CH703688B1 - A method for manufacturing a metal-reinforced plastic composite tube and metal-reinforced plastic composite pipe. - Google Patents

Abstract

A method of making a metal-reinforced plastic composite tube comprises the steps of: a) providing a plastic tube (10); b) feeding a metal strip (11) in the vicinity of the outer periphery of the plastic tube (10); c) deforming the metal strip (11) in such a way that it partially surrounds the plastic tube (10) in a C-shaped manner at a distance from its outer circumference; d) applying a first adhesive layer (12) on the outer circumference of the plastic tube (10); e) deforming the cross-sectionally C-shaped metal strip (11 ') to a plastic tube (10) surrounding the metal tube (14), wherein the longitudinal edges (13, 15) of the metal tube (14) overlap each other; f) applying a second adhesive layer (16) on the outer circumference of the metal tube (14); g) compressing the metal tube (14) in the radial direction to press the inner periphery of the metal tube (14) on the outer periphery of the plastic tube (10) provided with the first adhesive layer (12); h) extruding a plastic sheath (18) onto the outer circumference of the metal tube (14) provided with the second adhesive layer (16).

Description

Technical area

The present invention relates to a method for producing a metal-reinforced plastic composite pipe, a metal-reinforced plastic composite pipe produced by this method and an apparatus for producing a metal-reinforced plastic composite pipe.

State of the art

Commercially available and well known are metal-reinforced plastic pipes, also called composite pipes, which consist of several layers, of which at least one layer of metal is formed. Due to its significantly lower thermal expansion compared to plastic, this metal layer ensures a significantly improved length consistency with temperature fluctuations compared with a plastic pipe.

In these known composite pipes, an adhesive is applied to a plastic inner tube and the adhesive layer is a welded together to form a tube metal shell, which consists of aluminum or steel, pushed. In order to achieve a good adhesion of the metal tube on the outer peripheral surface of the inner plastic tube, the welded metal tube is compacted after application to the plastic tube, so radially compressed, so that it rests evenly over its circumference on the plastic tube. After this mechanical compaction, the metal tube is heated to the extent that the underlying adhesive melts and so glued the inner plastic tube to the outer metal tube. Subsequently, a further adhesive layer and then a plastic layer are applied to the metal tube. Such composite pipes are gas-tight, can be bent without forming wrinkles and are stabilized in the longitudinal direction, in contrast to a plastic pipe. This means that when heated only a small axial expansion occurs. Disadvantage of such composite pipes, however, is the relatively high production price.

Furthermore, composite pipes are known and available on the market, which are also provided with a thin-walled metal tube, but this metal tube is not welded, but is molded around the inner plastic tube around, with the longitudinal edges of the metal tube either overlap or shock Bump. The manufacturing process of these known composite pipes is similar to the manufacturing process described above, but a compacting as in the welded composite pipes is not possible.

It is also known to press the heated metal tube onto the plastic pipe, or to use a metal already coated with an adhesive or a copolymer, which is heated and pressed onto the inner plastic pipe. However, this procedure must be carried out when using aluminum with a coated aluminum, since the aluminum can otherwise tear on pressing on the plastic tube. For this reason, this method is also relatively expensive.

Presentation of the invention

The object of the present invention is to provide a method for producing a metal-reinforced plastic composite pipe, which allows the cost-effective production of metal-reinforced plastic composite pipes. Furthermore, it is an object of the present invention to provide a corresponding inexpensive producible metal reinforced plastic composite pipe.

The object of the method is achieved by the features of claim 1.

According to the invention, the method for producing a metal-reinforced plastic composite tube comprises the following steps: <tb> a) <sep> Providing a plastic pipe; <b> <b> <sep> supplying a metal strip near the outer circumference of the plastic tube; <tb> c) <sep> deforming the metal strip so as to partially surround the plastic tube C-shapedly spaced from the outer circumference thereof; <tb> d) <sep> applying a first adhesive layer to the outer circumference of the plastic tube; <tb> e) <sep> deforming the cross-sectionally C-shaped metal strip to a metal tube surrounding the plastic tube, wherein the longitudinal edges of the metal tube overlap each other; <tb> f) <sep> applying a second adhesive layer to the outer circumference of the metal tube; <tb> g) compressing the metal pipe in the radial direction to press the inner periphery of the metal pipe onto the outer periphery of the plastic pipe provided with the first adhesive layer; <h> Extruding a plastic sheath onto the outer circumference of the metal tube provided with the second adhesive layer.

advantages

This method makes it possible to produce a simple, cost-effective manner metal-reinforced plastic composite pipes that are reliably stabilized in the longitudinal direction and have compared to a pure plastic pipe only very small elongation.

It is particularly advantageous if the adhesive during application of the second adhesive layer in step f) is also introduced between the overlapping longitudinal edge regions of the metal tube, so that after hardening or solidification of the adhesive and the metal tube is stabilized in the circumferential direction is particularly advantageous.

Preferably, the step of compressing the metal tube in the radial direction in step g) is performed in an annular compression nozzle. Such a compression nozzle allows the continuous production of the plastic composite pipe according to the invention with exact constancy of the outside diameter.

Particularly preferred is an embodiment of the method in which the application of at least a portion of the second adhesive layer in step f) takes place immediately in front of the compression nozzle for compressing the metal tube. The application of the adhesive in front of the compression nozzle causes the adhesive to act as a lubricant upon passage of the metal tube inner plastic tube through the compression nozzle so as to allow low friction passage of the metal tube inner plastic tube through the compression nozzle Pass through the compression nozzle and thus a higher production speed can be achieved.

In this case, the application of the second adhesive layer in step f) is preferably carried out by two flow paths, the mouth areas are spaced from each other to the outer periphery of the metal tube in the axial direction. In this case, a first flow path can open directly in front of the compression nozzle to the outer circumference of the metal tube and a second flow path opens in the interior of the compression nozzle or behind it.

Preferably, the unit provided with the adhesive layer made of plastic pipe and metal tube is heated when passing through the compression nozzle. As a result, the adhesive of the first adhesive layer, which in some cases has already solidified or has become viscous, can be heated and softened and reactivated, so that its adhesiveness is improved again.

It is particularly preferred if the process is carried out continuously under constant feed of the inner plastic tube and the metal strip.

The specified in claim 1 sequence of steps b), c) and d) is not necessarily chronological, but the step d) can also be performed before step c) or before step b).

The object of the plastic composite pipe is achieved by the specified in claim 10 metal-reinforced plastic composite pipe.

This plastic composite pipe consists of a radially inner plastic tube, the outer periphery is firmly bonded to the inner periphery of a metal tube, wherein the longitudinal edges of the metal tube overlap each other and are glued together and wherein a plastic jacket surrounds the outer periphery of the metal tube and is glued thereto , Such a metal-reinforced plastic composite pipe is inexpensive to manufacture continuously and has after curing or solidification of the adhesive on a high longitudinal stability and circumferential stability.

Preferably, the metal tube is formed from a perforated metal sheet. This variant of the plastic composite pipe according to the invention makes it possible for gases formed in the interior to occur when a gas diffusion through the wall of the plastic composite tube occurs without hindrance through the holes of the metal jacket, so that the formation of gas bubbles in the wall under the metal jacket is avoided becomes.

An apparatus for producing a metal-reinforced plastic composite pipe according to the inventive method is specified in claim 2.

Advantageous developments are specified in the dependent claims.

The invention will be explained in more detail below by means of an example with reference to the drawing:

Brief description of the drawings

In this shows: <Tb> FIG. 1 <sep> is a perspective view of a partially cut inventive metal-reinforced plastic composite pipe; <Tb> FIG. 2 <sep> a cross section through the metal-reinforced plastic composite pipe according to FIG. 1; <Tb> FIG. 3 <sep> is a perspective view of an alternative embodiment of the metal-reinforced plastic composite pipe according to the invention; <Tb> FIG. 4 is a schematic representation of a production line for producing the metal-reinforced plastic composite pipe according to the invention in accordance with the method according to the invention; <Tb> FIG. FIG. 5 shows a longitudinal section through a third production stage of the production line shown in FIG. 4; FIG. <Tb> FIG. FIG. 6 shows a cross section through the third manufacturing stage of FIG. 5 in the direction of the material flow; FIG. <Tb> FIG. 7 <sep> a longitudinal section through the compression stage of the production line according to Fig. 4und <Tb> FIG. 8 <sep> an enlarged detail from FIG. 7.

Representation of preferred embodiments

Fig. 1 shows a perspective view of a partially cut metal-reinforced plastic composite tube 1 according to the present invention with an inner plastic tube 10, an applied on the outer periphery of the inner plastic tube 10 first adhesive layer 12, one applied to the first adhesive layer 12, the inner plastic tube 10 surrounding metal tube 14, a surrounding the outer circumference of the metal tube 14 second adhesive layer 16 and an applied to the second adhesive layer 16, the metal tube 14 surrounding the plastic sheath 18th

As can be seen from the cross-sectional view of the plastic composite tube 1 shown in Fig. 1 in Fig. 2, overlap the longitudinal edges 13, 15 of the metal strip 11 to the metal tube 14 bent metal shell each other, wherein between the at the longitudinal edges 13th , 15 adjacent longitudinal edge portions of the metal tube 14 adhesive 17 from the first adhesive layer 12 and / or the second adhesive layer 16 has penetrated. In this way, not only the metal tube 14 with the inner plastic tube 10 and the outer plastic sheath 18 are bonded by the two adhesive layers 12, 16, but the metal tube not welded together at its longitudinal edges obtained by the adhesive 17 after curing the desired metal tube stability.

The illustrated in Fig. 3 alternative embodiment of the inventive plastic composite pipe 1 corresponds in construction to the plastic composite pipe 1 shown in Fig. 1, but wherein the metal tube 14 is formed of a perforated metal sheet and so in the longitudinal direction and over distributed around the circumference is provided with a plurality of holes 14. These holes 14 allow gas diffusion through the wall of the plastic composite pipe, wherein gases formed inside can pass outwardly through the holes of the metal shell unhindered, so that the formation of gas bubbles in the wall under the metal jacket is avoided.

4, a production line 100 for producing a plastic composite pipe 1 according to the inventive method is shown. Instead of the plastic composite pipe 1, the metal-reinforced plastic composite pipe 1 can be manufactured on this production line 100.

The production line 100 consists of a first section 101, in which the deformation steps take place, and a second section 102, in which the extrusion of the plastic jacket takes place. The first section 101 has a mechanical substructure 103 on which the individual production stations are mounted. The second section 102 also has a mechanical substructure 104 on which the extruder 105 is mounted. The material passage takes place in the production line 100 in FIG. 4 from right to left and is symbolized by the arrow M.

In the material flow direction M, a first production stage 110 is initially provided in the first section 101 of the production line 100 (in FIG. 4, from right to left). The first manufacturing stage 110, the plastic tube 10 and the metal strip 11 are supplied from the right. In this first manufacturing stage 110, the metal strip 11 is brought into the vicinity of the outer circumference of the plastic tube 10 and aligned in a parallel transport position to the axis X of the plastic tube 10.

The plastic tube 10 and the metal strip 11 then pass through a second manufacturing stage 120, in which the metal strip 11 passes through a plurality of roll forming devices 121, 122, 123 and 124 and deformed into a bent in cross-section the shape of a lying "C" bent metal strip 11 which partially surrounds the plastic pipe 10 (see FIG. 6). The roll forming devices may be arranged horizontally or vertically.

The plastic pipe 10 emerging from the second production stage 120 and the metal strip 11 deformed in the second production stage 120 then enter a third production stage 130 of the first section 101 of the production line 100. The third manufacturing stage 130 is shown in detail in FIGS. 5 and 6.

Fig. 5 shows partially cut an adhesive applicator 131, the manner known in the art, a first adhesive C1 is supplied. The adhesive C1 is heated in a heating head of the adhesive applicator 131 to a temperature of about 220 ° C and passed to a below the heating head 132 applicator sleeve 133 through which the plastic tube 10 passes.

The applicator sleeve 133 is provided over its circumference with a plurality of passage openings 134 which open into an annular space 135 which is formed between the outer periphery of the plastic tube 10 and the inner periphery of the applicator sleeve 133. On the rear side of the applicator sleeve 133 facing away from the annular space, the passage openings 134 are connected to an adhesive channel 136 in the interior of the heating head 132. In this way, the adhesive heated in the heating head 132 can flow through the passage openings 134 into the annular space 135, through which the plastic pipe 10 passes. The plastic tube 10 is wetted on its outer circumference with the adhesive C1.

The bent metal strip 11 passes below the adhesive applicator 131 past this.

In a subsequent to the third manufacturing stage 130 fourth manufacturing stage 140 further deformation of the bent metal strip 11 takes place such that the metal strip 11 is formed into a metal tube 14 surrounding the plastic layer 10 provided with the first adhesive layer 12. The longitudinal edges 13, 15 of the metal tube overlap each other. In a modified variant, two or more of the fourth production stages 140 are provided one behind the other.

The plastic tube 10 emerging from the fourth production stage 140 and provided with the first adhesive layer 12, and the metal tube 14 surrounding it, subsequently enter a fifth production stage 150, which is described in more detail below in connection with FIG. 7 and FIG.

The third manufacturing stage 130, the fourth (n) manufacturing stage (s) 140 and the fifth stage 150 are directly, that is, without significant distance between them, one behind the other, so that a decrease in the adhesive capacity of the adhesive applied in the third manufacturing stage first Adhesive layer until it passes through the fifth manufacturing stage 150 (for example, by setting) is minimized.

The fifth manufacturing stage 150 has an adhesive applicator 151, which is formed substantially the same as the adhesive applicator 131 of the third manufacturing stage and an adhesive C2 is supplied. The adhesive C2 may be the same adhesive as the adhesive C1 or may be another adhesive. The adhesive applicator 151 is provided with a heating head 152 which heats the adhesive C2 to a suitable flow temperature, for example also 220 ° C. Below the heating head 152, the adhesive applicator 151 is provided with an application and compression device 153. The application and compression device 153 has a sleeve-like construction and the metal tube 14 and the plastic tube 10 provided with the first adhesive layer 12 pass through the sleeve-like application and compression device 153. The application and compression device has a sleeve-like housing part 154, which is provided with a radial adhesive channel 155 which is in fluid communication with an adhesive channel 156 in the heating head 152.

The inner peripheral surface of the sleeve-like housing part 154 is formed conically with a decreasing in material flow direction M diameter. In the sleeve-like housing part 154, an inner conical sleeve 157 is used, which is formed on its outer circumference so cone-shaped that it can be brought against the inner cone of the sleeve-like housing part 154 for conditioning. The inner conical sleeve 157 has an axial passage opening of constant diameter, wherein the diameter is greater than that of the metal tube 14. The inserted into the sleeve-like housing part 154 inner conical sleeve 157 is screwed by a screwed into the rear opening of the sleeve-like housing part 154 threaded sleeve 158 against the pressed conical inner surface of the sleeve-like housing part 154 and fixed in this way.

In the material flow direction behind the front portion of the inner tapered sleeve 157 (in Fig. 7links thereof), an adhesive application and compression structure 159 is provided, which will be described below with reference to FIG. 8.

Fig. 8 shows the front portion of the application and compression device 153 in an enlarged view. The inner conical sleeve 157 abuts the adhesive application and compression structure 159 with its front end in the material flow direction M. This has an annular nozzle body 160, the inner diameter of which tapers from the inner diameter of the inner conical sleeve 157 in the material flow direction to an inner diameter that is slightly larger than the outer diameter of the supplied metal tube 14.

In the region of the taper of the inner diameter of the annular nozzle body 160 is provided with an inner circumferential groove 161, in which a plurality of adhesive channels 162 open, which are arranged distributed over the circumference and penetrate the annular nozzle body 160 substantially radially. On the radially outer rear side of the adhesive channels 162, these are in communication with a plurality of adhesive supply channels 163 formed between the conical outer periphery of the inner tapered sleeve 157 and the conical inner periphery of the sleeve-like housing portion 154 and on its rear side into an outer peripheral groove 164 of the inner Conical sleeve 157 open, which is in fluid communication with the adhesive channel 155.

The adhesive C2 can therefore flow from the adhesive channel 155 via the outer annular groove 164 in the Klebstoffzuführkanäle 163 and through the adhesive channels 162 in the inner annular groove 161, from which the adhesive C2 reaches the outer periphery of the metal tube 14 and wetted. In this case, adhesive also penetrates into the intermediate space between the mutually overlapping longitudinal edge regions of the metal tube 14.

The adhesive applied to the outer circumference of the metal tube 14 acts as the metal tube 14 passes through the first section 165 of the compression nozzle following the inner circumferential annular groove 161 and the subsequent second section 168 of the compression nozzle, that is the area of the adhesive application and compression structure 159 narrowest diameter, as a lubricant. In this way, a friction between the metal tube 14 and the compression nozzle 165, 168 is reduced or at least significantly reduced. The adhesive acts as a lubricant here.

When passing through the metal tube 14 through the compression nozzle 165, 168, the metal tube is radially compressed so that the metal tube 14 is pressed firmly against the plastic tube 10 located on the first adhesive layer 12 and connected to the plastic pipe 10 to a tube unit 19.

In the material flow direction M behind the first section 165 of the compression nozzle (ie in Fig. 8links thereof), a further annular groove 166 is formed on the inner periphery of the adhesive application and compression structure 159. This further inner circumferential annular groove 166 is in fluid communication with the adhesive supply channels 163 via an annular adhesive channel 167 running obliquely to the longitudinal axis X. Through the annular adhesive channel 167 and the further inner circumferential annular groove 166 adhesive is applied evenly over the entire circumference of the tube unit 19 to the outer circumference of the tube unit 19 after passing through the first section 165 of the compression nozzle so that a second adhesive layer is formed on the outer circumference of the metal tube 14 16 is created. The amount of adhesive applied here can be adjusted by adjusting the opening cross-section of the annular adhesive channel 167. This second layer of adhesive also acts as a lubricant as it passes through the adjoining second portion 168 of the compression nozzle.

The compression nozzle 165, 168, preferably the second portion 168 thereof, may be heated, for example, by a resistor, to heat and relink the adhesive of the first adhesive layer 12 by heating the composite tube passing through the compression nozzle herein and to reactivate its adhesiveness.

The tube unit 19 provided with the second adhesive layer 16 subsequently enters the extruder 105, in which a plastic sheath 18 is extruded onto the second adhesive layer 16. After passing through the extruder 105, the plastic composite pipe 1 according to the invention is completed.

As has already been stated, instead of the closed metal strip 11 and a perforated metal strip may be used, which is then converted to the perforated metal tube 14, as shown in Fig. 3, wherein the above-executed method steps for the preparation of Plastic composite pipe 1 are the same as for the plastic composite pipe 1 with perforated metal pipe 14th

The invention is not limited to the above embodiment, which merely serves for the general explanation of the essence of the invention. Within the scope of protection, the device according to the invention may, on the contrary, also assume other than the embodiments described above.

Reference signs in the claims, the description and the drawings are only for the better understanding of the invention and are not intended to limit the scope.

Claims (13)

1. A method for producing a metal-reinforced plastic composite pipe, comprising the steps of: a) providing a plastic tube (10); b) feeding a metal strip (11) in the vicinity of the outer periphery of the plastic tube (10); c) deforming the metal strip (11) in such a way that it partially surrounds the plastic tube (10) in a C-shaped manner at a distance from its outer circumference; d) applying a first adhesive layer (12) on the outer circumference of the plastic tube (10); e) deforming the cross-sectionally C-shaped metal strip (11) to a plastic tube (10) surrounding the metal tube (14), wherein the longitudinal edges (13, 15) of the metal tube (14) overlap each other; f) applying a second adhesive layer (16) on the outer circumference of the metal tube (14); g) compressing the metal tube (14) in the radial direction to press the inner periphery of the metal tube (14) on the outer periphery of the plastic tube (10) provided with the first adhesive layer (12); h) extruding a plastic sheath (18) onto the outer circumference of the metal tube (14) provided with the second adhesive layer (16). 2. The method according to claim 1, characterized in that when applying the second adhesive layer (16) in step f) adhesive is also introduced between the overlapping longitudinal edge regions of the metal tube (14). 3. The method according to claim 1 or 2, characterized in that the compression of the metal tube (14) in the radial direction in step g) in an annular compression nozzle (165, 168) takes place. 4. The method according to claim 3, characterized in that the application of at least a portion of the second adhesive layer (16) in step f) immediately before the compression nozzle (165, 168) for compressing the metal tube (14). 5. The method according to claim 4, characterized in that the application of the second adhesive layer (16) in step f) by two flow paths (162, 161; 167, 166) takes place, the mouth areas to the outer periphery of the metal tube (14) spaced apart in the axial direction are. 6. The method of claim 3, 4 or 5, characterized in that the with the adhesive layers (12, 16) provided unit of plastic pipe (10) and metal pipe (14) is heated when passing through the compression nozzle (165, 168). 7. The method according to any one of the preceding claims, characterized in that the method is carried out continuously under constant feed of the plastic tube (10) and the metal strip (11). 8. The method according to any one of the preceding claims, characterized in that the step d) before step c) is performed. 9. The method according to any one of claims 1 to 7, characterized in that the step d) before step b) is performed. 10. Metal-reinforced plastic composite pipe consisting of a radially inner plastic tube (10) whose outer circumference with the inner circumference of a metal tube (14) is firmly bonded, wherein the longitudinal edges (13,15) of the metal tube (14), overlap each other and are glued together and wherein an extruded plastic jacket (18) surrounds the outer circumference of the metal tube (14) and is glued thereto. 11. Metal reinforced plastic composite pipe according to claim 10, characterized in that the metal pipe (14) is formed from a perforated metal sheet. 12. An apparatus for producing a metal-reinforced plastic composite pipe with a method according to any one of claims 1 to 9 with - A first feed device for a plastic tube (10); - A second feed device for a metal strip (11); - A first manufacturing stage (110) which positions the metal strip (11) and the plastic tube (10) relative to each other; - A second manufacturing stage (120) having at least one deformation means (121, 122, 123, 124) for the metal strip (11); - a third manufacturing stage (130) comprising a first adhesive applicator (131) adapted to allow the plastic tube to pass through the first adhesive applicator (131); - At least a fourth manufacturing stage (140) having a further deformation device for the already partially deformed metal strip; - A fifth manufacturing stage (150) comprising a second adhesive applicator (151) which is formed so that the plastic tube and the surrounding metal tube can pass through the second adhesive applicator (151), and a compression means (159) for surrounding the plastic tube Metal tube has; and - An extruder (105) which is designed so that the composite of plastic pipe and metal pipe can pass through the extruder (131) and provided there with a plastic jacket. 13. The apparatus according to claim 12, characterized in that the compression device (159) has a compression nozzle (165, 168) which, preferably with an electrical resistance, can be heated.