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:
Feb. 22, 1994
Filed:
May. 11, 1993
Chung P Park, Pickerington, OH (US);
Kyung W Suh, Granville, OH (US);
The Dow Chemical Company, Midland, MI (US);
Abstract
Disclosed is a process for making closed-cell, alkenyl aromatic polymer foam packing bodies. An alkenyl aromatic polymer material is heated to form a melt polymer material. The melt polymer material comprises greater than 50 percent by weight alkenyl aromatic monomeric units. A blowing agent is incorporated into the melt polymer material at an elevated pressure to form a foamable gel. The blowing agent has about 20 weight percent or more based upon the total weight of the first blowing agent selected from the group consisting of carbon dioxide and ethane. The foamable gel is extruded through a die to form a foam strand. The foam strand is pelletized to form a plurality of foam bodies. The bodies are further expanded by exposing them one or more times to heated air or steam. Preferably, the bodies are allowed to age for a preselected period of time after pelletizing and between subsequent expansions. The use of carbon dioxide and/or ethane as blowing agents allows the reduction or elimination of certain blowing agents classified as volatile organic contaminants, which are currently being employed commercially. Further disclosed is a process for making an article formed from the foam packing bodies. Further disclosed is a process for making discrete foam strands.