Abstract: A method of incorporating a preformed shape into a rotational molded product by a method that comprises the steps of a) forming a first resin into an uncured preformed shape having perimeter edges; b) positioning the uncured preformed shape having perimeter edges against an inside wall of a rotational mold; c) adding a second resin into the rotational mold; heating and rotating the rotational mold to form the rotational molded product, wherein said second resin binds to the perimeter edges of the preformed shape and the preformed shape becomes cured. The invention also relates to a rotationally molded product that has a preformed shape made of a first resin incorporated into an object or vessel made of a second resin, wherein the preformed shape is integral with the object or vessel.

Abstract: A multiple walled enclosure with low permeation properties and rugged impact resistance useful as a fuel tank or chemical container. The enclosure is made by rotomolding a first charge of thermosetting polymer into an outer layer, then rotomolding a charge of EVOH or other low permeation thermoplastic into a second layer, then rotomolding a second charge of thermosetting polymer into a third layer so that the low permeation thermoplastic layer is fully enclosed by layers of thermoset polymer. The preferred thermosetting polymer is crosslinkable polyethylene and the preferred low permeation thermoplastic is EVOH.

Abstract: A method to form a multiple walled enclosure with low permeation properties and rugged impact resistance useful as a fuel tank or chemical container. The enclosure is made by rotomolding a first charge of thermosetting polymer into an outer layer, then rotomolding a charge of EVOH or other low permeation thermoplastic into a second layer, then rotomolding a second charge of thermosetting polymer into a third layer so that the low permeation thermoplastic layer is fully enclosed by layers of thermoset polymer. The preferred thermosetting polymer is crosslinkable polyethylene and the preferred low permeation thermoplastic is EVOH.

Abstract: A multiple walled enclosure with low permeation properties and rugged impact resistance useful as a fuel tank or chemical container. The enclosure is made by rotomolding a first charge of thermosetting polymer into an outer layer, then rotomolding a charge of EVOH or other low permeation thermoplastic into a second layer, then rotomolding a second charge of thermosetting polymer into a third layer so that the low permeation thermoplastic layer is fully enclosed by layers of thermoset polymer. The preferred thermosetting polymer is crosslinkable polyethylene and the preferred low permeation thermoplastic is EVOH.

Abstract: A multiple walled enclosure with low permeation properties and rugged impact resistance useful as a fuel tank or chemical container. The enclosure is made by rotomolding a first charge of thermosetting polymer into an outer layer, then rotomolding a charge of EVOH or other low permeation thermoplastic into a second layer, then rotomolding a second charge of thermosetting polymer into a third layer so that the low permeation thermoplastic layer is fully enclosed by layers of thermoset polymer. The preferred thermosetting polymer is crosslinkable polyethylene and the preferred low permeation thermoplastic is EVOH.

Abstract: A method to form a multiple walled enclosure with low permeation properties and rugged impact resistance useful as a fuel tank or chemical container. The enclosure is made by rotomolding a first charge of thermosetting polymer into an outer layer, then rotomolding a charge of EVOH or other low permeation thermoplastic into a second layer, then rotomolding a second charge of thermosetting polymer into a third layer so that the low permeation thermoplastic layer is fully enclosed by layers of thermoset polymer. The preferred thermosetting polymer is crosslinkable polyethylene and the preferred low permeation thermoplastic is EVOH.

Abstract: A multiple walled enclosure with low permeation properties and rugged impact resistance useful as a fuel tank or chemical container. The enclosure is made by rotomolding a first charge of thermosetting polymer into an outer layer, then rotomolding a charge of EVOH or other low permeation thermoplastic into a second layer, then rotomolding a second charge of thermosetting polymer into a third layer so that the low permeation thermoplastic layer is fully enclosed by layers of thermoset polymer. The preferred thermosetting polymer is crosslinkable polyethylene and the preferred low permeation thermoplastic is EVOH.