Incoe: Localized Variothermal Mold Temperature Control Aims to Eliminate Visible Weld-Line Marks

Localized variothermal mold temperature control: Heated tempering stamps deliver targeted heat pulses to prevent visible weld-line marks on injection-molded parts - (Photo: Incoe).

Hot-runner manufacturer Incoe offers "Heat-Inject", a localized variothermal mold temperature control system for injection molding applications. The system is designed to prevent weld lines from appearing as visible notches on the surface of molded parts. Weld lines occur when separate melt fronts converge in the mold cavity. While the technology does not prevent weld lines from forming, it modifies the surface conditions at the point where the melt fronts meet.

Brief, Localized Heating of the Mold Surface
The system uses a heated tempering stamp that is briefly pressed against the rear of the cavity wall. The stamp delivers a localized heat pulse, temporarily increasing the cavity surface temperature in the area where the melt fronts converge. This precisely timed temperature increase is intended to prevent the formation of a visible weld-line notch on the molded part.

Advert

Because only a small amount of thermal energy is introduced, the heat can be quickly dissipated through the mold plate after the pulse. According to Incoe, the overall thermal balance of the mold remains largely unaffected, without interfering with the rest of the injection molding process. The localized temperature control therefore targets only those areas where visible surface defects are likely to occur.

Integration with Hot-Runner Systems
"Heat-Inject" is available either as a preassembled unit mounted directly on the hot-runner system or as a separate modular assembly. The targeted heating technology is particularly suitable for molded parts where converging melt fronts would otherwise leave visible weld-line marks on the part surface.

Incoe has been developing and manufacturing hot-runner systems for plastics injection molding since 1958. Its European subsidiary was established in 1975. The company operates manufacturing facilities in the United States, Brazil, Germany, Singapore and China, supported by a service network spanning more than 45 countries. Its products are used in various industries, including automotive, electronics, packaging, medical technology and household goods.

Fakuma 2026
Friedrichshafen, Germany
October 12–16, 2026
Hall A2, Stand 2210

More information: www.incoe.com

Incoe, USA + Incoe International Europe, Rödermark, Germany

back to news list