Venting arrangement for matched molds and method

A mold assembly for molding a thermosetting resinous article, said mold including first and second mold members which are fabricated of resinous material and which are assembled together to define a mold cavity including a main portion which defines the desired article and a flange space extending from the perimeter of the main portion, said first and second mold members each including a central surface defining the cavity main portion and a peripheral surface extending outwardly from said central surface to partially define said flange space, a gasket captured between said peripheral surfaces and spaced from said central surfaces to define the periphery of said flange space, and a plurality of vent tubes extending in spaced relation to each other through said gasket in spaced relation from said peripheral surfaces and around the periphery of said flange space to provide communication between said cavity and the atmosphere, said vent tubes each having an internal diameter and a length which are dimensioned so as to permit air flow from said cavity while minimizing resin flow from said cavity.

A process for making an article from a thermosetting resin, said process comprising the steps of providing a pair of opposed mold members each fabricated of resinous material and including a central surface which, when the pair of mold members are assembled in opposing relation, define a central cavity, and a peripheral flange surface which extends outwardly from the central surface, providing a gasket member, providing a plurality of vent tubes, assemblying the mold members in opposed relation and with the gasket member located between the peripheral surfaces in spaced relation from the central surfaces to provide a flange space and with the vent tubes extending in spaced relation to each other through the gasket and in spaced relation from the peripheral surfaces and around the periphery of the flange space so as to provide, when the mold members are assembled, communication between the cavity and the atmosphere, clamping together the mold members with the assembled gasket member and vent tubes to provide a mold assembly which is sealed except for communication through the vent tubes with the atmosphere, and inserting thermosetting resinous material into the cavity under relatively low pressure conditions until resinous material is present in all of the vent tubes.

A process for making an article from a thermosetting resin, said process comprising the steps of providing a pair of upper and lower mold members each fabricated of resinous material and including a planar flange surface and a central surface which extends inwardly from the flange surface and which, when the pair of mold members are assembled in opposing relation, define a central cavity which extends downwardly from the planar flange surfaces, providing a gasket member, providing a plurality of translucent vent tubes, assemblying the mold members in opposed relation and with the gasket member located between the flange surfaces in spaced relation from the central surfaces to provide a flange space and with the vent tubes extending in spaced relation to each other through the gasket and in spaced relation from the flange surfaces and around the periphery of the flange space so as to provide, when the mold members are assembled, communication between the cavity and the atmosphere, clamping together the mold members with the assembled gasket member and vent tubes to provide a mold assembly which is sealed except for communication through the vent tubes and the atmosphere, and inserting thermosetting resinous material into the cavity under relatively low pressure conditions until resinous material is visually present in all of the vent tubes.

A process for making an article from a thermosetting resin, said process comprising the steps of providing a pair of opposed mold members each fabricated of resinous material and including a central surface which, when the pair of mold members are assembled in opposing relation, define a central cavity, and a peripheral flange surface which extends outwardly from the central surface, providing a gasket member, providing a plurality of vent tubes dimensioned to permit free air flow therethrough and to restrict resin flow therethrough, assemblying the mold members in opposed relation and with the gasket member located between the peripheral surfaces in spaced relation from the central surfaces to provide a flange space and with the vent tubes extending in spaced relation to each other through the gasket and in spaced relation from the peripheral surfaces and around the periphery of the flange space so as to provide, when the mold members are assembled, communication between the cavity and the atmosphere, clamping together the mold members with the assembled gasket member and vent tubes to provide a mold assembly which is sealed except for communication through the vent tubes with the atmosphere, and inserting thermosetting resinous material into the cavity under relatively low pressure conditions until resinous material is present in all of the vent tubes.