Understanding and Resolving Flash in Overmolding
Time of issue:2024-09-14
Title: Understanding and Resolving Flash in Overmolding
What is "flash"? This term originates from Taiwan and is also used elsewhere; in textbooks, it is referred to as "overflow," while commonly it is known as burrs or flash, which often appear at the parting lines, seams, or hole positions of overmolded injection molded products. The main causes of flash are:
1. Mold-related issues: Gaps in the mold's closing surfaces, poor fit or deformation of machine components, or uneven surfaces can all lead to flash formation.
2. Excessive pressure and speed during the injection molding process.
Solutions:
1. Inspect the mold for any foreign objects attached to the parting line that could prevent proper closure; check for damaged components or poor fit, and perform targeted maintenance.
2. Adjust the injection molding process parameters:
a) If the injection pressure is too high, reduce it or switch from injection pressure to holding pressure earlier.
b) Decrease the screw advance time and lower the injection speed.
c) Appropriately reduce the shot volume and lower the melt temperature.
TEL: +86-0752-6768128 FAX: +86-0752-6768088 MAIL: sales@tpe-sp.com WEB: en.tpe-sp.com
ADD: Huangxi Industrial Park, Shiwan Town, Boluo County, Huizhou City, Guangdong Province，China