US 4,364,893 A · Mold atmosphere control system

Abstract

A method and apparatus for maintaining a dehumidified atmosphere or other controlled atmosphere around the mold of a reciprocating-platen molding press, in which a sheet of light weight flexible material, preferably a transparent plastic film, is mounted on the platens, as by a plurality of permanent magnets, to form an open bottom tent enclosing both halves of the mold. For a dehumidified atmosphere, a dehumidifier generates a stream of warm dry air that is continuously discharged into the tent, from locations adjacent each platen, with a volume sufficient to maintain the tent inflated for all platen positions despite continuing air loss through the open bottom of the tent. The dehumidifier preferably uses a chilled water supply that is also employed to cool the molds in order to obtain automatic dew point correction. For other atmospheres, an appropriate source is substituted for the dehumidifier.

Claims21

Dependent claims

A mold atmosphere control system for a molding press of the kind comprising two platens, each bearing a mold half, cyclically movable between a closed molding position in which the mold halves are closed upon each other and an open discharge position in which the mold halves are substantially displaced from each other, the system comprising:

a tent formed of flexible sheet material;
mounting means for mounting the tent on the platens with the tent substantially enclosing the mold halves except for a bottom opening large enough to allow discharge of molded products formed in the press;
an gas diffuser mounted on one of the platens, within the tent;
and gas supply means, connected to the diffuser, for continuously supplying a stream of gas, under pressure, flowing through the diffuser into the tent and out through the bottom opening, the gas stream having a volume sufficient to maintaim the tent inflated throughout the mold cycle of the press.

1 more element

The method of maintaining a controlled atmosphere encompassing the mold halves of a molding press of the kind including a molding station comprising two platens, each bearing a mold half, which platens move cyclically between a closed molding position in which the mold halves are closed upon each other and an open discharge position in which the mold halves are substantially displaced from each other, that method comprising:

mounting a sheet of relatively light weight flexible sheet material on the two platens to form a tent extending between the platens and enclosing both mold halves, the bottom of the tent being open to permit discharge of gas and of products molded in the press;
generating a stream of gas of controlled characteristics, under pressure;
and continuously discharging the gas stream into the interior of the tent in sufficient volume to maintain the tent inflated throughout the molding cycle, despite substantial continuing gas loss through the open bottom of the tent, thereby maintaining a controlled atmosphere encompassing the mold halves.

Dependencies are inferred from the claim text.

Mold atmosphere control system

Life of this patent

Mold atmosphere control system

Life of this patent

Abstract

Claims21