CPC B29C 43/003 (2013.01) [B29C 44/3453 (2013.01); B29C 44/5636 (2013.01); B29K 2071/12 (2013.01); B29K 2079/085 (2013.01); B29K 2105/0026 (2013.01); B29K 2105/0088 (2013.01); B29K 2105/04 (2013.01); B29K 2995/0012 (2013.01); B29L 2031/3468 (2013.01)] | 15 Claims |
1. A method of foaming and shaping a thermoplastic sheet, comprising:
foaming a thermoplastic sheet with supercritical carbon dioxide to form a foamed thermoplastic sheet; wherein the thermoplastic sheet comprises a thermoplastic composition comprising a poly (phenylene ether), a polyetherimide, or a combination thereof; and wherein the thermoplastic composition is characterized by a glass transition temperature of 20 to 300° C. determined by differential scanning calorimetry according to ASTM D3418-15 at heating rate of 20° C./minute; and
shaping the foamed thermoplastic sheet to form a shaped foamed thermoplastic sheet; wherein the shaping comprises compressing the foamed thermoplastic sheet between a first metal plate and a second metal plate; wherein a surface of the first metal plate and a surface of the second metal plate comprise a plurality of grooves, each groove having a width of 0.1 to 1 millimeter and a depth of 0.1 to 1 millimeter, and each groove being separated from the nearest groove by a center-to-center distance of 0.5 to 5 millimeters; wherein the first metal plate and the second metal plate are connected by a flexible linkage capable of modulating a separation between the first metal plate and the second metal plate; and wherein the compressing the foamed thermoplastic sheet between a first metal plate and a second metal plate comprises controlling a minimum separation of the first metal plate and the second metal plate.
|