DE1759909A1 - Plastic irrigation or drainage pipe - Google Patents

Description

Francis BUTRUILLE Lille / France

Plastic irrigation or drainage pipe

The invention relates to an irrigation or drainage pipe made of Kunstsotff and a method for its production.

There are various devices for watering the soil Designs known, for example sprinklers, which apply water in the form of a jet or mist to the surface to be irrigated. Other designs, which are suitable for both drainage and irrigation, consist of a pipe, which at least

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is partially permeable to water, either because of its special design or because it is installed later Openings.

One of the first tubes of this type consisted of a hose made of fabric, which however has several disadvantages, e.g. a swallowing up when it is laid or the risk of it getting smeared when it is stored. In addition, the In such hoses, the water is distributed unevenly along the length of the hose and it is impossible to use such hoses to sink into the earth, as this would easily destroy them and thus become unusable.

There are also water and drainage pipes made of plastic known, but which are impermeable to water and which openings have, whereby the water can exit either directly or through nozzles. These plastic pipes are indeed more convenient and advantageous in their practical use, but they present considerable difficulties in their production.

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Numerous other types of pipes are also known to be used for irrigation or drainage of the soil is not possible. So it is known, for example, a thermoplastic, foamed Draw synthetic resin in the form of a tube. At the end of this process, the exterior and the Inner surfaces of the tube are blown, but the dimensions vary greatly and therefore make a particular application difficult. In this procedure, too, is the porosity or permeability of the pipe practically impossible to steer and control.

For certain purposes, pipes of this type are then made completely tight by sudden cooling with the aid a water jet on the inner and outer surfaces, whereby the expansion process is interrupted and the wall of the pipe a has a fairly thick layer of non-expanded plastic, while only a relatively thin middle layer foamed is.

The purpose of the present invention is to avoid these disadvantages and the creation of an irrigation or drainage pipe made of plastic, which is predominantly made of expanded or foamed

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Made of plastic.

Such a watering or drainage pipe is characterized according to the invention through a wall of many small, interconnected cells, of which at least the outer surface is covered with a more or less permeable surface skin formed during manufacture.

Depending on the intended use of such a tube can this surface skin can be provided with openings by means of incisions or punctures. These cuts or punctures can also again depending on the intended use along a surface line or a helical line be distributed on the pipe.

The division s mate rial expediently consists of one thermoplastic, foamed plastic, which is made from a mixture of polyethylene and sodium bicarbonate as well as an oil additive is composed as a binder.

The method for producing such a watering or drainage pipe made of plastic is another feature of the invention characterized in that a mixture consists of a

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bi thermoplastic plastic, e.g. polyethylene, and sodium carbonate as well as an oil additive as a binding agent with heating from an annular nozzle pressed and at least the outer surface is smoothed while quenching.

After the aforementioned surface skin has formed through this quenching and smoothing, this can then be cut with incisions or Punctures are provided.

In the accompanying drawings, there are exemplary embodiments of the invention shown, wherein show;

Figure 1; A scheme of the manufacturing process,

Figure 2; a pipe in perspective view,

Figure 3: a cross section of the pipe,

Figure 4; a cross-section of the water-carrying pipe and

Figures 5 and 6: two possible arrangements of the incisions

or punctures.

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The production of the irrigation or drainage pipe according to the invention takes place in three or four process stages, namely stage 1: the mixing of the starting material, stage 2 J drawing the pipe, stage 3: the expansion and the formation of the surface skin by quenching and, if necessary, stage 4: the making of incisions or punctures in this surface skin.

Particularly advantageous properties are obtained when using a plastic compound which consists of a polyethylene of low or medium density (0.91), 1.5 % sodium bicarbonate and one drop of oil per kg of polyethylene. This oil is selected to have a low viscosity, such as

SS U "100" at 37.8 ° C. This mixture is then heated to a temperature

temperature between 150 and 182 C.

To do this, first mix the oil and polyethylene and set then the sodium carbonate. The oil addition has two main tasks, namely the distribution of the sodium bicarbonate around the polyethylene and a serving of polyethylene grains. This OeI has a direct effect on the degree of connection between the individual small cells. If necessary, binders other than oil can also be used if this should prove necessary for the intended purpose.

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This mixture is then ready for processing in a conventional extruder, a hollow body 5 being formed, the wall 6 of which consists of foamed plastic and which has a cavity 7 inside for the passage of water. This processing the plastic mass usually takes place in the heat

a temperature between 150 and 200 through an annular nozzle, which can have any shape, but generally is circular.

As soon as the processing of the plastic compound is finished in this way is, the tube, if necessary after renewed heating, is quenched in a suitable knee device, with at least one of the outer surfaces of the pipe is smoothed and consequently the outermost cells are closed so that a surface skin 8 forms which is more or less permeable to water. During this treatment it is advisable to Introduce air into the inside of the pipe, whereby the plastic pipe to be processed is in close contact with the molding and cooling device remain. In this way, the pipe keeps its final shape the intended dimensions, with its outer surface being more or less smooth. The injection of air during this

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Ganges also favors the connection between the small cells.

After this treatment, the tube is then finally cooled by being pulled through a water bath.

The relatively impermeable outer skin is then provided with incisions or punctures 9, for which purpose a device with a corresponding number of suitable tools can be used. The penetration depth of these tools can be adjusted so that the depth of the incisions or grooves can be precisely set up to 50% of the wall thickness «

When manufactured in the manner mentioned above using a cooling device for quenching the outer surface of about 10 cm in length, a tube with a diameter of 25 mm and a wall thickness of 4.5-5 mm can be obtained. By cutting such a pipe along four equally spaced surface lines, one obtains a water discharge over a length of 150 m at a water pressure of 6.7 atm

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of 772 liters, at 1.05 atm of 335 liters, at 1.4 of 415 liters, at 2.1 atm of 556 liters, at 2.8 atm of 704 liters, at 3.5 atm of 885 liters and at 4.2 atm of 1146 liters,

The irrigation or watering pipe made of plastic, designed and manufactured in the manner according to the invention, offers numerous Advantages, e.g.

Due to its low permeability, it is uniform Distribution of the water outlet along the entire length of the pipe, even if this is very considerable;

the permeability of the pipes can be precisely determined by making the aforementioned punctures or incisions, whereby such a procedure is very simple and safe;

the tube has sufficient rigidity to resist damage to be quite resilient even when buried in the ground;

on the other hand, the pipe is also sufficiently soft to be handled without difficulty;

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it can be produced with relatively low production costs;

it allows them to be made stronger and more permanent in a simple manner Irrigation or drainage systems that do not require permanent monitoring and require entertainment.

Of course, the invention is not limited to the example mentioned manufacturing material or its composition is limited, in particular by changing the addition of a Blowing agent the formation of the cells and their connection with each other can be changed within wide limits. In this way can be the impermeability for water both from the inside out as well as from the outside inwards according to the respective purpose.

In addition, further substances can be added to the starting mixture for the production of the pipe according to the invention, e.g. Dyes, fungicides, fillers, etc.

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Claims (7)

PATENT CLAIMS: 1. Irrigation or drainage pipe made of plastic, marked by a wall (6) made up of many small, interconnected cells, of which at least the outer surface is covered with a more or less permeable surface skin (8) formed during manufacture. 2. Tube according to claim 1, characterized by openings in the surface skin (8) obtained by means of incisions or punctures (9). 3. Pipe according to claim 1 and 2, characterized by along a jacket or helically distributed incisions or recesses (9). 4. Pipe according to claim 1, characterized by a thermoplastic, foamed plastic as a manufacturing material. 5. Tube according to claim 4, characterized by a mixture of Polyethylene and sodium bicarbonate as well as an oil additive as a binding agent as a manufacturing material. 109829/0481 6. A method for producing a watering or drainage pipe made of plastic according to claims 1-5, characterized in that that a mixture of a thermoplastic material, e.g. polyethylene, sodium bicarbonate and an oil additive as a binding agent while being heated, it is pressed out of an annular nozzle and at least the outer surface is smoothed while quenching. 7. The method according to claim 6, characterized in that the surface skin formed by quenching and smoothing is provided with incisions or punctures. 109829/0481 Blank page