Dupont Canada Inc.

Du Pont of Canada Limited

Eldon Lawrence Fletcher

Anthony Joseph Cesaroni

Tiong Hap Kho

Rodney Martin

David H Dawes

An apparatus and method for making thermotropic liquid crystalline polymer films with improved transverse direction properties comprises two preferably embossed rollers which oscillate oppositely with respect to each along their respective rotational axes. Film made by passing a liquid crystalline polymer between such rolls has improved transverse direction properties. Such films are useful in multilayer containers and for circuit boards.

Manufacture of liquid crystalline polymer films

A process and the product thereof, wherein thermoplastic tubing for use in a heat exchanger is extruded with a multifilament yarn inside to act as a turbulator. The extrusion is started with a small rod or a lead-in wire pushing the end of the yarn through the die into the tubing to a place where it adheres to the inner wall of the tubing as it is cooling, then the yarn is pulled into the tubing as it is extruded. The part of the tubing with the lead-in wire is cut off, leaving tubing with efficient turbulation.

Heat exchanger tubing with yarn turbulator

A method for making thermotropic liquid crystalline polymer films with improved transverse direction properties comprises two preferably embossed rollers which oscillate oppositely with respect to each along their respective rotational axes. Film made by passing a liquid crystalline polymer between such rolls has improved transverse direction properties. Such films are useful in multilayer containers and for circuit boards.

Method for manufacture of liquid crystalline polymer films

A method for making multilayer polymer films with involves the use of preferably embossed rollers which oscillate oppositely with respect to each along their respective rotational axis. Multilayer film is made by passing two or more molten thermoplastic films through the nip of these rollers, thereby laminating the individual films together. The method is particularly useful for improving the adhesion between film layers, and/or when at least one of the layer is a liquid crystalline polymer. Such films are useful in packaging, multilayer containers and for circuit boards.

Manufacture of multilayer polymer films

A heat exchanger, especially a heat exchanger in the form of a comfort heat exchanger, includes two manifold elements adapted to receive and discharge fluid, and a plurality of tube units transversely located between the manifolds, each tube unit being integrally connected to substantially rigid end elements that fit into the manifolds. The tubes are preferably oriented and expanded to about their original diameter. The heat exchanger is intended to be fabricated from polymer, especially polyamide compositions. The tube units are intended to be manufactured using injection moulding techniques, and then subjected to orientation and expansion steps. Parts fabricated during manufacture of the heat exchangers are also included. The heat exchangers are particularly intended for use as comfort heat exchangers in automobiles.

Method for the manufacture of a comfort heat exchanger

A panel heat exchanger formed from two sheets of thermoplastic polymer is disclosed. Each sheet has a thickness of 0.07-0.7 mm and a plurality of grooves extending at least partially across the width of the sheet. Each sheet has a recess located at at least one end. The sheets are superimposed in face to face relationship and bonded together in a fluid tight bond such that (i) the recesses form portions of inlet and outlet header means at opposite ends of the panel, and (ii) the grooves form a plurality of fluid-flow channels between the inlet and outlet header means. The end of each groove of one sheet of the panel heat exchanger overlays the end of a groove of the other sheet. The panel heat exchangers are readily fabricated by simple means, preferably from polyamide compositions. The heat exchangers may be used in a variety of end-uses, including automotive oil coolers, automotive comfort heaters, refrigerators and industrial uses.

Panel heat exchangers formed from thermoplastic polymers

A heat exchanger, especially a heat exchanger in the form of a comfort heat exchanger, is disclosed. The heat exchanger is comprised of two manifold elements adapted to receive and discharge fluid, and a plurality of tube units transversely located between the manifolds, each tube unit being integrally connected to substantially rigid end elements that fit into the manifolds. The tubes are preferably oriented and expanded to about their original diameter. The heat exchanger is intended to be fabricated from polymer, especially polyamide compositions. The tube units are intended to be manufactured using injection moulding techniques, and then subjected to orientation and expansion steps. Parts fabricated during manufacture of the heat exchangers are also disclosed. The heat exchangers are particularly intended for use as comfort heat exchangers in automobiles.

Comfort heat exchanger

The present invention provides a method for heating food comprising heating in a microwave oven for at least 2 minutes a food package which comprises food placed in an injection moulded food container, made from a partially crystalline polyamide, optionally containing a compatibilized olefin-based polymer and/or a filler. The food container has wall and floor thicknesses of 1.6 mm or less.

Method for microwave cooking of foods

An aquatic weed barrier is disclosed which comprises a film having a plurality of incisions therein. Each incision is shaped to form at least one flap adjacent the incision. The film has a light transmittance of less than 50% in the 200 to 650 nm wavelength range.

Aquatic weed barrier

An apparatus is disclosed for lagging (in-process storing) packages of textile yarn on wheeled buggies. At least one storage lane for textile yarn buggies is provided and a plurality of wheeled textile yarn buggies with connecting hooks having depending tail portions for joining the buggies together as a train are positioned in the storage lane. Air switch pads are provided at the exit from the storage lane for detecting the presence of a buggy. A driven chain with lugs thereon for moving the train of buggies forward one buggy length and then engaging the depending portion of the hooks for disconnecting the buggy nearest the exit from the remainder of the train is actuated by a signal from the air switch pads each time the air switch pads fail to detect the presence of a buggy.

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Kingston, Canada

Eldon Lawrence Fletcher