Leesona Corporation

Christopher G Bradbury

Gomer E Kropa

Walter Buchan

Edward J Winiarski

Joseph Paul Wudyka

Stanley Thomas Gotham

An extrusion process is disclosed wherein coolant under pressure is directed against the outer surface of a thermoplastic material being forced through an extrusion orifice such that at least a portion of the coolant immediately vaporizes and the resultant heat of vaporization required for such action is taken from the material immediately contacting such. The coolant is introduced into an intermediate zone downstream from an initial extrusion zone and the interface between such zones is insulated so as to restrict conductive heat transfer between such zones immediately adjacent thereto so as to prevent possible freeze ups of said material in the initial extrusion zone.

Extrusion process

An improved method and apparatus for shaping sheets of thermoplastic material is disclosed in which sheets are pressure molded against a mold member by the direct application of a liquid coolant under pressure thereto. The coolant contacts the surface of the sheet and upon pressure reduction vaporizes and accordingly, due to the heat of vaporization effect, rapidly absorbs a large amount of heat from the sheet so as to form a solidified skin on the outer surface of the sheet after or simultaneously with the shaping of said sheet. The sheet thus remains in the mold for a shorter dwell time inasmuch as the sheet becomes more quickly shape retentive because of the rapid cooling. This accordingly permits smaller and less bulky equipment to be utilized in sheet shaping processes. The attendant reduction in equipment size can result in substantial cost savings for such equipment.

Sheet shaping method

A pellet cooling system including a novel coolant cage construction and operational manner so as to insure the cooling of warm thermoplastic pellets as they emerge from a die head and are cut by rotating knives is disclosed. After cooling, as by entrainment in coolant flows simultaneously directed peripherally about the cage sides and radially across the front face thereof, the pellets are immediately withdrawn from the cage. Additionally, a feature of the coolant cage is the provision of a novel slinger for distributing a coolant flow evenly over its front face.

Method of cooling pellets

Pellet cooling system

A system for size reduction and separation of plastic-metal assemblies for the purpose of reclaiming the plastic and/or metal for reuse. The system includes a granulator followed by a fiber/dust separator with these components preferably being repeated, followed by a screening separator, and finally a hightension separator for separating plastic and metal. The system particularly incorporates an impact-counterflow separator for removing fiber/dust from heavier plastic and metallic particles.

Growing community of inventors

Rumford, RI, United States of America

Christopher G Bradbury