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Low Pressure Overmolding

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Technomelt is a versatile low temperature thermoplastic similar to the hot melt plastics widely used for glue guns. With its improved formulation, Technomelt is a consistent engineering plastic that has guaranteed mechanical and electrical properties suitable for the exacting standards of the electrical and electronic industries.

Technomelt’s low temperature and pressure profile makes it especially useful for electrical and electronic applications. Its tensile strength makes it suitable for strain relief, for example, needing above 45kg/cm2 to yield. Electrically, it’s an excellent insulator–just 1cm of Technomelt withstands 200kV. At around 200 degrees it flows like maple syrup enabling it to be applied to electronic components and soldering at low injection pressure while achieving a mold definition suitable for a wide range of applications. Macromelt is a class of molding between open pouring and high pressure injection molding.


Light, insects, rain and dust are a few possible contaminants that affect function or long term reliability of electronic components. Encapsulation is a good strategy: low cost Technomelt makes it easy. A typical component for which environmental protection is desirable. This device is fitted to equipment that has potential for both water and dust pollution. Without Technomelt, the designer would need to provide a housing which would increase cost, build time and design effort. This device is also encapsulated with Technomelt. It is fully sealed against moisture and dust and its reliability has been increased. Encapsulation requires little skill and throughput is fast enough for production processes. If desired, identification marks or characters can be impressed in the mold tool and additional holes or features can be incorporated.


Low cost mold tools for Technomelt can create components that add strength to vulnerable assemblies.

Strain Relief

A popular application for wiring. Technomelt has adhesive properties enabling it to bond to wire jackets and casings. By placing the wire (or cable or bundle) in the mold tool, a strong plastic feature with holes or lugs etc. can be fixed to the wiring. Exposed joints can be enclosed.


Although quantity is required to make colored Technomelt as economical as black or neutral; red, blue and other colors can be obtained for cosmetics or identity. But identity can be shown by letters, numbers or symbols and these can be engraved on the wall of the mold tool. Black Macromelt shows characters with good detail.

Blanking components, etc.

Sometimes a chassis part needs a shaped bung, or a cavity needs a cover. Perhaps a sharp metal feature needs a plastic boot. When the component cannot be sourced from a catalog, Technomelt and low cost mold tooling can provide a solution. The applications are numerous and diverse.


Technomelt is a versatile plastic and will serve to make prototype casework and components from low cost tooling. Being a low pressure system, surface detail is below that possible with injection molding, but basic shapes and structures are excellent.


At 10^13 ohms per cm^3, Technomelt’s insulation properties, together with its physical strength, make it suitable for mains protection and shrouding of high voltage. It ruptures above 200kV per cm. Its high volume resistivity means that it cannot disturb most electronic circuits.

Tamper Proofing

Some assemblies must not be touched and made tamper proof. If the assembly can be encapsulated, Technomelt is a good solution.

Injection Molding Option

Integrating electronics into molded structures gives designers ways to improve functionality and reliability. But injection molding flow rates can be aggressive and assembly positioning can be a problem. Fine wire structures, for instance, can be damaged within the stream of melt and sensitive components can be thermally shocked. Technomelt can provide a solution by encapsulating vulnerable features at a low temperature and pressure.

A simple, low cost aluminum mold tool with basic shapes is all that is needed to encapsulate an assembly: an advantage of low pressure molding. Low cost and speed of production is a major benefit of Technomelt molding.