A new product for rotational molds called Technovent performs three functions in a single device it vents the mold, allows the addition of compressed air and measures the air temperature inside the mold.
Norstar Aluminum Molds Inc. of Cedarburg is the North American distributor of Technovent, made by La Plastecnica of New Zealand. Norstar manufactures cast aluminum molds for rotomolding.
The vent portion of Technovent is based in La Plastecnica's Supavent, a flexible polymer vent that improves consistency of molding. A rotational mold starts out cold, then gets heated up as it rotates through a large oven, before getting cooled back down again by water or air. Vents are needed to let the hot air out and allow cool air into the mold.
Measuring internal air temperature, instead of simply monitoring the amount of time spent in the oven, can help molders reach an optimum cycle time, said Norstar President Sandy Scaccia. Also, increasing the air pressure inside the mold can reduce cycle times.
Traditionally, thermocouples to gauge temperature are placed inside the rotational mold via a separate hole in the mold. Air pressure required its own hole.
Technovent does all those things. It includes a thermocouple and air vent, with only one hole required in the plastic part.
La Plastecnica developed the Supavent as a more precise alternative to packing various porous materials into vent tubes of a rotational mold.
Scaccia said Norstar will display Technovent at Rotoplas '08, Oct. 22-23 in Rosemont, Ill.