CA2829251C - Method and device for producing a nonwoven geotextile, and geotextile thus produced - Google Patents

Abstract

The invention relates to a nonwoven geotextile comprising: crushed plant stems (305) having a diameter of more than 5 mm, plant stem fragments (310), and plant fibers (315) partially attached to the crushed stems, wherein the plant stems and the plant stem fragments are interwoven by means of mechanical connections produced by spraying water. In preferred embodiments, the plants comprise hemp. The device for producing such a nonwoven geotextile comprises: a means for arranging plants in a sheet comprising crushed plant stems having a diameter of more than 5 mm, plant stem fragments and plant fibers partially attached to the crushed stems; and a means for spraying water onto said sheet so as to form mechanical connections between the crushed plant stems, the plant stem fragments and the plant fibers of the sheet.

Description

PROCESS AND DEVICE FOR PRODUCING NON-WOVEN GEOTEXTILE AND
GEOTEXTILE SO PRODUCED
Technical area The present invention relates to a method and a device for producing non-woven geotextile and a geotextile thus produced, in particular based on vegetable fibers long mechanically related.
State of the art Biodegradable geotextiles are usually made in three ways :
- from coir or jute fibers woven manually or - from short fibers mechanically bonded by processes needling mechanical with metal needles.
chemical assemblies with binders for example based on starch.
These techniques have several disadvantages. The first is that they require the use of a large workforce, that they are tributary a geographical concentration of the fibers used, and that a cost of high production. The risks of blocking machinery mechanisms constrain manufacturers to use short fibers in the form of flakes as input (length less than ten centimeters), resulting in a manufacturing step additional upstream and a restriction of the choice of fibers.
With regard to nonwovens, whatever the fibers used, they are preliminarily refined, which involves complex treatments and expensive.
Presentation of the invention The present invention aims to remedy all or part of these disadvantages. AT
this effect, according to a first aspect, the present invention is a non-geotextile woven comprising:
- crushed plant stalks with a diameter greater than five millimeters, - fragments of vegetable stems and vegetable fibers partially attached to said stems crushed the stems and fragments of stems being interwoven by mechanical links produced by water projection.
According to a second aspect, the present invention aims at a device for production of a nonwoven geotextile, which comprises:
a means for disposing plants in a layer of stems of crushed vegetables with a diameter greater than five millimeters, fragments of vegetable stems and of

2 raw vegetable fibers partially attached to said crushed stems and a means for projecting water onto said sheet to form mechanical connections between stems of crushed plants, fragments of plant stems and fibers of said web.
According to a third aspect, the present invention aims at a production process a non-woven geotextile, which comprises a step of disposing plants in a layer of stems of crushed vegetables with a diameter greater than five millimeters, fragments of vegetable stems and of raw vegetable fibers partially attached to said crushed stems and a step of spraying water on said sheet to form bonds mechanical between stems of crushed plants, fragments of plant stems and fibers of said web.
Through each aspect of the present invention, a geotextile is created which has mechanical characteristics similar to, or even superior to, those of known geotextiles, at lower cost. By eliminating the transformation plants, in upstream of the formation of the aquifer, we reduce the complexity of the implementation artwork. Moreover, the necessary manpower is limited and the manufacture can be strongly automated.
The various aspects of the present invention thus make it possible to lift this who is regarded as a technical impossibility related to the use of rods and long fibers and to produce an in-woven with mechanical properties superior to the productions geotextiles nonwovens known in the prior art.
In addition, it eliminates the risk of machine locks because the creation of bonds mechanical is done without contact, by projection of water.
According to particular features of each aspect of the invention, said vegetables include hemp.
According to particular characteristics of the geotextile object of the invention, the stems, fragments of stems and plant fibers are coated with earth.
According to particular characteristics of the geotextile object of the invention, Earth contains clay.
With each of these arrangements, a layer of material is formed, watertight in the case of the use of clay, which makes it possible to constitute drains at a lower cost, with natural materials.
According to particular characteristics, the means of disposing of plants in one plant fiber web comprises means for crushing and / or carding the plants.
According to particular characteristics, the means of disposing of plants in one plant fiber web comprises a means for orienting the fibers according to less two different orientations, under the vibration action of a support, or by crossing of

3 supply routes.
According to particular characteristics, the means of disposing of the plants in vegetable fiber web comprises a cord incorporating device or cables, parallel to the greater length of the sheet to serve as guides.
It is noted that the ropes or cables may be of plant origin or other, in particular plastic or metallic.
According to particular characteristics, the means of disposing of plants in one plant fiber web comprises a means of uniformizing the thickness of the the tablecloth vegetable fibers.
According to particular features, the device that is the subject of the invention has a means of coating the web of plant fibers with soil.
According to particular features of the device which is the subject of the invention, the way of coating of the vegetable fiber web is adapted to coat the tablecloth with fibers plants with clay.
According to particular features, the method which is the subject of the invention has a step of coating the sheet of vegetable fibers with soil.
According to particular features of the method which is the subject of the invention, during the step of coating the layer of plant fibers, the coating is coated with vegetable fibers with earth with clay.
The advantages, goals and special characteristics of the geotextile the current particular advantages, purposes and features of the process and device objects of the present invention and vice versa. They are therefore not remembered here.
Brief presentation of the figures Other advantages, aims and features of the present invention will come out of the following description, for purposes of explanation and not at all limiting, with regard to attached drawings, in which:
FIG. 1 is a developed view of the device object of the present invention, in a particular embodiment, FIG. 2 represents, in the form of a logic diagram, the steps implemented work in a particular embodiment of the device that is the subject of this invention, FIG. 3 represents, schematically, a sheet of rods, fragments of stems and fibers before splashing water, FIG. 4 represents, schematically, a sheet of rods, fragments of stems and fibers before water splash and FIG. 5 represents, schematically and in section, a drain realized on the base a geotextile object of the present invention.

4 Presentation of at least one embodiment We note, first of all, that the figures are not to scale.
FIG. 1 shows a device 105 for producing a geotextile 110.
The device 105 has a means 115 for disposing plants in a sheet 125, a means 165 for forming mechanical connections in said sheet 125 and optionally, a means 170 for coating the sheet 125.
Plants are introduced at the inlet 140 of the device 105.
The means 115 of arrangement of the plants constitutes a table illustrated in figure 3, crushed plant stalks with a diameter greater than five millimeters, fragments of vegetable stems and raw vegetable fibers partially attached to said stems crushed.
The means 115 of arrangement of the plants comprises, in the embodiment illustrated in Figure 1:
a means 140 for entering raw plants, in the form of plants great dimension, typically rods up to 2.5 m, a means 145 for partial reduction of the plants in stems, thanks to a knife, for to form rod elements of a length preferably greater than a few centimeters, and even more preferentially greater than ten centimeters, a means 150 for crushing and / or carding plants, a means 155 for orienting the fibers according to at least two different orientations, a means 160 for standardizing the thickness of the layer 125 of vegetable fibers, also called compaction and topping.
Preferentially, the plants used comprise hemp. In embodiments, hemp is combined with stems of other plants in order to produce a non-woven geotextile but with a shorter shelf life and a faster biodegradability. Such a geotextile is, for example, adapted to gardening seasonal.
In embodiments, the fiber orientation means 155 according to less two different orientations acts by vibrating a support of the tablecloth 125 (the means 155 of orientation comprises, for example a vibrating corrugated sheet, which divide fibers in a uniform way, in different directions), or by crossroads supply.
In embodiments, the compaction and lapping means 160 is consisting of crushing rollers.
In embodiments (not shown), the arrangement means 115 of the plants in a layer of plant fibers has a device for incorporating of ropes or cables parallel to the longest length of the sheet intended to serve as guides, after means 160. Thus, in order to facilitate the subsequent handling of the product, guides (ropes, cables, wires) can be introduced into the thickness of the layer 125.

Then, mechanical connections between the stems, the fragments of stems and the fibers of the web 125 are created in the thickness of the web 125 by means 165 of training of links. This means 165 operates by spraying water under pressure. More precisely, several ramps of high pressure jets perforate and / or crush for parts the stems in partially defibrating them. In addition, fine materials stick and / or adsorb the various fine elements.
At the output of the device illustrated in FIG. 1, the finished geotextile 110 is set in rolls or in semi-rigid plates. The geotextile thus produced can then be treated according to the uses.
The device 105 is particularly intended for the manufacture of geotextiles nonwoven for use in substitution for products used for mulch and, in particular, the replacement of coconut or jute fiber fabrics soaked with woven made from hemp.
In the case where the device comprises a coating means 170, a coating with of the land can be provided. In particular, a coating with soil containing the clay, in particular made of pure clay, makes it possible to form a geotextile waterproof.
For example, such a geotextile may form a protection against water penetration into a building or a drain, such as the drain shown in Figure 5. The coating may to be done by projection or by impregnation or by crushing rendered earth furniture.
FIG. 2 shows that, in a particular embodiment of the invention, process object of the present invention, during a step 205, we introduce plants in entry, in the form of large plants, typically stems measuring up to 2.5 m.
During a step 210, a partial reduction of the plants is carried out in rods, in the form of large plants, to form elements of stem of a length preferably greater than twenty centimeters, and preferentially higher at fifty centimeters.
During a step 220, the plants are crushed to form a layer of stems of crushed plants of a diameter greater than five millimeters, fragments stems vegetable and raw vegetable fibers partially attached to the so-called crushed stems.
During a step 225, the rods and / or the fibers are oriented in such a way that according to different directions.
During a step 230, the thickness of the sheet of fibers is uniform.
During a step 235, fibers are incorporated into the strings or cable

6 parallel to the long length of the fiber web.
During a step 240, mechanical bonds are created between the fibers of the sheet, in the thickness of the sheet, by projection of water under pressure on fibers or, alternatively, with a multi needle needle-punching machine (Needling).
As can be understood from the above, thanks to the implementation of of the present invention, a nonwoven geotextile is created which has characteristics similar to, or better than, those of known geotextiles, lower cost.
During an optional step 245, this geotextile can be coated, in particular with of the earth, for example based on clay.
FIG. 3 shows, in a sheet 125, crushed raw stems 305, a diameter greater than five millimeters, small raw stems and fragments of stems 310 (length from a few centimeters to several tens of centimeters, diameter from 0.1 to 1 centimeter) and plant fibers 315 intertwined. Vegetable fibers are, for a part of them, attached to the crushed stems.
FIG. 4 shows in a nonwoven geotextile 110 raw rods crushed 305 mechanically connected by fragments of stems, plant fibers and subjects fine hanging between them, the rods 305.
It is observed that the implementation of entirely natural stems provides geotextiles with different thicknesses and thus a different grammage some products nonwovens known in the prior art. For example, the geotextile object of the present The invention has a weight of 200 to 5,000 g / m2, and preferably 400 to 1000 g / m2.
FIG. 5 shows a 405 nonwoven geotextile coated with clay 410 for to form a drain, here covered with stones 415. Geotextile 405 provides the structure and clay 410 seals, partial or complete, the drain thus formed. The stones 415 retain the geotextile and avoid rapid clogging of the drain by leaves, for example.
The drained water flows around the stones on the clay layer 410 coating the geotextile 405.
In the embodiment illustrated in FIG. 4, a second layer of geotextile object of the present invention 420 is positioned above the first, to maintain the intermediate elements. In case there is no stone between two layers of geotextile 405 and 420, the upper layer serves to maintain the clay between both layers.
Preferably, in this case, the geotextile layer 420 is less rude that the geotextile layer 405.

Claims (16)

1. Geotextile (405) nonwoven, characterized in that it comprises:
- stems (305) of crushed plants of diameter greater than five millimeters, - fragments of vegetable stems (310) and plant fibers (315) partially attached to said stems crushed, the stems and fragments of stems being interwoven by mechanical bonds produced by projection of water. The geotextile (405) according to claim 1, wherein said plants have some hemp. The geotextile (405) according to one of claims 1 or 2, wherein the stems, fragments of Stems and plant fibers are coated with soil (410). The geotextile (405) according to claim 3, wherein the earth (410) contains clay. 5. Device for producing a non-woven geotextile, characterized in that includes means (115) for disposing plants in a layer (125) of stems (305) crushed plants of a diameter greater than five millimeters, fragments stems plants (310) and vegetable fibers (315) partially attached to said crushed stems and means (165) for projecting water onto said sheet to form bonds between crushed plant stalks, stem fragments plants and vegetable fibers of said web. 6. Device according to claim 5, wherein said plants include hemp. 7. Device according to one of claims 5 or 6, wherein the means (115) of disposition of plants into a web of plant fibers has a crushing means and / or carding plants. 8. Device according to one of claims 5 to 7, wherein the means (115) of disposition of plants into a web of plant fibers comprises a means of orientation fibers according to at least two different orientations, under the vibration action of a support, or by crossing of supply routes. 9. Device according to one of claims 5 to 8, wherein the means (115) of disposition plants in a layer of plant fibers comprises a device of incorporation of strings or cables, parallel to the longest length of the tablecloth intended to serve of guides. 10. Device according to one of claims 5 to 9, wherein the means (115) of disposition plants into a web of plant fibers has a means of standardization the thickness of the plant fiber web. 11. Device according to one of claims 5 to 10, which comprises a means coating (170) of the plant fiber web with soil (410). 12. Device according to claim 11, wherein the coating means (170) of the tablecloth of vegetable fibers is adapted to coat the web of vegetable fibers with the earth (410) comprising clay. 13. A process for producing a nonwoven geotextile, characterized in that includes a step (205 to 235) of placing plants in a layer (125) of stems (305) crushed plants with a diameter greater than five millimeters, fragments of stems plants (310) and vegetable fibers (315) partially attached to said crushed stems and a step (240) for projecting water onto said sheet to form bonds between crushed plant stalks, stem fragments plants and vegetable fibers of said web. The method of claim 13, wherein said plants comprise hemp. 15. Method according to one of claims 13 or 14, which comprises a step (245) coating the plant fiber web with soil (410). The method of claim 15, wherein during step coating of vegetable fibers, the layer of vegetable fibers is coated with earth (410) comprising clay.