Patent classifications
B29C48/78
High strength biomedical materials
High strength biomedical materials and processes for making the same are disclosed. Included in the disclosure are nanoporous hydrophilic solids that can be extruded with a high aspect ratio to make high strength medical catheters and other devices with lubricious and biocompatible surfaces.
Production of semicrystalline parts from pseudo-amorphous polymers
A method of manufacturing a semi-crystalline article from at least one pseudo-amorphous polymer including a poly aryl ether ketone, such as PEKK, including a softening step, wherein the at least one pseudo-amorphous polymer is heated to a temperature above its glass transition temperature to soften the polymer, and a crystallization step, wherein the at least one pseudo-amorphous polymer is heated to a temperature between its glass transition temperature and melting temperature, the pseudo-amorphous polymer being placed on a mold during either the softening step or the crystallization step before at least some crystallization takes place. The method results in articles demonstrating increased opacity, increased crystallinity, increased thermal resistance, improved chemical resistance, and improved mechanical properties over articles formed by traditional thermoforming processes.
Production of semicrystalline parts from pseudo-amorphous polymers
A method of manufacturing a semi-crystalline article from at least one pseudo-amorphous polymer including a poly aryl ether ketone, such as PEKK, including a softening step, wherein the at least one pseudo-amorphous polymer is heated to a temperature above its glass transition temperature to soften the polymer, and a crystallization step, wherein the at least one pseudo-amorphous polymer is heated to a temperature between its glass transition temperature and melting temperature, the pseudo-amorphous polymer being placed on a mold during either the softening step or the crystallization step before at least some crystallization takes place. The method results in articles demonstrating increased opacity, increased crystallinity, increased thermal resistance, improved chemical resistance, and improved mechanical properties over articles formed by traditional thermoforming processes.
Adhesive articles comprising polylactic acid polymer film and method of making
A method of making an adhesive article is described comprising melt extruding a core film layer comprising a composition comprising at least 50% of a polylactic acid polymer. The method further comprises melt extruding an adhesive layer on a major surface of the core film layer such that regions of interdiffusion are present between the core film layer and adhesive layer. The adhesive layer may comprise C1-C10 (meth)acrylic acid or ester thereof, vinyl acetate, ethylene vinyl acetate, hydrolysed polyvinyl alcohol and combinations thereof. The adhesive layer may also be a pressure sensitive adhesive. The method further comprises melt extruding a release film layer on an opposing major surface of the core film layer. The layers are sequentially extruded or co-extruded and can be uniaxially or biaxially oriented. Articles comprising a core film layer comprising a composition comprising at least 50% of a polylactic acid polymer and an adhesive layer disposed on a major surface of the core layer are also described.
Extrusion device for the processing of plastics, which can be coupled to systems for supplying thermosetting and thermoplastic polymers
A group of hollow modules through which the material to be extruded flows, is provided that includes at least: a rectangular heating-shaping module, in which the material undergoes a temperature increase and takes on the desired shape; and a tubular cooling-solidification module, in which the material changes from liquid to solid. A heating-reaction module is provided upstream of the heating-shaping module. The heating-reaction module includes an interchangeable hollow tube with an external heating system. The heating-shaping module includes detachable parts and includes another external heating system based on the auto-acceleration of the curing reaction and of the heat supply from said external heating system. The tubular portion between the heating-reaction module and the heating-shaping module includes a shaping coupling equipped with a through-hole. The extrusion module includes a circuit through which the polymer flows into at least two push compartments.
Extrusion device for the processing of plastics, which can be coupled to systems for supplying thermosetting and thermoplastic polymers
A group of hollow modules through which the material to be extruded flows, is provided that includes at least: a rectangular heating-shaping module, in which the material undergoes a temperature increase and takes on the desired shape; and a tubular cooling-solidification module, in which the material changes from liquid to solid. A heating-reaction module is provided upstream of the heating-shaping module. The heating-reaction module includes an interchangeable hollow tube with an external heating system. The heating-shaping module includes detachable parts and includes another external heating system based on the auto-acceleration of the curing reaction and of the heat supply from said external heating system. The tubular portion between the heating-reaction module and the heating-shaping module includes a shaping coupling equipped with a through-hole. The extrusion module includes a circuit through which the polymer flows into at least two push compartments.
Ram extruding thin panels of UHMW polymers
A ram extrusion apparatus including a die having several thermal zones, a hopper for introducing a granular polymer resin to the die, and a ram for moving the granular polymer resin through the thermal zones of the die and out from an outlet end thereof at a temperature above the crystalline melt temperature of the polymer resin. The hopper may be designed to deliver the polymer resin into a resin inlet of the die in a plurality of specifically metered amounts which may vary across a width of the resin inlet end of the die. The apparatus may further include one or more finishing tables positioned after the outlet end of the die for receiving and moving the extruded resin away from the outlet end of the die so that there is no backpressure on the extruded resin, and which provide compression force and even cooling to the extruded resin.
Ram extruding thin panels of UHMW polymers
A ram extrusion apparatus including a die having several thermal zones, a hopper for introducing a granular polymer resin to the die, and a ram for moving the granular polymer resin through the thermal zones of the die and out from an outlet end thereof at a temperature above the crystalline melt temperature of the polymer resin. The hopper may be designed to deliver the polymer resin into a resin inlet of the die in a plurality of specifically metered amounts which may vary across a width of the resin inlet end of the die. The apparatus may further include one or more finishing tables positioned after the outlet end of the die for receiving and moving the extruded resin away from the outlet end of the die so that there is no backpressure on the extruded resin, and which provide compression force and even cooling to the extruded resin.
Extruder with feed block for promoting increased mass transport rate
A feeder for an extruder includes a feed flow passage extending in an axial direction from a feeder inlet to a feeder outlet, and an axially extending rotatable screw provided in the feed flow passage. Rotation of the screw draws a feedstock in a direction of flow to the feeder outlet. The feeder inlet has an inlet passage that overlies the screw. The inlet passage has a width in a plane transverse to the axial direction, and the width decreases in the direction of flow.
Extruder with feed block for promoting increased mass transport rate
A feeder for an extruder includes a feed flow passage extending in an axial direction from a feeder inlet to a feeder outlet, and an axially extending rotatable screw provided in the feed flow passage. Rotation of the screw draws a feedstock in a direction of flow to the feeder outlet. The feeder inlet has an inlet passage that overlies the screw. The inlet passage has a width in a plane transverse to the axial direction, and the width decreases in the direction of flow.