WO2002060664A1

WO2002060664A1 - Composite constructive material, and method for fabricating artefacts of said material

Info

Publication number: WO2002060664A1
Application number: PCT/IB2002/000189
Authority: WO
Inventors: Michele Drelli; Ciro Migliore; Annibale Tontini
Original assignee: Individual
Current assignee: Individual
Priority date: 2001-01-31
Filing date: 2002-01-21
Publication date: 2002-08-08
Anticipated expiration: 2003-07-31
Also published as: ITRN20010010A0; WO2002060664A9; ITRN20010010A1

Abstract

A construction material for building artefacts, in particular conglomerate panels, comprises natural or artificial textile fibres, possibly mixed with straw (1) of cereals in stems and/or also with fragments of ligneous, or vegetable materials; and a synthetic resin (3), adhesive, ureic based, which, in the fluid state, is able to impregnate and to agglomerate the fibres, the straw (1) and the fragments and which, soldifying, is able to make them mutually integral in such a way as to form a structurally resistant monolithic material (3). An artefact and a method for fabricating artefacts of said material are integral parts of the inventions.

Description

Description Composite Constructive Material, and Method for Fabricating Artefacts of Said

Material

Technical Field

The present invention relates to the production of structurally resistant construction materials destined to the manufacture of artefacts usable directly as finished products, or able to constitute semi-finished products usable in various types of industries, for instance to replace wood, or its derivatives.

Some types of industries are known to employ construction materials derived from wood, or packaged with wood, preferably shavings, chips or fibres, which with or without using binders are worked in such a way as to provide panels or plates. Such panels can find application in decorations, by means of applications of grooves or surface contours; in pavements; or as woodworking coatings by means of gluing with artificial resins. In the furniture industry, such panels are then employed as basic components for the fabrication of the furniture itself.

Background Art Known wood chip panels are obtained by means of fabrication methods and plants that perform the hot pressing of wood shavings and of binding resins; resins which in particular are obtained by mixing various adhesive substances (for instance: ureca, cement, formaldehyde) suitably mixed and appropriately dosed with each other.

The ligneous material, once coming from the shaving of selected wood, having well determined nature and characteristics, is currently constituted in ever more preponderant measure by recycled material, of various origins and quality. It is not infrequent for said material to contain materials other than wood, such as metal parts, parts of plastic origin which are incorporated in the panel itself.

The mixing of such materials, having very different characteristics, to be conglomerated and made integral with each other in any case, has determined the need to make use of particular mixtures of glues and to cause, in favour of the glues, an increase in the weight ratio with respect to the weight of the ligneous mass of the panel.

Due to the progressive decrease in the availability of quality wood, the panels, produced over the years, have become progressively more heterogeneous, ever richer in recycled materials and ever heavier, with other disadvantageous consequences in terms of ease of manipulation and transportation; moreover, they also have degraded workability which is felt in sectioning and in drilling operations which are the most common and recurring in construction practice. Both traditional chip panels, which are those most recently obtained with the inclusion of recycled ligneous material, have an alveolar, porous structure, and hence suffer from the general limitation of not being waterproof, tending to absorb humidity and to expand in the presence of water. Moreover, these panels have no fire-retardant properties. As a consequence thereof, wherever said characteristics are made indispensable by the use of the product whereto the panels are destined, or vice versa desirable or advisable for safety reasons, conventional panels are subjected, depending on the case, to particular and specific treatments able to occlude the natural porosity of the panel by laying suitable occlusive and/or protective materials, and/or materials suitable to inhibit the ability to combust.

Such treatments are carried out by means of costly and special plants and equipment and hence they bear to a fairly significant extent on the final cost of the panel and/or of the products that use said panels.

A different solution to the aforesaid problems, already known in the art, and described in document WO 0025998, uses, to replace the wooden chips, straw that has been previously ground until forming a fine flour which is then mixed to the adhesive resin, so as to form a paste-like mass which is then compressed and solidified under heat using very complex and costly production plants. Disclosure of Invention

The aim of the present invention is to overcome all the drawbacks of the prior art by means of a construction material which, in accordance to the invention, comprises at least textile fibres and an adhesive synthetic resin, ureic based which in the fluid state, is able to impregnate, conglomerate the fibres and which, solidifying, is able to make them integral thereby forming a monolithic, structurally resistant material.

The ureic based synthetic resin, constituted in particular by high viscosity urea- formaldehyde (also commercially known as "ureca"), advantageously with the addition of a vinyl resin, has revealed the surprising ability to be absorbed by the textile fibres and also be any additional fragments of added materials, of natural origin, so that it has been experimentally verified that it possible, surprisingly, to obtain in a very simple and economical manner a construction material with structural resistance characteristics that are suited to meet a wide variety of different uses; material which moreover combines to a reduced weight also the property of being at the same time waterproof and fire retardant and which, therefore, does not require any further particular type of treatment aimed at obtaining said results.

The material, according to the invention, is advantageously suitable for being used for the fabrication of semi-finished or finished panels, destined for instance to the fabrication of furniture or tiles for floors; fabrication which can be obtained by means of work methods, also part of the invention, which respectively comprise - after impregnating the various types of fibres and the other materials which may be mixed therewith - a phase of pressing in a mould; or a lamination phase; or also an extrusion phase. Advantageously, the material is suited also to be injected directly in the fluid state into the cavity of a forming mould, to assume the shapes of the most widely varying artefacts. Description of the Drawings

The technical characteristics of the invention, according to the aforesaid aims, can be clearly noted from the content of the claims set out below and its advantages shall become more readily apparent in the detailed description that follows, made with reference to the accompanying drawings, which represent an embodiment provided purely by way of non limiting example, in which:

Figure 1 is a representation of an artefact, shaped as a panel or plate, made with a material according to the invention;

Figures 2, 3, 4 and 5 are schematic representations of examples of possible work methods, in accordance with which the material according to the invention can be used.

Description of the Illustrative Embodiment

With reference to the accompanying drawings, Figure 1 shows an artefact having, as an example, generally parallelepiped shape, obtained with a construction material essentially comprising, in combination, natural or artificial textile fibres 40, possibly conglomerated with a fragments 1 of straw in stems, at the natural state, subdivided into pieces of appropriate size, possibly also conglomerated with fragments of ligneous materials of various origins and characteristics; and a synthetic adhesive ureic based resin 2 able, in the liquid state, to impregnate the fibres 40 and the various materials conglomerated thereto and, solidifying, to agglomerate it and make it integral thereby forming a structurally resistant, compact monolithic material 3.

The textile fibres 40 can be obtained from various origins, for instance from scraps of textile industries. The straw, of vegetable origin, can be obtained from the mechanical break-up of cereal stalks, such as wheat, rice, corn, which, at the natural state, are water-repellent in themselves. Said straw can also be combined with other materials, such as ligneous fragments 20 obtained by breaking up nutshells, peanuts, pine nuts, pine cones, reeds or other scrap materials obtained from squeezing sugarcane; or combined with fragments 30 of vegetable materials, originated from some fibrous plants, such as sunflowers, prickly pears, brooms. The resin is preferably constituted by a urea-formaldehyde based liquid glue with high viscosity and high dry content, currently also known as "ureca"; preferably inclusive of a vinyl resin present in a percent ratio of between 10% and 20% of the total. The construction material obtained by the aggregation of the aforesaid components can be used for the manufacture of artefacts of wholly general shape which, merely by way of applicative and wholly indicative example, can find application in the furniture industry in lieu of conventional wood shavings panels or also to obtain paving plates. The artefacts thereby obtained have a relatively low unit weight and are water-repellent and fire retardant; they also have very good heat and sound insulation characteristics.

According to a first fabrication method, said artefacts can be obtained by a succession of phases, providing for: impregnating the fibres 40 and the various fragments 1, 20, 30 which may have been added - in the synthetic resin 2 in the fluid state to obtain a physically heterogeneous, more or less consistent fluid mass 4; heating the mass 4 to an appropriate temperature; pressing; and solidification in a mould 5 until obtaining the compact, monolithic, structurally resistant artefact.

A variation to this method, schematically shown in Figure 3, can be obtained by instead carrying out, after the impregnation and heating phase, a forming phase by lamination between rollers 6 and, subsequently, a solidification phase by means of an appropriate heat treatment.

Figure 4 schematically shows a production method whereby the artefacts can be obtained by carrying out, after the impregnation and partial solidification of the heterogeneous mass 4, a phase of extrusion through a suitable die 7. A further possible method for fabricating the artefacts is also shown in Figure 5, which depicts how the artefacts can be obtained by impregnating the fibres 40 and the fragments 1, 20, 30 of other materials in the synthetic resin 2 and by subsequently injecting the previously obtained heterogeneous mass 4 under pressure directly into a forming mould 5, appropriately heated, in which the material solidifies assuming the shape of the finished product.

The invention thus conceived is susceptible for evident industrial application; furthermore, it can be subject to numerous modifications and variations, without thereby departing from the scope of the inventive concept. Moreover, all components can be replaced with technically equivalent elements.

Claims

1. Construction material for manufacturing artefacts, characterised in that it comprises at least textile fibres (40) and a ureic-based adhesive synthetic resin which, in the fluid state, is able to impregnate and agglomerate said fibres (40) and which, solidifying, is able to make them mutually integral to form a structurally resistant monolithic material (3).

2. Material, as claimed in claim 1, characterised in that it comprises fragments (1) of straw obtained from the break-up of stalks of cereals, such as wheat, rice, corn.

3. Material, as claimed in claim 1, characterised in that it comprises fragments or fibres (30) of materials obtained from the break-up of vegetable stalks of plants, such as sunflowers, prickly pears, brooms.

4. Material, as claimed in claim 1, characterised in that it comprises ligneous fragments (20) obtained from the break-up of sugarcane.

5. Material, as claimed in claim 1, characterised in that it comprises ligneous fragments (20) obtained from the break-up of nutshells, peanuts, pine nuts, and/or from the break-up of pine cones.

6. Material, as claimed in one of the previous claims, characterised in that said synthetic resin (2) in the fluid state includes a vinyl resin.

7. Material, as claimed in claim 6, characterised in that said ureic base synthetic resin (2) includes said vinyl resin in a ratio of between 10% and 20%.

8. Artefact constituted by material as claimed in one of the previous claims, characterised in that it is included in an artefact shaped as a panel.

9. Method for fabricating a material, as claimed in one of the previous claims, characterised in that it comprises the phases of impregnating at least textile fibres (40) in a ureic base adhesive fluid synthetic resin (2) to obtain a heterogeneous mass (4) in the fluid state; heating the heterogeneous mass (4) to obtain a partial solidification of said mass (4); pressing in a mould (5); and completely solidifying said fluid mass (4), until obtaining a structurally resistant artefact.

10. Method for fabricating a material, as claimed in one of the claims 1 through 8, characterised in that it comprises the phases of impregnating at least textile fibres (40) in a ureic base adhesive fluid synthetic resin (2) to obtain a heterogeneous mass (4) in the fluid state; heating the heterogeneous mass (4) to obtain a partial solidification of said mass (4); laminating; and completely solidifying said fluid mass (4), until obtaining a structurally resistant artefact.

11. Method for fabricating a material, as claimed in one of the claims 1 through 8, characterised in that it comprises the phases of impregnating at least textile fibres (40) in a ureic base adhesive fluid synthetic resin (2) to obtain a heterogeneous mass (4) in the fluid state; heating the heterogeneous mass (4) to obtain a partial solidification of said mass (4); extruding; and completely solidifying said fluid mass (4), until obtaining a structurally resistant artefact.

12. Method for fabricating a material, as claimed in one of the claims 1 through 8, characterised in that it comprises the phases of impregnating fragments (1) of straw in stalks in a ureic base adhesive fluid synthetic resin (2) to obtain a heterogeneous mass (4) in the fluid state; heating the heterogeneous mass (4) to obtain a partial solidification of said mass (4); injecting and completely solidifying said fluid mass (4) inside a forming mould (5), until obtaining a structurally resistant artefact.