Injection Molding: Check Ring Resists Corrosive Flame-Retardant Additives
Zeiger Industries’ new nonreturn valve lasts 85 times longer in molding test with nonhalogen flame retardant.
At the recent K 2019 show in Germany, Zeiger Industries exhibited a new nonreturn check-ring valve assembly with a solid tungsten carbide ring, designed to resist the corrosive effects of halogen-free flame retardants (HFFR) used in plastics resins today. The rear seat of the check-ring valve is a steel with 20% chrome matrix, while the tip is coated with 1 mm of tungsten carbide. According to Stan Glover, director of technical sales, the new check-ring assembly showed no corrosion after 680 hr in molding tests, while standard powder-metallurgy (PM) stainless steel showed damage after 8 hr.

Zeiger’s new nonreturn valve check-ring assembly resists corrosion from currently popular HFFR additives.
Related Content
-
Back to Basics on Mold Venting (Part 2: Shape, Dimensions, Details)
Here’s how to get the most out of your stationary mold vents.
-
Optimizing Pack & Hold Times for Hot-Runner & Valve-Gated Molds
Using scientific procedures will help you put an end to all that time-consuming trial and error. Part 1 of 2.
-
A Systematic Approach to Process Development
The path to a no-baby-sitting injection molding process is paved with data and can be found by following certain steps.