Other

Polymer Processing Institute

Apv Chemical Machinery, Inc.

David B Todd

Joseph A Biesenberger

Costas George Gogos

Subir K Dey

Demosthenis Chaparampopoulos

A rheometer and method for determining rheological characteristics of a composition, the rheometer including: a housing member; a helical flange disposed on an inner surface of the housing member; a rotor disposed concentrically within the helical flange and abutting the helical flange while maintaining sliding contact with the flange, wherein the rotor and the helical flange form a helical channel; a mechanism for rotating the rotor; a mechanism for introducing a sample of the composition into one end of the channel; a mechanism for controlling removal of the sample from the other end of the channel; and a mechanism for measuring a pressure difference of the sample between an upstream location and a downstream location in the channel.

Helical barrel rheometer

Thermoplastic foams are provided by a process in which a gaseous blowing agent of nitrogen, air, carbon dioxide, argon or mixtures thereof is injected into a melted thermoplastic polymer and the pressure is used to form a solution of the blowing agent and the melted polymer. The solution is cooled to a temperature which is within 10.degree. C. of the polymer freezing point while the pressure is held to a point within which both of the following conditions exist: A) the pressure must be high enough to keep the gas blowing agent in the solution with the melt, and B) the pressure must be low enough to avoid adding more heat to the solution. Just before the cooled solution is extruded, it is important to have the solution at a temperature which is sufficiently uniform to make: A) the thermoplastic foam at least about 65% by volume in closed cells, and B) a substantially uniform cell size in the product. The cooled solution is then extruded out of an extruder die to where the pressure drop across the die is in the range of from about 70 to about 90% of the pressure in the extruder so that a cellular product is formed.

Method of preparing thermoplastic foams using a gaseous blowing agent

A back mix, drag-flow apparatus that provides both radial and axial mixing of materials comprising at least two worms in screw form and parallel and tangential to one another that are of opposite hands and are rotatable only in the same direction or are of the same hand and are rotatable only in opposite directions; and a barrel casing completely enclosing said worms and containing a feed inlet and a product outlet.

Back mix drag-flow apparatus

A continuous, self-wiping, multiple parallel shaft processing and/or extruding system wherein material is charged to a barrel in which the shafts extend at one end and discharged at another. The barrel has an interior chamber defined by parallel intersecting cylinders providing generally V-shaped saddles at their confluence, and parallel shaft rotate within the cylinders at the same speed of rotation and in the same direction of rotation Radially co-wiping helical processing elements are fixed respectively on the shafts and are configured to also wipe the walls of said cylinders. A vent for egressing volatiles leads from the chamber, and a vent bypass passage has a first section leading from the chamber upstream from the vent, a midsection extending coextensively with the chamber within the barrel, and a return section returning to the chamber. The helical processing elements including forwardly pitched elements for moving material in the chamber toward the vent and reversely pitched helical elements immediately upstream from the vent.

Devolatilizing and/or processing systems and methods

An art form where earth in powdered form from specific locations--earth from a country, states, counties, a person's yard or other locations with sample records maintained is, after being heat sterilized sized to designate size range limits, and then embedded within plastic and formed to the desired shape. The shape may be a micro-dot insertable in commemorative coins or utilized in jewelry of all sizes and shapes or molded into a whole range of jewelry shapes and sizes. The plastic may be a thermo softening and setting plastic, a chemical reactive setting plastic or even a thermo setting resin such as an epoxy resin into which some of the desired powdered earth is entrained.

Growing community of inventors

Princeton, NJ, United States of America

David B Todd