Sensor film reveals flash to reduce defects in plastics molding

10-Aug-10

Staying abreast of technology and exhibiting discipline in production operations are key to keeping molding plants and services internationally competitive, according to plastics consultant John Bozzelli, of Scientific Molding. According to Bozzelli, processes need to be developed based on plastic variables that enable identical parts to be formed consistently. A tool that supports this because it eliminates “flash” which causes excess material is Pressurex® pressure indicating sensor film. To detect and correct flash, the flexible sensor film, which measures surface contact pressures from 2 - 43,200 PSI (0.14 – 3,000 kg/cm2), is placed around the parting line of a mold that is subjected to pressure. The clamp pressure is then reduced to as low as possible on the machine to prevent tool damage, and the sensor film is clamped up. The mold is then opened and the film checked for color variations along the parting line. Pressurex® is used by plastics processors for quality control to check the mold prior to injection molding. The color the film turns is directly proportional to the amount of pressure applied. It is an alternative to bluing agents which does not show pressure distribution with the same precision and are messy to handle.