overmolded electrical connectors

Cryogenic Deflashing for Overmolded Electrical Connectors


Deflashing for Overmolded Connectors

Nitrofreeze provides deflashing services and equipment for overmolded electrical connectors. Overmolded electrical connectors protect wires, cables, sockets and other electrically conductive components against environmental conditions such as dust, moisture, weather, and heat. Overmolding, an injection molding process, molds a polymer such as Bakelite over these electrical components. Bakelite combines high electrical resistance with mechanical strength and can withstand relatively high temperatures without softening. This thermosetting phenolic resin also provides flame resistance.

Importantly, Bakelite overmolding enables manufacturers of electrical connectors to create seamlessly integrated products. By eliminating manual assembly operations, manufacturers can improve efficiency and reduce operational costs. During the injection molding process, however, flash forms on part surfaces. This excess material is usually forced out of the mold cavity at the parting line; however, mold flash can also be caused by improper venting, low clamping pressure, or low viscosity and uneven flow.

Bakelite mold flash can be trimmed by hand, but manual deflashing is labor-intensive and time-consuming. Hand trimming is also inconsistent since different workers may achieve different results. There can even be part-to-part differences by the same worker during the same shift. Outsourced deflashing might seem cost-prohibitive, but Nitrofreeze® Cryogenic Deflashing is an automated, computer-controlled batch process that saves electrical connector manufacturers time and money.

How to Remove Flash from Overmolded Bakelite 

Nitrofreeze® Cryogenic Deflashing begins when batches of parts such as overmolded electrical connectors are put in a perforated drum and subjected to very low temperatures, while being blasted with a fine polycarbonate media. Like other polymers, once Bakelite approaches the glass transition temperature (Tg) the flash becomes hard and brittle like glass. This embrittlement allows the cryogenic-grade polycarbonate media that impacts the overmolded Bakelite to remove the flash, without affecting part tolerances or surface finish.

This YouTube video shows how cryogenic deflashing works, and the before and after pictures that precede this article show the results of a recent Nitrofreeze® project. As you can see, flash along the straight edges of the overmolded area was cleanly removed. Yet, cryogenic deflashing can also remove mold flash from complex geometries and intricate part features. That’s because the cryogenic-grade polycarbonate that Nitrofreeze® uses comes in different lengths and diameters for application-specific challenges.

Nitrofreeze® Cryogenic Deflashing for Electrical Connectors 

What’s the best way to remove flash from batches of overmolded electrical connectors? 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 patented process. The consultation is free of charge, so send us your part drawings, photos, or actual part samples.

To get started, contact Nitrofreeze® at the phone number and email listed below.

(508) 459-7447 x 105 | info@nitrofreeze.com