 and another material, e.g., hot-melt adhesive, is introduced
between the edges to accomplish the joining and form seam 65 (FIG.
5).
[0038] Located on mandrel 60 at a position downstream from the
longitudinal edge joining apparatus 58 is a rotating collar 70
which is equipped with a bias cutter 66. As the tubular product
passes over rotating collar 70, bias cutter 66 cuts the tubular
product continuously on the bias to convert the tubular product
into ribbon form 10. The resulting fastener product 10 is then
stripped from mandrel 60 and wound into a continuous roll of
fastener product or is further split by a cutter 68 into multiple
fastener tape products (2 fastener tape product rolls, 67, 69 are
shown in FIG. 3, but additional splitting may be performed as
desired).
[0039] The resulting fastener product 10 has all of the features
discussed above in reference to FIG. 1. The above described process
transforms machine direction longitudinal edges 52, 53 of pre-form
product 50 into transverse seams 18 and provides fastener product
10 having a crook overhang direction (arrow d in FIG. 2) parallel
to seams 18, i.e., the crooks overhang base 12 in a direction
transverse to longitudinal fastener tape edges 14, 15.
[0040] FIG. 6 illustrates an alternative process for transforming
pre-form product 50 to product fastener tape 10. Again referring
also to FIG. 3, to transform pre-form product 50 as illustrated in
FIG. 6, stationary mandrel 60 is replaced with a rotating mandrel
(not shown). As pre-form product 50 is introduced onto the rotating
mandrel, the rate of mandrel rotation is coordinated with the feed
speed of pre-form product 50 and its approach angle to rotating
mandrel 60 so that pre-form product 50 is wrapped about the
rotating mandrel with longitudinal edges 52, 53 in adjacent wraps
either overlapped or slightly spaced adjacently as described above.
Joining apparatus 58 is positioned on the bias to bond overlapped
or adjacent longitudinal edges as the mandrel turns to form a
spiral seam 82 along the resulting tubular fastener product 80.
Tubular fastener product 80 exits mandrel 60 and is straight-cut by
a stationary cutter along a line parallel to the central axis of
tubular fastener product 80 to form fastener tape 10.
[0041] In another embodiment, illustrated in FIG. 7, a fastener
product 90 similar to that of FIG. 1 is formed having stretchy
zones 92 of a relatively elastic material interposed between
relatively inelastic bands 94 of rows of fastener elements, e.g.,
hooks 16 of FIGS. 1 and 2. For ease of manufacturing, as further
described below, the elasticity of the material of zones 92 is
limited to a direction orthogonal to seams 96 and the material is
relatively inelastic in a direction parallel to seams 96. The
resulting fastener product 90 has a degree of longitudinal
stretchiness, i.e., fastener product 90, in relaxed condition (FIG.
7), has inelastic bands 94 of rows of fastener elements of width
w.sub.h and stretchy zones 92 of width w.sub.s, and in tension
(arrows T, FIG. 7A) inelastic bands 94 of rows of fastener elements
remain of width w.sub.h while stretchy zones 92 have increased
width w.sub.S1.
[0042] In one particularly important example of the embodiment of
FIG. 7, uni-directionally stretchy material of zones 92 has at
least its surface opposite the bands of hooks comprised of a
hook-engageable loop material engageable by fastener elements,
e.g., hooks of bands 94. As illustrated in FIG. 8, this allows the
fastener tape 90 to be pulled from a continuous roll 97, stretched,
wrapped, and continuously fastened to itself in its stretched
condition about, for example, a human joint, e.g., elbow 98, to
support the joint. The fastener tape can then be cut to a desired
length.
[0043] Fastener product 90 is formed by a modification of the
above-described process in which the material of elastic zones 92
is laminated to bands 94 of rows of hooks. In one example, the
modified process builds upon the continuous extrusion/roll-forming
method for molding fastener elements on an integral, sheet-form
base of previously incorporated U.S. Pat. No. 4,794,028, and the
nip lamination process described by Kennedy et al. in U.S. Pat. No.
5,260,015, the contents of which are hereby incorporated by
reference.
[0044] Referring to FIG. 9, pre-form product 50' is produced having
a multiplicity of spaced narrow longitudinal (machine direction)
bands 92' of fastener hooks, similar to those described above, on a
base of uni-directionally stretchy loop material 94'. Bands of
stretchy loop material are exposed between the spaced bands 92' of
fastener hooks. Pre-form product 50' presents a striped appearance
sometimes referred to here as a "zebra-like" appearance. For
further details of producing such "zebra-like" materials, and for
variations of "zebra-like" products and materials, processes, and
apparatus for making such products, the reader is referred to
co-pending U.S. patent application Ser. No.______, to Krantz et
al., entitled "Hook and Loop Fastening", and filed Oct. 24, 2000,
the entire contents of which are hereby incorporated by
reference.
[0045] One such "zebra-like" product, illustrated in FIGS. 9 and
9A, is made by modifications to the process described above with
reference to FIG. 3. As more fully described in the above
incorporated references, pre-form product 50' (FIGS. 9, 9A) is
formed by an in situ lamination process in which molten resin 32 is
extruded through nip 34. However, in this embodiment, extruder head
30 is equipped with a slot-form die (not shown) to provide molten
resin 32 in multiple narrow bands spaced at predetermined intervals
across the width of nip 34. Mold roll 36 has fastener
element-shaped mold cavities in regions corresponding to the narrow
bands of resin. As indicated by dashed lines, uni-directionally
stretchy (i.e., stretchy only in the cross-machine direction as
indicated by arrows CM in FIG. 9) loop material 92' is
simultaneously fed into nip 34 and is at least partially penetrated
by the bands of resin 32 while the bands 94' of resin are also
molded to have fastener elements 16 extending from a surface to in
situ laminate bands 92' of fastener elements to loop material
92'.
[0046] The relative inelasticity of loop material 92' in the
machine direction advantageously allows suitable machine direction
tension to be maintained on the material to ensure that it tracks
well to the machine, and can be removed from the machine without
undue concern as to the complete solidification of the resin, or
risk that the web will wander from its desired track or wrinkle or
otherwise distort.
[0047] Pre-form product 50' is removed from mold roll 36 by
stripper roll 42 and is then formed into a tube, welded, and cut
into strips of desired width in a process similar to those
described above with reference to FIGS. 5 and 6. The resulting
fastener product 90 (FIG. 7) has a degree of longitudinal
stretchiness due to the transformation of seamless, width-wise
stretchy, pre-form product 50' into a continuous series of bonded
transverse bands of fastener material that is stretchy in a
direction orthogonal to seams 96.
[0048] Referring now to FIGS. 9A and 9B, pre-form product 50' (or
pre-form product 50 of FIG. 4) advantageously has selvedge portions
152, 153 along longitudinal edges 52', 53' formed of thermoplastic
resin. Thermoplastic selvedge portions 152, 153 facilitate joining
longitudinal edges 52', 53' by e.g., thermobonding, during
formation of the tubular fastener product 64' (FIG. 9B) from which
fastener product 90 is cut, as in the above described process.
Selvedge portions 152, 153 have tapered surfaces 154, 155,
respectively, that allow the longitudinal edges to have an
overlapped thickness, t, (FIG. 9B) that differs insubstantially
from the thickness of the base of fastener product 90 so that the
profile of seams 96 is minimized. Additionally, thermoplastic
selvedge portions 152, 153 can be shaped to form, e.g., tongue in
groove, dovetail, or other mating arrangements, to aid in alignment
of longitudinal edges 152, 153 during the joining of longitudinal
edges.
[0049] Selvedge portions 152, 153 can be formed by modifying the
above described process to provide extruded strips of resin 32
along longitudinal edges of loop material 92' as it is fed through
nip 34 so that the resin strips at least partially penetrate and
bond to loop material 92'. The resin strips are formed into
selvedge portions 152, 153 of desired shape by providing
corresponding appropriately shaped portions of mold roll 36 and
pressure roll 38.
[0050] In another embodiment, illustrated in FIGS. 10-12, a
"zebra-like" pre-form product 50" is produced having a multiplicity
of alternating narrow longitudinal (machine direction) bands 94" of
fastener hooks and narrow longitudinal bands 92" of fastener
hook-engageable loop material. Both the fastener hook bands 94" and
the fastener hook-engageable bands are exposed on the same surface
of pre-form product 50". The underlying base 12" of pre-form
product 50" and the bands 94" of fastener hooks are of the same
relatively inelastic material.
[0051] Pre-form product 50" is made by another modification to the
above described process wherein, referring again to FIG. 3, a
single band of resin 32 sufficient to form the entire base of
pre-form 50" is fed into nip 34 simultaneously with narrow bands
92" of loop material (a single band of such loop material is
represented by dashed lines in FIG. 3) spaced at desired intervals.
Mold roll 36 has spacer rolls to accommodate bands of loop material
92" with adjacent bands of rows of hook cavities to form bands 94"
of fastener hooks. As the bands of loop material are fed through
the nip, they are in situ laminated to the base and hook band
forming resin, i.e., the loop bands are at least partially
penetrated by the molten resin as described above and illustrated
in FIGS. 11, 11A, to be permanently bonded to the base 12".
[0052] Subsequently, pre-form product 50" can be helically
converted, as described above with reference to FIGS. 3, 5, and 6,
to form the fastener product 90" illustrated in FIG. 12 having a
series of seams 96" parallel to alternating angled bands 94", 92"
of hook and loop fasteners. Such a fastener product can be
self-engaged, as illustrated in FIG. 13, by exposing hook and loop
band bearing surfaces of the product 90" for face-to-face contact.
Through the helical conversion process described above, the bands
of hook and loop are angled to allow opposing fastener portions to
be presented for fastening with opposite angular orientations of
the hook and loop bands (as shown in FIG. 13). This opposite
angular orientation avoids a potential failure of opposing fastener
portions, e.g., of fastening material that has not been helically
transformed as described herein, to fasten caused by loop band to
loop band and hook band to hook band alignment of opposing fastener
portions, i.e., the opposite angular orientation of the bands
ensures contact of a portion of a loop band of one opposing
fastener portion with a portion of a hook band of another opposing
fastener portion to achieve fastening.
[0053] A number of embodiments of the invention have been
described. Nevertheless, it will be understood that various
modifications may be made without departing from the spirit and
scope of the invention. Accordingly, other embodiments are within
the scope of the following claims.
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