ULTRASONIC INJECTION MOLDING ON A WEB
First Claim
1. A method of injection molding comprising:
- providing an injection molding apparatus having a first mold member and at least one movable mold member that can move toward and away from the first mold member to close the mold, in which there is a mold cavity, in at least one of the first or movable mold members;
injecting a polymer melt into the mold cavity while it is closed;
applying ultrasonic vibrations to the mold cavity by means of an ultrasonic horn;
which method is characterized by positioning a carrier web so that, when the mold is closed, the carrier web is between the first mold member and the moving mold member, part of the web faces the mold cavity and part of it is outside of the closed mold and steps and conditions selected from;
(1) using a mold cavity having a plurality of microstructural features having an aspect ratio of at least 2;
1 heating the mold cavity by an electromagnetic induction heating means; and
optionally heating the mold cavity by electric resistance heating;
or(2) injecting polymer melt into mold cavities in both the first and movable mold members between which the carrier web is positioned.
2 Assignments
0 Petitions
Accused Products
Abstract
Injection molding, parts onto a carrier web (34) located between mold halves (18,20). Flow of polymer melt into the mold is assisted by application of ultrasonic energy to the mold cavity. After the molding operation, mold halves are separated, and the carrier web is advanced, or indexed, to a next position for another molding sequence. Molding apparatus comprises a moving mold face (20), that can move toward and away from a first mold member (18) (which can be stationary) in which the mold cavity is located, a means (24,25,26,30,32) for moving and/or indexing carrier web between the first mold member and the moving mold face, means (16) to inject polymer melt into the mold cavity, and an ultrasonic system (42) providing ultrasonic energy to the mold cavity. The carrier web can transport molded parts to subsequent process steps, such as coating, drying, inspection, curing, assembly or packaging.
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Citations
22 Claims
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1. A method of injection molding comprising:
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providing an injection molding apparatus having a first mold member and at least one movable mold member that can move toward and away from the first mold member to close the mold, in which there is a mold cavity, in at least one of the first or movable mold members; injecting a polymer melt into the mold cavity while it is closed; applying ultrasonic vibrations to the mold cavity by means of an ultrasonic horn; which method is characterized by positioning a carrier web so that, when the mold is closed, the carrier web is between the first mold member and the moving mold member, part of the web faces the mold cavity and part of it is outside of the closed mold and steps and conditions selected from; (1) using a mold cavity having a plurality of microstructural features having an aspect ratio of at least 2;
1 heating the mold cavity by an electromagnetic induction heating means; and
optionally heating the mold cavity by electric resistance heating;
or(2) injecting polymer melt into mold cavities in both the first and movable mold members between which the carrier web is positioned. - View Dependent Claims (2, 3, 4, 5, 6, 9, 10, 11, 12, 14, 15)
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7-8. -8. (canceled)
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13. (canceled)
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16. An injection molding apparatus comprising:
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a first mold member; a moving mold member that can move toward and away from the first mold member; a mold cavity within the first mold member and facing the moving mold member; a web handling means for moving a carrier web between the first mold member and the moving mold member so that part of the carrier web faces the mold cavity and part of the carrier web is outside of the area enclosed by the first and moving mold members when they are in the closed position; a means to inject melt into the mold cavity; and an ultrasonic system for providing ultrasonic vibrations to the melt in the mold cavity; characterized by further comprising; A. a web indexing means to index the carrier web to a different position along its length each time the moving mold member moves toward the first mold member to close the mold; and B. an electromagnetic induction heater capable of heating a mold insert within the mold cavity and/or metal surrounding the mold cavity. - View Dependent Claims (17, 18, 19, 20)
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21. An article comprising the combination of a carrier web and an array of molded articles adhered to the carrier web which articles are characterized by microstructural features having an aspect ratio of at least 2:
- 1 said array comprising columns of molded articles aligned in the down-web direction and rows in the cross-web direction and in which array the closest center-to-center, or edge-to-edge, distance between the molded articles is closer than the diagonal center-to-center, or edge-to-edge, distance between a molded article and another molded article in the next adjacent row and next adjacent column.
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22. A microneedle array made of polymeric material comprising a plurality of microneedles having a height of 20 to 1000 micrometers and an aspect ratio greater than 2:
- 1 on a land characterized by at least 60 percent of the microneedles across the array being filled.
Specification