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.
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