US 4,314,799 A · Compression molding machine for organic thermoplastic materials

Abstract

This invention provides a high output machine for effecting the production of organic thermoplastic articles by the compression molding technique. A plurality of molding members having open top molding cavities are movable around a horizontal closed loop path. A plurality of horizontally moving plungers are provided which are respectively co-operable with the molding members in a portion of their path to close the open top of the molding cavities. Successive gobs of heated organic thermoplastic material are deposited in the open top molding cavities at a point prior to the molding members moving into vertical alignment with the plungers. A relative vertical displacement between the plunger and the molding members is then effected to bring each plunger into engagement with the respective molding member and effect the compression molding of the inserted gob to conform to the molding cavity. After formation of the molded article and appropriate time for cooling, the molding members and plungers are relatively vertically displaced to permit the molded thermoplastic article to be removed from the molding cavity. In accordance with a specific embodiment of this invention, the molded article may comprise the end wall of a can and successive can side walls or bodies are respectively disposed in surrounding relationship to the plungers and carried into the compression molding area with the end portions of such bodies entering the molding cavity so that the compression molded end wall is formed around and united to the side wall in the compression molding operation.

Claims12

Dependent claims

In an apparatus for press forming organic thermoplastic material into molded parts having an extruder continuously producing a rodlike formation of hot moldable organic thermoplastic material and gob feeding means periodically engaging said formation to sever same into discrete gobs of substantially the same quantity of material, the improvement comprising:

(1) a plurality of mold members having exposed molding cavities;
(2) means for moving said mold members in timed relationship to said feeding means along a closed loop path intersecting the gravity path of said severed gobs, whereby each gob is deposited in a molding cavity;
(3) a plurality of molding plungers respectively cooperable with said mold members to close said molding cavity and compress the inserted gob into conformity with the closed cavity;
(4) means mounting said plungers for movement in timed relationship with said mold members along a closed loop path having a portion parallel and adjacent to the path of said mold members after receiving the severed gobs therein;
(5) means for relatively vertically displacing said plungers respectively into engagement with said mold members for a period of time sufficient to mold a respective inserted gob to conform to the closed molding cavity, and
(6) means for successively separating the plungers and molding members for respectively removing the molded plastic articles.

3 more elements

Apparatus for molding a thermoplastic can end into assembled relationship with a preformed can body comprising, in combination:

(1) means for periodically producing gobs of hot moldable thermoplastic material;
(2) a plurality of mold members having exposed molding cavities;
(3) means for moving said mold members along a closed loop horizontal path;
(4) means for transferring said gobs successively into said molding cavities;
(5) a plurality of mandrels mounted for movement in vertical alignment with the mold member
(6) means for mounting a can body on each mandrel prior to such mandrel moving into alignment with a mold member;
(7) means for relatively vertically moving each said mandrel into engagement with a mold member to define a molding cavity therebetween corresponding to the configuration of a desired can end, with the end portion of said can body projecting into said molding cavity, whereby said thermoplastic gob is displaced throughout said molding cavity by compression molding;
(8) means for relatively vertically separating said mandrels and said mold members leaving the can bodies on the respective mandrels, and
(9) means for successively removing the can bodies with the thermoplastic ends assembled thereon from said mandrels.

6 more elements

Dependencies are inferred from the claim text.

Compression molding machine for organic thermoplastic materials

Life of this patent

Compression molding machine for organic thermoplastic materials

Life of this patent

Abstract

Claims12