Abstract: In the case of a drip irrigation tube the dosing elements which are inserted therein and are connected to the walling of the drip irrigation tube each comprise inlet regions, dosing regions and outlet regions, through which the water issues out of the drip irrigation tube via outlet openings installed in the tube walling. The outlet openings are in the form of a slit, the edge regions of the slit are supported by supporting means in such a manner as to limit bending of the edge regions of the slit towards the dosing elements. As a consequence, when negative pressure prevails in the tube contaminants are prevented from being able to penetrate through the slits into the dosing elements and block same.

Abstract: In the case of a drip irrigation tube the dosing elements which are inserted therein and are connected to the walling of the drip irrigation tube each comprise inlet regions, dosing regions and outlet regions, through which the water issues out of the drip irrigation tube via outlet openings installed in the tube walling. The outlet openings are in the form of a slit, the edge regions of the slit are supported by supporting means in such a manner as to limit bending of the edge regions of the slit towards the dosing elements. As a consequence, when negative pressure prevails in the tube contaminants are prevented from being able to penetrate through the slits into the dosing elements and block same.

Abstract: In a method for producing drip irrigation tubes, a body is extruded, from which the tube is formed and in which metering elements (10) are attached, which are connected to the body by means of ultrasonic welding. For such drip irrigation tubes, the water enters the metering elements (10) from the inside of the drip irrigation tubes through inlet openings, flows through the metering elements, and exits the drip irrigation tubes through outlet openings in a metered manner. The body is formed into a tube body, which is flattened, and the metering elements (10) come to be situated in a central region inside this flattened tube body. The flat tube body is fed between a sonotrode (6) and an anvil (7) of an ultrasonic welding device (3), and the metering elements (10) are welded to the walling of the tube body. The invention further relates to a device for carrying out the method.

Abstract: In a method for producing drip irrigation tubes, a body is extruded, from which the tube is formed and in which metering elements (10) are attached, which are connected to the body by means of ultrasonic welding. For such drip irrigation tubes, the water enters the metering elements (10) from the inside of the drip irrigation tubes through inlet openings, flows through the metering elements, and exits the drip irrigation tubes through outlet openings in a metered manner. The body is formed into a tube body, which is flattened, and the metering elements (10) come to be situated in a central region inside this flattened tube body. The flat tube body is fed between a sonotrode (6) and an anvil (7) of an ultrasonic welding device (3), and the metering elements (10) are welded to the walling of the tube body. The invention further relates to a device for carrying out the method.

Abstract: A device for producing a drip irrigation tube comprising an extrusion apparatus for extruding a tube body made from a thermoplastic synthetic material is provided. Metering elements are inserted in the extruded tube body and connected to the tube body. A calibrating device adjusts the tube body to the desired outer shape, and a cooling device cools the tube body. Outlet holes are made in the tube body in the vicinity of the metering elements to permit the passage of water from the tube body during use. A control unit for controlling the device for making outlet holes is provided, and a sensor which upon lifting of the roller during passage of a metering element emits a signal to the control unit which emits a signal to the device for making outlet holes.

Abstract: In a method for producing drip irrigation pipes, a tube body is extruded from a thermoplastic synthetic material and provided with a wall. The tube body is led directly and in non-contact fashion to a pre-cooling chamber in which the tube body is pre-cooled and in which metering elements are pressed on to the wall and connected to the wall. The tube body is sized to a final diameter and further cooled in a cooling chamber.

Abstract: A device for producing a drip irrigation tube comprises an extrusion apparatus for extruding a tube body made of a thermoplastic synthetic material, a device for inserting metering elements in the extruded tube body and for pressing and connecting the metering elements in the tube body. Furthermore, a calibrating device for adjusting the extruded tube body to the desired outer shape is provided. Provided in addition are cooling devices, for cooling the extruded tube body with coolant, and a drilling device for making outlet holes in the vicinity of the metering elements for the water. The device for pressing and connecting the metering elements in the tube body is disposed in a pre-cooling chamber. Disposed after the pre-cooling chamber is a further chamber, in which the drilling device is disposed. Disposed following the further chamber is the main cooling chamber, the calibrating device being inserted between the further chamber and the main cooling chamber.

Abstract: In a method for producing drip irrigation pipes, a tube body is extruded from a thermoplastic synthetic material and provided with a wall. The tube body is led directly and in non-contact fashion to a pre-cooling chamber in which the tube body is pre-cooled and in which metering elements are pressed on to the wall and connected to the wall. The tube body is sized to a final diameter and further cooled in a cooling chamber.

Abstract: The invention concerns an installation for manufacturing a drip irrigation pipe (8) formed of a pipe (8) provided with drippers (4), including a dripper feed station (37), followed by an extrusion station (10), including an extrusion head (14) producing a tubular blank (22) and means for welding the drippers (4) to the inner wall of said blank (22), characterized in that the dripper welding means (4) include a support surface (50) and a counter-support surface (56) between which the drippers (4) are pressed against said tubular blank (22) so as to be welded thereto, said support (50) and counter-support (56) surfaces being arranged upstream of the calibrating means (24).

Abstract: A device for continuously producing drip irrigation tubes comprises an extruding device (1) for producing a tube body (2), a calibrating device (3), and a cooling device (19) for the tube body (6). In addition, a feeding device (5) for feeding dosing elements (6) into the tube body (2) and means for joining these dosing elements (6) to the inner wall of the tube body (2) are provided. This feeding device is comprised of a pressing element (17) that is formed by the end area of the guideway (4) while protruding into the extruded tube body (2), and of a pressing member (18) that can be pressed against the tube body (2) from the exterior in the vicinity of pressing element (17). The calibrating device (3) is made of a tubular body (22) whose insertion area (23) narrows to the desired diameter of the tube body (2) and whose longitudinally elongated body area (24) protrudes into the cooling device (19).

Abstract: Dosing elements for a drip irrigation tube are produced in the form of a band. On one side of this band, structured elements are formed, disposed one behind the other. The band is connectible by this one side to the walling of a drip irrigation tube. Each structured area here has an inlet region, a dosing region, and an outlet region. The band consists of a support band which is longitudinally stable and flexible, which is provided on one side with a layer, in which layer structured areas are made. Described furthermore is a method for producing these dosing elements as well as a device for carrying out this method.

Abstract: The invention concerns an installation for manufacturing a drip irrigation pipe (8) formed of a pipe (8) provided with drippers (4), including a dripper feed station (37), followed by an extrusion station (10), including an extrusion head (14) producing a tubular blank (22) and means for welding the drippers (4) to the inner wall of said blank (22), characterized in that the dripper welding means (4) include a support surface (50) and a counter-support surface (56) between which the drippers (4) are pressed against said tubular blank (22) so as to be welded thereto, said support (50) and counter-support (56) surfaces being arranged upstream of the calibrating means (24).

Abstract: The invention concerns an installation for manufacturing drip irrigation pipes comprising a dripper feed station followed by an extrusion station comprising extrusion means, means for calibrating the pipe and means for welding the drippers to the inner wall of the pipe, and followed by a cooling station for the pipe, of the type wherein the cooling station includes a cooling tank containing a cooling fluid in which the pipe is immersed, characterized in that a detection device is provided for detecting, in the cooling fluid, the emission of gas bubbles through the wall of the pipe, so as to deduce therefrom the presence of perforations and/or cracks. The invention also concerns a method for detecting perforations and/or cracks.

Abstract: A device for continuously producing drip irrigation tubes comprises an extruding device (1) for producing a tube body (2), a calibrating device (3), and a cooling device (19) for the tube body (6). In addition, a feeding device (5) for feeding dosing elements (6) into the tube body (2) and means for joining these dosing elements (6) to the inner wall of the tube body (2) are provided. This feeding device is comprised of a pressing element (17) that is formed by the end area of the guideway (4) while protruding into the extruded tube body (2), and of a pressing member (18) that can be pressed against the tube body (2) from the exterior in the vicinity of pressing element (17). The calibrating device (3) is made of a tubular body (22) whose insertion area (23) narrows to the desired diameter of the tube body (2) and whose longitudinally elongated body area (24) protrudes into the cooling device (19).

Abstract: In a method for the continuous manufacture of drip irrigation tubes which comprise a tube body (1) into which dosing elements are set (6), a hole is created in the walling of the tube body (1). This takes place by a laser beam (13) which is directed by an optical device (16). This optical device (16) has the effect of converting the laser beam (13) into the form of a ring, a line (19) of high energy density being formed corresponding substantially to the ring shape at a separation (a) from optical device (16), in which a particle (20) is cut from the walling.

Abstract: A drilling apparatus for making holes in a tube body in the area of metering elements comprises drilling means which are disposed on a framework. Via sensor means, the position of the metering elements in the tube body are ascertained. Based upon a signal triggered thereby, the drilling operation is carried out. For this purpose, the tube body is led over a roller which is rotatingly held on the framework. The tube body to be drilled wraps around the roller around an area and is then led away. In this wrap-around area, in which the tube body rests upon the roller, the position of the metering means in the tube body is ascertained by the sensor means; the holes can then be made. The making of these holes can take place very precisely since the tube body cannot undergo any longitudinal stretching when it is resting on the roller.

Abstract: This method allows manufacture of an optical cable including optical fibers (1) placed in a protective sheath including two coaxial tubes (3, 5), of which the inner tube (3) which is made of plastic material, contains said fiber (1). The method consists in placing the fibers in the first tube (3) so that they have a certain overlength with respect to said tube. Then, the assembly (1, 2, 3) is surrounded by second tube (5). The second tube (5) is placed around the first tube (1) after obtaining the overlength, from a metal tape whose longitudinal edges are butted together progressive around the assembly while being fixed to each other, then the second tube (5) is shrunk against the first tube (3). A layer adhesive material (4) is preferably interposed between the two tubes (3, 5).

Abstract: A method for recovering materials, in particular rejects or scraps of sheathed cables or wires, comprises introducing the parts into an enclosed space and placing them on a support provided with a drain, removing the oxygen from the enclosed space, raising the temperature inside the enclosed spaced until it reaches a melting temperature of one of the materials so that it drains through the drain, collecting the melted material in a recovery tank maintained at a temperature less than or equal to the melting temperature, then raising the temperature inside the enclosed space to cause the material remaining on the parts to dissipate in the form of vapour or gas, and recovering after cooling, the material drained into the recovery tank and the material or materials remaining on the support.

Abstract: An optical fiber cable, including optical fibers and a tube housing the fibers, is made by a process wherein optical fibers are fed from one or more pay-out device to the interior of an extrusion head which also receives a sheathing material in viscous form. The extrusion head extrudes the viscous material to form a sheath surrounding, but out of contact with the fibers. With the fibers still out of contact with the sheath, the fibers and sheath pass through a jig which calibrates the sheath to the final form of the tube, and cools the viscous material in a first stage of solidification. Thereafter, the cable comprising the tube and optical fibers is would up around a first draw-in device and heat treated. From the first draw-in device the cable passes to a second draw-in device with the tension of the cable between the two draw-in devices being regulated.

Abstract: A mixture of substances is fed to an extruder and, after being homogenized and liquefied, is extruded on an electric conductor or as a pipe. To meet electric cable specifications, the insulating material used is a polyolefin, such as polyethylene, cross-linking of which is brought about by the addition of a silane, a free-radical generator, and a silanol condensation catalyst. After extrusion, cross-linking takes place in the presence of moisture. To facilitate penetration of the moisture and accelerate cross-linking, an agent capable of reducing the rate of crystallization of the polymer, such as vinyl acetate, is used as a further additive.