Artigo

There are several industrial activities that use materials and processes that undermine the balance of the environment, as well as being pollutants by using exhaustible natural resources and have already started to show worrying levels of scarcity, leading the company to seek alternative solutions to this problem.

Currently, arise up alternatives and seeking ways to reconcile the objectives of economic, environmental and social, adopting environmental management programs as option gains ahead.

In general, when considering the environmental aspect recycling can help reduce the progressive accumulation of waste, the production of new materials, such as paper, which requires a greater number of cutting trees; emissions gases; aggression to the soil, air and water, among many other negative factors.

In the social sphere, recycling not only provides a better quality of life for individuals, through environmental improvement, but has also generated many jobs and opportunities in the area of recycling.

On the economic side, recycling contributes to the rational use of natural resources and the replacement of those assets that are likely to be reused becoming important study and the advent of new materials and forms for reuse or recycling.

Among the new materials available, may be listed in the WPCs - wood-plastic composites. They are made from wood waste and recycled thermoplastics and can be considered as composite echo-figuring a new class of materials with great commercial potential in many different applications.

A material shall not be classified as waste because most of its value as raw material, aiming to produce new products. Thus, the residue is treated as a byproduct of the production process (SAVASTRANO, 2000). When it comes to waste recovery, the trend remains the reuse of materials that take years to complete deterioration.

It can be argued that the emergence and development of production processes and products need to walk with the requirements of innovative sustainability urgent. Currently, it is remarkable that the discussions on sustainability assume operational nature.

The concept of "green operations" green operations or seeking the design and manufacture of products, developing processes rationally and intelligently, seeking the maximum reduction of waste found. This need is found in the industrial sector of environmentally suit has caused many companies to review their processes.

In fact, it is known that isolated actions will not solve the problems arisen by this residue and that the industry should try to close production cycle so as to minimize waste output and input of non-renewable raw materials (DORSTHORST; HENDRIKS, 2000).

This study was based on these aspects: clear plastic and waste wood and the possibility of reuse of such waste by applying the principles of sustainability.

2 Theoretical Foundation

The wood-plastic composites (WPCs) are made from waste wood and recycled thermoplastics and can be considered as eco-composites, although they did not look that would be considered natural. From the 90, the market recorded significant growth of this composite, doubling year on year to their demand, especially in niche markets where priorities as weather resistance and lower maintenance costs become relevant for the application of the material.

The term "plastic composites reinforced with wood" is now accepted by referring to the composites of thermoplastic matrix reinforced with particles or fibers, of wood. The thermoplastic composites reinforced with wood, in general, and as described ahead, consist of compounds that disperse particles of wood, usually thin, flour or sawdust called in everyday language, or wood fibers, thermoplastic brought to a state liquid melt, utilizing manufacturing techniques such as extrusion and injection molding.

The powder timber provides a reduction in cost, but will not automatically change to the better the performance of such materials. Recently, the uses of natural fibers have been interesting as it promotes character reinforcement for thermoplastic materials.

The term "eco-composite" is described by Forestry (2004) as a material that can both contain natural fibers such as hemp, sisal, jute or flax, as a natural polymer matrix. Compounds based on natural starch can be produced with the important advantage of biodegradability. A compound which is easier to recycle as a material comprising polypropylene, can also be termed as an eco-composite.

Much of the recent growth, development and use of WPCs was driven by initiatives funded by the Ministry of Agriculture and other groups associated with forestry and lumber industries in the U.S.A. Therefore, many of the companies involved in the production of WPCs in the U.S. are timber companies that have invested in product development and added these alternative materials to its product portfolio (OPITMAT Ltd and MERL Lta, 2003).

The new generation WPCs is produced by mixing wood flour or fiber & plastics to produce the materials that can be processed like a conventional plastic & has the best features of wood & plastic.

According to the same author, in general, the WPCs are a new class of materials with great commercial potential, as applications for the composite plastic-wood overlays, doors and windows, floors, doors and ceilings, interior panels, tubes, boats plates, frames, boxes, trash, mobile external and internal, recreational facilities, among others.

The future of wood plastic composites will depend on many factors. Ultimately, including new product identification, product quality, consumer perception & performance of these materials.

3 Materials and Methods

In this study was used for the production of composite wood-plastic (60mesh) derived from mixtures of Pinnus Elliotii and Taeda, besides the recycled polypropylene. The details follow in Figure 1 below.

Figure 1: Polymer recycled process of separation and cleaning.

After separation of the raw material were prepared four strokes being that for each 05kg of material was used. The formulations were 100% PP-T1, T2-90% PP +10% FM, 80% T3-PP +20% FM and T4-70% PP +30% FM.

Aiming the production of such composites (Figure 2), we used a brand extruder “Extrusão Brasil”, twin screw, co-rotating and L / D = 40, possessing eleven heating zones.

Figure 2: Pellets of wood-plastic composite in 30%, 20%, 10% and 100% PP FM, respectively.

After extrusion, the formulations stood