DE1915768B2 - Pipes of different diameters can be mass-produced from a web (or sheets) of thermoplastic foam resin, e.g. polyolefin, by rolling it up into a cylindrical shape - Google Patents

Abstract

Pipes of different diameters can be mass-produced from a web (or sheets) of thermoplastic foam resin, e.g. polyolefin, by rolling it up into a cylindrical shape, heating the hot surfaces together to form a tube which is then temporarily subjected to the pressure or moving belts on all sides and to a guide roller, care being taken that the heated seam does not touch the guide roller. Alternatively, a core can be covered helically with two layers of foam in opposite directions and the surfaces heated continuously. Insulated composite pipes can be made by fixing one end of the foam web to a rotating core or glass wool, asbestos or copper. Rods, electric wires etc could also be covered in this way.

Description

rens has a forming device for merging the longitudinal edge of the web and a heating device for heating these longitudinal edges and is characterized according to the invention by a pressure device arranged downstream of the heating device, consisting of composed of two horizontally and two vertically arranged endless belts a printed sireck bildui. whose cross-section corresponds to the cross-section of the flat compressed web is equivalent to. Advantageously, there is between the molding device and a pressure roller is provided to the four endless belts.

The printing device expediently consists of a roller which is provided with a groove on its circumference is. and from an endless printing belt guided in the groove, with a printing path in the groove is formed. whose cross-section corresponds to the cross-section of the flat compressed web.

The invention offers over the known method <\ cn advantage that the z in joining? - A particularly homogeneous and durable seam is obtained by thermal welding between the edges of the web. The method of the present invention does not use a mandrel, so that the problem of high friction of the foamed resin material when it is pulled from a mandrel is eliminated. thereby a high production speed. is achieved.

The method and the device according to the invention are particularly economical; because tubes made of foamed resin have a very large specific volume, and therefore the transportation cost is high are. However, since the device according to the invention is very cheap. can establishments that have such tubular Need items in bulk, easily acquire or simply set up this device and take over the manufacture yourself, which saves the transport costs arise when purchasing from the manufacturer.

Materials that are used in the method according to the invention can be used are e.g. B. polyolefins, copolymerized with other components Olefins, crosslinked polyolefins. Vinyl polymers and natural or mixed with these polymers synthetic rubber.

In the following the invention on the basis of embodiments with reference to the Drawing explained in more detail.

F i g. 1 shows in a plan view an apparatus for the continuous production of tubular Foamed thermoplastic resin articles according to one embodiment of the invention:

F i ε. Figure 2 is a side view of the device of Figure 1;

F i g. 3a through 3f are successive cross-sectional views of the web as it is being deformed into a tube, taken along section lines 3α through 3 / of FIG. 1 and 2;

F i g. Fig. 4 is an enlarged side view of part of the apparatus according to a second embodiment;

F ie. Fig. 5 is a section along line V-V of Fig. 5 ;. 4;

F i g. 6 is a section along the line VI-VI in FIG. 4;

F i g. 7 is a section along the line VII-VII of FIG F i g. 4th

The first embodiment of the invention is shown in FIGS. 1, 2 and 3 a to 3 f. In Figs. 1 and 2, 1 denotes a foamed thermoplastic resin sheet. By means of a forming device 17, this path is gradually / u the in the F ig, 3a. 3 b. 3c and 3d shown cross-sectional shapes are deformed, with their longitudinal surface areas \ a and Ib may come into contact with one another. The longitudinal side surfaces 1 a and 1 b are heated and melted by a heating device 18, after which the tube-shaped web is flattened by a pressure roller 19 - as shown in FIG. 3e - so that the longitudinal sides are connected to one another.

While the tube formed in this way continues to be flat by four bands at the top, bottom, right and left is kept pressed together, it cools down on the interconnected longitudinal side surfaces. and when no more pressure is exerted, it again assumes the tube order shown in FIG. 3f. The forming device 17 is designed so that the cross section of the web - as shown in FIGS. 3 a to 3 d shown - is progressively changed as it "passes through the molding device. After exiting

of the forming device 17, the web assumes a tubular shape, wherein - as in FIG. 3 d shown - the longitudinally parallel side surfaces 1 α and 1 b are opposite one another so that a V-shaped gap is formed. To the forming device 17

the heating device 18 connects, for example, an electric soldering iron, a burner or a hot air nozzle, and the pressure roller 19. The pressure roller 19 has a predetermined width and is provided with two flanges on both sides at a predetermined interval. The pressure roller 19 is further arranged (for example higher than the shape unit 17) that the longitudinal sides of the web are brought into close contact with one another. Accordingly, when the web reaches the pressure roller 19, it is subjected to a certain tension and. as in Fig. 3 e shown, flattened. In this compressed state the Läng ^r .seitenf be! Surfaces 1 α and 1 b of the web which were previously heated by the heater 18, fixedly connected with each other.

It is important that the heated seam does not come into contact with the pressure roller 19.

The longitudinal side surfaces 1 α and 1 b of the web can not only by the heater 18 verlun together are ^ eu but also by the use of molten resin of the same kind as that of the web.

A printing device is composed of four endless belts, namely 2, 6, 6 and 13 and transports the tubular object forward, keeping it compressed as flat as it is flattened by the platen 19 was while its fused crinkle seam cools down.

On the underside of this printing device ". ^ Is a arranged lower circumferential horizontal belt 2, which is guided over three pulleys 3, 4 and 5. Furthermore, two perpendicular endless belts 6 are arranged on both sides, each over three larger pulleys 7, 8 and 9 and two smaller Fuhrungsrollcn 10 and 11 are performed. Between the smaller guide rollers 10 and 11 (only a pair of which will be described below

5 6

is) a guide plate 12 extends to allow side surfaces of the web to cool so that it selects

the printing device over the entire distance between its passage through the printing device

see the guide rollers 10 and 11 remain firmly connected to one another in the same way, the received

maintains a moderate width. Furthermore, an upper, horizontally heated panel is the flattened shape. At the

zontally lying band 13 is provided, which extends over 5 leaving the printing device, the flat-

swivel castors 14. 15 and 16 revolves. These four press the web due to the elasticity of the

Tapes 2, 6, 6 and 13 forming the pressure device foamed the material by itself. so that one

form over the distance between the smaller filling tube with a circular cross-section received. the

Rollers 10 and 11 have a rectangular cross-sectional view. Figs. 5, 6 and 7 are cross-sectional views along the

form. Accordingly, if the tube made of foamed io lines V-V, VI-VI and VII-VII of FIG. 4 that the

Resin fed into this pressure device will show un- different shapes that the web during

it is always subject to one of the bands 2, 6, 6 and its passage through the printing device.

13 applied pressure and maintains the above, flattened. The reference numerals of FIG. 5 to 7 are the

Expressed shape, the circumference of which is approximately the same as that in FIG. 4th

is rectangular. The cross-sectional size of the pressure inlet 15 In the first embodiment, a

direction can be used by changing the position of these four pressure roller 19, but a device is

Bands can be varied freely. without such a pressure roller, in which a heating

It is therefore with one and the same system without device 18 subsequent to the molding device

further possible, tubular objects are seen below, followed by the printing device,

of different sizes from foamed resin for the production of tubes from foamed resin

len. thermoplastic resin perfectly adequate.

The printing device formed by the printing device The second embodiment shows such a case,

route is usually about 0.5 to 8 m long. The one in which no pressure roller 19 is used. the

Throughput speed in this printing device pressure roller 19 has the function of a tensile stress

is about 1 to 10 m / min. 25 to exercise on the web in order to

Compared to the first embodiment, in which the surfaces are pressed against one another, and the printing device is formed from four bands, the operation is facilitated when they are shown between the molding devices, FIGS. 4 to 7 a second embodiment, 17 and the printing device - as in the first in which a roller 20 is provided, in the form of which it is shown - is arranged,
A groove is cut out, as well as an endless belt 30. The tubes shown according to the invention can 21, which is guided in the groove. If necessary, guide rollers 22, 23 and 24 can advantageously be used in a number of areas of application. They have a smooth and equal den. The groove in the roller 20 has a width that is moderate in appearance and is excellent in terms of heat iso substantially equal to the width of the side of the cross-lath. Experiments with regard to the blank shape of the flattened web according to FIG. 3 e 35 samir.enbaren of the connected longitudinal side surfaces is. So that tubes with different diameters and wall thicknesses can be produced according to the invention, the connected longitudinal side surfaces should preferably not detach the groove in the roller 20 from one another if one tries to undo Device to be adjustable in width. How force is applied to the joined surfaces from one another in the first embodiment, the joint 40 of the to separate. The other parts of the tube tear geroliie web 1, the longitudinal side surfaces of which have been heated by the or break to form a fresh break heater 18, between the surface first, which proves that the connection of the bottom surface of the groove in the roll 20 and the endless Long side surfaces is far stronger than the strength of the printing tape 21 out. While heating the foamed resin material itself.

1 sheet of drawings

Claims (4)

the abutting edges of these webs are thermally welded, but these methods cannot be used with webs made of foamed resin. That 1. The method for continuously producing foamed resin is namely easily deformable and a tubular object made of a 5 elastic, so that it does not come on without a guide Foamed thermoplastic resin sheet that can be held in a mandrel, it has a in which the web continuously around its longitudinal very low thermal conductivity, so that only one axis is bent together and their superficial heating for welding the abutting longitudinal side surfaces is possible with each other, it has a high coefficient of friction be characterized, so that a pulling off of a mandrel shows that the long side surfaces is difficult and it allows for welding be warmed that then along the connection only a heating of the contact surfaces, since a dun ^ s line a radial pressure on the tubular- complete heating the cell structure of the gemig exerted curved path and this thereby foamed material destroyed. Tubular counter flattened and that this pressure after 15 stands of foamed resin are therefore after the fusing of the side surface still produced in a known method in that W.ge is maintained until the side faces the resin material directly into the desired shape have cooled down. is foamed so that the desired tube - 2. Device for carrying out the procedural object is obtained directly. Dier.s according to claim 1 with a Formeinrich- 20 ses process has considerable economic night to merge the longitudinal edges of the parts, as for each diameter and length of the Track and a heater for heating tubular object has its own shape Longitudinal margins, marked duah a is required and since the process is only chargender Heating device (18) can be carried out in a downstream pressure mode and not continuously device consisting of two horizontal and 25 can, d. that is, for every object the form must have two vertically arranged endless belts are heated and then cooled again (2,6, 13). which are composed of a printing. Form stretch, the cross-section of which the transverse It is also known a method in which the cut de: - flatly compressed web (1) corresponds to a tubular object from a web. 30 foamed resin is made by the web 3. Device according to claim 2, characterized in that it is bent around a mandrel until its indicates that longitudinal side surfaces touch between the forming device. Since the web is made of cool?) And the four endless ribbons (2,6, 13) of foamed resin, as already mentioned, a high EIaeine Pressure roller (19) is provided. Has sticity, it has a tendency to move away from that 4. Apparatus according to claim 2, characterized in that the mandrel is lifted off and its original shape indicates that the printing device should assume one, so that the abutting Rän roll (20), which gape on their circumference with a groove of the track when they Vv.p d ^ r is provided, and a guided in the groove end pressure roller come free, which they against the shapeless There is pressure band (21), the mandrel pressing in the groove. In this process, therefore, a a printing path is formed, the cross-section of which is 40 quick-setting adhesive for connecting the aneindem Cross-section of the flattened butted rangers, and that Corresponds to web (1). Peeling off the tubular article from the Formation can only take place so slowly that the other butting edges for a sufficient amount of time 45 pressed by the pressure roller against the mandrel The invention relates to a method of being continuous, in order to ensure hardening of the crushing point Manufacture of a tubular counterstay. The particularly advantageous thermal Verdes Welding the tape edges from a sheet of foamed thermoplastic is therefore modest with these Resin, in which the web is continuous in order not to apply known processes, as there is a too their longitudinal axis is bent and their 50 requires a long cooling time. abutting longitudinal edges to one another The object of the invention is to be the konverbunden, and a device for carrying ^tinuierl: che method of producing röhrenförführung this method. like objects made of foamed thermoplastic Recently, foamed resin is found on the shem resin to be formed in such a way that the most different from each other Areas of use, e.g. as 55 ßenden edges of the sheet of foamed resin thermal insulation, packaging material and internal can be thermally welded together, lining of vehicles. Foamed tubes without reducing the production speed tem resin are used for thermal insulation of pipes. and as packaging for rod-shaped goods. According to the invention, this is done in a method helix, in particular for those whose surface 60 of the type described above is achieved by can be easily damaged. that the long side surfaces of the web are heated The manufacture of tubular articles, that thereafter a straight line of foamed thermoplastic resin along the joint line, presents numerous difficulties by applying pressure to the tubular curved sheet. Numerous are indeed exercised and this is flattened in the process and processes for the production of tubular articles 65 that this pressure is maintained until the apparent resin is known in which webs from this side surfaces have cooled.
Resin on.; Incn mandrel wound and attached to each other. The device for carrying out this process-