Feed system for an injection molding machine
A feed system for an injection molding machine. The feed system includes a first part with a first channel, and a second part with a second channel. The first channel and the second channel together form a molten plastic feed conduit when they are engaged. The first part and the second part are unbonded to one another.
1. A multi-part feed system for an injection molding system having a mold including a plurality of mold cavities, an injection system for injecting molten plastic through a nozzle and through one or more gates into the mold cavities, and a controller for controlling the injection system to maintain the molten plastic at a substantially constant pressure, the feed system being located between the nozzle and the gates, the feed system comprising:
a first part including a first feed channel and a crush bead proximate to the first feed channel, the first part being made of metal; and
a second part including a second feed channel, the second part being made of metal;
wherein, when the first part is engaged with the second part, the first feed channel and the second feed channel together at least partially define a molten plastic feed conduit;
wherein the first part and the second part are unbonded, with respect to each other;
wherein the first part and the second part are separable from each other, to expose the first channel and the second channel; and
wherein the molten plastic feed conduit is configured for molten plastic having a pressure that is less than 15,000 psi.
2. The feed system of claim 1 , further comprising a gasket disposed between the first part and the second part when the first part is engaged with the second part.
3. The feed system of claim 2 , wherein the gasket comprises an elastic material.
4. The feed system of claim 2 , wherein the gasket comprises a metal material.
5. The feed system of claim 4 , wherein the metal material is selected from the group consisting of: aluminum, aluminum alloys, copper, copper alloys, beryllium copper, and combinations of these.
6. The feed system of claim 2 , wherein the gasket has a non-stick coating.
7. The feed system of claim 6 , wherein the coating is a silicone based coating.
8. The feed system of claim 1 , wherein, when the first part is engaged with the second part the first part is directly connected to the second part.
9. The feed system of claim 8 , wherein:
the first feed channel has an outward chamfered surface;
the second feed channel has an inward chamfered surface; and
when the first part is engaged with the second part, the outward chamfered surface compliments the inward chamfered surface, such that a ridge formed on the second part to align and seal the first and second parts.
10. The feed system of claim 1 , wherein the crush bead follows a contour of the first feed channel.
11. The feed system of claim 1 , wherein the first part is made from an aluminum alloy.
12. The feed system of claim 1 , wherein the molten plastic feed conduit is configured such that, when a molten plastic material is flowing through the molten plastic feed conduit, the molten plastic material has a maximum Reynolds number that is less than 1.0.
13. The feed system of claim 1 , including a heater configured to heat the molten plastic feed conduit.
14. The feed system of claim 1 , wherein the molten plastic feed conduit has an overall cross-sectional dimension that is between 0.3 centimeters and 3 centimeters.
15. The feed system of claim 1 , wherein the molten plastic feed conduit an overall cross-sectional dimension that is between 0.1 centimeters and 0.3 centimeters.
16. The feed system of claim 1 , wherein the molten plastic feed conduit is configured for molten plastic having a pressure that is less than 12,000 psi.
17. The feed system of claim 1 , wherein the molten plastic feed conduit is configured for molten plastic having a pressure that is less than 10,000 psi.