MATERIALS, SYSTEMS AND METHODS INVOLVING PLASTICS MATERIAL FIELD OF INVENTION

The present invention relates to materials, systems and methods involving plastics material. In one form, the present invention relates to the recycling of waste electrical and electronic equipment (WEEE).

In a particularly preferred arrangement the present invention relates to a multilayered building product. BACKGROUND ART

Environmental, financial and legislative drivers are pushing towards a more rigorous approach to recycling. Currently recycling technologies are optimised for precious and ferrous metal recycling. These technologies are considered not suitable for recycling of products that are mostly of other materials such as plastics. Current technologies are not directed at providing zero landfill. Thus there is a need to process the WEEE materials considered to be 'waste' in various other industries.

The inventors have realised that there are four types of plastics which dominate the polymeric materials found in WEEE ₁ nameiy acrylonitrUe butadiene styrene (ABS), high-impact polystyrene (HIPS), polycarbonate (PC) and an ABS/polycarbonate (ABS/PC) blend. There are also many different polymer types of materials in WEEE, for example, with some WEEE streams some 35 types of polymer materials have been identified. Plastic sorting and separation is required to maximize economic return. Plastic enrichment and purification to a level to enable marketability is therefore required.

It is an object of the present invention to provide a use for recycled plastics which is advantageous, or in the alternative to at least provide the public with a useful choice. SUMMARY OF INVENTION

According to a first aspect of the invention there is provided a building product comprising a first layer of plastics material and a second layer of plastics material with a core layer therebetween, the core layer containing processed waste electrical and electronic equipment material.

According to a second aspect of the invention there is provided a process of forming material into a product comprising:

processing waste electrical and electronic equipment material to incorporate waste toner and waste plastics; providing two layers of plastics material either side of the processed waste electrical and electronic equipment material to provide a first and a second layer with a core layer therebetween, the core layer being provided by the processed waste electrical and electronic equipment material.

According to a third aspect of the present invention there is provided a product produced as a result of a process according to the second aspect.

Other aspects and preferred aspects are disclosed in the specification and/or defined in the appended claims, forming a part of the description of the invention.

For example, the building product may be provided with cellular morphology with the use of a blowing agent comprising azodicarbonamide. A compatibilizer comprising a styrene acrylate copolymer may be added. Preferred arrangements provide a manner in which the material of obsolete electronic products can be reused. In these arrangements the obsolete electronic products are recycled into a core comprising the waste that is hidden from view and which locks away toner. Advantageous strength and rigidity characteristics are, in arrangements, provided in a building product which can be used in situations requiring an aesthetically pleasing result. Advantageous acoustics and thermal properties are also preferably provided.

Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

Further disclosure, objects, advantages and aspects of the present application may be better understood by those skilled in the relevant art by reference to the following description of preferred embodiments taken in conjunction with the accompanying drawings, which are given by way of illustration only, and thus are not limitative of the present invention, and in which:

Figure 1 is a perspective view of a building product according to a first preferred embodiment of the present invention; and

Figure 2 is a schematic view of a method according to a second preferred embodiment of the present invention. DETAILED DESCRIPTION

Referring to Figure 1 there is shown a building product 10 according to a first preferred embodiment of the present invention. The building product 10 comprises a first layer of plastics material 12 and a second layer of plastics material 14 with a core layer 16 containing processed waste electrical and electronic equipment material 18 between the first and second layers 12, 14. The building product 10 advantageously provides beneficial aesthetic and mechanical properties.

The building product 10 forms a multilayer moulded unit that is anticipated will find application in a wide number of areas such as in the construction of barriers, walls, marina walkways, concrete formwork, marine plywood substitution, marine dryboard applications, thermal insulation panels, containers including insulated fruit and vegetable crates and boxes, slip sheets for wooden pallets, layer pads for stacking glass bottles, and containers on pallets.

Figure 2 illustrates a process 20 according to a second preferred embodiment of the present invention in which the building product 10 is produced.

In the moulding process 20 the building product 10 is formed as a product 22 that incorporates waste toner 24 and waste plastics 26 from waste electrical and electronic equipment material 28. In the -embodiment the waste electrical and electronic equipment material 28 comprises used computer printer cartridges. In the moulding process 20 at block 30, waste styrene-acrylate toner 29 and styrenic plastics 32 are incorporated to form the core layer 16. At block 34 the core layer 16 is sandwiched between first and second layers 12, 14 which in this embodiment comprise layers of polyolefin plastic. The process 20 includes at block 35 adding a comptabtlizer 36 to the waste styrene-acrylate toner 29 and the styrenic plastics 32. In this embodiment the compatibilizer 36 is added at the same time as the waste toner 29 and mixed styrenic plastics 32 and is then mixed to form a homogeneous mixture.

. In the process 20, waste electrical and electronic equipment is processed to provide the processed waste electrical and electronic equipment material 18. Advantageously the processed material comprises processed computer printers, fn other embodiments the processed material comprises processed mobile phones and other electronic equipment. The waste plastics 26 comprises styrenic polymer based on styrene-butylene-styrene/ethylene-propylene monomer (SBS/EPM). In other embodiments the waste plastics 26 comprises, strene- ethylene-butylene-b-polystyrene (SEBS).

It is to be appreciated that the styrenic blend nature of the waste plastics 26 advantageously provides stiffness and rigidity that offsets the inherent flexibility of the first and second layers 12, 14 which comprise polyolefins. Moreover the compatibifeer 36 achieves good interfadal adhesion between the core layer 16 and the first and second layers 12, 14. This serves to prevent interlamellar fracture. Without the compatibilizer 36 the components would be largely immisicle and would not bond together well. This would result In planes of weaknesses which under the application of mechanical stress would lead to delamination.

It is considered that suitable compatibilizers should have both a styrene character and an olefin character. Block copolymers of these two classes of compound are preferred.

The compatibilizer, in particular forms of the invention, may be one or more of the following class of materials, waste toner powder (styrene acrylate copolymer), ethylene vinyl acetate, styrene-butylene-styrene/ethylene-propylene monomer (SBS/EPM) or strene-ethylene-butylene-poiystyrene (SEBS). The compatibilizer reduces the interfacial surface tension, allows the different phases to 'wet' out each other and thereby promotes good adhesion. The compatibilizer makes the polar and non-polar substituents of the mixture "hold hands".

In terms of aesthetics, the core layer 16 is sandwiched between the first and second layers 12, 14 to mask any inconsistencies in the appearance of the core layer 16. The first and second layers 12, 14 each comprise non transparent virgin materials so that any inconsistencies in the physical appearance in the core layer 16, resulting from the presence of contamination by foreign objects or irregular colour tones in the core 16 are, by and large, hidden from view.

Furthermore by the recycled core 16 being buried between two layers of virgin polymer 12, 14 there is provided good surface finish, uniform colour, good gloss and no voids, inclusions or obvious defects that detract from the visual appearance. This is provided despite the core layer 16 being of a variable colour and consistency.

In this embodiment polyethylene or polypropylene is added to the waste electrical and electronic equipment material 18 to vary the overall stiffness of the core layer 16. Advantageously, the core 16 is provided with a cellular morphology 38 by adding blowing agents. In one preferred embodiment the core 16 is made into a cellular structure through the use of blowing agents whose activation temperature falls in the temperature range of the moulding process used, in this embodiment blowing agents for the core i&yer 16 comprise sodium bicarbonate/citric acid mixes and azodicarbonamide. Advantageously the use of the blowing agent stiffens the core layer 16 to provide a strong and lightweight product with a cellular morphology.

As would be apparent from the above the core layer 16 advantageously comprises waste toner powder and mixed styrenic polymers which in the building product 10 imparts rigidity. As such, the toner is advantageously 'locked away ¹ within the core 16. The first and second layers 12, 14 form aesthetic skin layers comprising polyolefin either side of a core having a styrenic blend nature. A coupling agent/s in the form of compatibilizer 36 is used to prevent debonding and delamination between the styrenics layer and the polyolefin skin layers. The process 20 incorporates recycled plastic into an aesthetically and mechanically advantageous component having advantageous, mechanical properties. These properties include acoustic properties, thermal properties and strength properties.

It is to be appreciated that the first and second layers form two skins of virgin plastics material preferably a polyolefin such as polyethylene or polypropylene. The moulding process 20 is preferably a powder impression moulding process in which the core is sandwiched.

The powder impression moulding process is used to mould plastic building products 10 comprising an expanded foamed plastics core comprised of mixed styrenic plastics and/or waste toner powder sandwiched between the first and

second layers 12, 14. It is considered that the production of relatively thin-walled plastic building products using commodity polyolefins applied either side of a core formed from waste toner powder and/or styrenic piastics is particularly advantageous. In the moulding process in the present embodiment waste toner and mixed styrenic plastics are poured into an open mould to 200-300 degrees Celsius such that the mould is at a higher temperature than the melting point of the plastic particulate material. The mould is then closed for a period of time known as the residence time, which couid be between 1 and 20 minutes so that the mixed plastics melts to form a skin of thickness between 1 mm and 10 mm. An appropriate blowing agent such as sodium bicarbonate/citric acid mixes and azodicarbonamide is used.

In the process two complementary male and female moulds are used in the formation of the opposed surfaces of a core layer over which granulate or powder plastics and/or toner powder are placed. The moulds are heated by conduction to melt and form a molten plastics material that is then shaped under pressure to adopt the form of the moulds.

Nestable male and female moulds could be used which under heat and pressure impart a predetermined shape to fused plastic. Suitable release agents can be used such as silicone oil or fatty acid amide waxes so that the heated male and female moulds do not adhere to the two skins of plastic article.

In one arrangement the moulded product is released from the moulds after moulding, however in alternative process thin-walled mould sheets are retained on the finaf moulded product to give integrally bonded faces to the underlying plastics material. The thin walled mould panels may be aluminium sheet, galvanized steel sheet, sheet metal depending on the particular requirement. The thin walled mould sheets may comprise Colourbond steel sheet to give a decorative outer appearance and strength properties combined with the insulating properties of the plastics material of the core therebetween. In the moulding process 20 adhesion promoters such as titanates or zirconates are used so that the heated male and female moulds adhere to the two skins of plastic articles such that an article is formed having a moulded surface on both sides with a

metallic skin on top. In such embodiment mould releases agents would not be used.

One example of a moulding process, for example a powder impression moulding process, applicable to the present invention is disclosed in WO2005090041 entitled MOULDING PLASTICS ARTICLES, to 3DM WORLDWIDE PLC ₁ having an international filing date of 21 March 2005. WO2005090041 is hereby fully incorporated by reference. Advantageously, the present invention utilizes waste electrical and electronic equipment material as a core. This is achieved as described. In another preferred embodiment of the present invention there is provided a material which comprises of a formulation including waste toner, cellulose material mixed with dye and pigment Ink concentrates, waste plastics, and crushed waste glass(silica) from electrical / electronics scrap. In the formation of building products similar to building product 10 various compatibiiizers and foaming agents are used in the formation of the material.

In a further embodiment building products comprise powdered CRT glass or powdered PU foam possibly mixed with powdered styrenics, nylons, toner powder in the core. In some variations the waste electrical and electronic equipment material is mixed with a foaming agent and be used as a core layer in sandwich moulding process to form a multilayered component similar to building product 10. As with building product 10 suitable compatibiiizers are used to ensure good wetting and adhesion between the core layer and the different materials of the adjoining layers.

The building product due to its cellular core and rigid skin is advantageously lightweight, rigid and exhibits good acoustic attenuation properties for applications such as highway barriers walls and good thermal insulation properties to reduce heating losses.

While this invention has been described in connection with specific embodiments thereof, it will be understood that it is capable of further modification(s). This application is intended to cover any variations uses or adaptations of the invention following in general, the principles of the invention and including such departures from the present disclosure as come within known

or customary practice within the art to which the invention pertains and as may be applied to the essential features hereinbefore set forth.

As the present invention may be embodied in several forms without departing from the spirit of the essential characteristics of the invention, it should be understood that the above described embodiments are not to limit the present invention unless otherwise specified, but rather should be construed broadly within the spirit and scope of the invention as defined in the appended claims. Various modifications and equivalent arrangements are intended to be included within the spirit and scope of the invention and appended claims. Therefore, the specific embodiments are to be understood to be illustrative of the many ways in which the principles of the present invention may be practiced, in the following claims, means-plus-function clauses are intended to cover structures as performing the defined function and not only structural equivalents, but also equivalent structures. For example, although a nail and a screw may not be structural equivalents in that a nail employs a cylindrical surface to secure wooden parts together, whereas a screw employs a helical surface to secure wooden parts together, in the environment of fastening wooden parts, a nail and a screw are equivalent structures.

"Comprises/comprising" when used in this specification is taken to specify the presence of stated features, integers, steps or components but does not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof." Thus, unless the context clearly requires otherwise, throughout the description and the claims, the words 'comprise', 'comprising', and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of "including, but not Jimited to".