Nitrofreeze® cryogenic deflashing is a quick and cost-effective way to remove flash from silicone molded parts. Flash is usually a cosmetic defect, but it can interfere with seating or sealing in medical devices, aerospace assemblies, and other products that contain molded silicone parts. Companies that provide injection molding, compression molding, or transfer molding services also want to avoid visible defects that suggest poor part quality.
Manual Silicone Deflashing vs. Nitrofreeze® Cryogenic Deflashing
Silicone mold flash can be removed by hand, but manual deflashing is labor-intensive and time-consuming. Hand trimming is also inconsistent since different workers may achieve different results. There’s also a risk of removing too much or too little material. By contrast, Nitrofreeze® cryogenic deflashing is an automated, computer-controlled process that provides consistent, high-quality results for batches of parts. Our patented process removes surface flash but can also access intricate features and complex geometries that are hard-to-reach with hand tools.
Nitrofreeze® cryogenic deflashing begins when batches of molded parts are put in a perforated drum and subjected to very low temperatures. These cold temperatures result in silicone becoming hard and brittle like glass. In turn, this embrittlement allows the cryogenic-grade polycarbonate media that Nitrofreeze® uses to remove the flash. Importantly, our process won’t affect critical tolerances or surface finish. Only the flash is removed.
This YouTube video shows how Nitrofreeze® cryogenic deflashing works.
Types of Silicone Materials
Silicones are a polymer composed of repeating units of siloxane that combine broad temperature resistance with good chemical resistance and dimensional stability. There are four basic types of silicone materials, each of which Nitrofreeze® cryogenic deflashing can deflash.
- Room temperature vulcanizing (RTV) silicones cure at room temperature with minimal shrinking. They’re often used to produce silicone molds.
- Liquid silicone rubber (LSR) cures into a flexible elastomer and can produce injection molded parts with intricate and complex shapes. Examples include catheters and inhalers.
- High consistency rubber (HCR) has a thick, putty-like consistency and can be compression molded or transfer molded into gaskets or O-rings.
- Fluorosilicones provide expanded resistance to fuels, chemicals, and oils. Like HCR, they can be compression molded or transfer molded.
Deflashing Silicone Molded Parts
Nitrofreeze® has used cryogenic deflashing on many different types of molded silicone parts, including blocks and bumper stops, distal handles, O-rings, gaskets, housings, overmolded springs, and electrical grommets. Proof-of-concept case studies are available on our website, and the following sections provide an overview of some of the cryogenic deflashing work we’ve performed.
Silicone Blocks and Bumper Stops
Nitrofreeze® cryogenic deflashing removed mold flash from silicone bumpers stops that were gray in color and rectangular in shape. Block-shaped silicone implants are used in surgical applications. In building and construction, silicone blocks provides an alternative to mortar. Nitrofreeze® used cryogenic deflashing remove both outer diameter (OD) flash and inner diameter (ID) flash.
Silicone Distal Handles
Nitrofreeze® cryogenic deflashing removed mold flash from silicone distal handles that are used with handheld instruments. The silicone molder had tried buffing and trimming, but these manual methods were becoming too labor-intensive. Nitrofreeze® cryogenic deflashing saved over 6 hours of deflashing labor for every 1,000 pieces. Typical volumes were 3,000 to 4,000 parts per release.
Silicone O-Rings and Gaskets
Nitrofreeze® cryogenic deflashing removed mold flash from a 1.50” OD silicone O-ring for the oil and gas industry. Quality assurance demonstrated that our process achieved the required tolerance of 0.005” while removing both OD and ID flash. Nitrofreeze® cryogenic deburring has also been used with both round silicone gaskets and square silicone gaskets.
Silicone Housings, Overmolded Springs, and Electrical Grommets
Nitrofreeze® cryogenic deburring eliminated mold flash from silicone housings made of 60 durometer (Shore A) LSR. The part measured 1 cubic inch and had flash that was 0.005” thick and extended 0.200”. Lot sizes averaged 2,000 pieces per week. For both the silicone overmolded springs and the 60-durometer silicone electrical grommets, our process also meet all requirements.
Choose Nitrofreeze® Cryogenic Deflashing Silicone Molded Parts
Do you need a fast, efficient, and cost-effective way to remove flash from molded silicone parts? Contact the experts at Nitrofreeze® to discuss your requirements. No job is too large or too small, and our standard turnaround time is two days after receipt.
If your part is a viable candidate for cryogenic deflashing, we can perform sampling to demonstrate our process. The consultation is free of charge, so send us your part drawings, photos, or actual samples of molded silicone parts.
To get started, contact Nitrofreeze® at the phone number and email listed below.
(508) 459-7447 x 105 | info@nitrofreeze.com