Method of thermoforming plastic articles
AssigneeSencorp Systems, Inc.
InventorsAnthony Giovannone, David Mitchell
Life of this patent
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Abstract
A precut die apparatus arranged and adapted for use in a thermoform-trimming method and system to produce plastic molded articles, and to the method and system in which the apparatus is employed. The precut apparatus is positioned, in the method and system, between the form press and the trim station. The precut apparatus is arranged to precut, in a desired and selected manner, the thermoformed sheet material containing thermoformed articles therein, about the periphery of the thermoformed articles. The precut provides for a bridged and joining area of the sheet material to allow for slight movement and adjusting of the molded articles for precise alignment in the punch and die trim step of the thermoforming and trimming operation.
Claims19
A method for the production of a plastic article from a thermoplastic sheet material in a thermoforming operation, which method comprises:
- a) providing a thermoplastic sheet material;
- b) heating the thermoplastic sheet material to a selected temperature to form a preheated thermoplastic sheet material;
- c) thermoforming the preheated thermoplastic sheet material in a thermoform press, forming a plurality of thermoformed articles having an outer periphery in the sheet material, the articles formed in a spaced-apart arrangement from each other in the sheet material, and to define a surround area of the sheet material about each article;
- d) trimming in a diecutting trim press the thermoformed articles from the sheet material, and
- e) recovering accurately cut plastic articles from the trim press at a recovery station, the improvement which comprises:
- precutting in a striking operation about the outer periphery of each of the thermoformed articles employing a die platen with a plurality of spaced apart overlapping cutting blades and a striking platen to form, in the surround area of each of the articles, a plurality of overlapping diecut lines and elongated, spaced apart joining strips of selected length and defined width between ends of the overlapping diecut lines, the diecut lines extending about the outer periphery of each of said articles, the joining strips to provide for retaining the thermoformed articles in the sheet material and to permit a slight movement and accurate alignment of the thermoformed articles in the trimming step.
A method for the production of a plastic article from a thermoplastic sheet material in a thermoforming operation, which method comprises:
- a) providing a thermoplastic sheet material;
- b) heating the thermoplastic sheet material to a selected temperature to form a preheated thermoplastic sheet material;
- c) thermoforming the preheated thermoplastic sheet material in a thermoform press, forming a plurality of thermoformed articles having an outer periphery in the sheet material, the articles formed in a spaced apart arrangement from each other in the sheet material, and to define a surround area of the sheet material about each article;
- d) trimming in a diecutting trim press the thermoformed articles from the sheet material, and
- e) recovering accurately cut plastic articles from the trim pres at a recovery station, the improvement which comprises:
- forming in the surround area about each thermoformed article a plurality of separate, generally arcuate cut lines, which in total surround the outer periphery of each thermoformed article, and which cut lines are spaced apart and overlap at each end an adjacent cut line to form a plurality of separate spaced apart, generally arcuate joining strips of selected width and length to provide for slight movement and accurate alignment of the thermoformed articles during trimming.
Dependencies are inferred from the claim text.