Calendering safety

The importance of scorch control cannot be overemphasized. Present-day tire plants could not compete without good control of scorch resistance or processing safety as it is commonly called. Such safety is necessary in order to rapidly process rubber mixes at high temperatures (through extrusion, calendering, etc.) into preforms for molding (e.g., tire components). 

Poly(vinyl butyral) used in safety glass generally has 78—80% butyral content, 18-19% hydroxy content and less than 2% acetate content. For this application the polymer is plasticized with an ester such as dibutyl sebacate to the extent of about 30 parts of plasticizer per 100 parts of polymer the compound is then sheeted by calendering. To produce safety glass, the sheet is placed between two pieces of glass and the laminate is then bonded under heat and pressure. 

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