Since Plasti-Coil, Inc’s beginning, coil winding bobbins have been at the core of our business. Partnering with hundreds of manufacturers over the years has elevated us to “Experts” in the realm of custom bobbins. The coil winding bobbins that we manufacture have been used in practically every application that call for a plastic bobbin; transformers, solenoids, relays, motors, fuel pumps, s.m.d.s, and many other electrical and electronic devices. 

Many coil winding bobbins are subjected to high heat either through their application or from the overmolding process. Thermoplastic materials such as Rynite, Ryton, High Temperature Nylon, or L.C.P. are used in these plastic bobbins and molded to a crystalline state so as to withstand these high temperature environments. To produce a fully crystalline plastic bobbin requires many years of experience that we have at Plasti-Coil. We are the experts when it comes to high temperature crystalline molding. Every facet from precision tooling, shrink factor, hot oil/water heaters, thermoplastic control process, and molding parameters need to be factored in.

At Plasti-Coil, Inc., “custom” is an everyday term in what we achieve for our customers. When it comes to custom plastic molders, we’re simply the best! Our team of engineers and marketing professionals will meet with you to discuss your needs, then offer specific recommendations for your plastic parts. Every detail of your project is taken into account.Our mission? To maximize production capabilities in order to achieve the most cost-efficient processing of your injection molded parts. We can also create a Stereo Lithography model of your plastic parts which provides full conceptualization.

Customer interaction is what make our team most effective and results in a truly cooperative effort. Our engineers and marketing staff will work with you until your injection molded parts design fits the requirements precisely.

At Plasti-Coil, Inc., not only do we produce millions of plastic injection molded bobbins annually, but provide many secondary operations such as terminal and pin insertion. We operate many specialized machines that makes this process possible. After the injection molding of the bobbins we can either insert one of many types of quick connect terminals; or, you can choose from many different wire sizes for pinning to tie off after the coil winding operation.

We provide the terminal insertion or pinning procedures for many customers, so that when the bobbins are delivered they are ready to start winding. We also have had many instances where the customer requirements call for the insert molding of the pins/terminals. This procedure is accomplished with specifically designed molds where the bobbin is molded with the pin/terminal molded into it at the same time.

Plastic insert molding is a custom molding process where plastic is injected into a mold partially or fully encapsulating a part placed into the same mold just prior to injection of the plastic.  The inserts are generally metal or some other higher temperature plastic. 

Insert molding can be an effective alternative to assembly of multiple parts.  Benefits include:

 Reduced assembly and labor costs.

• Reduced size and weight of the finished part through use of fewer parts.
• Increased reliability through elimination of adhesives and fasteners.
• Increased design flexibility

Overmolding is the injection molding process whereby two or move plastic and/or elastomeric materials are molded simultaneously within the same tool.  Proper material selection is critical to assure that the materials remain bonded over the life of the part.

The benefits of Insert molding also apply to overmolding plus overmolding has the additional advantages of:

Eliminating the manual or robotic pick-place of a plastic insert into the mold.

Further design flexibility allowing the creation of plastic injection molded logos and lettering eliminating printed/applied graphics and; the molding-in of elastomeric shapes into rigid plastic parts.  The ultimate in this regards is probably a small, overmolded appliance cover using one two-material part to replace a 17-piece manual assembly plus post-assembly graphics.