3D-printed mould with conformal cooling

3D printing is becoming increasingly popular. The plastic industry is no exception. Rompa has been using a partially 3D-printed mould with conformal cooling for a while. Using this relatively new cooling technology, the product cools down faster and in a more constant manner, which allows it to retain its shape even better afterwards. Project manager Léon Brands explains how this technology works.

Léon first explains traditional cooling methods. “With injection moulding, molten plastic with a temperature of circa 250 degrees Celsius is injected into the mould. Cooling channels in the mould then cool down the plastic as fast as possible. Normally, these channels are drilled into the steel mould. That limits your options because you can only drill straight channels. As a result, the cooling channels are not all equally close to the sides of the mould, which causes the product to cool down slower or faster in some places than in others. This can result in minor differences or deformations.”

Léon believes 3D printing offers a solution. “With 3D printing, the mould is constructed one layer at a time. This not only allows you to include straight cooling channels, but also curved or spiral-shaped ones. The cooling channels are all equally close to the product.” The result: a plastic product in top shape. It also saves time, Léon says. “In this case, the cooling process is ten to fifteen percent faster.” This mould also presents new challenges to Rompa: “The channels are very narrow, so it is important to install good filters to prevent them from clogging up.”

The 3D-printed mould was developed in Portugal, where the printed components were also made. The mould is currently being used at our production site in the Czech Republic. “It concerns a quadruple mould,” Léon says. “That means that we make four products in one cycle.” What products, exactly? “The mould is designed to produce gateway-housing for the car industry for our automotive customer Bosch,” Léon says. He has high expectations for the 3D-printed moulds. “At the moment, moulds with conformal cooling are fairly expensive, but this is the future of injection moulding.a