Cold runner system
As a cold-channel systems are runners of injection molding referred to, which are maintained at a temperature lower than the mold temperature. They are used for sprueless thermoset and elastomer injection molding . They fulfill the same function as hot runner systems when processing thermoplastics .
If the mass in the sprue was at the same temperature as the tool, the sprue would also crosslink and would have to be separated, the material would be waste. However, if the sprue is kept at a colder temperature, the crosslinking reaction is delayed and the material remains liquid. It is pressed into the cavity during the next injection process and used for the next component. For optimal functionality, the sprue and cavity must be separated by a valve gate system during demolding .
See also
Individual evidence
- ↑ a b Peter Unger (Ed.): Gastrow - injection molding toolmaking in 130 examples . 6th edition. Hanser Verlag, Munich / Vienna 2007, ISBN 978-3-446-40389-5 , chap. 1.2.3 Cold runner systems , p. 10 ( limited preview in Google Book search).