Stratasys has invented a new technology to make plastics molds using 3D printers and layers of thermoset UV absorbing plastics with different thermal profiles.
One layer of the mold would have a heat deflection temperature (HDT) lower than 80ºC and a second layer above 80ºC.
Polymers produced by UV curing during an additive manufacturing process posessing HDT lower than about 80ºC. offer dimensional accuracy, while the second, smaller, layer provides better thermal properties.
“The second material may have much better thermal stability at the injection molding temperature, thus the mold region covered by the second material may be exposed to a high temperature material being injected into the mold without significant geometrical deformations or distortions,” say Israeli inventors Daniel DIkovsky and Ido Eylon. Stratasys is based in Rehovot, Israel.
Tolerances are within 1 mm in any direction for a part 500 mm by 400 mm by 200 mm.
The resin composition may include acrylic monomers such as phenoxyethyl acrylate, marketed by Sartomer under the trade name SR-339. Also possible is a urethane-acrylate oligomer marketed by Cognis under the trade name Photomer-6010.
The composition for the second material may include at least 45 percent of multi-functional monomers such as SR-9003 marketed by Sartomer.
The printer referenced in the patent is Objet Eden500. The U.S. patent application was published today.