Method of manufacture of packing containers and packing containers manufactured in accordance with the method
AssigneeTetra Pak Developpement SA
InventorsAnders R. Rausing, E. Ingvar Nilsson
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Abstract
The invention relates to a method for the manufacture of packing containers. The container body of the packing container is manufactured by spiral winding of a monoaxially molecular-oriented polyester film. The polyester film is spirally wound onto a mandrel to form a tube with the edge zones of successive turns of the strip overlapping in a continuous joint. The material is sealed within the edge zones by means of surface fusion. The invention also relates to a packing container manufactured in accordance with the method.
Claims9
A method for the manufacture of packing containers from a striplike film, comprising the steps of coating a polyester strip which is monoaxially molecular-oriented in the strip direction with a layer of a non-molecular-oriented amorphous polyester material, spirally winding the coated polyester strip onto a mandrel to form a tube, overlapping edge zones of successive turns of the strip during winding with the width of the said overlapped zones constituting at the most 15% of the width of said strip, sealing the edge zones together in a continuous joint by applying heat to the edge zones for melting and fusing together of the non-molecular-oriented polyester coating, the width of said strip being 75-150% of the diameter of the tube.
Dependencies are inferred from the claim text.