Case Study: Cryogenic Deflashing for Rubber Grommets

Nitrofreeze® Cryogenic Deflashing provides part molders and OEMs with a fast, consistent way to remove flash from rubber components including natural rubber, silicones, EPDM, Polyurethane, Neoprene, Viton, Vamac,butylrubber, and more . Cryogenic deflashing uses gaseous nitrogen to freeze the parts, and plastic media to break-off the surface imperfections and excess material. This safe, clean process is also cost-effective because it supports batch processing. The report below examines a real EPDM job processed with Nitrofreeze® Cryogenic Deflashing:

Material : Silicone   Description : Distal Handle    Area for Concern : OD Parting Lines

The Challenge
Nitrofreeze was asked to remove flash from 50-durometer EPDM grommets that protect runs of wire. These low-cost rubber products have delicate, cone-shaped features and may be inserted into openings in panels or other surfaces. EPDM is a good choice for grommets because this material resists indoor and outdoor environments, provides electrical insulation, and is extremely resistant to wear.

Mold flash is typical, but part defects that can affect performance must be removed. To meet the application’s requirements, Nitrofreeze needed to remove excess material from critical inner diameter (ID) holes to support the smooth feeding of wires. Nitrofreeze also needed to remove outer diameter (OD) flash that could distort the part’s cone-shaped features.

The Solution
Nitrofreeze used cryogenic deflashing to remove both ID flash and OD flash. First, the rubber grommets were cooled to cryogenic temperature so that the flash became brittle and easy-to-break. The parts were then tumbled and blasted with polycarbonate media. Manual trimming, the customer’s previous process, had been effective for OD flash but unsatisfactory for critical ID holes.

Cryogenic deflashing is a computer-controlled process that provides repeatable, reliable results. It’s more economical than manual deflashing and can extend the life of worn molds that would be expensive to replace. With cryogenic deflashing, no job is too large or too small for parts that have been injection molded, extrusion molded, or compression molded.

The Result
As the image that accompanies this case study shows, Nitrofreeze used cryogenic deflashing to remove unwanted material while protecting the surface finish and critical dimensions. Process development during sampling ensured that deflashing would maintain the part’s cone-shaped features. Cryogenic deflashing is ideal for EDPM rubber but can also be used with plastic and silicone materials.

Learn More
Contact one of our product experts today to discuss your deflashing requirements. If the part is deemed a viable candidate for the Nitrofreeze® Deflashing process, sampling can be performed to prove out the concept. A consultation is free of charge, so we encourage you to contact us today. To learn more, contact Nitrofreeze at the phone number or email listed below:

(508)459-7447 x105