Method for producing a pressure-resistant and/or leak-tight vessel for holding a gas and/or liquid
The present invention relates to a method for the manufacture of pressure-resistant gas and/or liquid tight containers made from thermoplastic materials. To this end the method comprises the following steps: providing a removable external mandrel around a neckpiece, followed by providing at the inside of such mandrel a thermoplastic material for the manufacture of a thermoplastic internal wall. Hereupon the external mandrel is removed and the thermoplastic internal wall is filled with a cooling liquid. Hereupon additional thermoplastic material is provided to the external side of the thermoplastic wall and is consolidated either during the provision hereof, or thereafter or both. Hereupon the cooling liquid is removed and the container is ready for being used.
1. Method for the manufacture of a pressure resistant gas and/or liquid tight vessel, comprising:
a) providing a removable external mandrel around a neckpiece;
b) providing at the inside of such mandrel a thermoplastic material for the manufacture of a thermoplastic internal wall;
c) removing the external mandrel from said neckpiece and the thermoplastic internal wall;
d) filling of the thermoplastic internal wall with a cooling liquid;
e) providing to the external side of the thermoplastic wall additional thermoplastic material;
f) consolidating the additionally provided thermoplastic material while the cooling liquid remains in contact with the thermoplastic internal wall to sufficiently cool the internal wall to avoid deformation thereof; and
g) removing the cooling liquid from the thermoplastic internal wall.
2. Method according to claim 1 , wherein the thermoplastic internal wall is made by roto-molding or blow-molding.
3. Method according to claim 1 , wherein the additionally provided thermoplastic material is consolidated by heat.
4. Method according to claim 1 , wherein the additional thermoplastic material is provided through winding.
5. Method according to claim 1 , wherein the thermoplastic material is polybutene-1 and the additional thermoplastic material is glass fiber-reinforced polybutene-1.
6. Method according to claim 1 , wherein the cooling liquid is water.
7. Method according to claim 1 , wherein the neckpiece of the container is made of metal and provided with an external screw thread.
8. Method according to claim 7 , wherein the container is sealed by a stopper, provided with an internal screw thread connection that is operatively connected to an external screw thread of the metal neckpiece of the container.
9. Method according to claim 8 wherein a sealing is provided between the stopper and the neckpiece of the container.
10. Method according to claim 8 wherein a sealing ring is provided between the stopper and the neckpiece of the container.