Troubleshooting Focus: Sprue Sticking

Material sticking can bring processing to a standstill, regardless of its source. When troubleshooting, keep in mind that the location of a sticky part in the mold is not necessarily the area of the mold that is the cause. Different sections of the mold can hang onto the part and exerted force can cause the part to bind in another section. Carefully evaluate what happens as the mold opens with special attention to four possible causes for sticking at the sprue.

Sprue sticking

 

TMI TIP: Proper cooling is well worth the wait when processing copolyesters. Their relatively low flexural modulus gives copolyesters a greater ability to flex and rebound. Allowing the skin to freeze is the best way to ensure optimum results, with less chance of sprue sticking. For more information, check out the August 17 blog or watch the webinar Copolyester Processing Solutions


If you have more questions about sprue sticking, talk with your Eastman technical service representative and ask for a free copy of our Injection Molding Troubleshooting Guide