Preparation of Foamed Composites

A typical example of a monoaxially reinforced foamed composite is that developed by Sekisui Chem. Co., Ltd., Japan. Eslon Nro-Liunber FFU has this structure (22). Its production process has not been disclosed. An example of a two-dimensionally reinforced foamed composite was developed by Nisshinbo Ind. Inc., Japan. The production process employed was the compression-molding process (2). The structure of the 

FRU-L after a sheet of glass-fiber continuous-strand mat was placed in an open mold, the prescribed amount of PUF solution, prepared by hand mixing was poured into the mold and the contents were pressed to the fixed thickness (3 mm). 

FRU-M the prescribed amount of chopped glass strand (13 mm in length) was mixed with the prescribed amount of isocyanate-component and thoroughly dispersed before the addition of the polyol component. Then the following operations were carried out according to the procedure of FRU-L without strand mat. 

FRU-S Every operation was carried out according to the FRU-M using chopped -glass strand 3 mm in length instead of 13 mm. The physical properties of these foams wiU be discussed later. 

Another example of the two-dimensionally reinforced foamed composite was developed by Celotex Corp., USA. The production process consists of the use of continuous-glass-strand mat and a horizontal conveyer process. Continuous-strand mat is supplied on a moving horizontal conveyer. The foaming mixture is then applied onto the glass mat through the mixing head of a dispensing machine (35). 

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