MXPA99009334A - Process for the production of a plastic product from recycled material - Google Patents

Abstract

La presente invención se refiere a la producción de un elemento para construcción de casas, elementos como plafones, láminas onduladas para exteriores, tejas, entre otros, a partir de materiales de reciclado y de bajo precio. Teniendo la cualidad de permitir el uso de plástico reciclado en un 100%, permitiendo obtener un producto de valor comercial interesante, con un aspecto similar a los tradicionales, pero con cualidades de funcionamiento mejoradas y logrando piezas de grosores de más de cita pulgada sin que se deformen, no importando sus otras dimensiones de largo y ancho. Dicho proceso es del tipo que comprende los siguientes pasos 1)se recupera el material, 2)se selecciona y 3)se limpia y se 4)funde para posteriormente 5)moldear la pieza, y es innovado en el aspecto que el material ya limpio se muele y antes de fundirse se le agrega arena sílica, dispersando homogéneamente dicha arena en el plástico molido y porque el moldeo se lleva a cabo a presión.

Description

PROCESS OF PRODUCTION OF A PLASTIC PRODUCT FROM RECYCLED MATERIAL The present invention is related to a process of producing a plastic product from recycled material. More specifically it refers to the production of an element for the construction of houses, elements such as panels, corrugated sheets for exteriors, tiles, among others, from recycled materials and of low price.

BACKGROUND OF THE INVENTION With the so high production that exists of plastics at present, plastics that are used in the production of products that are discarded after their use, have a quite strong ecological problem. The recycling of plastics has the problem of requiring a conditioning that consumes too many resources and can not use more than a percentage of plastic recycling and the rest must be virgin plastic. This is because despite the conditioning of the recycling plastic, it is not possible to completely eliminate the impurities adhered to said plastic, in addition to which said plastic already underwent a thermal treatment that modified its physical and chemical qualities.

A process that would allow 100% recycled plastic to be used would make it possible to alleviate the pollution problem, and at the same time produce a product with low production costs and, therefore, cheap.

Currently, all garbage, including plastic waste, is being used in the so-called sanitary landfill. This use has a low added value and is more aimed at eliminating waste, than to obtain an additional benefit.

On the other hand, there are some products whose production materials have been little modified with respect to time, which have many drawbacks in terms of mechanical strength and life time, and which could be feasible to be produced by recycled plastic materials.

There is for example traditional clay tiles that are very fragile and of short duration when exposed to elements such as branches or fruits of trees that fall, too strong winds, extreme climates, places of difficult access and for maintenance.

On the other hand, fiberglass tiles and fiber cement tiles, which do not give the appearance of clay tiles, are very expensive or are equally fragile than mud tiles.

There are products that are manufactured with thermoformed plastic, with agglomerated wood, with mineral fiber laminates, injected plastics, fiberglass, among others, but they have a relatively high production cost, resist little impact and abrasion, are easy prey for weathering and when the product is more than 2.5 cm thick, they are deformed by the change in temperature.

OBJECTIVES OF THE INVENTION One of the objectives of the present invention is to make possible a new process that allows the use of 100% recycled plastic.

Another objective of the present invention is to make possible a process with the above qualities, which also allows obtaining a product of interesting commercial value.

Still another objective of the present invention is to have a process that allows obtaining products that look similar to the traditional ones, but with improved operating qualities.

Still another objective of the present invention is to achieve pieces of thicknesses of more than one inch without deforming, no matter their other length and width dimensions.

And all those qualities and objectives that will become apparent when making a description of the present invention supported by the illustrated modalities.

BRIEF DESCRIPTION OF THE INVENTION Broadly speaking, the present invention consists, in one of its aspects, in a process of producing plastic articles from recycled plastics. For this l) recycled plastic is mixed with silica sand inside a container, 2) it is heated while keeping the mixture moving until it has a more or less homogeneous and homogeneous paste, 3) it is molded in a mold and countermold, 4) pressure is applied, maintaining this, 5) the product is demold and 6) the final finish is given.

The addition of the silica sand was found to be better added before melting the plastic, mixing as homogeneous as possible and then melting, than adding the silica sand to the already melted material.

Due to the composition of the present material, it comprises an important load of silica sand, it is not possible to use an injection molding or extrusion since it is very abrasive with a very viscous rheology. That is why it is molded by casting in a mold and counter-mold.

In another of its aspects, the present invention consists of the new products that can be manufactured from said material. Some of these products, without being exhaustive the list, consist of tiles of various shapes and sizes, corrugated sheets for exteriors, panels with different coating such as metal sheets, varnishes, wood, products for architectural uses, pots, other products that require resistance to weathering, pieces resistant to impact or friction, such as furniture legs, stops for automotive vehicles, wheels, among others.

For a better understanding of the invention, we will now turn to the detailed description of some embodiments of the invention object of the present invention.

DETAILED DESCRIPTION OF THE INVENTION Said process consists of 1) selecting, cleaning and grinding high density polypropylene waste; 2) mix them, until homogenised, with fine silica sand in an approximate proportion of 700 g of sand for each 900 g of polypropylene; 3) heating said mixture to a temperature of 350 to 450 (C, 4) empty in a mold that is closed and pressed with a pressure of approximately 1000 kg; 5) Allow to cool and unmold; 6) deburr, degrease and clean and 7) apply a coating, such as exterior glaze or acrylic resin with a load of ceramic microspheres, such as that marketed under the brand Hydro-coat.

The main advantage of this product with respect to other similar, such as made in thermoformed plastic, agglomerated wood, mineral fiber laminates, injected plastic, fiberglass, etc., are its low cost to be manufactured from made of recycled material, resistant to impact and abrasion, resistant to weathering.

Unlike injected or thermoformed plastics, solid walls of more than 2.5 cm can be obtained without deforming the piece, thanks to its load of silica sand and the process of pressure molding.

EXAMPLES Example 1 The waste plastic was taken, selected, cleaned and ground, melted and molded at normal pressure, the resulting part was deformed.

Example 2 The waste plastic was taken, selected, cleaned and milled, mixed until homogeneous with silica sand in a proportion of about 700 g of silica sand per 900 g of plastic, melted and molded at a pressure of 1000 kg. The resulting piece had good mechanical characteristics, it was not deformed, but of an unpleasant visual perception.

Example 3 The waste plastic was taken, selected, cleaned and ground, melted, silica sand was added in a proportion of about 700 g of silica sand per 900 g of plastic, and molded at a pressure of 1000 kg. The mixture of molten material and silica sand could not be completely homogenized and the product showed poor mechanical qualities due to this lack of homogenization.

Example 4 The waste plastic was taken, selected, cleaned and milled, mixed until homogeneous with silica sand in a proportion of about 700 g of silica sand per 900 g of plastic, melted and molded at a pressure of 1000 kg, in a tile-shaped mold The resulting piece had good mechanical characteristics but an unpleasant visual perception. It was coated with enamel for exteriors, greatly improving its appearance. The resulting product was resistant to impact, with characteristics of perception similar to that of clay tiles, and with resistance to abrasion and weathering.

Example 5

Claims (5)

CLAIMS Having sufficiently described the invention as above, is considered as a novelty and therefore claimed as property expressed and contained in the following clauses claim.

1. Process of producing a plastic product from recycled material, of the type in which the material is recovered, selected and cleaned and melted to subsequently mold the piece, characterized in that the already cleaned material is milled and before being melted it adds silica sand, dispersing homogeneously said sand in the ground plastic and because the molding is carried out under pressure.

2. Process of producing a plastic product from recycled material, as claimed in claim 1, further characterized in that the proportion of silica sand added to the plastic is 700 g of silica sand per 900 g of plastic or more.

3. Process of producing a plastic product from recycled material, as claimed in claim 1, further characterized in that the molding pressure is 1000 Kg or more.

4. Process of producing a plastic product from recycled material, as claimed in any of claims 1 to 3, further characterized in that the recovery plastic is selected from the group formed of low density polyethylene, high polyethylene. density, polypropylene or a mixture thereof.

5. Process of production of a plastic product from recycled material, as claimed in any of claims 1 to 4, further characterized in that the mold used adopts a foi ma of the set formed by a tile of various shapes and sizes, sheets corrugated for exteriors, panels with different coating such as metal sheets, varnishes, wood, products for architectural uses, pots, other products that require resistance to weathering, impact or friction resistant pieces, such as furniture legs, stops for motor vehicles, wheels, among others