Method and device for welding polyolefinic objects
AssigneeWavin B.V.
InventorGerhard Harmsen
Life of this patent
Estimating the term…
Abstract
A method and apparatus for butt welding two surfaces of different polyethylenes by heating the two surfaces up to different temperatures at which the viscosities of the two different polyethylenes of the two surfaces are equal. The heating device for heating the polyethylene surfaces comprises two separate plates which can be heated up to different temperatures. The device is also provided with pressure regulating means for controlling the pressure at which the two surfaces are pressed onto each other.
Claims8
A method of welding two polyolefinic surfaces, each comprised of a material having a respective melt-flow index, the material of the first surface having a higher melt-flow index than the material of the second surface and the materials of both surfaces having different melting points;
- said method comprising the steps of:
- heating the first surface to a predetermined temperature and for such time that the material of the first surface has a predetermined flow behavior characteristic;
- heating the second surface to a predetermined temperature and for such time that the material of the second surface has a flow behavior characteristic substantially equal to the predetermined flow behavior characteristic;
- moving the heated surfaces when they are at substantially equal flow behavior characteristics into abutment so as to cause the materials of the surfaces to weld.
Dependencies are inferred from the claim text.