초록 ▼

A mold for molding articles of plastic or other like materials, having a plurality of vertically extending internal passages, is connected by inlet and return conduits into a closed loop that includes a heat exchanger partially filled with a liquid supply of a cooling fluid or a heating fluid. For c

A mold for molding articles of plastic or other like materials, having a plurality of vertically extending internal passages, is connected by inlet and return conduits into a closed loop that includes a heat exchanger partially filled with a liquid supply of a cooling fluid or a heating fluid. For cooling the heat exchanger is positioned with its liquid level above the top of the mold, the inlet conduit connects the lower part of the heat exchanger, below the liquid level, to the lower ends of the mold passages, and the return conduit connects the upper ends of the mold passages to the upper part of the heat exchanger; for heating these relationships are reversed. In operation the fluid changes its physical state at critical points in the mold passages, going from liquid to vapor for cooling and from vapor to liquid for heating; circulation in the closed loop is in response to the effect of gravity. Operation of the heat exchanger is controlled to maintain a controlled pressure in the closed loop.

대표청구항 ▼

The method of modifying the temperature of a mold for molding articles of plastic or like materials, the mold including a plurality of vertically extending internal passages for a heat transfer fluid, the method comprising: A. connecting the internal passages of the mold into a closed loop with a he

The method of modifying the temperature of a mold for molding articles of plastic or like materials, the mold including a plurality of vertically extending internal passages for a heat transfer fluid, the method comprising: A. connecting the internal passages of the mold into a closed loop with a heat exchanger, the relative elevations of the mold and the heat exchanger being such that a heat transfer fluid tends to flow from the mold passages to the heat exchanger in response to the effect of gravity when the fluid is in a given physical state; B. filling the closed loop, including the mold passages and the heat exchanger, with a heat transfer fluid that changes from an initial physical state to the given physical state in response to thermal conditions occurring in critical portions of the mold passages during operation of the mold, the fluid in the mold passages being in the initial physical state and the heat exchanger containing fluid in both physical states when filling is completed; C. Establishing a predetermined operating pressure in the closed loop; and D. controlling operation of the heat exchanger to maintain a controlled operating pressure in the closed loop and to change fluid in the heat exchanger from the given physical state back to the initial physical state at approximately the same rate as the fluid flows from the mold to the heat exchanger, thus achieving basic circulation of heat transfer fluid in the closed loop through the effect of gravity based upon a change of state of the heat transfer fluid.