For design and processing of Liquid Silicone Rubber (LSR) parts, in the silicone injection molding vulcanization process, the curing and respective flow behavior must be known. The two components begin to cure immediately after mixing. During curing the chemical bonds formed release heat which causes a temperature rise. Increasing the temperature of the resin decreases the viscosity, allowing better mold flow and exhaustion of air bubbles.
Abrasion: the process of scraping or wearing away.
An informative presentation of the silicone liquid rubber curing incorporating the degree of cure is the Time-Temperature-Transformation (TTT) diagram, developed by Enns and Gillham. It can be used to relate the material properties of thermosets, such as Silicone Liquid Rubber (LSR), as a function of time and processing temperature. The diagram visually presents various lines representing constant degrees of cure. The curve labeled c=,c-g. represents the gel point and c=1 represents the fully cured resin.
Professor Tim A. Osswald, Director of SIMTEC Silicone Parts’ Technical Advisory Board will be one of the prestigious speakers presenting at this year’s Silicone Elastomers US 2011 event. Held at the Hyatt Rosemont Hotel in Rosemont, IL, Professor Osswald will be discussing the viscoelastic behavior of Liquid Silicone Rubber (LSR) at 11:45 CST, Wednesday, December 7th 2011.
Two shot (2K) injection thermoplastic molding dates back several decades, from the multicolor molding of typewriter keys (to produce permanent characters on the keys), to the integration of the multiple parts that make up a car’s headlights. This process has since advanced to allow for the consistent and cost-effective manufacture of multicolor/multifunction thermoplastic/thermoset products for a variety of innovative applications. SIMTEC Silicone Parts prides itself in being at the forefront of two shot LSR/Thermoplastic technology.