Continuous molding of fastener products

An apparatus for continuously molding a fastener product having a wide array of fastener elements in multiple rows extending from a common continuous, strip-form base, the apparatus comprising

• first and second rolls;
• a mold belt defining an array of cavities extending from an outer surface thereof in at least three rows, the mold belt trained about both the first and second rolls;
• a source of molten plastic resin arranged to deliver resin to the outer surface of the mold belt, the apparatus constructed to force the plastic resin into the cavities of the belt under pressure to fill the cavities to mold the array of fastener elements in multiple rows as the common continuous base of the product is formed on the outer surface of the mold belt;
• and
• means for cooling the resin in the cavities of the belt to solidify the resin while on the belt;
• and
• means for stripping the cooled resin from the belt, the fastener elements pulled complete from the belt cavities,
• wherein each cavity includes a stem-forming portion extending inwardly from the outer surface, and a head-forming portion at an inner end of the stem-forming portion, the head-forming portion shaped to form a fastener element head of greater lateral extent than the stem-forming portion and multiple, discrete projections extending from the head along different lateral axes.

A method of continuously forming a fastener product having an array of fastener elements extending from a continuous, sheet-form base, the method comprising

• providing a continuous mold substrate defining an array of holes extending completely through the substrate from an outer surface of the substrate to an inner surface of the substrate, the holes each forming a mold cavity for molding a discrete fastener element extending from a base formed on the outer surface of the substrate, each cavity including a stem-forming portion extending inwardly from the outer surface, and a head-forming portion at an inner end of the stem-forming portion, the head-forming portion shaped to form a fastener element head of greater lateral extent than the stem-forming portion and, extending from the head in multiple directions, discrete projections for snagging fibers;
• introducing molten plastic resin to the outer surface of the mold substrate;
• forcing the plastic resin into the cavities under pressure in a gap to fill the cavities while forming the sheet-form base of the product on the outer surface of the mold substrate;
• solidifying the resin as the resin is carried on the mold substrate;
• and then
• stripping the solidified resin from the mold substrate.

An apparatus for continuously molding a fastener product having an array of fastener elements integrally molded with and extending from a continuous strip form base, the apparatus comprising

• a continuous mold substrate cyclable through a pressure region, the mold substrate defining an array of holes extending completely through the substrate from an outer surface of the substrate to an inner surface of the substrate, the holes each forming a mold cavity for molding a discrete fastener element extending from a base formed on the outer surface of the substrate, each cavity including a stem-forming portion extending inwardly from the outer surface, and a head-forming portion at an inner end of the stem-forming portion, the head-forming portion shaped to form a fastener element head of greater lateral extent than the stem-forming portion and, extending from the head in multiple directions, discrete projections for snagging fibers;
• a source of molten resin positioned to direct molten resin onto the outer surface of the substrate and into the pressure region, where the molten resin is forced into the head-forming portions of the cavities through their respective stem-forming portions, to form the fastener elements;
• and
• a fastener product stripper positioned downstream of the molten resin source and adapted to strip the molded fastener product from the mold substrate.

A method of continuously forming a fastener product having an array of fastener elements extending from a continuous, sheet-form base, the method comprising

• providing a continuous mold substrate defining an array of holes extending inwardly from an outer surface of the substrate, the holes each forming a mold cavity for molding a discrete fastener element extending from a base formed on the outer surface of the substrate, each cavity including a stem-forming portion extending inwardly from the outer surface, and a head-forming portion at an inner end of the stem-forming portion, the head-forming portion bounded by a substantially flat surface distal from the outer surface of the substrate and shaped to form a fastener element head of greater lateral extent than the stem-forming portion and, extending from the head in multiple directions, discrete projections for snagging fibers;
• introducing molten plastic resin to the outer surface of the mold substrate;
• forcing the plastic resin into the cavities under pressure in a gap to fill the cavities while forming the sheet-form base of the product of the outer surface of the mold substrate;
• solidifying the resin as the resin is carried on the mold substrate;
• and then
• stripping the solidified resin from the mold substrate.

A method of continuously forming a fastener product having an array of fastener elements extending from a continuous, sheet-form base, the method comprising

• providing a continuous mold substrate having layers of first and second materials and defining an array of holes extending upwardly from an outer surface of the substrate, the holes each forming a mold cavity for molding a discrete fastener element extending from a base formed on the outer surface of the substrate, each cavity including a stem-forming portion defining in the layer of first material and extending inwardly from the outer surface, and a head-forming a portion defined in the layer of second material at an inner end of the stem-forming portion, the head-forming portion shaped to form a fastener element head of greater lateral extent than the stem-forming portion and, extending from the head in multiple directions, discrete projections for snagging fibers;
• introducing molten plastic resin to the outer surface of the mold substrate;
• forcing the plastic resin into the cavities under pressure in a gap to fill the cavities while forming the sheet-form base of the product on the outer surface of the mold substrate;
• solidifying the resin as the resin is carried on the mold substrate;
• and then
• stripping the solidified resin from the mold substrate.

An apparatus for continuously molding a fastener product having an array of fastener elements integrally molded with and extending from a continuous, strip-form base, the apparatus comprising

• first and second rolls;
• a flexible mold belt defining an array of fastener element-shaped cavities extending from an outer surface thereof, the mold belt trained about both said rolls;
• and
• a source of molten plastic resin arranged to deliver resin to the mold belt, the apparatus constructed to force the plastic resin into the fastener element shaped cavities of the belt under pressure in a gap to mold the array of fastener elements while forming the strip-form base of the product, wherein each cavity includes a stem-forming portion extending inwardly from the outer surface, and a head-forming portion at an inner end of the stem-forming portion, the head-forming portion shaped to form a fastener element head of greater lateral extent than the stem-forming portion and multiple, discrete projections extending from the head along different lateral axes, and wherein the mold belt consists essentially of metal, the fastener element-shaped cavities comprising holes extending through the mold belt between two opposite broad sides thereof.

An apparatus for continuously molding a fastener product having a wide array of fastener elements extending from a continuous, strip-form base, the apparatus comprising

• first and second rolls;
• a mold belt defining an array of cavities extending from an outer surface thereof in at least three rows, the mold belt trained about both the first and second rolls;
• a source of molten plastic resin arranged to deliver resin to the outer surface of the mold belt, the apparatus constructed to force the plastic resin into the cavities of the belt under pressure to fill the cavities as the continuous base of the product is formed on the outer surface of the mold belt;
• and
• means for cooling the resin in the cavities of the belt to solidify the resin while on the belt;
• and
• means for stripping the cooled resin from the belt, the fastener elements pulled complete from the belt cavities, wherein each cavity includes a stem-forming portion extending inwardly from the outer surface, and a head-forming portion at an inner end of the stem-forming portion, the head-forming portion shaped to form a fastener element head of greater lateral extent than the stem-forming portion and multiple, discrete projections extending from the head along different lateral axes, and wherein the stripping means comprises an array of projections extending radially from a peripheral surface of the second roll, the second roll also having an array of pins extending radially therefrom for engaging a row of holes in the mold belt to align the cavities of the mold belt with the projections, the projections adapted to push the cooled fastener elements from the cavities of the mold belt.