Coating former with blood compatible elastomer film - by dipping in elastomer soln. and removing using control circuit

摘要

A former is coated with polymer, partic. with an elastomer compatible with blood, by dipping in liquid polymer (e.g. soln. in volatile solvent, polymer melt, or pure polymer plus cross-linking agent) to obtain a coating of desired thickness. The process is pref. effected mechanically so that the surface of the liquid elastomer passes over the former surface at constant speed, the coated article is held so that the liquid drains off under gravity to give the desired coating thickness distribution, and this distribution is maintained during the final drying stage. Pre-selected coating distribution is obtd. accurately and consistently; process is suitable for making e.g. blood pump diaphragm. The apparatus has a pump for a cylinder and plunger to move the container for the polymer liquid at a speed controlled by a DC motor and regulator.