Method for forming a groove in a thermoplastic article
OwnerRonald Brochu, James Burnesinventors
Life of this patent
Estimating the term…
Abstract
To make a thin-wall bottom groove in an injection molded plastic article, such as the type of V-shape grooves which define tear-out portions of an article, the space between the groove-defining land of the mold and the opposing part of the mold is changeable. During injection and filling of the mold, the space is large, to enable filling of the mold. As the mold fills, the space is made small, so the desired finished dimension in the part is obtained.
Claims12
(canceled)
(canceled)
A method of forming a groove in an injection molded article made of a thermoplastic material by means of a land part of the mold which projects into the article defining cavity of the mold, which comprises:
- providing a mold having
- a first mold part which comprises said projecting land part;
- a second mold part opposing and spaced apart from said first mold part;
- wherein the spacing between the first and second mold parts, in vicinity of said projecting land, is changeable by movement of at least one of said mold parts;
- injecting hot thermoplastic material into the article defining cavity of the mold while spacing apart the mold parts sufficient to enable thermoplastic to flow by and around said projecting land part;
- moving said mold parts closer together, to deform and shape said thermoplastic so the desired dimension article is formed;
- and,
- opening the mold parts and removing the article from the mold.
A method of forming a V-shape groove in an injection molded article made of a thermoplastic polypropylene material by means of a land part of the mold which projects into the article defining cavity of the mold, which comprises:
- providing a mold having
- a first mold part which comprises said projecting land part;
- a second mold part opposing and spaced apart from said first mold part;
- wherein the spacing between the first and second mold parts, in vicinity of said projection is changeable by movement of at least one of said mold parts;
- injecting said softened hot thermoplastic material into the article defining cavity of the mold while spacing apart the mold parts sufficient to enable thermoplastic to flow by and around said projecting land part;
- moving said mold parts closer together, so the land part is less than about 0.01 inch spaced apart from the opposing mold part, to thereby shape said thermoplastic so the desired dimension article is formed;
- and,
- opening the mold parts and removing the article from the mold.
Dependencies are inferred from the claim text.