Classifications

• • A—HUMAN NECESSITIES
  • A44—HABERDASHERY; JEWELLERY
  • A44B—BUTTONS, PINS, BUCKLES, SLIDE FASTENERS, OR THE LIKE
  • A44B18/00—Fasteners of the touch-and-close type; Making such fasteners
• • A—HUMAN NECESSITIES
  • A44—HABERDASHERY; JEWELLERY
  • A44B—BUTTONS, PINS, BUCKLES, SLIDE FASTENERS, OR THE LIKE
  • A44B18/00—Fasteners of the touch-and-close type; Making such fasteners
  • A44B18/0046—Fasteners made integrally of plastics
  • A44B18/0061—Male or hook elements
  • A44B18/0065—Male or hook elements of a mushroom type
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T24/00—Buckles, buttons, clasps, etc.
  • Y10T24/27—Buckles, buttons, clasps, etc. including readily dissociable fastener having numerous, protruding, unitary filaments randomly interlocking with, and simultaneously moving towards, mating structure [e.g., hook-loop type fastener]
  • Y10T24/2792—Buckles, buttons, clasps, etc. including readily dissociable fastener having numerous, protruding, unitary filaments randomly interlocking with, and simultaneously moving towards, mating structure [e.g., hook-loop type fastener] having mounting surface and filaments constructed from common piece of material

Definitions

• hook materials for hook and loop fasteners.
• One solution is generally the use of continuous extrusion methods that simultaneously form the base layer and the hook elements, or precursors to the hook elements.
• direct extrusion molding formation of the hook elements see for example U.S. Patent No. 5,315,740, the hook elements must continuously taper from the base layer to the hook tip to allow the hook elements to be pulled from the molding surface. This generally inherently limits the individual hooks to those capable of engaging only in a single direction while also limiting the strength of the engaging head portion of the hook element, as well as the density of the hook structures, which generally must point in the machine direction.
• the die forms the spaced ridges and induces machine direction molecular orientation in the ridges by directing the molten polymer flow in the machine direction (the direction of polymer flow or extrusion). These ridges or ribs will also form the cross sectional shape of the projections as the ridges are formed by the die plate.
• the initial projection precursor thickness is formed by transversely cutting the ridges at spaced locations along their lengths to form discrete cut portions of the ridges. These cut portions are directly adjacent one another along the cut line so at this point they do not form discrete projections or form projections separated by only a minimal distance.
• the heat treatment can then continue to shrink more or all of the cut portion (e.g., at least a portion of the stem portion of the hook members or down as far as the cut of the cut portion).
• the resulting heat treated projections, preferably hooks, are preferably substantially upstanding and/or rigid.
• FIGURE 7a is a schematic front view of a hook member of the present invention.
• FIGURE 7b is a schematic side view of a hook member of the present invention.
• a hook portion is generally designated by the reference numeral 10.
• the hook fastener portion 10 comprises a filmlike base layer 11 having generally parallel upper and lower major surfaces 12 and 13, and a multiplicity of spaced hook members 14 projecting from at least the upper surface 12 of the base layer 11.
• the base layer can have planar surfaces or surface features as could be desired for tear resistance or reinforcement.
• the strip 50 is pulled around rollers 55 through a quench tank 56 filled with a cooling liquid (e.g., water), after which the ridges or ribs 54 (but not the base layer 53) are transversely slit or cut at spaced locations along their lengths by a cutter 58.
• the cutter forms discrete portions 57 of the ribs 54 having lengths corresponding to about the desired initial thicknesses of the cut portions to be formed into discrete projections , as is shown in Fig. 3. Different cut angles or periods can also be used on the same strip, if desired.
• the cut can be at any desired angle, generally from 90° to 30° from the lengthwise extension of the ribs.
• the invention projections can be arranged in very close proximity, for example, if closely spaced hooks or projections are desired, there can be 25/cm or more hooks or projections in a single row.
• a row is defined by hooks or projections that extend in a direction or extent and at least partially overlap in that direction or extent, preferably overlap by 50 percent or more most preferably 90 percent or more.
• the hooks or projections can be at least 30/cm even 50/cm or more up to 100/cm or possibly more.
• the overall density of the projections or hook members can be extremely high based on the closeness and width of the original rib members. If the rib members are closely spaced, extremely high hook densities are possible.
• Wider spacing between rib members can be created after the ribs are formed by stretch orientation of the base in a direction transverse to the rib members or hook rows. This can be beneficial to reduce the base layer thickness and made it more softer or less rigid while maintaining high number of projections in a row.
• Suitable polymeric materials from which the hook fastener portion can be made include thermoplastic resins capable of melt flow induced molecular orientation such as those comprising polyolef ⁇ ns, e.g. polypropylene and polyethylene, polyvinyl chloride, polystyrene, nylons, polyester such as polyethylene terephthalate and the like and copolymers and blends thereof.
• the resin is a polypropylene, polyethylene, polypropylene-polyethylene copolymer or blends thereof.
• the orientation and crystallinity is measured using X-ray diffraction techniques. Data is collected using a Bruker microdiffractometer (Bruker AXS, Madison, Wisconsin), using copper K ⁇ radiation, and HiSTARTM 2-dimensional detector registry of scattered radiation. The diffractometer is fitted with a graphite incident beam monochromator and a 200 micrometer pinhole collimator. The X-ray source consisted of a Rigaku RU200
• the background and amorphous intensities in trace (B) are interpolated for each element and subtracted from the trace to produce (B').
• Plot of trace (B') has constant intensity in absence of orientation or oscillatory intensity pattern when preferred orientation present.
• the magnitude of the crystalline fraction possessing no preferred orientation is defined by the minimum in the oscillatory pattern.
• the magnitude of the oriented crystalline fraction is defined by the intensity exceeding the oscillatory pattern minimum.
• the percent orientation is calculated by integration of the individual components from trace (B').
• % oriented material (Area (o rie n ted ) / Area tota i) ) x 100
• FIG. 1 A polypropylene/polyethylene impact copolymer (SRC7-644, 1.5 MFI, Dow Chemical) pigmented with Ti02 (0.5%) was extruded with a 6.35 cm single screw extruder (24:1 L/D) using a barrel temperature profile of 177°C-232°C-246°C and a die temperature of approximately 235°C.
• the extrudate was extruded vertically downward through a die having an opening cut by electron discharge machining. After being shaped by the die, the extrudate is quenched in a water tank at a speed of 6.1 meter/min with the water being maintained at approximately 10°C.
• the web was then advanced through a cutting station where the ribs (but not the base layer) were transversely cut at an angle of 23 degrees measured from the transverse direction of the web.
• the spacing of the cuts was 305 microns. There were approximately 10 rows of ribs or cut hooks per centimeter.
• Comparative Example CI The precursor hook web described above was longitudinally (MD) drawn approximately 3.65 to 1 between two pairs of nip rolls to further separate the individual hook elements after the cutting step without any heat treatment of the hook side of the web. There were approximately 15 rows of ribs or cut hooks per centimeter crossweb after drawing. The dimensions of the resulting non heat-treated hook material are shown in Table 1 below.
• Example 1 The precursor hook web described above was subjected to a non-contact heat treatment on the hook side of the web by passing said web underneath a perforated metal plate at a speed of 2.4 meter/min producing hook members having a profile substantially as shown in Fig. 7. Hot air at a temperature of approximately 185°C, provided by a 15 kW electric heater, was blown through the perforations in the metal plate onto the hook side of the web at a velocity of approximately 3350 meter/min. The hooks were approximately 46 cm from the perforated plate. The smooth base film side of the web was supported on a chill roll at approximately 149°C. After heat treatment the web was cooled by passing the web over a chill roll maintained at 11°C. The dimensions of the resulting heat-treated hook material are shown in Table 1 below.
• Example 2 The precursor hook web described above was subjected to a non-contact heat treatment on the hook side of the web using the following procedure.
• a 13 cm x 43 cm piece of web was placed onto a 13 cm x 43 cm steel plate(1.3 cm thick), hook-side up, and edge clamped to prevent the web from shrinking.
• Hot air from a Master brand hot air gun(14.5 amp) at 400°C was blown vertically down onto the web by passing the air gun uniformly over the web for about 20 seconds.
• the hot air gun vent was set at 50%.
• Table 1 The dimensions of the resulting heat-treated hook material are shown in Table 1 below.

Landscapes

• Slide Fasteners, Snap Fasteners, And Hook Fasteners (AREA)
• Extrusion Moulding Of Plastics Or The Like (AREA)
• Shaping By String And By Release Of Stress In Plastics And The Like (AREA)

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Applications Claiming Priority (2)

Publications (1)

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• 2002
  • 2002-12-17 US US10/321,899 patent/US6814912B2/en not_active Expired - Fee Related
• 2003
  • 2003-11-03 EP EP03779460.9A patent/EP1578223B1/en not_active Expired - Lifetime
  • 2003-11-03 AU AU2003285139A patent/AU2003285139A1/en not_active Abandoned
  • 2003-11-03 WO PCT/US2003/034994 patent/WO2004060096A1/en not_active Ceased
  • 2003-11-03 TR TR2018/02816T patent/TR201802816T4/tr unknown
  • 2003-11-03 MX MXPA05006387A patent/MXPA05006387A/es active IP Right Grant
  • 2003-11-03 KR KR1020057010888A patent/KR20050085651A/ko not_active Withdrawn
  • 2003-11-03 BR BR0317073-0A patent/BR0317073A/pt not_active IP Right Cessation
  • 2003-11-03 CN CN2003801066129A patent/CN1809296B/zh not_active Expired - Fee Related
  • 2003-11-03 RU RU2005115838/12A patent/RU2005115838A/ru not_active Application Discontinuation
  • 2003-11-03 JP JP2004564855A patent/JP4732760B2/ja not_active Expired - Fee Related
  • 2003-12-08 TW TW092134552A patent/TW200508018A/zh unknown
  • 2003-12-15 AR ARP030104623A patent/AR042786A1/es active IP Right Grant
• 2004
  • 2004-02-25 US US10/786,486 patent/US7007351B2/en not_active Expired - Lifetime
• 2010
  • 2010-12-21 JP JP2010284676A patent/JP2011072810A/ja active Pending

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