The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 09, 1990
Filed:
Jul. 05, 1988
Klaus-Dieter Kolossow, Hambuhren, DE;
Hermann Berstorff Maschinenbau GmbH, Hanover, DE;
Abstract
A method and apparatus are provided for producing a mixture of plastics materials which are capable of being foamed with propellants. The method permits plastics materials, which require considerably different processing conditions, to be fused, homogenized and mixed with a propellant in an extruder. By feeding a high-molecular weight high-temperature resistant plastics material into the extruder through a first feed opening and subsequently feeding a low-molecular weight, low-temperature-resistant plastics material into the extruder through a second feed opening disposed downstream of the first feed opening but where the first plastics material is in a fused and homogeneous state and by introducing the propellant through a third feed opening downstream of the second feed opening, the desired homogenisation of the two plastics materials and propellant is ensured.