Method of blow-molding and blow-molded product
A method of blow-molding comprises forming a parison of a thermoplastics material, closing a mold around the parison, injecting compressed gas into the parison through a blowing hole to form a molded product that is shaped according to the shape of the mold, then deforming a seal forming portion of the molded product with a heated sealing tool to seal the blowing hole. The seal-forming portion preferably comprises a tubular collar that surrounds the blowing hole.
1 . A method of blow-molding, the method comprising:
forming a parison of a thermoplastics material,
closing a mold around the parison,
injecting compressed gas into the parison through a blowing hole to form a molded product that is shaped according to the shape of the mold, and
deforming a seal forming portion of the molded product with a heated sealing tool to seal the blowing hole.
2 . A method according to claim 1 , wherein the mold is shaped to provide the molded product with a seal forming portion.
3 . A method according to claim 2 , wherein the mold is shaped such that the seal-forming portion is located adjacent the blowing hole.
4 . A method according to claim 2 , wherein the seal forming portion includes a tubular collar that surrounds the blowing hole.
5 . A method according to claim 4 , wherein the tubular collar extends outwards from the molded product.
6 . A method according to claim 4 , wherein the mold is shaped to form a locking element that restricts movement between the tubular collar and the mold.
7 . A method according to claim 6 , wherein the locking element includes a flange element that is provided on the tubular collar.
8 . A method according to claim 1 , wherein the mold is shaped to provide the molded product with a recess in the vicinity of the blowing hole.
9 . A method according to claim 8 , wherein the seal forming portion is deformed to form a seal element that is located within the recess.
10 . A blow-molded product comprising a hollow molded body portion and a seal element that seals a blowing hole in the body portion, wherein the body portion and the seal element are made of a thermoplastics material and the seal element comprises a deformed seal forming portion of the body portion.
11 . A blow-molded product according to claim 10 , wherein the seal-forming portion is located within a recess provided in the molded body portion.
12 . A blow-molded product according to claim 10 , wherein the blow-molded product comprises a wall panel of a container.