Apparatus and method for encapsulating contoured articles
AssigneeManville Corporation
InventorsSteven E. Hale, James W. Sherman, Daniel J. Batdorf
Life of this patent
Estimating the term…
Abstract
A method and apparatus for encapsulating a porous article in plastic film without employing supporting molds. The article is deposited onto a lower web and an upper web is moved into overlying position. The edges of the webs are gripped by moving teeth to move the webs and the article in unison. The webs are then pinched together adjacent the article to form an enclosed volume. The film is heated to its fusing temperature and the enclosed volume is evacuated through a tube inserted through the lower web and into the article. The tube is removed and the fused webs are trimmed adjacent the edges of the article, resulting in an encapsulated article.
Claims23
A continuous method of encapsulating a contoured generally porous article within a plastic film, comprising the steps of:
- moving a lower web of plastic film in a downstream direction;
- causing at least a portion of a first surface of the article to engage the lower web and the article to be moved with the lower web;
- covering the article with an upper web of plastic film, wherein the upper web engages at least a portion of a second surface of the article, and moving the upper and lower webs as a unit;
- forcing the upper and lower webs together generally adjacent the periphery of the article to form an enclosed volume therebetween containing the article;
- heating the upper and lower webs of plastic film in the area associated with the article to a predetermined fusing temperature at which the films are capable of adhering to said article and to each other;
- piercing one of the webs to form an opening therein;
- evacuating air from the enclosed volume through the opening to cause the upper and lower webs to engage and conform to the shape of the article and to engage each other in areas unobstructed by the article, wherein the heated lower web adheres to the first surface of the article, the heated upper web adheres to the second surface of the article, and the heated upper and lower webs fuse together in the engaged areas;
- and
- trimming the fused webs of film adjacent the periphery of the article.
Apparatus for continuously encapsulating a contoured generally porous article within a plastic film, comprising:
- means for moving a lower web of plastic film in a downstream direction;
- means for causing at least a portion of a first surface of the article to engage the lower web;
- means for covering the article with an upper web of plastic film whereby the upper web engages at least a portion of a second surface of the article, said means for moving the lower web moving the upper and lower webs as a unit;
- means for forcing portions of the upper and lower webs together generally adjacent the periphery of the article to form an enclosed volume containing the article;
- means for heating the upper and lower webs of plastic film to a predetermined fusing temperature at which the films are capable of adhering to said article and to each other;
- means for piercing one of the webs to form an opening therein;
- means for evacuating air from the enclosed volume through the opening to cause the upper and lower webs to engage and conform to the shape of the article, to engage each other in areas unobstructed by the article, to adhere to the second surface and the first surface respectively and to fuse together in the engaged areas;
- means for supporting said article without the use of a supporting mold by supporting the lower web at multiple spaced locations directly beneath the article during the heating of said films;
- and
- means for trimming the fused webs of film adjacent the periphery of the article.
A method of encapsulating a contoured, generally porous article in a plastic film without the use of a supporting mold, comprising the steps of:
- disposing said article between opposed sheets of plastic film, one of said sheets being in a generally lowermost position and the other sheet being in a generally uppermost position relative to each other;
- pinching said sheets together generally adjacent the periphery of said article to form an enclosed volume containing said article;
- heating said sheets to a predetermined fusing temperature capable of causing said sheets to adhere to the article or to one another;
- during heating supporting said article without the use of a supporting mold by supporting the lowermost sheet at multiple spaced locations directly beneath the article;
- evacuating the enclosed volume and the interior of said porous article by inserting a tube into said article for air flow communication exteriorly of the enclosed volume and applying a vacuum to the tube, thereby causing said plastic sheets to intimately engage the surfaces of said article and assume the same contour as the article;
- lowering the temperature of the plastic sheets below their predetermined fusing temperature;
- and
- trimming the fused sheets adjacent the periphery of the article.
Apparatus for encapsulating a contoured, generally porous article in a plastic film without the use of a supporting mold, comprising:
- means for maintaining said article between opposed sheets of plastic film, one of said sheets being in a generally lowermost position and the other sheet being in a generally uppermost position relative to each other;
- means for forcing said sheets together generally adjacent the periphery of said article to form an enclosed volume containing said article;
- means for heating said sheets to a predetermined fusing temperature capable of causing said sheets to adhere to the article or to one another;
- means for supporting said article without the use of a supporting mold by supporting the lowermost sheet at multiple spaced locations directly beneath the article while said article and plastic sheets are being heated;
- means for inserting a tube into said article for air flow communication exteriorly of the enclosed volume and applying a vacuum to the tube, to evacuate the enclosed volume and the interior of said porous article, and to cause said plastic sheets to intimately engage the surfaces of said article and assume the same contour as the article;
- means for lowering the temperature of the plastic sheets below their predetermined fusing temperature;
- and
- means for trimming the fused sheets adjacent the periphery of the article.
Dependencies are inferred from the claim text.