Two-Color LSR Molding Fine-Tuned with Flow Simulation
CAE simulation software provider Sigma Plastic Services is demonstrating an unusual two-color LSR molding application. Egg cups of white and yellow LSR are run in a 4 + 4 cavity Elmet mold using that company’s new TOP5000 dosing system. Its closed-loop controls document the real amount of colorant used, which is particularly relevant to the healthcare industry. Especially remarkable is the special hardware system that allows two-component molding on a standard one-component Arburg injection press with only one LSR dosing system.
In this project, Sigma used its Sigmasoft Virtual Molding software to determine the filling time, injection pressure needed, and selection of the optimal LSR material grades from Momentive. Sigma’s highly developed LSR simulation can show such details as air temperature at the vents, formation of flow lines during fill, and percent cure to indicate when parts can be ejected.
Producing plastics parts with undercuts presents distinct challenges for molders.
Weld or knit lines are perhaps the most common and difficult injection molding defect to eliminate.
First find out if they are the result of trapped gas or a vacuum void. Then follow these steps to get rid of them.