Process for reducing cross link vapors from rotomolded products made of cross link polyethlylene
AssigneeCentro Corporation
InventorBrian M. Weber
Life of this patent
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Abstract
A method to reduce cross link vapors trapped in hollow cross link polyethylene products produced by rotomolding is disclosed. Ozone is introduced into the hollow product after the polymer has cross linked. Compressed air is delivered with the ozone to circulate the ozone effectively. Use of the ozone oxidizes the cross link vapors and permits reduction in stored inventory of units awaiting dissipation of the cross link polyethylene vapors. A system for batch treatment of the products is also disclosed.
Claims24
In a rotomolding system operated in accordance with the method comprising the steps of introducing a powdered mixture of polyethylene and free radical generator into a hollow mold, biaxially rotating the mold in an oven, heating the mold sufficiently to cross link the polyethylene, curing and solidifying the cross linked polyethylene into a hollow body, removing the mold from the oven to a cooling station, cooling the mold, opening the mold to withdraw the hollow body from the mold,
- the improvement comprising the steps of introducing ozone into the hollow body after tho polyethylene begins to cure whereby the cross link vapors generated arc reduced.
A method to produce a molded form from cross link polyethylene comprising the steps of
- introducing a mixture of powdered polyethylene resin and a cross linking agent into a hollow mold,
- biaxially rotating the mold in an oven,
- heating the mold sufficiently to cause the resin to be cross linked,
- curing and solidifying the cross linked polyethylene into a form,
- exposing the form to ozone for a predetermined time whereby the vapors generated by cross linking are reduced.
A method of reducing malodorous oxidizable gaseous byproducts generated in the forming of a hollow workpiece from a powdered mixture of polyethylene and free radical generator in molds carried in a rotomolding apparatus, the workpiece having an interior space, comprising introducing ozone into said interior space of said workpiece.
Dependencies are inferred from the claim text.