FI88372B - FOERFARANDE OCH ANORDNING FOER KONTINUERLIG FRAMSTAELLNING AV FIBERFOERSTAERKTA IHAOLIG PLASTPROFILER SAMT IHAOLIG PLASTPROFIL - Google Patents

Abstract

1. A process for the continuous production of fibre-reinforced plastics hollow sections, wherein a parting foil (3), and inner gel coat and a first layer of fibrous material (20, 21) are applied round a stationary mandrel (1), then further layers (34, 37) of fibrous material and liquid plastics material are laid round the first layer of fibrous material (20, 21), the hollow section is calibrated in a forming tool (40) and then heated so that the plastics material is cured, and wherein the cured hollow section is continously withdrawn from the mandrel (1) by a gripping device (52) and is finally cut into lengths, characterized in that the inner gel coat is applied to the parting foil (3) provided on the mandrel (1) and is gelled by heating, that the first layer of fibrous material (20, 21) with the liquid plastics material is laid, overlapping, on the inner gel coat, and that before the further layers (34, 37) of fibrous material are applied, the hollow section is heated and the plastics material in the first layer of fibrous material (20, 21) is cured.

Description

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Method and apparatus for continuous production of fiber-reinforced hollow plastic profiles and hollow plastic profile 5 U.S. Pat. No. 3,689,343 discloses a method and apparatus for the production of fiber-reinforced hollow profiles according to the preambles of claims 1 and 5. In this known method, a gel spin-10 support layer is formed on a portion of the width of the intermediate foil drawn from the storage space and gelled. A nonwoven mat is then pressed onto the gel coat layer. The mandrel is covered with this laminate so that the longitudinal edges of the gel coat layer and the mat adhere to each other. The free longitudinal edges of the intermediate foil come into the outside into the opening in the pan-15 mandrel. Plastic-impregnated longitudinal roving yarns are placed on the inner wall of the hollow profile thus formed. A outer wall is formed around these in the shaping device and is tightly pressed in the radial direction, which also comprises an intermediate foil, a gel coating layer formed and gelled thereon and a nonwoven pressed thereon. The plastic is cured in a heating device at the end of the forming device. The hollow profile is pulled out of the rear end of the device as a continuous function by means of a gripping device and cut off with a cutting device.

Due to the gel coating layer, the hollow profile thus prepared has a smooth surface and good corrosion resistance. Hollow; However, the disadvantages of these profiles are the contacting side edges of the gel coat layers, which are only incompletely connected to each other after gelling. At the same seam point, the long - *: · “full edges of the non-fibrous mats that are not joined together also touch each other, so the seam point is easily damaged. . 35 posts. The hollow profile compresses well in the ‘* radial direction’ in the shaping device. However, the compression pressures 2 88372 cannot be chosen to be high, because the friction in the shaping device and on the fixed mandrel then exceeds the tensile strength of the hollow profile. Thus, air seals that reduce the durability of the hollow profile cannot be avoided. The Ro-5 spinning threads are connected to each other only with plastic. Although they improve the bending and tensile strength of the hollow profile, they do not increase its compressive strength. It is quite small due to the seams of the fiber mats.

The object of the invention is therefore to develop a method and a device for the continuous production of fiber-reinforced hollow profiles which are capable of producing hollow profiles with good durability. This object is achieved by the structures set out in the characterizing part of claims 1 and 5. The hollow profile according to the invention is described in claim 9.

Because the inner gel coat layer is formed on the intermediate foil of the mandrel, it is seamless and provides secure protection for fiber-reinforced plastic layers. The overlap of the innermost fibrous layer and the hardening of the plastic 20 contained therein make the hollow profile strong enough that the mandrel can be detached from the profile in connection with the third heating device. In this case, the support formed by the mandrel is no longer required when forming other plastic-impregnated fibrous layers, so that the air entrapments in these layers 25 can be mainly removed by rolling the mandrel without increasing friction as a result. In addition, it is possible to form at least some additional layers without increasing the friction of the mandrel. This gives the hollow profile good compressive strength.

Also known from the 30 GB patent 1,350,298 is a method and apparatus for making fiber-reinforced plastic profiles. The continuously fed intermediate foil is coated on the gel coat on a flat track and the gel coat is gelled. On top of the gel coat layer. 35 is placed in liquid plastic and fiber tape. In this connection, a still flat laminate is formed into a profile of 88882 and the plastic is cured in a through-feed furnace. However, GB patent 1,350,298 mentions that the longitudinal edges of the laminate can be overlapped to form a hollow profile. However, this is not possible, 5 because the intermediate foil prevents the joining of the overlapping longitudinal edges. Thus, this method cannot produce a hermetic hollow profile with good strength.

U.S. Patent 3,033,729 discloses a method and apparatus for the continuous manufacture of GFK tubes. In this case, the roving yarns are fed through the liquid plastic and then into the heated mandrel approximately axially. In this heating, the plastic hardens somewhat. The partially cured plastic is then wound with roving yarns and the plastic is finally cured in a feed-through furnace. With this method, it is not possible to form an inner gel coat layer on the tube. Only partially cured plastic is not stable enough, so the roving yarns can only be twisted loosely, but on the other hand, it is also not flowable enough for the twisted roving-20 yarns to be securely attached to the plastic. This. . Due to these • / reasons, the pipe made according to the method has a lot of air closures, it is not tight and its strength is very low.

A structural example 25 of the present invention will now be described with reference to the drawing. In it: Figures 1a and Ib are schematic views of the device,: Figure 2 is a longitudinal section through the mandrel, Figure 3 is a cross-section along the line III-III in Figure 1, and

Fig. 4 is a cross-sectional view taken along line IV-IV of Fig. 1

along.

Figure 1 is a diagram to facilitate understanding of its various functions, with Figure Ib coming to the right of Figure 1a.

: 35 An intermediate foil 3 pulled from a bearing strip container 2 is first placed on top of the fixed mandrel 1.

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The foil 3 comes completely around the mandrel 1. The longitudinal edges of the foil then overlap. The outer overlapping longitudinal edge is fastened to the second longitudinal edge with an adhesive tape 5 drawn from the storage roll 4. The strip 5 of Lii-5 is pressed down by a roller 6. The intermediate foil 3 then forms a tubular intermediate layer which slides on the mandrel 1.

After the roller 6, a layer of liquid gel coating about 0.4 mm strong is applied to the intermediate foil 3 by means of an annular feeder 7 10 comprising an annular gap and is calibrated on the annular plate 8 so that a seamless gel coating layer is formed around the foil 3. The gel coating is a thermosetting plastic, for example a polyester with a lot of plasticizer. The gel coat-15 layer is more flexible than the associated fiber-reinforced thermosetting plastic and can be adapted to the respective application based on its composition. The liquid gel coating enters the feeder 7 from the container 9.

In the drawing direction A of the profile 20 after the annular plate 8, the mandrel 1 is heated by a heating device 12, whereby the gel coating layer is partially gelled. The heat transfer is very good due to the direct contact of the foil 3 and the mandrel 1, so that the temperature required for gelling the gel coat layer can be achieved over a short distance and prevent this layer from overheating. In connection with the heating device 12, the mandrel 1 is cooled by a cooling coil 13.

If greater layer thicknesses are desired for the gel coat layer, a second layer is sprayed on the first layer formed by the feeder 7 in the region of the heater 12, i.e. where the viscosity of the first layer is already significantly higher, with nozzles 35 rotating about the mandrel axis. 11 with a pump 10 from a tank 9. If even greater wall thicknesses of 5 88372 are desired for the profile, several such spraying devices can be arranged in succession, whereby the heating device is extended accordingly. When the gel coat layer is formed in several layers, it is ensured that, despite the effect of gravity, the wall thickness of this layer is similar over the entire circumference of the profile.

Then, a woven fiberglass mat 20 is drawn from a storage space 19 having a fixed axis of rotation from a storage space 19 having a fixed axis of rotation by means of an annular feeder 17 having an annular gap 10 in the form of a hollow profile overlapping it. The second woven fiberglass tape 21 is then drawn from a storage roll 22 mounted on a container 23 rotating about the axis of the mandrel and wound on the mat 20 in a helical overlap. After said container 23 in the drawing direction A, the mandrel 1 is heated by a second heating device 24, 25, whereby the first heating coil 24 utilizes the exhaust heat of the cooling coil 13 and / or the associated second cooling coil 26. The energy consumption required for heating can thus be kept low. Heat recovery is possible by direct heat transfer through the mandrel 25. As the disposable plastic passes through the heating device 24, 25, it cures to form a thin-walled, fiber-reinforced hollow thermoplastic profile as a support profile for the additional layers to be formed in this connection. This support profile is supported by support rollers 27 which move on top of already hardened fiber-reinforced thermosetting plastic. In connection with the heating device ·. * ·: The mandrel has the above-mentioned second cooling coil 26 for cooling the support profile, so that the thermoplastic layers to be formed thereafter do not. : 35 harden too early. The support profile is sufficiently rigid for the following functions, so that a smaller diameter part 28 is arranged in the mandrel in connection with the 6 88372 cooling coil 26. The mandrel 1 can also end at this point.

At this stage, a liquid support plastic, a longitudinal fiberglass mat 34 and a helically wound fiberglass tape 37 are placed on the stable support profile 5 in several successive steps a, b, respectively. In this case, the thermoset feeders 31a, 31b correspond to their inner diameter 32 The woven fiberglass mats 34a, 34b are pulled from the fixed bearing rollers 33a, 33b in a manner similar to the mat 20. The longitudinal edges of the glass fiber mats overlap, respectively, whereby the overlapping points are moved in the circumferential direction opposite to each other. In addition, the axes of rotation of the storage rollers 19, 33a, 33b are also arranged around the axis of the mandrel. In Fig. Ib, for the sake of clarity only, they are shown in the direction of the axis of the mandrel, successively coaxial. Correspondingly, the woven glass fiber strip 37a, 37b is wound around the glass fiber mats 34a, 34b in a helically overlapping manner and is compressed in the radial direction as a strip pull so that the previously fed thermosetting plastic is absorbed into the layers 34a, 37a and 34b, 37b. For this purpose, a rolling device 35 rotating about the axis of the mandrel 25 is also used, which has a plurality of rollers 36 evenly spaced around the circumference of the hollow profile. The rolling device 35 may be arranged in front of or behind the last strip station 37b, 38b, 39b. The hollow profile is then drawn through the calibration plate-30, where the wall of the profile condenses and the excess thermosetting plastic comes off. After the calibration plate 40 * the outer gel coating layer is sprayed into the profile by a plurality of nozzles 44 rotating about the mandrel axis, which is calibrated by a second calibration plate 45. A liquid-35 gel coating, for example again a polyester containing 7 88372 plasticizers

The hollow profile then passes through a feed nozzle 50 where the thermoplastic and the outer gel coat layer 5 heat and cure and through a plurality of measuring stations 51 to check the diameter, wall strength and hardness of the profile.

The finished hollow profile is continuously drawn from the mandrel 1 by the gripping device 52 and cut off by the breaker-10 with the melting device 53 to the desired profile length. Suitable gripping and cutting devices are known from mouth-pulling devices for closed profiles.

Figure 2 shows a longitudinal section of a mandrel 1 with heating and cooling devices. The mandrel 1 15 is fixed to a bearing body 57 and comprises a steel pipe through which a cooling water supply pipe 59 and an outlet pipe 60 and electrical heating wires 61 are laid. Each heating device 12 and 25 has an aluminum a copper sleeve 62 having a plurality of evenly spaced thermostatically controlled electric heating rods 63 on its circumference 20. The heating rods 63 are electrically connected to each other in each heating device 12, 25 and connected to the other twice by a wire 61. Each cooling device 13 and 26 comprises:. t 25 a tube coil 64 connected to the tube 58 as heat conducting, the rear end (viewed in the drawing direction A) being connected to: Y: a supply line 59 and the front end of which is connected to the rear end of the second tube coil 65 forming the preheater 24. . ·. : The front end of the coil 65 is connected to the discharge line 60. The preheater 24 thus utilizes the exhaust heat of both cooling devices 13, 26.

* ·. ’·: Figure 3 shows a cross-section of the device ____ 11 used to form the inner gel coat layer. A roller is mounted around the axis of the mandrel 1. : 35 an annular support 68 rotating over the lien 69. Four radially inwardly directed spray nozzles 70 are fixed at regular intervals to the circumference of the support 68. The pump 9 feeds a liquid gel coating to the spray nozzles 70 via a flexible hose 72 through a manifold 71. A spray air line (not shown) is further connected to the spray nozzles 70 to spray the gel coat material. The nozzles 70 can be fixed to the support 68 in a radially adjustable manner, so that hollow profiles of different internal dimensions can be produced after the replacement of the mandrel 1. The gel coat material 10 exits the nozzles 70 as a fine jet 73. To obtain a uniform thickness of the gel coat layer, the support 68 is rotated about the mandrel axis back and forth by a motor 74 and a crank mechanism 75. The device 15 used to form the outer gel coat layer is constructed

Figure 4 shows the feeding of fiberglass tape 21 from a tape container 23. The tape container 23 comprises a tubular support 77 arranged coaxially with the mandrel 1, which is driven, for example, by rollers 78 rotated about an axis of the mandrel and driven by a gear 80 and a gear 79 of the motor 81. A support plate 82 at a certain radial distance is welded to the support 77.

Attached to this is a holder 83 of a storage roll 22 and a spare roll 22a rotating about an axis 84. The holder 83 locks in the position shown and rotated 180 °. The belt 21 is guided over a turning roller 85, a pair of rollers 86 and a second pair of rollers 30 87 with a brake for adjusting the tension of the belt. The pair of rollers 86 is attached to a carriage 90 preloaded by a spring 89 in a displaceable rod shown in the basic position 89. The carriage 90 has a pressing surface 91 over which the strip 21 is guided. Opposite the pressing surface 91 on the carriage 90, a pressing beam 92 is mounted as a displacement. The beam 35 can be pressed against the pressing surface 91 by means of a solenoid 93. The initial end 21a of the strip of the spare roll 22a is guided over the second turning roll 94. The front end of the strip portion 21a is attached to the beam 92 in an easily removable manner. A double-sided unsupported adhesive tape 95 is glued to the lower surface of the front end of the tape portion 21a on the side of the tape 21.

When the device is used, the support 77 and with it the strip container 23 rotate at the same speed about the axis of the mandrel 1 to pull the profile out of the mandrel, respectively, so that the longitudinal edges of the strip 21 overlap. When the storage roll 22 is empty, the photocell 96 detects the end of the strip and then activates the solenoid. The beam 92 now presses the front end of the strip portion 22a of the spare roll 22a with the adhesive strip 95 against the rear end of the strip 21 and connects these ends to each other. During compression, the carriage 90 moves against the force of the spring 89 as the belt 21 moves with it. The solenoid 93 is disengaged again, returning the carriage to the basic position shown. The strip container 23 rotates relatively slowly about the axis of the mandrel, so that the following operations for inserting a new storage roll can be performed manually. Thereafter, the holder 83 rotates 180 °. . clockwise and the beginning of the strip 21a moves from the turntable 94 onto the turntable 85 and further to the photocell 96.

A new spare roll 22a is placed on top of the now empty mandrel, an adhesive tape-25 ha 95 is glued to the front end of the beginning of its strip and this end is attached to the beam 92. Thus, the strip | the tank 23 is made for the next strip change.

The tape containers 38a and 38b correspond to the container 23 shown in Fig. 4. The automatic connection of the storage roll: tape end shown in Fig. 4 to the initial end of the spare roll tape 30 is in principle also possible with fiberglass mats 20, 34a and 34b and intermediate foil 3 and adhesive tape *. 5 in the case. However, since the drawing speeds of the mats 20, 34, the foil 3 and the adhesive tape 5 are considerably lower than the drawing speed of the tape 21, it is more advantageous. ; 35 that the storage rollers are replaced and the ends of the strips are joined together by hand.

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In addition to glass fibers, carbon fibers, aramid fibers or silicate fibers are also suitable for fiber-reinforced structures. In principle, disposable plastics, in particular polyester, are suitable binders. The described method 5 can be used to produce hollow profiles having the desired cross-sectional shape, provided that no concave points are associated with their surface. The method is very well suited for the production of pipes with a circular cross-section.

Claims (10)

A method for the continuous production of fiber-reinforced hollow plastic profiles, comprising placing an intermediate foil (3) on a fixed mandrel (1), followed by an inner gel coating layer and a first fibrous material layer (20, 21) and a first fibrous material layer ( 20, 21) are surrounded by other layers (34, 37) comprising fibrous material and liquid plastic, the hollow profile is then calibrated in a forming device (40) and heated so that the plastic hardens and the hardened hollow profile is drawn in continuous operation by a gripping device ( 52) out of the mandrel (1) and finally cut, characterized in that the inner gel coating layer 15 is formed on the intermediate foil (3) placed on the mandrel (1) and gelled by heating so that the first layer of fibrous material (20, 21) containing liquid plastic is placed overlapping. on top of the inner gel coat layer, and that before the other fiber-20 placing the material layers (34, 37), the hollow profile is heated and the plastic of the first fibrous material layer (20, 21) hardens. The method according to claim 1, characterized in that the inner gel coat layer: consists of at least two layers, wherein the layer (s) following the first layer are injected after the first gel coat layer has started to heat up, and that the inner gel coat layer is cooled. preferably after heating it and before forming the first layer of fibrous material (20, 21), and / or before injecting a liquid plastic into the gel coating layer before forming the first layer of fibrous material (20, 21). A method according to claim 1 or 2; 35 characterized in that the hollow profile is heated from the inside after the first fibrous material layer 12 88372 (20, 21) is formed, and / or that the hollow profile is cooled before the other plastic-containing fibrous material layers (34, 37) are formed. Method according to one of Claims 1 to 3, characterized in that a liquid plastic layer, a longitudinal fibrous mat (34) with a hollow profile, the longitudinal edges of which overlap each other and a helically wound, are arranged in succession to form the other fibrous material layers (34, 37). fiber-10 strip (37), and that the other fibrous material layers (34, 37) are rolled, and / or that the hollow profile is calibrated after the other fibrous material layers (34, 37) are formed, and that an outer gel coat is formed before the profile is finally heated to the calibrated hollow profile. layer, preferably by spraying, and calibrated accordingly. Apparatus for the continuous production of fiber-reinforced hollow plastic profiles provided with a fixed mandrel (1), an intermediate foil (3) feeding device 20 (2), a device (7, 11) for forming an inner gel coating layer on the intermediate foil (3), a first fibrous material layer (20), 21) a feed device (19, 23), additional feed devices (31, 33, 38) for other layers of fibrous material (34, 37) and liquid plastic, a calibration device (40), a first heating device (50), a gripping device (52) for drawing the hollow profile away from the mandrel (1) as a continuous operation and with a cutting device (53), characterized in that a device (7, 11) for forming an inner gel coating layer around the mandrel (1) and a second heating device (12) are arranged downstream of the hollow profile feed device (2) and a third heater after the feed device (19, 23) of the first layer of fibrous material (20, 21) device (24, 25), and that the mandrel (1) is detached from the profile after the third heating device (24, 25) and before the other additional feed devices (33, 38) for the fibrous material layers. Device according to Claim 5, characterized in that the second and third heating devices 5 (12, 24, 25) are arranged in the mandrel (1), and that a cooling device (12) is preferably arranged downstream of the second and third heating devices (12, 24, 25), respectively. 13, 26), and / or that, viewed in the pulling direction of the hollow profile, a device (17) for coating the gel-coating layer with liquid plastic is arranged before the feed device (19, 23) of the first fibrous material layer (20, 21). Device according to Claim 5 or 6, characterized in that a rolling device (35) is provided before the calibration device (40), and / or in that at least one (38) additional feed device (33, 38) for other layers of fibrous material (34, 37). is a belt container (38) rotating about the axis of the mandrel. Device according to one of Claims 5 to 7, characterized in that, viewed in the drawing direction of the hollow profile, a device (44) for forming an outer gel coating layer is arranged before the first heating device (50), and / or that the first fibrous material layer (20) , 21) the feed device (19, 23) comprises a strip container 25 (23) rotating about the axis of the mandrel, and / or that, looking in the direction of pull of the hollow profile, after the third heating device (24, 25) there is: arranged support rollers (27) for the hollow profile. Y; 9. A fiber-reinforced hollow profile having an inner and an outer gel coat layer and interlayer fibrous material and thermoplastic layers 30, characterized in that the fibrous material layers (20, 21, 34, 37) have a plurality of layers joined to the inner gel coat layer. a longitudinal fiber mat (20, 34) in the profile, the longitudinal edges 35 of which overlap, and a fibrous strip (21, 37) wound in an overlapping spiral. and 88372 Hollow profile according to Claim 9, characterized in that both the fibrous mats (20, 34) and also the fibrous strips (21, 37) consist of fabric, and / or that the overlaps 5 of the different nonwoven layers (20, 34) are displaced circumferentially relative to one another. is 8 8 3 72