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US 8,771,568 B2Granted
Offset mold twinning
OwnerLance T. Hampelinventor
Life of this patent
Estimating the term…
Abstract
Thermoplastic parts are made of predominantly single unit thickness but with marginal areas of increased thickness by molding two parts in a common mold having overlapping mold portions. Two thicknesses of thermoplastic material are molded together in the areas of increased thickness at opposite ends of the common mold and the parts are separated from one another by trimming such that each part has an area of increased solid wall thickness and an area of reduced thickness.
Claims20
A method of making at least two molded parts, comprising:
- providing a first mold half having a first mold portion against which a first plastic sheet is molded;
- providing a second mold half having a second mold portion against which a second plastic sheet is molded;
- molding the first plastic sheet and the second plastic sheet between the first mold portion and the second mold portion into a composite part having a first plastic layer and a second plastic layer such that the first plastic layer and the second plastic layer are fused during the molding at a pair of twinning sections forming a first double layer area and a second double layer area, and the first plastic layer and the second plastic layer are not fused during the molding at a primary section forming a first single layer area and a second single layer area;
- and
- separating the composite part into a first molded part and a second molded part by cutting the first plastic layer in the primary section and cutting the second plastic layer in the primary section;
- wherein the first molded part includes the first double layer area and at least one of the first single layer area and the second single layer area, and the second molded part includes the second double layer area.
3 more elements
A method of making at least two molded parts, comprising:
- providing a first mold portion defining a first primary section and a first twinning section;
- providing a second mold portion facing the first mold portion defining a second primary section and a second twinning section;
- molding a composite part having a first plastic layer and a second plastic layer between the first mold portion and the second mold portion such that the first plastic layer and the second plastic layer are twinned during the molding at the first twinning section forming a first double layer area and at the second twinning section forming a second double layer area, and the first plastic layer and the second plastic layer are spaced apart during the molding at the first primary section forming a first single layer area and at the second primary section forming a second single layer area;
- separating a first molded part from the composite part including the first double layer area and at least one of the first single layer area and the second single layer area by cutting at least one of the first plastic layer at the first single layer area and the second plastic layer at the second single layer area;
- and
- separating a second molded part from the composite part including the second double layer area.
3 more elements
Dependencies are inferred from the claim text.