Sprue Adjuster Offers Melt Flow Flexibility

Now offered in a Ø24-mm diameter, the CUMSA Sprue Adjuster (SA) family has been made available in 4 sizes. As with its smaller SA types, CUMSA says these sprue adjusters are offered in two versions—SA240022 and SA240822—which are suitable for molded parts which require larger runner gates, and are compatible with larger nozzle diameters up to 22 mm.

A sprue adjuster is to be set manually from the mold parting line when the mold is open, by turning the cylindrical body, to open or close them, as necessary. It can be installed in the cavity or in the core, enabling trapezoidal or full-round runners. The main component of the sprue adjuster, the rotating cylindrical body, is tightly fitted and screwed into the mold and can be set to any desired position. Additionally, it is sealed by a high-temperature Viton O-ring, with a maximum working temperature of 100°C (212°F).

According to the company, the component enables toolmakers/molders to easily change the direction of melt flow in the runner and requires brief molding cycle interruptions. CUMSA sprue adjusters can be used with most thermoplastic polymers, including filled, reinforced and flame-retardant polymers.

Further, CUMSA says turning off the sprue adjuster will block melt flow, which can temporarily isolate a defective cavity in a multi-cavity mold without risking damage to the rest of the cavities.