3D printed injection side of a multi-piece mold with internal thermal manifold
We disclose a component of an injection molding tool that includes a one piece side of a mold built up by additive manufacturing using a polymer, the side of the mold defining part of an injection cavity. The side of the mold further includes an injection port coupled to the injection cavity and a heating fluid manifold separated from the injection cavity by a heat transfer wall. The heat transfer wall is reinforced against pressure in the injection cavity by a backing of engineered supports. Inlet and outlet ports are coupled to the heating fluid manifold, configured to channel a thermally conductive fluid into and out of the heating fluid manifold. Additional additive manufacturing features and material properties are described. Complementary methods of manufacturing also are disclosed.
1. A component of an injection molding tool comprising:
a one-piece half mold built up by additive manufacturing using a 3D printing polymer, the one-piece half mold defining part of an injection cavity, the one-piece half-mold further comprising:
an injection port coupled to the injection cavity;
a heating fluid manifold cavity separated from the injection cavity by a heat transfer wall made of the polymer, wherein the heat transfer wall is reinforced against pressure in the injection cavity by a backing of engineered supports that are a unitary part of the one-piece half mold;
wherein the engineered supports are configured to strengthen the heat transfer wall and create a non-laminar flow of a thermally conductive fluid through the heating fluid manifold cavity; and
inlet and outlet ports coupled to the heating fluid manifold cavity, configured to channel the thermally conductive fluid into and out of the heating fluid manifold cavity.
2. The component of claim 1 , wherein the polymer from which the heat transfer wall is built up has a thermal conductivity in a range of 0.1 to 1.0 W/(m·K).
3. The component of claim 1 , wherein the polymer from which the heat transfer wall is built up has a thermal conductivity in a range of 0.1 to 5.0 W/(m·K).
4. The component of claim 1 , wherein the side of the mold is built up from an epoxy based photopolymer liquid resin that is hardened by stereolithography.
5. The component of claim 1 , wherein the side of the mold is built up from cyanate ester based photopolymer liquid resin.
6. The component of claim 1 , wherein the engineered supports are columns.
7. The component of claim 1 , wherein the engineered supports are trusses.
8. The component of claim 1 , wherein the engineered supports are branching structures.
9. The component of claim 1 , wherein the heat transfer wall deflects less than 0.15 mm under an injection pressure of 200 psi at a temperature of the heat transfer wall of 80 degrees Celsius.
10. The component of claim 1 , wherein the heat transfer wall is an average of 0.75 to 1.25 mm thick where the heat transfer wall separates the injection cavity from the heating fluid manifold cavity, after excluding the engineered supports from calculating the average.
11. The component of claim 1 , wherein the heat transfer wall is an average of 1.25 to 2.5 mm thick where the heat transfer wall separates the injection cavity from the heating fluid manifold cavity, after excluding the engineered supports from calculating the average.
12. The component of claim 1 , wherein the side of the mold further comprises:
a face adapted to fit against a complementary face of an additional side of the mold that further defines the injection cavity;
wherein the face comprises a scalloped mating surface extending fully around a circumference of the injection cavity and adapted to interlock with the complementary face of the additional side.
13. The component of claim 1 , wherein the side of the mold further comprises:
a face adapted to fit against a complementary face of an additional side of the mold that further defines the injection cavity;
wherein the face comprises a scalloped mating surface extending fully around a circumference of the injection cavity and adapted to interlock with the complementary face of the additional side; and
the scalloped mating service is patterned to a parametric equation comprising one or more sinusoidal curves.
14. The component of claim 1 , wherein the side of the mold further comprises:
a face adapted to fit against a complementary face of an additional side of the mold that further defines the injection cavity, wherein the face comprises a scalloped mating surface extending fully around the circumference of the injection cavity and adapted to interlock with the complementary face of the additional side; and
an alignment relief notch groove extending fully around the injection cavity.