Stable foil for container and pipe lining - contg. PVC powder added to rubber, resin, plasticiser and stabiliser pre-mix before vulcaniser addn.

摘要

A chemically stable foil compsn. is made by (a) kneading a pre-mix of rubber chips, liq. resins, plasticisers and stabilisers and letting the pre-mix, leaving the kneader at >100 degrees C, to cool to room temp. in 18-20 hrs.; (b) admixing 1 pt. PVC powder for each 2 pts. rubber chips, on a mixer, while heating to 70 degrees C; (c) cooling to room temp. in 8-12 hrs. and (d) mixing with vulcanisers, in kneader, while heating to 70 degrees C and (e) calendering to a foil or injection-moulding. The foil is used for lining containers and pipes. PVC powder addn. improves stability against oxidising acids. Intermediate cooling steps and tempering before vulcaniser addn. prevent foil shrinkage before vulcanisation.