초록 ▼

A method and apparatus are provided for forming two-piece drinking cups and containers from conventionally shaped arcuate sidewall blank and bottom blanks of filled polypropylene sheet material or polypropylene-polyethylene copolymer sheet material with approximately 40% talc or calcium carbonate as

A method and apparatus are provided for forming two-piece drinking cups and containers from conventionally shaped arcuate sidewall blank and bottom blanks of filled polypropylene sheet material or polypropylene-polyethylene copolymer sheet material with approximately 40% talc or calcium carbonate as a filler. The arcuate blanks for the sidewall and the bottom blanks are run through relatively standard two-piece container or cup making machinery utilizing patterned air jet heating means to heat areas of the filled plastic sheet material such that the sidewall and bottom curl seams can be heat sealed on the forming mandrels of the machinery and the top curl can be placed in the container by heating and substantially conventional forming dies. The seaming structures so produced are extremely water tight and of high strength characteristics.

대표청구항 ▼

The method of forming a liquid tight and substantially undistorted seam in a thermoplastic sheet material including dispersed inorganic filler on the order of 30% to 50% by weight of the sheet material, comprising the steps of: heating opposing faces of the opposed areas to be joined at a seam in su

The method of forming a liquid tight and substantially undistorted seam in a thermoplastic sheet material including dispersed inorganic filler on the order of 30% to 50% by weight of the sheet material, comprising the steps of: heating opposing faces of the opposed areas to be joined at a seam in substantially similar patterns of discrete heat softened and fusible areas, thereby creating interspersed areas softened to a lesser degree; and clamping said opposed areas together over substantially the entire area of the seam.