Abstract: The polyethylene caulking composition of the invention is a mixture of a carrier and binder component and polyethylene powder. The carrier and binder component is a liquid hydrocarbon oil. The polymer is finely subdivided polyethylene, preferably ultra high molecular weight, having a low melt index, no greater than 30. The composition is thixotropic with a consistency of toothpaste, typically having a stirred viscosity up to 30,000 centipoise at ambient temperature, which is suitable for use as a caulking composition. The caulking composition of the invention can be extruded at low pressures through a caulking gun or from a squeeze tube to plug vent holes or perforations in molded, hollow-form polyethylene parts, or applied as a caulk onto the flange surfaces of rotational molds.

Abstract: This invention comprises a self-supporting, temperature-stable, indicia-bearing laminate of at least one layer of a non-oriented polyolefin film having an indicia array and a layer of a non-oriented polyolefin support film. The indicia layer laminate is formed by printing a carrier sheet with at least one layer of a printing ink comprising a mixture of particulate polyolefin, indicia material and a polyolefin-compatible resin. The polyolefin support film is printed as a layer over the indicia layer with a mixture of a polyolefin and a polyolefin-compatible resin. The printed layers are cured into non-oriented films, forming an indicia transfer. The transfer is used by removing the indicia-bearing laminate from the carrier sheet and applying the laminate to the inside surface of a rotational mold where it melts and fuses into the outer wall of a polyolefin product during the formation of the product in the rotational molding cycle.

Abstract: The molding method of the invention is a low-temperature, liquid-phase, injection molding process using an externally heated mold. This molding process is ideally suited for production of limited quantities of molded parts, as comparatively low cost molds can be used. The molding composition used in the invention is a mixture of a carrier and binder component and a powdered polyethylene component. The carrier and binder component can be a very low density polyethylene, petroleum jelly, hydrocarbon waxes, liquid hydrocarbon oils, or mixtures thereof. The powdered polyethylene component is finely subdivided polyethylene, preferably ultra high molecular weight, having a low melt index, at least no greater than 30. The carrier and binder component is used in sufficient quantity to provide a thixotropic mixture with a consistency of toothpaste, typically having a stirred viscosity up to 30,000 centipoise at the injection temperature of the molding process.

Abstract: This invention is a method for the precise placement of indicia with high resolution into the wall of a hollow-form, molded plastisol part. The method includes the steps of preparing a plastisol graphic transfer by casting a base layer of plastisol onto a carrier sheet, printing indicia with pigmented plastisols onto the base layer of plastisol to form a graphic transfer, and over printing the graphic transfer with a body layer of plastisol. After each layer of plastisol is deposit, the layer cured by heating before depositing the next layer and the transfer is heated to cure the final, body layer.

Abstract: This invention is an indica transfer and method for its use to impart indica to polyolefin objects during rotational molding. The transfer is a laminate of at least two coats on a carrier sheet, which is preferably a flexible, transparent polymer sheet. The coats, as successive layers on the carrier sheet are: an indica coat of indica material in a graphic or alphanumerical array and a top coat of a top-coat pressure sensitive adhesive. Preferably the transfer also includes a backing coat of a backing-coat pressure sensitive adhesive between the carrier sheet and the indica coat, The pressure sensitive adhesive used for the top coat has a transition temperature less than the mold surface temperature onto which the transfer is applied to enable transfer of the coats to the interior surface of a rotational mold.

Abstract: A mixture of a carrier and binder component and polymer powders is provided as a molding composition for sealing rotational molds or for reinforcing selected areas of rotationally molded parts. The carrier and binder component can be very low density polyethylene, petroleum jelly, hydrocarbon wax, hydrocarbon tackifier, or mixtures thereof, and the polymer powders are thermoplastics having a low melt index. The molding composition is applied to selected areas of the rotational mold, such as to the mating flanges of the mold halves to seal the parting line of the mold, or to areas within the mold where it is desired to have reinforced regions of greater wall thickness, such as ribs or bosses.

Abstract: There is disclosed a method for permanently and decoratively enhancing a polyethylene surface of a preformed article. In this method, a decorative enhancement composition is created by blending particulate thermoplastic powder, a binder solid, and a colorant into a liquid carrier. The particulate thermoplastic powder bonds to the colorant, the binder solid promotes adhesion of the colored thermoplastic to the polyethylene surface until it can be bonded, and the liquid carrier facilitates the transfer of the colored thermoplastic to the polyethylene surface of the preformed article. The decorative enhancement composition is applied to the polyethylene surface. The deposited decorative enhancement composition and the interfacing polyethylene surface are heated sufficiently to incorporate the decorative enhancement composition into the polyethylene surface. The enhanced polyethylene surface is allowed to cure by removal of the application of heat.

Abstract: A permanent, roughened or textured surface is applied to parts molded from polyolefins, particularly from polyethylene by applying to the surface of the part a coating mixture of a tackifier resin and polyolefin particles in a liquid carrier and incorporating a granular or particulate matter in the coating, either by application to the coating or by admixing the granular or particulate matter into the coating mixture. The coated surface is heated to the melt temperature of the polyolefin surface for a short time, sufficient to gel the polyolefin particles of the coating into the surface of the part, but insufficient to cause any thermal distortion of the part.

Abstract: Electrical circuit elements such as electrically conductive strips are permanently applied to the surface of polyolefin parts, such as polyethylene parts which are manufactured by rotational molding, by use of a transfer which can be applied to the interior surface of a rotational mold at the start of the molding cycle or can be applied to the molded part after its formation. The transfer comprises a carrier sheet on which the conductive circuit elements are printed with a mixture of wax or polyethylene powders containing from 30 to about 60 weight percent of conductive particles, preferably metal flakes. After application, the carrier sheet is removed and the conductive circuit elements are permanently incorporated into the surface of the polyethylene part by heating, either during the rotational molding cycle or by post-cycle heating of the formed part.

Abstract: There is disclosed an aqueous-base coating composition containing, as essential components, finely-divided, water-dispersable: colorant, polyethylene, binder and water with sufficient of a surface active agent to form a stable suspension. The coating composition is applied as a film coating onto a polyethylene surface and the binder temporarily binds the coating to the surface until the coating can be thermally treated to incorporate the coating into the polyethylene, permanently coloring the surface. The invention also comprises a method for the preparation of the aqueous-base coating composition in which the essential components are prepared as aqueous dispersions or emulsions which are blended together to form the final coating composition.

Abstract: Anti-microbial activity is permanently applied to the surfaces of polyolefin objects by incorporating anti-microbial metals and metal salts into the surfaces. This is achieved by coating the selected surface of a preformed polyolefin part with the anti-microbial composition of this invention and then heating the surface of the object to fuse the coating into the polyolefin wall. Alternatively, the composition can be applied to the interior surface of a manufacturing mold at the start of the molding cycle from where it is incorporated into the wall of the molded object during its manufacture. The antimicrobial composition comprises from 0.5 to 5 weight percent of an anti-microbial additive in a hydrocarbon resin or polyolefin having a low melt index. This composition can be diluted with an organic or aqueous carrier for ease of application.

Abstract: This invention is an indicia transfer and method for its use to impart indicia to polyolefin objects during rotational molding. The transfer is a laminate of at least two, and preferably, three coats on a carrier sheet, which is preferably a flexible, transparent polymer sheet. The coats, as successive layers on the carrier sheet are: an optional backing coat of a backing-coat pressure sensitive adhesive, an indicia coat of a colorants in a graphic or alphanumerical array, and a top coat of a pressure sensitive adhesive. The pressure sensitive adhesive used for the backing coat has a transition melting temperature less than the surface temperature of the mold to which the transfer is to be applied while the top-coat pressure sensitive adhesive has a temperature sensitive adhesive which becomes tacky at the demolding temperature to enable transfer of the coats to the interior surface of a rotational mold.

Abstract: A mixture of a carrier and binder component and polymer powders is provided as a molding composition for sealing rotational molds or for reinforcing selected areas of rotationally molded parts. The carrier and binder component can be very low density polyethylene, petroleum jelly, hydrocarbon wax, hydrocarbon tackifier, or mixtures thereof, and the polymer powders are thermoplastics having a low melt index. The molding composition is applied to selected areas of the rotational mold, such as to the mating flanges of the mold halves to seal the parting line of the mold, or to areas within the mold where it is desired to have reinforced regions of greater wall thickness, such as ribs or bosses.

Abstract: Electrical circuit elements such as electrically conductive strips are permanently applied to the surface of polyolefin parts, such as polyethylene parts which are manufactured by rotational molding, by use of a transfer which can be applied to the interior surface of a rotational mold at the start of the molding cycle or can be applied to the molded part after its formation. The transfer comprises a carrier sheet on which the conductive circuit elements are printed with a mixture of wax or polyethylene powders containing from 30 to about 60 weight percent of conductive particles, preferably metal flakes. After application, the carrier sheet is removed and the conductive circuit elements are permanently incorporated into the surface of the polyethylene part by heating, either during the rotational molding cycle or by post-cycle heating of the formed part.

Abstract: A permanent roughened or textured surface is applied to parts molded from polyolefins, particularly from polyethylene by applying to the surface of the part a coating mixture of a tackifier resin and polyolefin particles in a liquid carrier and incorporating a granular or particulate matter in the coating, either by application to the coating or by admixing the granular or particulate matter into the coating mixture. The coated surfaced is heated to the melt temperature of the polyolefin for a short time, sufficient to gel the polyolefin particles of the coating into the surface of the part, but insufficient to cause any thermal distortion of the part.

Abstract: This invention is an indica transfer and method for its use to impart indica to polyolefin objects during rotational molding. The transfer is a laminate of at least two coats on a carrier sheet, which is preferably a flexible, transparent polymer sheet. The coats, as successive layers on the carrier sheet are: an indica coat of indica material in a graphic or alphanumerical array and a top coat of a top-coat pressure sensitive adhesive. Preferably the transfer also includes a backing coat of a backing-coat pressure sensitive adhesive between the carrier sheet and the indica coat, The pressure sensitive adhesive used for the top coat has a transition temperature less than the mold surface temperature onto which the transfer is applied to enable transfer of the coats to the interior surface of a rotational mold.

Abstract: There is disclosed an aqueous-base coating composition containing, as essential components, finely-divided, water-dispersable: colorant, polyethylene, binder and water with sufficient of a surface active agent to form a stable suspension. The coating composition is applied as a film coating onto a polyethylene surface and the binder temporarily binds the coating to the surface until the coating can be thermally treated to incorporate the coating into the polyethylene, permanently coloring the surface. The invention also comprises a method for the preparation of the aqueous-base coating composition in which the essential components are prepared as aqueous dispersions or emulsions which are blended together to form the final coating composition.

Abstract: There is disclosed a method for permanently and decoratively enhancing a polyethylene surface of a preformed article. In this method, a decorative enhancement composition is created by blending particulate thermoplastic powder, a binder solid, and a colorant into a liquid carrier. The particulate thermoplastic powder bonds to the colorant, the binder solid promotes adhesion of the colored thermoplastic to the polyethylene surface until it can be bonded, and the liquid carrier facilitates the transfer of the colored thermoplastic to the polyethylene surface of the preformed article. The decorative enhancement composition is applied to the polyethylene surface. The deposited decorative enhancement composition and the interfacing polyethylene surface are heated sufficiently to incorporate the decorative enhancement composition into the polyethylene surface. The enhanced polyethylene surface is allowed to cure by removal of the application of heat.

Abstract: There is disclosed a method and composition for cosmetically repairing a surface void in polyolefin objects. The method involves inserting a repair composition into the void and then applying heat thereto to fuse the repair composition with a surrounding portion of the polyolefin object. The repair composition is a physical mixture of a thermoplastic powder, a resin binder, and a solvent, having a paste-like consistency. The repair composition may be neutral in color, or may contain a colorant to closely match the underlying object. The heating step can be performed with an open flame or with a heat gun.

Abstract: There is disclosed a method for the permanent application of indicia to the surface of the polyolefin object by applying pigmented material to the surface in an indica pattern, preferably from a transfer sheet. Preferably the pigmented material is a mixture of finely divided pigment, hydrocarbon wax and finely divided polyolefin. The polyolefin surface bearing the indicia is coated with a coating mixture comprising a mixture of polyolefin and a binder such as a rosin or wax. Thereafter, the coated, indicia-bearing polyolefin surface is surface-heated to a temperature sufficient to fuse the coating and incorporate the coating and indicia permanently into the polyolefin object. The heating can be performed by passing a heat source across the surface.