U.S. patent application number 14/289927 was filed with the patent office on 2015-03-19 for method and apparatus for producing hook fasteners.
The applicant listed for this patent is Gerald Rocha. Invention is credited to Gerald Rocha.
Application Number | 20150076727 14/289927 |
Document ID | / |
Family ID | 42335774 |
Filed Date | 2015-03-19 |
United States Patent
Application |
20150076727 |
Kind Code |
A2 |
Rocha; Gerald |
March 19, 2015 |
METHOD AND APPARATUS FOR PRODUCING HOOK FASTENERS
Abstract
Apparatus and process are described for forming projections on a
substrate for use as hook-type fasteners in touch fastening
systems, wherein vibration energy may be used to soften a substrate
which may be positioned between a mold and a source of vibration.
The mold may include a plurality of cavities into which the
softened substrate may be forced to form the projections. The
substrate may comprise a film, sheet, web, composite, laminate,
etc. and be useful as an attachment strip for temporary or
permanent fastening. The source of vibration may be an ultrasonic
horn. The process to form such projections may be operated in a
continuous, semi-continuous or intermittent manner.
Inventors: |
Rocha; Gerald; (Bedford,
NH) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Rocha; Gerald
Rocha; Gerald |
Derry
Derry |
NH
NH |
US
US |
|
|
Prior
Publication: |
|
Document Identifier |
Publication Date |
|
US 20140264996 A1 |
September 18, 2014 |
|
|
Family ID: |
42335774 |
Appl. No.: |
14/289927 |
Filed: |
May 29, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12690700 |
Jul 22, 2014 |
8784722 |
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14289927 |
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61145883 |
Jan 20, 2009 |
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Current U.S.
Class: |
264/71 |
Current CPC
Class: |
Y10T 24/2792 20150115;
B29C 59/046 20130101; A44B 18/0046 20130101; B29L 2031/729
20130101; B29C 59/04 20130101; B29C 59/025 20130101; A44B 18/0049
20130101 |
Class at
Publication: |
264/71 |
International
Class: |
A44B 18/00 20060101
A44B018/00 |
Claims
1. A process for forming projections suitable for use in a touch
fastener on a diaper comprising: providing a diaper; providing a
first device having an outer surface; providing a second device as
a source of vibration energy; wherein said first device and/or said
second device comprises a plurality of cavities, at least some of
said cavities having a shape to produce a projection suitable for
use in a touch fastener; positioning a region of said diaper
between said first device and said second device; and applying
power to said second device to locally soften said diaper region
such that a portion of said softened diaper region is forced into
said cavities to form projections suitable for use in a touch
fastener on a portion of said diaper.
2-41. (canceled)
42. The process of claim 1 wherein said diaper region comprises an
extendible material.
43. The process of claim 1 wherein at least a portion of said first
device and/or said second device includes a wavy surface and
further comprising forming at least a portion of said diaper into a
creped area.
44. The process of claim 43 wherein forming at least a portion of
said diaper into said creped area comprises forming at least a
portion of said diaper into said creped area adjacent said an area
containing said projections.
45. The process of claim 1 wherein applying power to said second
device comprises applying intermittent power to said second
device.
46. The process of claim 1 wherein providing a first device
comprises providing a first rotating roll.
47. The process of claim 46 wherein providing a second device
comprises providing a second rotating roll.
48. The process of claim 1 wherein providing a first device
comprises providing a rotating roll and wherein providing a second
device comprises providing a stationary second device.
49. The process of claim 1 wherein providing a second device as a
source of vibration energy comprises providing a second device as a
source of mechanical or electromechanical or acoustical vibration
energy.
50. The process of claim 1 wherein providing a second device
comprises providing an ultrasonic horn.
51. The process of claim 1 wherein providing a diaper comprises
providing a first layer and a second layer, with said first layer
having one or more openings which expose a surface of a second
layer, and wherein forming projections comprises forming
projections on said second layer.
52. The process of claim 51 wherein forming projections on said
second layer comprises forming projections with a height less than
a height of said first layer surrounding an area of the
projections.
53. The process of claim 1 wherein providing a diaper comprises
providing a laminate comprising continuous and/or intermittent
layers.
54. The process of claim 1 further comprising post-forming said
projections into a desired shape.
55. The process of claim 54 wherein post-forming said projections
comprises applying vibration energy to said projections.
56. The process of claim 54 wherein post-forming said projections
comprises post-forming said projections to include mushroom-shaped
heads, multi-lobed heads, multi-limbed heads, grappling hook heads
or combinations thereof.
57. The process of claim 1 further comprising applying vibration
energy to aid in removing said projections from said cavities.
58. The process of claim 1 wherein providing a diaper comprises
providing a laminate of woven, non-woven and/or film layers.
59. The process of claim 1 wherein said cavities are shaped to form
projections which are shaped as one or more of hooks, mushrooms,
straight pins, angled pins, tapered pins, curved pins, grappling
hook, multi-limbed, cross-shaped, Y-shaped and multi-lobed, each
having cross-sections which are round, oval, square, rectangular,
trapezoidal, solid, hollow and combinations thereof.
60. The process of claim 1 further comprising applying power to
said second device to form projections suitable for use in a touch
fastener on a portion of an opposite surface of said diaper.
61. A process for forming projections suitable for use in a touch
fastener on a diaper closure tab comprising: providing a diaper tab
material; providing a second material; providing a first device
having an outer surface; providing a second device as a source of
vibration energy; wherein said first device and/or said second
device comprises a plurality of cavities, at least some of said
cavities having a shape to produce a projection suitable for use in
a touch fastener; positioning said diaper tab material and said
second material between said first device and said second device;
and applying power to said second device to locally soften said
second material such that a portion of said softened second
material is forced into said cavities to form projections suitable
for use in a touch fastener on said diaper closure tab.
62. The process of claim 61 wherein applying power to said second
device causes said diaper tab material and said second material to
adhere to each other.
63. The process of claim 62 further comprising producing a diaper
closure tab.
64. The process of claim 61 further comprising producing a diaper
closure tab.
65. The process of claim 61 wherein providing a diaper tab material
comprises providing an extendible diaper tab material.
66. The process of claim 61 wherein at least a portion of said
first device and/or said second device includes a wavy surface and
further comprising forming at least a portion of said diaper tab
material into a creped area.
67. The process of claim 66 wherein forming at least a portion of
said diaper tab material into said creped area comprises forming at
least a portion of said diaper tab material into said creped area
adjacent an area containing said projections.
68. The process of claim 61 wherein providing a diaper tab material
and providing a second material comprises providing a preformed
laminate.
69. The process of claim 68 wherein said diaper tab material is a
non-woven material and wherein said second material is a film
material.
70. The process of claim 68 wherein said preformed laminate
comprises providing a laminate of continuous and/or intermittent
layers.
71. The process of claim 61 wherein said diaper tab material has
one or more openings which expose said second material, and wherein
forming projections comprises forming projections with said second
material, with said diaper tab material surrounding an area of the
projections.
72. The process of claim 71 wherein applying power to said second
device to locally soften said second material such that a portion
of said softened second material is forced into said cavities to
form projections suitable for use in a touch fastener on diaper tab
comprises forming projections with a height less than a height of
said diaper tab material surrounding said area of the
projections.
73. The process of claim 61 wherein providing a diaper tab material
comprises providing a non-woven material.
74. The process of claim 62 wherein said second material comprises
a film material.
75. The process of claim 61 wherein said second material comprises
a film material.
76. The process of claim 61 wherein providing a diaper tab material
comprises providing one of a woven material and a film
material.
77. The process of claim 61 further comprising applying power to
said second device to form projections suitable for use in a touch
fastener on a portion of an opposite surface of said diaper tab
material.
78. The process of claim 61 wherein applying power to said second
device comprises applying intermittent power to said second
device.
79. The process of claim 61 wherein providing a first device
comprises providing a first rotating roll.
80. The process of claim 79 wherein providing a second device
comprises providing a second rotating roll.
81. The process of claim 61 wherein providing a first device
comprises providing a rotating roll and wherein providing a second
device comprises providing a stationary second device.
82. The process of claim 61 wherein providing a second device as a
source of vibration energy comprises providing a second device as a
source of mechanical or electromechanical or acoustical vibration
energy.
83. The process of claim 61 wherein providing a second device
comprises providing an ultrasonic horn.
84. The process of claim 61 further comprising post-forming said
projections into a desired shape.
85. The process of claim 84 wherein post-forming said projections
comprises applying vibration energy to said projections.
86. The process of claim 84 wherein post-forming said projections
comprises post-forming said projections to include mushroom-shaped
heads, multi-lobed heads, multi-limbed heads, grappling hook heads
or combinations thereof.
87. The process of claim 61 further comprising applying vibration
energy to aid in removing said projections from said cavities.
88. The process of claim 61 wherein said cavities are shaped to
form projections which are shaped as one or more of hooks,
mushrooms, straight pins, angled pins, tapered pins, curved pins,
grappling hook, multi-limbed, cross-shaped, Y-shaped and
multi-lobed, each having cross-sections which are round, oval,
square, rectangular, trapezoidal, solid, hollow and combinations
thereof.
89. A process for forming projections suitable for use in a touch
fastener on a diaper closure tab comprising: providing a diaper
closure tab; providing a first device having an outer surface;
providing a second device as a source of vibration energy; wherein
said first device and/or said second device comprises a plurality
of cavities, at least some of said cavities having a shape to
produce a projection suitable for use in a touch fastener;
positioning said diaper closure tab between said first device and
said second device; and applying power to said second device to
locally soften said diaper closure tab material such that a portion
of said softened diaper closure tab material is forced into said
cavities to form projections suitable for use in a touch fastener
on said diaper closure tab material.
90. The process of claim 89 wherein providing a diaper closure tab
comprises providing an extendible diaper closure tab.
91. The process of claim 89 wherein at least a portion of said
first device and/or said second device includes a wavy surface and
further comprising forming at least a portion of said diaper
closure tab into a creped area.
92. The process of claim 91 wherein forming at least a portion of
said diaper closure tab into said creped area comprises forming at
least a portion of said diaper closure tab into said creped area
adjacent an area containing said projections.
93. The process of claim 89 wherein providing a diaper closure tab
comprises providing a preformed laminate.
94. The process of claim 93 wherein a first layer of said laminate
comprises a non-woven material and wherein a second layer of said
laminate comprises a film material.
95. The process of claim 93 wherein said preformed laminate
comprises providing a laminate of continuous and/or intermittent
layers.
96. The process of claim 93 wherein a first layer of said diaper
closure tab has one or more openings which expose a surface of a
second layer of said diaper closure tab, and wherein forming
projections comprises forming projections on said second layer,
with said first layer surrounding an area of the projections.
97. The process of claim 96 further comprising forming projections
with a height less than a height of said first layer surrounding
said area of the projections.
98. The process of claim 89 wherein providing a diaper closure tab
comprises providing a woven, non-woven and/or film material.
99. The process of claim 89 further comprising applying power to
said second device to form projections suitable for use in a touch
fastener on a portion of an opposite surface of said diaper closure
tab.
100. The process of claim 89 wherein applying power to said second
device comprises applying intermittent power to said second
device.
101. The process of claim 89 wherein providing a first device
comprises providing a first rotating roll.
102. The process of claim 101 wherein providing a second device
comprises providing a second rotating roll.
103. The process of claim 89 wherein providing a first device
comprises providing a rotating roll and wherein providing a second
device comprises providing a stationary second device.
104. The process of claim 89 wherein providing a second device as a
source of vibration energy comprises providing a second device as a
source of mechanical or electromechanical or acoustical vibration
energy.
105. The process of claim 89 wherein providing a second device
comprises providing an ultrasonic horn.
106. The process of claim 89 further comprising post-forming said
projections into a desired shape.
107. The process of claim 106 wherein post-forming said projections
comprises applying vibration energy to said projections.
108. The process of claim 106 wherein post-forming said projections
comprises post-forming said projections to include mushroom-shaped
heads, multi-lobed heads, multi-limbed heads, grappling hook heads
or combinations thereof.
109. The process of claim 89 further comprising applying vibration
energy to aid in removing said projections from said cavities.
110. The process of claim 89 wherein said cavities are shaped to
form projections which are shaped as one or more of hooks,
mushrooms, straight pins, angled pins, tapered pins, curved pins,
grappling hook, multi-limbed, cross-shaped, Y-shaped and
multi-lobed, each having cross-sections which are round, oval,
square, rectangular, trapezoidal, solid, hollow and combinations
thereof.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 12/690,700, filed on Jan. 20, 2010, which
claims the benefit of U.S. Provisional Patent Application Ser. No.
61/145,883, filed on Jan. 20, 2009, the disclosures of which are
each hereby incorporated herein by reference in their
entireties.
FIELD
[0002] This disclosure relates generally to mechanical fasteners,
such as hook and loop fasteners or touch fasteners, and more
particularly, to a method and apparatus for producing "hook"
fasteners using vibration energy.
BACKGROUND
[0003] Touch fasteners (known commercially as Velcro.RTM.,
Scotchmate.RTM., Tri-Hook.RTM., etc.) were originally produced
using textile technology. Two of the most common types of touch
fasteners are hook and loop fasteners and mushroom and loop
fasteners.
[0004] Hook and loop type fasteners may consist of a pair of
textile strips. These textile strips may be mated to form a
recyclable closure; one of the mates being a strip of textile
fabric having numerous monofilament elements, shaped like hooks,
projecting from one surface and the other mate being a textile
strip with multifilamented elements woven into loop shaped
projections on one surface. When the mating surfaces of these
strips are pressed together, numerous hook shaped elements on one
strip snare loop elements on the opposing strip and create a
temporary, reusable bond. As the strips are peeled apart, the hook
elements may deform and separate from the loop elements allowing
the fastener to be reused many times.
[0005] In the case of mushroom and loop fasteners, the hook type
mating strip is replaced with a strip containing numerous
monofilament projections having mushroom shaped or blunted heads.
The mushroom shaped heads may be formed by heating the tips of
straight monofilament projections until a flattened "mushroom head"
is formed on each projection. When this strip is pressed together
with a strip having loop shaped projections on the surface, the
mushroom heads may snare loop elements on the opposing strip and
create a temporary, reusable bond. As the strips are peeled apart,
the mushroom shaped elements may occasionally deflect and release
the loop element. In addition, two strips each having mushroom
shaped projections may be engaged together with the blunted heads
interacting to form a mechanical bond.
[0006] More recently the use of thermoplastic extrusion/molding
methods for making touch fasteners has become popular. In the case
of hook and loop fasteners, the hook strip may be formed by
extruding a polymer into a web-like shape with integral
projections, while the loop strip may still be produced using
woven, knitted or non-woven technologies. In the case of mushroom
and loop fasteners, the mushroom strip may be produced by extruding
a polymer into a web-like shape with integral pin-like projections
and post forming mushroom-like heads on the pin-like
projections.
[0007] The use of extrusion/molding technologies for the production
of hook type and mushroom type touch fasteners has reduced the
manufacturing cost and improved the performance and aesthetics of
touch fasteners, thus allowing their use in large volume
applications such as tab closures on disposable diapers.
[0008] Examples of technologies used for the production of
extruded/molded type touch fasteners, include: [0009]
Extruding/molding a hook fastener with an integral base where the
base may be molded onto a molding roller wherein hooking elements
may be molded in discreet cavities. The mold may be opened and
closed continuously as it rotates to allow the hooks to be
extracted. (See for instance, U.S. Pat. Nos. 3,762,000; 3,758,657
and 3,752,619 to Menzin and U.S. Pat. No. 3,196,490 to Erb.) [0010]
Extruding/molding a hook fastener with an integral base where the
hooking elements may be molded in discreet cavities and the mold
remains closed. The hooks may be pulled from the cavities after
cooling. Geometry of the hooks may therefore be somewhat limited as
they must be extractable from a closed mold. (See, for instance,
U.S. Pat. Nos. 3,312,583 and 3,541,216 to Rochlis; U.S. Pat. Nos.
4,775,310 and 4,794,028 to Fischer; and U.S. Pat. No. 5,393,475 to
Murasaki.) [0011] Extruding a web of material with a series of
rails of hook-like cross section, running parallel along the top
surface of the web. The rails may be cross-cut intermittently down
to the base material. The base material may be stretched to obtain
spacing between the hook elements. (See for instance, U.S. Pat.
Nos. 3,665,504 and 3,735,468 to Erb.) [0012] Extruding a web of
material with a series of molded pins or similar elements and
post-forming the elements into a hook type or mushroom type
fastener. (See for instance, U.S. Pat. Nos. 3,182,589: 3,270,408;
5,607,635; 5,755,015; 5,781,969 and 5,792,408.)
[0012] One common theme among all of these processes is the melting
and feeding of thermoplastic material through an extruder or
similar device. Although often considered efficient methods for the
production of touch fasteners, extrusion/molding technologies may
typically require significant investment in capital equipment
(extruders, chillers, pumping systems, dryers, pellet transport
systems), high process energy consumption, handling and pre-drying
of raw materials, proper disposal of purging/cleaning materials and
startup materials, the ventilation of noxious gases, etc. and the
ability to wind rolls or otherwise process finished product
non-stop.
[0013] A need exists for a method and apparatus to prepare hook
type fastener elements for use in a closure system, particularly a
reusable closure system, without the high capital investment and
material inefficiencies as described above.
SUMMARY
[0014] In one exemplary embodiment, the present disclosure
describes a process for forming projections on a substrate
comprising providing a mold having an outer surface, providing a
substrate material having a surface and providing a device as a
source of vibration energy, wherein one or both of said mold and
device contain a plurality of cavities, the cavities having a
shape. This may then be followed by positioning the substrate
material between the mold and the device and applying power to the
device wherein a portion of the substrate material enters the
cavities in the mold surface and forms projections on at least a
portion of the surface of the substrate material, wherein the
cavities are shaped to form projections as one or more of hooks,
mushrooms, straight pins, angled pins, tapered pins, curved pins,
grappling hook, multi-limbed, cross-shaped, Y-shaped and
multi-lobed, each having cross-sections which are round, oval,
square, rectangular, trapezoidal, solid, hollow and combinations
thereof.
[0015] In another exemplary embodiment, the present disclosure
relates to a process for forming projections on a substrate
comprising providing a substrate material having a surface and
providing a device as a source of vibration energy, the device
having a surface containing a plurality of cavities, the cavities
arranged along at least a portion of the surface, the cavities
having a shape. This may then be followed by pressing the device
against the surface of the substrate material and applying power to
the device and forcing a portion of the substrate material into the
cavities in the surface of the device, forming projections on the
surface of the substrate material, the projections generally
conforming to the shape of the cavities wherein the cavities are
shaped to form projections as one or more of hooks, mushrooms,
straight pins, angled pins, tapered pins, curved pins, grappling
hook, multi-limbed, cross-shaped, Y-shaped and multi-lobed, each
having cross-sections which are round, oval, square, rectangular,
trapezoidal, solid, hollow and combinations thereof.
[0016] In another exemplary embodiment the present disclosure is
directed at an apparatus for forming projections on a substrate
comprising a mold having a surface and a device as source of
vibration energy. One or both of the mold and device may contain a
plurality of cavities, the cavities having a shape wherein the
shape provides for the formation of a projection that is or can be
post-processed into a shape suitable for mechanical engagement with
a loop element or complimentary shaped projection or other mating
material, such as foam, screen or non-woven material
[0017] In another exemplary embodiment the present disclosure
relates to apparatus for forming projections on a substrate
comprising a device as a source of vibration energy the device
containing a plurality of cavities where the cavities have a shape
and wherein the shape provides for the formation of projections in
a substrate that are or can be post-processed into a shape suitable
for mechanical engagement with a loop element or complimentary
shaped projection or other mating material.
[0018] The present disclosure also relates to an article for
mechanical engagement, the article comprising a substrate having
two sides and including one or more projections extending from one
or both sides, wherein the substrate has a machine direction (MD)
and cross-direction (CD), and the article is characterized as
having one or more of the following characteristics: [0020] i. the
substrate has a tensile strength in said machine direction of
TS.sub.1 and the one or more projections have a tensile strength of
TS.sub.2, where TS.sub.2 is equal to 50% of the value of TS.sub.1,
or higher; or [0021] ii. the substrate has a shrinkage in a given
direction of S.sub.1 and the one or more projections have a
shrinkage in the same direction of S.sub.2 and
S.sub.2.gtoreq.0.50(S.sub.1).
[0019] The present disclosure also relates to an article for
mechanical engagement, the article comprising a substrate having
two sides and including a plurality of projections extending from
one or both sides, wherein the substrate, prior to the formation of
a projection in the substrate surface, has a machine direction (MD)
and cross-direction (CD), and the substrate is characterized as
having biaxial orientation wherein the shrinkage in the machine
direction and cross-direction have shrinkage values that are within
+/-20% of one another, and wherein the substrate, after formation
of a projection on the substrate surface, has a biaxial orientation
wherein the shrinkage in the machine direction and cross-direction
indicate shrinkage values that are within +/-20% of one
another.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] The accompanying drawings, which are incorporated in and
constitute a part of the specification, illustrate embodiments of
the invention and, together with the description, serve to explain
principles of the invention.
[0021] FIG. 1 is a schematic cross-sectional side view of an
apparatus and process for forming projections which may be used as
hook-type fasteners in accordance with the present disclosure.
[0022] FIGS. 2A-N are schematic views of exemplary upstanding
shapes that may be used as projections in accordance with the
present disclosure.
[0023] FIG. 3 is a schematic cross-sectional side view of another
apparatus and process for making projections that may be used as
hook fasteners in accordance with the present disclosure.
[0024] FIG. 4 is a schematic cross-sectional side view of another
apparatus and process for making projections that may be used as
hook fasteners in accordance with the present disclosure.
[0025] FIG. 5 is a schematic cross-sectional side view of another
apparatus and process for making projections that may be used as
hook fasteners in accordance with the present disclosure.
[0026] FIG. 6 is a schematic cross-sectional side view of another
apparatus and process for making projections that may be used as
hook fasteners in accordance with the present disclosure.
[0027] FIG. 7 is a schematic cross-sectional side view of another
apparatus and process for making projections that may be used as
making hook fasteners in accordance with the present
disclosure.
[0028] FIG. 8 is a schematic view cross-sectional side of another
apparatus and process for making projections that may be used as
making hook fasteners in accordance with the present
disclosure.
[0029] FIG. 9 is a schematic cross-sectional side view of another
apparatus and process for making projections that may be used as
making hook fasteners in accordance with the present
disclosure.
[0030] FIG. 10A is a schematic front view and FIG. 10B a schematic
cross-sectional side view of another apparatus and process for
making projections that may be used as hook-type fasteners in
accordance with the present disclosure.
[0031] FIG. 11 is a schematic view of an article produced by the
process and apparatus of FIG. 10A.
[0032] FIG. 12 is a block diagram of an exemplary process to
provide hook-type fasteners, according to the present
disclosure.
[0033] FIG. 13 is a schematic cross-sectional side view of another
apparatus and process for making projections that may be used as
hook fasteners wherein other materials may be intermittently fed
between the source of vibration and the substrate in accordance
with the present disclosure.
[0034] FIGS. 14A-C are sequential schematic cross-sectional side
views of an apparatus and process for making projections that may
be used as hook fasteners in an intermittent manner at a location
on a thermoplastic object in accordance with the present
disclosure.
[0035] FIGS. 15A-C are sequential schematic cross-sectional side
views of another apparatus and process for making projections that
may be used as making hook fasteners in an intermittent manner at a
location on a thermoplastic object in accordance with the present
disclosure.
[0036] FIGS. 16A-C are sequential schematic cross-sectional side
views of another apparatus and process for making projections that
may be used as hook fasteners in an intermittent manner at a
location on a thermoplastic object in accordance with the present
disclosure.
[0037] FIGS. 17A-C are sequential schematic cross-sectional side
views of another apparatus and process for making projections that
may be used as making hook fasteners in an intermittent manner at a
location on a thermoplastic object in accordance with the present
disclosure.
[0038] FIG. 18 is an enlarged cross-sectional view of an exemplary
projection protruding from a substrate produced in accordance with
the present disclosure.
[0039] FIG. 19 is an enlarged cross-sectional view of an exemplary
projection protruding from a layered substrate produced in
accordance with an exemplary method of the present disclosure.
[0040] FIGS. 20A and 20B are top views of two exemplary masking
materials to be used in conjunction with processes of the present
disclosure.
[0041] FIG. 21 is a schematic cross-sectional side view of the
apparatus and process of FIG. 1 for making projections that may be
used as hook fasteners wherein a masking material is combined with
the substrate produced in accordance with the present
disclosure.
[0042] FIG. 22 is a schematic cross-sectional side view of the
apparatus and process of FIG. 1 for making projections that may be
used as hook fasteners wherein a masking material is used to
provide an intermittent pattern of projections on a substrate but
the mask is not combined with the substrate produced in accordance
with the present disclosure.
[0043] FIG. 23 is a prospective view of the apparatus of FIG.
21.
[0044] FIG. 24 is a schematic cross-sectional side view of the
apparatus and process of FIG. 1 for making projections that may be
used as hook fasteners wherein a gasketing material is provided an
intermittent pattern of projections on a substrate, the gasket
surrounding the discrete areas of projections, in accordance with
the present disclosure.
DETAILED DESCRIPTION
[0045] Molded hook fasteners have generally been molded by, for
instance, extruding or injecting a thermoplastic melt on a rotating
drum, or mold, the mold comprised of a lamination or stack of metal
plates, the plates having recessed or notched edges or otherwise
designed to provide a series of cavities along the outer periphery
that may be filled by the molten polymer. A strip-like base portion
may be simultaneously molded from which projections, or hooks,
molded in the cavities, may protrude.
[0046] It has been found that a relatively less complicated and
relatively less expensive process may use vibration energy to
soften the polymer to manufacture the projections (hooks, mushroom
heads, etc.) instead of the extrusion or injection processes. In
one exemplary embodiment, as shown in schematic cross-sectional
side view in FIG. 1, a substrate of thermoplastic material 11 may
be positioned or passed between a vibrating source 13 and a
rotating molding roll 15, the roll containing multiple hook-shaped
or otherwise shaped cavities 17, along the outer periphery. The
substrate 11 may include, but not be limited to, film, sheet, web,
composite, laminate or other form, or may be portions of a film,
sheet, web, laminate or substrate thermoplastic material which may
be used as individual fastening tabs, for instance on a disposable
infant diaper. In their use on infant diapers, touch fasteners may
be attached to a "side tab" that the consumer uses to secure a
diaper to the infant. These tabs may be constructed with a piece of
extensible material to allow the tab to stretch and flex when
attached or when the infant moves. The present disclosure further
contemplates the use of pre-formed film, sheet, web, composite,
laminate, etc. as a substrate material.
[0047] During operation, the vibrating source 13 is positioned in
close proximity to the outer surface of the rotating molding roll
15 and in contact with the substrate of thermoplastic material 11
being processed. The source of vibration 13 may include, but not be
limited to, a vibrating ultrasonic horn, for example. These horns
may be made from metals such as aluminum or titanium and are sold
in the United States by companies such as Branson Ultrasonics,
Dukane or Sonitek, and in Europe by a company such as Mecasonics.
The source of vibration 13 may be vibrated in frequencies between
about 50 Hz to about 50 kHz, as required. Other sources of
vibration energy may be utilized, including but not limited to, a
rotating eccentric roller, high pressure sound waves or other
mechanical and/or electromechanical or acoustical forms of
vibration energy. Such energy may therefore be transferred to a
substrate and assist in the formation of the projection herein.
[0048] A portion of the thermoplastic material substrate 11 in
contact with the molding roll 15 and vibrating source 13 may be
softened by the vibration energy from the source and a desired
portion of the thermoplastic material caused to enter into the
cavities 17 of the molding roll forming hook-shaped or otherwise
shaped elements or projections 19 on the front surface of the film
or sheet 21 as the roll turns. This process may be referred to as
rotary forming. Reference to a force may be understood as applying
a requisite amount of pressure to the thermoplastic material to
assist in its entry and fill-out of the cavities 17. The
thermoplastic sheet 21 may function as a carrying strip for the
hooks 19.
[0049] Thermoplastic materials which may be used to produce the
hook fasteners may include, but not be limited to, polyamides,
polyolefins such as polypropylene and polyethylene,
acrylonitrile-butadiene-styrene (ABS), polyester, polycarbonate,
polyvinyl chloride (PVC) and blends thereof. The thermoplastic
materials may also be modified or reinforced with fillers, fibers,
flame retardants, colorants, etc.
[0050] An advantage of the present invention is that the
thermoplastic material that is immediately adjacent to the
vibrating source may not melt and may therefore retain most, if not
all, of its' original properties, in other words, not be subjected
to a heat history which might detract from its' original
properties.
[0051] When a previously molecularly oriented material or,
alternatively, materials capable of being molecularly oriented are
used, the molecular orientation of the material entering into the
cavities may be maintained, increased or reduced by altering the
vibration energies applied
[0052] FIG. 18 is an enlarged cross-sectional view of an exemplary
projection 19 protruding from a substrate 21 produced in accordance
with an exemplary method of the present disclosure, such as shown
in FIG. 1. Due at least in part to the relatively lower amount of
heat imparted to the substrate by the vibratory action according to
the present disclosure, as compared to other processes wherein the
polymer is well-above the temperatures at which orientation is
destroyed (e.g. Tg in the case of an amorphous polymer or Tm in the
case of a crystalline polymer) the properties of the polymer which
may depend upon orientation may be more efficiently maintained
and/or even increased in value. That is, the stem portion 19A of
the projection formed from the imposition of vibration energy may
substantially maintain its molecular orientation or even increase
somewhat as measured by shrinkage after forming or by its tensile
strength after vs. before forming. For example, if the polymeric
material, prior to entering the cavities, has a tensile strength
(TS) in the direction of an orientation plane that is present (e.g.
in the machine direction which may be understood as, e.g., the
direction of extrusion) of TS.sub.1, the projections, formed due to
exposure to vibration energy, may still exhibit a tensile strength
(TS.sub.2) in a direction of orientation that is at least 50% of
TS.sub.1, or higher (e.g. up to 200%).
[0053] In addition, if the shrinkage attributable to orientation
prior to exposure to vibrational energy is of a given value
(S.sub.1), in a given direction in said substrate, the shrinkage
(S.sub.2) that may exist after exposure to vibrational energy, in
the same direction in the projection may be at least 50% of its
original value, or higher (e.g. 150%). That is,
S.sub.2.gtoreq.0.50(S.sub.1). Reference to shrinkage herein may be
understood as the loss in dimension that will occur when the
substrate is heated to a temperature above which the orientation
will relax and generally disappear. As noted herein, this may be
above the glass transition temperature (Tg) for an amorphous
polymer or about the melting point (Tm) for a crystalline
polymer.
[0054] In addition, it is contemplated herein that one may start
with a substrate that contains little or no orientation, which may
be understood as that situation where the shrinkage is less than or
equal to 5.0% in any given direction. It may also be characterized
as that situation where the Elmendorf Tear strength in a given
machine direction (ET.sub.MD) is approximately equal to the
Elmendorf Tear (ET.sub.CD) in a given cross direction, with respect
to a given substrate. Cross-direction may be understood as that
direction, e.g., that is transverse to a machined direction (MD).
That is, ET.sub.MD is within about +/-20% of ET.sub.CD. Elmendorf
tear strength may be measured by ASTM D1922 and may be understood
as the average force required to propagate tearing through a length
of the substrate at issue. Accordingly, for such substrate that
contains little or no orientation, the application of vibrational
energy and the formation of a projection for mechanical engagement
may provide a projection that includes orientation, relative to the
generally non-orientated substrate from which it was formed. The
orientation in such projection may be such that it includes
shrinkage in a given direction of greater than 5.0%.
[0055] Furthermore, it is contemplated herein that one may start
with a substrate that has biaxial orientation, which may be
understood as that situation where there is orientation in both the
machine and cross-directions. For example, the machine and
cross-direction may indicate relatively uniform shrinkage values of
greater than 5.0%. It may therefore be appreciated that upon
formation of a projection for mechanical engagement, the underlying
substrate will now substantially retain the biaxial orientation,
due to the ability to focus the vibration energy at the surface of
the substrate, to form the projection, without substantially
disturbing the underlying biaxial orientation present in the
substrate.
[0056] It should also be noted that with respect to the properties
of the substrate and projection noted above, one or more of such
properties may be present in any given substrate/projection
configuration.
[0057] In the case where a multilayered material (laminate) may be
utilized, a portion of one or more or the layered materials may be
formed into the cavities allowing for the production of a product
where the properties of the hook portion may be selectively
engineered. FIG. 19 is an example of an enlarged cross-sectional
view of an exemplary projection protruding from a layered substrate
produced in accordance with an exemplary method of the present
disclosure, such as shown in FIG. 1. Here, a second material 121
has been joined to the substrate material 21 and through processing
according to the present disclosure, projection 19 is formed. A
portion 122 of the second material 121 may extend into the body or
stem 19A of the projection 19 and may provide enhanced properties
to the projection. For example, portion 122, which is formed form
substrate material 121 may have a different Shore Hardness value
than the Shore Hardness value that is associated with substrate
material 21.
[0058] Where a multilayered laminate is utilized, the fastener
elements may be produced from one or more colors and the strip-like
base may be of a different color(s). In addition, if a multilayered
laminate is utilized having a transparent surface layer, the
fastening elements or the strip-like material may be formed to be
transparent.
[0059] Unlike prior art taught in this field where raw material is
converted to a molten state prior to forming a substrate in web
form to include integral projections, the present disclosure allows
the substrate material to retain such desirable properties as
molecular orientation, multicolored layers or composite structures
by softening the polymer and forming it into the desired shape
using vibratory energy, thereby also minimizing the thermal history
of the polymer(s) processed.
[0060] With reference to FIG. 1, a means for cooling may be
provided on or adjacent the molding roll 15 and the formed product,
a strip 21 of polymer including a plurality of hook-type
projections 19, may be peeled from the molding roll. Cooling may be
accomplished by, for instance, cooling the molding roll externally
and/or internally, cooling the vibrating source internally and/or
externally and/or cooling the thermoplastic material directly
and/or indirectly through the use of liquid, gas, air or other
means.
[0061] In some instances, an after-burst of ultrasonic energy may
be applied during or after cooling has taken place to aid in
"decoupling" the projections from the mold or horn. This may be
particularly useful when the projections are formed in the surface
of the source of energy, i.e. the horn.
[0062] One example of a process for providing projections on a
substrate which may be used as one of the mating portions in a
touch fastening system is shown in FIG. 12. As described at Block
100, a molding roll, or other shape, may be provided containing
multiple hook-shaped or otherwise shaped cavities, arranged along
the outer periphery of the molding roll, the cavities capable of
forming projections conforming to the shape of the cavities. In
Block 200, a source of vibration energy may be provided, for
instance an ultrasonic horn or roll. A substrate material may be
provided (Block 300), in, for instance, film, sheet, web, laminate,
composite, etc., form and the substrate positioned (Block 400)
between the molding roll and source of vibration.
[0063] Power may be applied (Block 500) to the source of vibration
to selectively soften the substrate material and allow material
into the cavities in the molding roll, forming projections.
Alternatively, the molding roll may be smooth and the cavities for
forming the projections may be formed into the surface of the
source of vibration as depicted in FIGS. 5, 7 and 8.
[0064] The projections, and substrate, if required, may be cooled
and the substrate including projections extending from the surface
thereof may be stripped from the molding roll to form a strip for
use in a touch fastener system. Cooling make take place between the
molding roll and the source of vibration, in the molding roll or on
the substrate after release from the roll. The projections may
subsequently be post-formed into a desired shape.
[0065] As described herein, the cavities for forming the
projections may be also be formed in the surface of a rotating horn
(see FIGS. 4-8).
[0066] Although hook-shaped cavities and hook-shaped projections
are referenced herein, it is anticipated that cavities may be
chosen to produce projections having other shapes which may
function as the "hook" portion of a touch fastener system
including, but not limited to, straight pins, angled pins, tapered
pins, mushroom headed pins and curved pins, as well as elements
with varying cross-sections such as, but not limited to round,
oval, square, rectangular, trapezoidal, cross, multi-lobed,
grappling hook, multi-limbed or combinations of these. The
projections may have a solid core or may be in hollow form such as
tubular. Examples of some of these shapes are shown in FIG. 2A-N.
For instance, FIG. 2G is an example of a multi-lobed projection,
FIG. 2I is an example of tubular, FIG. 2J is an example of
cross-shaped, FIG. 2K is an example of Y-shaped, FIG. 2L is an
example of a grappling hook and FIG. 2M is an example of
multi-limbed. It is further contemplated that where FIG. 2J is an
example of a four-limbed projection and FIG. 2K is an example of a
three-limbed projection, that projections may include additional
limbs, such as 5, 6, 7, 8, etc. Such projections may vary in
height, thickness and in the angle that they may project from the
carrying strip 21 or substrate. In addition, the projections may be
formed of a uniform height or may vary in height.
[0067] The surfaces of the vibrating source 13 may be shaped so as
to increase the length of time thermoplastic materials may be
subjected to the vibration energy or to otherwise improve the
properties and/or performance of the process. FIG. 3 shows one
example of one type of a modified surface for a vibrating source
13A wherein a portion of the surface 12A of the vibrating source
13A has been provided which is complementary in shape to the
surface of the molding roll 15. Also, in FIG. 3, a portion 12 of
the vibrating surface has been modified, in this example as a
complex curved surface, to allow thicker thermoplastic materials
11A to pass between the vibrating source 13A and the molding roll
15. Shaping of the vibrating source 13A may also be used to reduce
distortion of the finished product and to aid in guiding the
thermoplastic material substrate 11 between the vibrating source 13
and the rotating molding roll 15.
[0068] In another exemplary embodiment, as shown in FIG. 4, the
source of vibration may be a roll which may include cavities for
forming the projections and a rotating roll 22 may be positioned so
as to force the softened thermoplastic into the cavities. The
rotating vibration source 20 may contain multiple hook-shaped or
otherwise shaped cavities 17 along its' outer periphery and may be
used in place of the stationary vibrating source 13, 13A (as shown
in FIGS. 1 and 3) and positioned in close proximity to the rotating
roll 22. The vibrating source 20 may be a rotary ultrasonic horn.
These horns may be made from, for instance, titanium and are sold
in the United States by Branson Ultrasonics and in Europe by
Mecasonics. A roll with a patterned surface may be substituted for
the smooth roll if patterning the back surface 24 of the product is
desired. Patterning the back of the product to simulate woven
structures or leather materials or other designs may serve to
enhance the aesthetics and/or functionality of the product. In some
cases, a patterned surface may be designed on one or both rolls to
form apertures in the base material thereby making the fastener
breathable or permeable.
[0069] In another exemplary embodiment, as shown in FIG. 5, a
rotating vibration source 20 containing multiple hook-shaped or
otherwise shaped cavities 17, along its outer periphery as shown in
FIG. 4, may be positioned in close proximity to a non-rotating
stationary platen 26. The platen surface 28 may be smooth or
patterned if patterning the back surface of the product is
desired.
[0070] FIG. 6 shows an exemplary embodiment of another type of
modified stationary platen 30 in combination with a rotary
vibration source 20. In this example, one surface 32 of the platen
has been modified, in this example as a complex curved surface, to
allow thicker thermoplastic materials (substrates) to pass between
the vibrating source 20 and the modified stationary platen 30.
Reference numeral 32A indicates an area where the surface of the
platen 30 is complementary in shape to the shape of the surface of
the rotary vibration source 20. Shaping of the modified stationary
platen 30 may also be used to reduce distortion of the finished
product and aid in guiding the thermoplastic material substrate 11A
between the rotating vibration source 20 and the stationary platen
30. The platen surface 32 may be smooth or patterned if patterning
the back surface of the product is desired.
[0071] In another exemplary embodiment, as shown in FIG. 7, a
rotating vibration source 20 containing multiple hook-shaped or
otherwise shaped cavities 17 along its outer periphery, may be
combined with a rotating molding roll 15 (such as is shown in FIG.
1) to produce a polymeric strip having projections on both the
front and back side of the sheet 21A. The rotating vibration source
20 may be positioned in close proximity to the outer surface of the
rotating molding roll 15 and both rolls may contain multiple
hook-shaped or otherwise shaped cavities 17, along their outer
peripheries. As shown, this may allow for the production of
products with hook-shaped or otherwise shaped elements 19 on the
front surface 23 and back surface 24 of the carrying strip 21A
simultaneously.
[0072] In another exemplary embodiment, as shown in FIG. 8, a
rotating vibration source 20 containing multiple hook shaped or
otherwise shaped cavities 17, along its outer periphery may be
positioned in close proximity to another rotating vibration source
20A containing multiple hook shaped or otherwise shaped cavities 7,
along its' outer periphery. This would allow for the production of
products with hook-shaped or otherwise shaped elements 19 on the
front surface 23 and back surface 24 of the carrying strip 21A
simultaneously.
[0073] In still another exemplary embodiment, two or more sources
of vibration, either stationary or rotary in nature, may be
utilized simultaneously. FIG. 9 depicts the use of two vibrating
stationary sources 13 in close proximity to a rotating molding roll
15 containing multiple hook-shaped or otherwise shaped cavities 17,
along the outer periphery of the molding roll 15.
[0074] As described above, the process and apparatus according to
the present disclosure is suitable for forming a product having
projections which may function as hook fasteners or projecting
elements having other shapes in touch fastening systems on one or
more surfaces of a strip of thermoplastic material substrate, the
substrate comprising film, sheet, web, composite, laminate or other
form, or from portions thereof. The substrate may include a
cellular structure, such as a foamed polymer, for example, or be a
molecularly oriented film or a composite that may, for example,
include a fibrous reinforcement. The projections may have a variety
of shapes, lengths and dimensions. The projections may be formed
from one or more of the materials making up the multilayered film
or substrate sheet or portions of such.
[0075] It is contemplated that at least a portion of the substrate
may comprise a thermoset polymer.
[0076] It is further contemplated that the substrate upon which the
projections are formed may include continuous or intermittent
layers of materials and combinations thereof. For instance, it is
contemplated that projections may be formed on an intermittent web,
to produce diaper closure tabs, possibly inline with a diaper
manufacturing machine.
[0077] It is further contemplated that projections may be formed in
their final shape or produced partially shaped and post-formed to
obtain their final geometry, for instance, a straight pin that may
be reshaped into a hook shape, or a straight pin that may be
blunted into a mushroom shape in a subsequent processing step or a
deformed hook that may be post-formed into a hook capable of
functioning as a fastening element.
[0078] It is further contemplated that the projections as formed
herein may provide a means of fastening, either temporary or
permanent, by engaging with a material having loop elements (e.g.
structures that will mechanically engage a projection such as a
hook), or engaging to screen-like materials, open-celled foam-like
materials or a material having similar or mating projections (for
instance, hooks, mushrooms, etc.)
[0079] In a particular advantage of the process described herein,
the projections of the present disclosure may be formed
intermittently on a substrate by turning the source(s) of vibration
on and off as desired or by intermittently altering the position
and/or contacting force and/or vibration frequency of the vibrating
source. For example, one may move an ultrasonic horn or other
vibration source up and down intermittently while a web passes
through the process to intermittently form projections on a
substrate. As such, projections may be formed in a desired pattern,
and the pattern may be varied during the in-line processing of the
substrate. Accordingly, the projections may be of uniform height or
multilevel height depending on the conditions of operation of the
apparatus.
[0080] Projections, according to the present disclosure may be
formed on a substrate, such as a web, with portions of the web
formed to be creped or folded to allow the web to stretch. FIG. 10A
is a schematic front view showing an exemplary embodiment of a
configuration of apparatus wherein the molding roll 42 includes a
portion 44 of the surface including cavities to form projecting
elements and the vibrating source 40 and molding roll 42 each
include complementary portions of their surfaces 46, 46A configured
to form a creped area. FIG. 10B is a schematic cross-sectional side
view of FIG. 10A. FIG. 11 depicts an example of a product that may
be produced from the configuration depicted in FIG. 10A. In this
example, hook type elements 19 have been formed adjacent to creped
areas 48 on a web 21B. This type of configuration may prove
appealing if used to form hook elements and creped areas on diaper
closure tabs, eliminating the complex combinations of adhesive
bonded touch fasteners to elastomeric non-wovens currently employed
for this application. The creped portion and the fastening portion
may thus be formed into a web material simultaneously such that an
extendable diaper fastening tab is formed. Either of the surfaces
46, 46A may be configured to form a crepe area or one of the
surfaces may comprise a compliant material, such as rubber or an
elastomer, which under nip pressure will conform to the opposing
surface configuration. Reference to crepe, may be understood to
mean a quality in a web imparted by embossing to give a wavy
surface such as a crimp in a web. Reference to a wavy surface may
be understood to mean a surface that rises and falls in relative
position.
[0081] In another exemplary embodiment, projections may be formed
while simultaneously attaching them to an extensible or
non-extensible web. As shown in FIG. 13, an extensible material or
non-extensible material 11B may be fed between a rotating molding
roll 15 and a stationary source of vibration 13 (or rotating source
of vibration or other configurations of mold and vibration sources
for forming projections, as disclosed herein) (see, for instance,
FIGS. 1, 3-9, 10A and 10B). The vibration source 13 may be
positioned in close proximity to the mold 15, but far enough away
to avoid melting or deforming the extensible material or
non-extensible material 11B. Pieces of thermoplastic or
thermosettable materials 18 materials may be intermittently fed
between one or more sides of the extensible material or
non-extensible material 11B and the vibration source 13. When the
pieces pass between the vibration source 13 and the mold roll 15,
for example, the additional thickness may cause the thermoplastic
or thermosettable material to be forced into the cavities 17.
[0082] Further, a pattern of projections may be formed by passing a
pre-perforated or pre-die cut masking material between the
substrate (film, sheet, composite, etc.) and molding roll thereby
selectively covering areas of the molding roll and providing an
intermittent pattern of projections. The mask may be removed (FIG.
22) or may be bonded to the substrate (FIG. 21) if desired.
Accordingly, variations in patterns may be provided relatively
easily without having to change the configuration of the molding
roll. The die cutting, or other formation of a mask may be done
in-line or off-line.
[0083] FIGS. 20A and 20B illustrate examples of masking materials
for such a purpose. FIG. 20A is a top view of a mask 80 comprising
a sheet of material 82, such as paper, metal, film, fabric, etc.
which has one or more openings 84 formed therein. FIG. 21
illustrates the apparatus and process of FIG. 1 wherein a mask 80
in sheet form is fed into the nip between the vibration source 13
and the molding roll 15 such that portions of the mask cover
selected cavities 17 in the molding roll and an intermittent
pattern of projections 19 are formed through the openings 84 on the
surface of the formed substrate 21.
[0084] FIG. 22 illustrates a similar process where the mask 80 may
be separated from the substrate 21 and not become part of the
finished product.
[0085] FIG. 23 is a perspective view of the apparatus and process
of FIG. 21.
[0086] FIG. 24 illustrates another apparatus and process similar to
FIG. 1 wherein a material 90 in sheet form (such as a foam,
non-woven web, etc.) is laminated to a substrate material 11 and
fed into the nip between the vibration source 13 and the molding
roll 15. Portions 100 of the molding roll 15 may be removed to
allow portions of the material 90 to provide an intermittent
pattern of projections 19 and to further allow the material 90A to
surround the discrete areas of projections 19 and act as a gasket.
Accordingly, as shown an intermittent pattern of projections 19 are
formed like islands between the areas of material 90A. The
thermoplastic material of layer 11 impregnates the material 90 when
the projections 19 are formed. It is contemplated that the height
of the projections 19 may be less than the height of the material
90A such that the projections do not engage a mating fastening
system element and premature engagement is substantially prevented.
In an application such as a fastening tab for a diaper this may
also provide protection from the projections encountering the
baby's skin.
[0087] In addition, it is contemplated that projections may be
formed through openings in covering layers of material by passing
multiple layers of material between a molding roll and vibration
source where the covering layer may include holes that align with
the pattern of cavities in one or more of the rolls, or where
porous materials, such as textiles, may provide openings for the
substrate material to be forced through and into the cavities in
the roll(s), or where the strength of the covering layer is
sufficiently weak such that a substrate material may burst through
the covering material and into the cavities of the mold.
[0088] FIG. 20B illustrates another type of mask 80A made from a
porous substrate material 88, such as screen, non-woven, open-cell
foam, etc. that has been covered by, for instance a coating or by
laminating another material 86 except in areas wherein openings 84
are formed in the coating. The porous material 88 is visible
through the openings 84 such that projections may be formed
therethrough, while the coated areas of the mask act to prevent the
formation of projections 19. It is further contemplated that a mask
may be applied locally directly to a portion of the surface of the
molding roll such as by spraying or dipping a liquid and then
drying such. This coating may then prevent the formation of
projections in selected areas of the substrate. The mask may be
reused or peeled off and reapplied.
[0089] Further, a laminate of multiple layers, for instance,
thermoplastic substrate/fabric/thermoplastic fabric may be passed
between cooperating rolls/vibration sources (see, for instance,
FIGS. 7 and 8) to provide a pattern of back-to-back projections
having a reinforcing layer.
[0090] It is further contemplated that intermittent cuts or slits
or other wise shaped apertures may be produced in the substrate by
raising portions of the molding roll surface (or rotary horn
surface) to create cuts or very thin portions of the substrate.
These modifications to the substrate may serve to make the
fastening strip softer and/or stretchable and/or breathable.
[0091] The process and apparatus as described herein may provide
advantages over an extrusion/molding process as relatively less
heating and cooling energy may be consumed since only the material
used to form the projections may be heated and cooled. Further,
multiple colors may be provided by the choice of substrate material
and a broad variety of properties may be obtained through the
selection of substrate materials, including but not limited to,
molecularly oriented substrates or composite substrates. Materials
that have printed patterns, logos, etc., may be used as substrates
and thereby have projections formed into one or more of their
surfaces allowing the printed patterns, etc. to remain legible.
Start-up time for the process may be relatively fast and the
process may be started and stopped at will, eliminating the need
for complex and costly automated transfer winders, as are often
required in continuous extrusion processes. Finally, floor space
may be reduced substantially.
[0092] Touch fasteners are often adhered to various thermoplastic
objects. One such application involves the attachment of touch
fasteners to automotive door panels and interior headliner panels.
The materials chosen for use as touch fasteners (polyamides,
polyolefins, etc.) often make adhesive bonding difficult, expensive
and a common source of failure. It is contemplated that a version
of the process and apparatus described herein may eliminate or
reduce the need for adhesives to bond fasteners to base materials
as the hook-type fasteners (projections) may be formed as part of
or formed onto the surface of such base materials.
[0093] The processes and apparatus described heretofore are
primarily directed at continuous or semi-continuous methods of
forming projections on various surfaces. In another exemplary
embodiment, which may be described as "plunge forming", the
projections may be formed anywhere on a thermoplastic object using
automatic equipment, a robotically held or hand-held horn, or other
source of vibration, which may be brought to the location where the
projections are desired to be formed. FIGS. 14A, B and C illustrate
a process where an ultrasonic horn 54 may have a vibrating surface
50 which may be constructed with cavities 17 located thereupon
(FIG. 14A). The ultrasonic horn 54 may be pressed (arrow A) against
a thermoplastic object 52 (for instance, a door panel or headliner
substrate for a vehicle) and vibration energy applied (FIG. 14B),
selectively softening the thermoplastic material and forcing some
of the thermoplastic material 52 into the cavities 17. The
vibration energy may then be stopped, the thermoplastic material
allowed to cool and the ultrasonic horn retracted (arrow B, FIG.
14C) freeing the newly formed projections 19 from the cavities 17
and providing a plastic object having a surface with a local
pattern of projections for attachment formed thereupon.
[0094] In some instances, an after-burst of ultrasonic energy may
be applied during or after cooling has taken place to aid in
"decoupling" the projections from the mold or horn. This may be
particularly useful when the projections are formed in the surface
of the source of energy, i.e. the horn. It is contemplated that a
removable or replaceable horn tip may be used to allow relatively
rapid changing of the pattern of projections.
[0095] FIGS. 15A, B and C illustrate similarly that various
thermoplastic or thermosettable materials 60 may be positioned
between the ultrasonic horn 54 and the object 52 (FIG. 15A)
allowing for the formation of projections 19, fully or partially
from the positioned material 60 (FIG. 15B). In this manner, the
projections 19 may be formed from a second material 60 and through
the vibration process that material may be bonded to the object 52
(FIG. 15C). It may be appreciated that this will have particular
utility in that situation where the object 52 is an automotive trim
panel, which may be understood as a thermoplastic and/or thermoset
door panel, instrument panel, center console, rear close-out
panels, headliner, etc.
[0096] In another exemplary embodiment, as shown in FIGS. 16A, B
and C, the cavities may be provided in a mold-like base 56 and not
in the ultrasonic horn 54. The thermoplastic object 52 may be
positioned (FIG. 16A) and held under pressure (arrows A, FIG. 16B)
between the ultrasonic horn and the mold base 56. Vibration energy
may be applied to the horn (FIG. 16B), forcing some material from
the object 52 into the cavities 17 of the base. Again, the
vibration energy may be stopped, the thermoplastic material allowed
to cool and the ultrasonic horn retracted (arrows B) (FIG. 16C)
freeing the newly formed projections 19 from the cavities 17 and
providing a plastic panel having a surface with a local pattern of
projections formed thereupon for attachment thereto.
[0097] FIGS. 17A, B and C illustrate that various thermoplastic or
thermosetting materials 60 may be positioned between the object 52
requiring the projections 19 and the mold-like base 56 containing
the cavities 17 (FIG. 17A). The projections may be formed from the
material 60 by forcing the horn 54 and mold 56 together around the
object 52 and material 60 and applying vibration energy (arrows A,
FIG. 17B). Again, the vibration energy may be stopped, the
thermoplastic material allowed to cool and the ultrasonic horn
retracted (arrows B) (FIG. 17C) freeing the newly formed
projections 19 from the cavities 17 and providing a plastic panel
having a surface with a local pattern of projections formed
thereupon, the projections of a different material than the object
52.
[0098] The process and apparatus described herein may greatly
reduce the complexity of insert molding hook type materials into
larger molded objects as different types of materials may be fed in
layers to the apparatus and the projections formed on or through
one or more of the layers. Materials for a portion of the substrate
layer or for the projections may thus be different from the
substrate materials. The use of an ultrasonic horn or other source
of vibration energy and the use of a mold-like base as disclosed
herein to form projections on objects in a discontinuous or
intermittent process or to locally form a pattern of projections on
the surface of an object, may provide relatively lower capital and
space requirements as well as a very flexible process capable of
being easily moved. It is contemplated that all of the features
disclosed regarding the continuous or semi-continuous process
herein also may apply to the local application of projections on an
object.
[0099] The projections disclosed herein for use as elements in a
touch fastening system may be produced in a relatively wide range
of sizes and densities to provide a wide range of fastening or
holding strength. While not being held to any particular limits, it
is contemplated that the height of such projections may range from
less than about 10 microns to greater than about 5 mm.
[0100] The description and drawings illustratively set forth the
presently preferred invention embodiments. The description and
drawings are intended to describe these embodiments and not to
limit the scope of the invention. Those skilled in the art will
appreciate that still other modifications and variations of the
present invention are possible in light of the above teaching while
remaining within the scope of the following claims. Therefore,
within the scope of the claims, one may practice the invention
otherwise than as the description and drawings specifically show
and describe.
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