FR2813082A1 - PIECE OF THERMOPLASTIC MATERIAL CHARGED WITH FLOUR OF FRUIT CORES AND PROCESS FOR OBTAINING SUCH A PIECE - Google Patents

Abstract

The invention concerns a thermoplastic part filled with fruit stone flour and a method for obtaining such a part. Said thermoplastic part is characterised in that it comprises in its volume particles of fruit stone flour, mixed as filler with said thermoplastic material(s) before the part is manufactured.

Description

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DESCRIPTION The present invention relates to the field of plastic parts and their production, and relates to a piece of thermoplastic material, as well as its manufacturing process.

Thermoplastics have tended for many years, because of their ease of transformation of the multiple possibilities of configuration, confôrmation, coloration, shaping and surface conditions they offer, their stability and conservation in the time and their resistance to deformations and shocks, to systematically replace other materials in many areas of industrial and domestic capital goods, including natural materials such as wood.

Now, under the impetus of ecological movements and the so-called "organic" current, we have recently seen a rejection of so-called "artificial" or "synthetic" materials and a return to more natural materials or adding a natural character, also in a concern for aesthetic research.

At the same time, manufacturers of plastic parts and articles are constantly seeking to reduce their cost, especially by reducing raw material costs.

To meet these two aspirations, it has been proposed to introduce sawdust or wood flour as a component in the material formulations used in the production of such parts and articles. Solutions of this type are especially disclosed in US-A-5 951927 and EP-A-002 766.

However, such an addition of sawdust or wood flour, in particular in a relatively large amount or in a large particle size, considerably reduces the processability of the resulting composition, for example requiring prior encapsulation of the flour in pellets or pellets of plastics, and makes especially discontinuous manufacturing processes difficult to implement.

In addition, such an addition decreases the mechanical properties of the resulting part or article.

Finally, the parts and articles thus obtained do not exhibit good dimensional stability in the event of a change in humidity.

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 ambient, and are resistant to putrefaction under the action of moisture and atmospheric agents, and are sensitive to freezing, which limit their application in the external environment, unless subjecting said flour or sawdust to a chemical pretreatment hydrophobic and waterproofing, which again removes its natural product cachet.

The present invention is intended to overcome the aforementioned drawbacks. However, the inventors have found, unexpectedly and surprisingly, that the use of fruit stone flour can meet the above expectations by avoiding most of the limitations of existing solutions.

Thus, the object of the present invention consists of a workpiece (or article) of thermoplastic material (s), characterized in that it comprises in its mass fruit stone flour particles, mixed as that charge to said plastic material (s) before the manufacture or formation of said piece, and in a method of manufacturing such a part or such article.

The composition of thermoplastic material (s) forming the base material of the part may consist of either a single thermoplastic material or a mixture of several compatible or compatible thermoplastic materials.

Advantageously, the flour is essentially obtained from lignified endocarps or cores of cores and the latter advantageously come from oleaginous tree fruits, preferably olives.

According to a preferred embodiment of the invention, the average particle size of the flour is between 50 gm and 500 g, preferably between 70 gm and 120 gm, and the flour content is between about 5% and about 50%. %, advantageously between 10% and 20%, and preferably around 15% by weight of dry flour (moisture content below 10%, preferably below 5%) in the final composition of thermoplastic material (s) (s) used for the manufacture of said piece.

According to a characteristic of the invention, the particles obtained by fine grinding are dried and, if necessary, dyed or treated by coloring before mixing with the thermoplastics.

The present invention also relates to a process for manufacturing parts made of thermoplastic material (s), characterized in that it consists in forming a homogeneous mixture comprising as a

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 main component a composition of thermoplastic material (s) and as a load of fruit kernel flour, and then converting said mixture in plasticized form, to constitute pieces or articles as mentioned that (e) ) s above.

Said method may consist more precisely in providing dried fruit stone flour, a composition of thermoplastic material (s) and one or more additive (s) for stabilization, lubrication, increase of the impact strength. and / or facilitating the transformation, mixing and heating these ingredients at a temperature greater than about 5 to 20 C (preferably 10 to 15 C) at the normal temperature of heating said composition of thermoplastic material (s) ( s), for an identical transformation, in the absence of a charge in the form of flour, then allowing the resulting mixture to cool down and, optionally, allowing it to rest for a predetermined duration, said mixture retaining a powdery constitution during all the aforementioned operations, and, finally, to transform said mixture into one or more parts as described above by a suitable transformation operation, if necessary, after having granulated it.

The mixture thermoplastic material (s) / flour, and if necessary its heating, may be carried out on a separate station or on a station integrated in the machine operating the transformation of the resulting mixture.

Depending on the desired aesthetic appearance and decorative effect, it may be provided to stain or impregnate with coloring substances the fruit stone flour particles, preferably obtained from the hulls of olive kernels, before their mixture with the composition of thermoplastic material (s), and to vary the particle size of said particles (if necessary by mixing flours of different particle sizes).

Moreover, depending on the shape and the nature of the part or the article to be manufactured, this last) can be obtained by extrusion, injection molding or blowing, the thermoplastic material being preferentially chosen in the group formed by vinyl, olefinic and styrenic polymers, and compatible blends of these polymers.

By way of non-limiting example of the invention, the following describes the production of an extruded piece made of rigid PVC incorporating olive-stone flour.

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The composition of the mixture of materials and substances used for the manufacture of the aforementioned part is indicated in the table below in terms of weight parts Composition of the mixture / Formulation (rigid PVC type)

<tb> Proportion <SEP> Range <SEP> of <SEP> values
<tb> referential <SEP> usable
<tb> PVC <SEP> (Suspension) <SEP> 100 <SEP> parts <SEP> 100 <SEP> parts
<tb> Agents <SEP> of <SEP> Stabilization <SEP> / <SEP> 6 <SEP> parts <SEP> 4 <SEP> to <SEP> 8 <SEP> parts
<tb> Lubrication
<tb> Modifying <SEP> shock <SEP> / <SEP> agent <SEP> of <SEP> setting <SEP> 17 <SEP> parts <SEP> 5 <SEP> to <SEP> 25 <SEP> parts
<tb> in <SEP>
<tb> Flour <SEP> of <SEP> kernels <SEP> of olives <SEP> 25 <SEP> parts <SEP> 10 <SEP> to <SEP> 50 <SEP> parts
The hardness of the preferred blend is 80% ShD and has a specific gravity of 1.24 g / cc.

Depending on the color desired for the final piece, an addition of suitable coloring substance is operated.

Before the extrusion phase, it is necessary to carry out a mixing operation, in order to homogenize and pre-plasticize all the products.

For this purpose, a mixer of the type called rapid mixer is used, which is equipped with a heating tank and a cooling tank.

The heating temperature is raised to about 130 ° C to 160 ° C, preferably about 150 ° C, in the heating vessel. When the mixture has reached this temperature, it is passed into the cooling tank and allowed to cool to a temperature of about 40 C before transformation.

This results in a homogeneous mixture with optimal extraction of moisture without compromising the quality of the mixture. This mixture remains in powder form and must not be subjected to any other operation before extrusion.

Before extruding the mixture thus obtained, it is preferable to let it sit for a few hours, preferably for about three hours.

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 In order to carry out the extrusion itself, the extruder types best suited for this transformation are the twin screw extruders, the exact choice of the extruder, as to its capacity and extrusion volume performance, being linked to the metric weight of the profile to be obtained. The extrusion line as for it does not differ, in terms of structure and operation, the usual standard known to those skilled in the art.

The implementation in the extrusion process of the mixtures filled with olive kernel meal is similar at the level of the extrusion line settings (in particular at the temperature, pressure and suction), the settings of such a line for the extrusion of a rigid PVC unloaded.

Similarly, when the thermoplastic material consists of another polymer or mixture of polymers, said adjustments will be substantially equivalent to those necessary for the extrusion of such uncharged polymers (such as for example: PVC / Polypropylene / Acrylonitrile-Butadiene-Styrene) .

Thanks to the invention, it is therefore possible to produce parts or articles made of thermoplastic materials, especially PVC or PP (polypropylene), which stand out from comparable parts or articles existing (s) by a lower cost (use of non-recovered waste as substitute material), by an ecological touch and by numerous possibilities of declination from the point of view aesthetic aspect and surface condition (by modifying the content and the granulometry of the kernel meal, in varying the coloring of flour, thermoplastics or both), all with mechanical properties and durability substantially equivalent to those obtained with uncharged thermoplastic compositions.

In addition, and contrary to wood meal, fruit stone flour, especially olives, has a very low moisture intake and is very little fermentable, avoiding, among other things, the development of bacterial flora (fungi). ). These characteristics are essential for an external application of the parts or articles obtained. In addition, the stone flour particles have a hardness and a density of material much higher than those of traditional wood flour.

Moreover, the main results of the tests carried out by the inventors have demonstrated a very good aptitude for processing.

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 of the mixture of thermoplastic material (s) / stone flour, which also gives good dimensional stability to the parts obtained (no dimensional variation of the parts to moisture) Indeed, the fatty nature of the stone meal used in the The scope of the present invention limits the absorption of water and increases their compatibility with thermoplastics, also promoting the workability and the ability to process, especially extrusion of the resulting mixture. The parts and articles obtained by the process according to the present invention. The invention will find application both in internal use (eg chutes, skirting boards, moldings, furniture, ...) and external (eg carpentry elements, doors, windows, barriers, gates, ... ), and as decorative, functional and / or technical elements.

Of course, the invention is not limited to the embodiment described. Modifications are possible, particularly from the point of view of the constitution of the various elements or by substitution of technical equivalents, without departing from the scope of protection of the invention.

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Claims (11)

1. Part made of thermoplastic material (s), characterized in that it comprises in its mass fruit stone flour particles, mixed as a filler with said at least one plastic material (s) before manufacture of said part. 2. Part according to claim 1, characterized in that the flour is essentially obtained from lignified endocarps or cores of cores. 3. Part according to any one of claims 1 and 2, characterized in that the cores come from oleaginous tree fruits, preferably olives. 4. Part according to any one of claims 1 to 3, characterized in that the average particle size is between 50 gm and 500 gm, preferably between 70 gm and 120 gm and in that the flour content is between about 5% and about 50%, advantageously between 10% and 20%, and preferably around 15%, by weight of dry flour in the final composition of thermoplastic material (s) used for the manufacture of said piece. 5. Part according to any one of claims 1 to 4, characterized in that the particles are dried and, if necessary, dyed or treated by coloring before mixing with the thermoplastics. 6. Part according to any one of claims 1 to 5, characterized in that it is obtained by extrusion, injection molding or blowing, and in that the thermoplastic material is selected from the group formed by vinyl polymers, olefinic and styrenics, and compatible blends of these polymers. 7. A method of manufacturing a piece of thermoplastic material (s) according to any one of claims 1 to 6, characterized in that it consists in forming a homogeneous mixture comprising as main component a composition of matter ( s) thermoplastic (s) and as a filler of the fruit stone meal, then transforming said mixture into plasticized form, to form parts according to any one of claims 1 to 6. <Desc / Clms Page number 8>  8. Method according to claim 7, characterized in that it consists in providing dried fruit stone flour, a composition of thermoplastic material (s) and one or more additive (s) for stabilization, lubrication, increasing the resistance to shock and / or facilitating the transformation, mixing and heating these ingredients at a temperature which is approximately 5 to 20 ° C. higher than the normal temperature for heating said composition of thermoplastic material (s) ( s), for an identical transformation, in the absence of a charge in the form of flour, then allowing the resulting mixture to cool down and, optionally, allowing it to rest for a predetermined duration, said mixture retaining a powdery constitution during all the aforementioned operations, and, finally, to transform said mixture into one or parts according to any one of claims 1 to 6, if necessary after granulating. 9. Process according to any one of claims 7 and 8, characterized in that it consists in dyeing or impregnating with coloring substances the flour particles of fruit stones, preferably obtained from the hulls of olive stones, before mixing with the composition of thermoplastic material (s). 10. Process according to any one of claims 7 to 9, characterized in that the composition of thermoplastic material (s) consists of a suspension of polyvinyl chloride. 11. Method according to any one of claims 7 to 9 and 10, characterized in that the mixture is produced by means of a mixer equipped with a heating vessel and a cooling tank, the mixture being heated to a temperature of between 130 and 160 ° C., then allowed to cool to a temperature of about 40 ° C. before conversion, and in that the transformation operation consists of an extrusion carried out on a twin-screw extruder.