DE1504036A1 - Process for the production of workpieces made of plastics with at least longitudinal reinforcement inserts - Google Patents

Description

Josef BICHL

Grafrath - Amper

House on the moss ι ι γ * · "C - ** 1

Process for the production of at least longitudinal reinforcement inserts Workpieces made of plastics.

It is known that the properties of high-polymer materials can be improved by reinforcing inserts of all kinds and, in particular, the strength properties can be increased. For example, glass fiber reinforced plastics have been developed which are reinforced, for example, by rovings, ie by glass fiber strands running in the longitudinal direction of bores, rods, profiles or the like. The gain you make will affect in a significant improvement in tensile, bending and the compressive strength and the impact strength of which is opposite to the non-reinforced plastic significantly higher values accept _T

However, plastics should not only help i.e. strand-like reinforcement inserts, but also be reinforced in the transverse direction to this longitudinal direction. Reinforcement inserts are already in place for this purpose made of glass, asbestos, textiles, also made of nylon, perlon etc. as well as of metallic wires in proportion short sections that match the fiber length in the event that natural or synthetic fibers are used, cut up, or the natural fibers are used. These fibers or those in shorter parts cut reinforcement inserts are sucked into a preform, mostly with the help of an air stream, which is flocked in this way. Connecting

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Send the preform produced in this way is attached by means of a binding agent and then with plastics soaked, which harden after pressing the workpiece into the desired shape. With such workpieces The short reinforcing fibers lie randomly in the plastic in positions that are different during manufacture of the preform have happened by chance.

Another method that has become known for producing pipes and fittings is one Domes on which resin-impregnated glass fabric or tapes are wound, which are then hardened. The winding process has the disadvantage that it cannot be carried out continuously because of the mandrel must be pulled out of the workpiece after a certain length has been produced.

In another known method, carried out in principle in the same way, a distinction is made between different, successively applied winding layers of longitudinal glass strands on the walls of the dome and parallel to the pipe axis created.

It is also known, as already explained in the introduction, endless reinforcing inserts in the form of the glass threads mentioned, Fiberglass strands, textile thread, yarns made from textile materials, twisted threads, cords, braids, ribbons, Ropes, plaits and, in other textile forms, forms of strands as well as natural and synthetic fibers Introduce into the space between a core and a shell and at the same time synthetic resin by pressing screws to supply the mentioned space so that it is used to form workpieces designed as hollow bodies and in addition, these workpieces are reinforced in the longitudinal direction. However, the transverse reinforcement is missing here, which

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pieces only gives the required strength. This cross reinforcement is also missing in another suggestion, according to which a tube is inserted into a press nozzle, which is held by a core with a conical outlet is. The core is enclosed by a jacket piece with the formation of a space that is used for the supply of Resin is used. The tube has beads in which thinner tubes are used to feed thread or Wire-shaped reinforcement inserts are used. The tube ends shortly after the conical outlet of the core before the narrowest one Part of the press nozzle and the same is the case with the thinner tubes for feeding in the strand-like reinforcement inserts the case, so that in this way pipes made of plastics, in particular synthetic resin, with thread-like or wire-shaped Deposits are produced using this method it is that the reinforcement inserts are only on the surface of the synthetic resin pipes produced, while the inner pipe parts remain unreinforced both lengthways and crossways

In contrast, it is the object of the present invention to develop a method in which not only the plastic workpieces are stiffened by means of strands of endless reinforcing inserts, but above all the mentioned transverse reinforcement is realized that further reinforcement inserts one of the longitudinal direction of the Workpiece have a different position.

Starting from a method of manufacturing at least longitudinally Y / piece pieces made of plastics with reinforcing inserts by means of extrusion, the longitudinal Reinforcement inserts by means of parallel to the longitudinal direction of the workpiece and in relation to each other parallel pipes are fed and the plastic over an annular space surrounding a press nozzle is fed,

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According to the invention, the proposed method is characterized in that further reinforcement inserts are added to the plastic before it is fed to the press nozzle and the plastic and these further reinforcement inserts are first given a direction parallel to the longitudinal axis of the workpiece to be produced and then a radial direction until it is introduced into the press nozzle. The method leads to the desired success because the plastic having the further reinforcement inserts can be moved in a direction parallel to the workpiece axis over such a distance that the further reinforcement inserts assume a position parallel to the flow direction. It is not necessary here for the reinforcement inserts to be broken down into relatively short longitudinal sections. For example, make smooth ■ ^r erstärkungseinlagen in the form of threads or strands of extilem (Jut the direction changes that are imposed in carrying out the present invention the proposed method, readily with, while it is not readily in the case of metallic wires. In these cases It is therefore expedient to introduce the further reinforcing inserts in the form of pieces having a finite length or in the form of fibers of all kinds. The method can be carried out in such a way that the plastic containing the further reinforcing inserts is made of a plastic surrounding the workpiece cross-section at a distance, parallel to the workpiece axis extending annular gap is initially deflected in the centripetal direction towards the workpiece axis towards the latter and then both axially and equidistantly from the workpiece circumference, so that the reinforcement inserts run transversely to the workpiece longitudinal axis Tension are maintained, with the longitudinal reinforcement inserts coming into consideration, but also the further reinforcement inserts if they have the aforementioned suppleness and resilience.

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'At the transition of the further reinforcement inserts Plastic from a feed channel with a relatively large cross section into the much narrower one and the annular gap running approximately at right angles to this, flow conditions result in the flowing one Plastic, which means that most of the reinforcement inserts are aligned in the direction of flow to have. 2s has been found to be sufficient Length of the above-mentioned annular gap, the majority of the reinforcement inserts contained in the plastic, the desired pre-orientation occupies. Since the annular gap is then given a change in direction in the direction of the workpiece axis the reinforcement inserts contained in the plastic approach in a substantially transverse direction of the actual press nozzle from which the finished molded body is ejected in the axial direction. Since the change of direction into the press nozzle is essentially seamless, the overwhelming majority of the reinforcement inserts that have entered the nozzle in the above-mentioned manner retains the desired reinforcement in the workpiece that has now been formed Position at. The process according to the invention is surprising and extremely simple Way, preferably in the case of the occurrence of the reinforcing inserts in the form of each a finite length having sections, for example in the form of fibers, these initially contained completely randomly in the plastic mass Fibers through sensible choice of the flow path for the plastic in to the workpiece boundary surfaces essentially to orientate equidistant layers so that they are aligned with the reinforcement inserts that are continuously arranged in the longitudinal direction cross roughly at right angles. So it occurs with a circular cross-section, as it does with a Rohr occurs, a peripheral and, taking into account the always existing, axial displacement component, a helical distribution of the reinforcement inserts,

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a, which is crossed by the rovings, which in turn run parallel to mental lines of the tube; in the same Direction, other individual fibers can again be arranged in the longitudinal direction of the pipe or of the workpiece at all. Furthermore, the orientation of the fibers can be made the desired by attaching baffles in the flow channel Purposes are influenced accordingly.

Devices for carrying out the proposed according to the invention Process are preferably characterized in that, based on arrangements with a press nozzle, to which the plastic is fed via an annular channel and in which it is parallel to the longitudinal axis of the workpiece and Pipes arranged to one another for the introduction of endless reinforcing inserts open into the annular channel a section parallel to the workpiece axis and narrow in relation to the other cross sections of the extrusion press and has a radial, inwardly extending section which adjoins in the flow direction of the plastic and which opens into a press nozzle.

So that the longitudinally arranged, continuous strands of reinforcement inserts that come from the back can be introduced into the nozzle when it meets the plastic containing the additional reinforcement inserts are not displaced inward to a core defining a workpiece cavity, but within the Cross-section of the wall of the finished workpiece are located at the points provided for this purpose, are advantageous in the area of Confluence of the radially inwardly directed section of the annular channel into the nozzle cavity for axially parallel guides the longitudinal, continuous and endless strands of reinforcement inserts are arranged. By appropriate arrangement of said longitudinal guides in relation to the

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Between a core and an outer ring of the nozzle remaining cavity, it is possible to produce solid and hollow bodies of any desired cross-sections, including irregularly shaped cross-sections, the endless reinforcing strands running in the longitudinal direction in turn being the later ones Stresses can accordingly be arranged closer to one another in individual areas than in other areas and also with regard to the scheme according to which the reinforcement strands in the cross-section of the workpieces, For example, a hollow body wall are embedded, there is every conceivable freedom.

The invention also extends to some of the features described below and ultimately has their overall combination and all partial combinations of the features to the subject, insofar as the latter are technically sensible and feasible as well as usable, even if in the following the each achievable, new technical effects are not mentioned and described in detail. Likewise, all The details shown in the drawing are assumed as such and in their functional context as described.

The invention is explained in more detail below with reference to an embodiment shown in the drawing, wherein for longitudinal reinforcement of the hollow workpiece body to be produced rovings, i.e. strands of glass fibers and for transverse reinforcement Serving pieces from such.

Show it:

Fig. 1 shows an extruder for carrying out the inven-

according to the procedure in vertical section,

FIG. 2 shows a section through FIG. 1 along the line H-II of FIG. 1 with a partial front view,

Fig. 3 is a broken section along line HI-III of Figure 1 with a partial front view,

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4 shows a schematic representation of the alignment process of the reinforcing fibers during flow through the pressing device,

Fig. 5 partial cross-sections through two finished workpieces and

6 shows the overall arrangement.

The extrusion device shown in Fig. 1, its components for the purpose of facilitating replacement and the better Yfartung are assembled in a modular manner essentially from a hollow cylindrical insert 1, through whose longitudinal recess a cavity a finished workpiece defining core 3 passes, leaving an annular gap. On the free face The insert 1 has a cover 2 attached, the edges of which surrounding a central opening are rounded. At the same end of the core 3, a disk 4, which also has rounded edges, is attached. The on this Wise formed, approximately funnel-shaped opening is used to introduce extending in the longitudinal direction of the workpiece Reinforcement strands, which through recesses 6 of a molded piece 5 through in guide tubes 8 to the nozzle 10 back and forth are passed through the nozzle 10. The guide tubes 8 are in the annular space surrounding the core 4 by means of a further ring piece 7 and a closing ring 9 held in the intended position; the guide tubes 8 are further extended into the nozzle 10 by the sections 14 for a purpose which will be explained later.

The plastic to be pressed, containing reinforcing inserts in the form of fibers or pieces of fiber, is through the channel 11 is supplied under pressure. To generate pressure, extruders or presses with one or more plungers can be used Find use. The channel 11 goes into an annular gap surrounding the longitudinal recess of the device at a distance 12 with a length determined by experience

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same about. The cross-section of the annular gap Y1 is much narrower than that of the channel 11, so that a throttling or damming effect in the supplied plastic occurs at the inlet. This has the consequence that reinforcement inserts mixed with the plastic adjust themselves in the gap 12 essentially parallel to the flow direction of the plastic in this section.

The annular gap 12 then goes into a centripetal leading to the workpiece axis, i.e. essentially radially extending portion 13 over, which is thus within the nozzle insert 10 radially inward into the inside the nozzle lying cavity is introduced. The section 13 opens into the nozzle cavity within the area Over which the guide tubes 14 for the reinforcing inserts arranged to run in the longitudinal direction in the form of fiber strands over the inner end face of the insert 1 and its inner end body parts, to the exit of the strand-shaped reinforcement inserts from the extrusion press are extended.

Since the ring gap 17 (see FIG. 2) is located on the annular disk-shaped cavity 13 between an extension 18 of the core body 3 and the jacket body 19 adjoins, it comes to a helical entry of the other Reinforcement inserts 16 (see FIGS. 1 and 5) in the synthetic resin flow, because the radial flow between the nozzles 14 and axially pushing synthetic resin under the action of the core body, the further reinforcing inserts from the Radial deflects in the axially-peripheral direction, the slope of the helical curve depending on the ratio of the flow cross-sections for centripetal and axially moved goods is dependent or set by dimensioning these cross-sections can be; the cross-section between the parts 13, 19 is larger than the cross-sections between the parts 13, 12, 11, the slope of the helical

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fending flow is greater than in the reverse case, in which the further reinforcement inserts 16 practically each running approximately perpendicular to the longitudinal axis 20-20 of the whole Levels lie.

The longitudinal reinforcement inserts in fiber strands 15 unwound from supply spools known per se (not shown) emerge from those leading them Pipes 14 only behind the confluence of the annular gap section 13 into the cavity of the nozzle 10. The longitudinal strands 15 therefore come at the end of the tubes 14 only in contact with plastic, which is in the same direction as the fiber strands (based on Fig. 1 after left) moves forward. The fiber strands are therefore, in the desired manner over the cross section of the workpiece wall distributed, embedded in the plastic.

Figure 2 shows an end view with partial cross-section on or through the extruder, which is used to carry out the determined according to the invention proposed method and in the case of the embodiment on the production a hollow body 17, which is rectangular in cross-section and formed with an attached bead, is set up. Here are at 15 again the longitudinally embedded ones next to one another in the workpiece wall at regular intervals Called reinforcement strands. The profile of the hollow body 17 is between the core 3 and the guide pieces 25, 26 Recessed pipes 27 leading to a heat-conducting agent, with the connecting sleeves 29 arranged like a strip, provide the required temperature state Part 25, 26 and the hollow body 17 a.

The illustration according to FIG. 3 shows, partly in an end view, partly in cross section, the tubes 14 and 8 leading the longitudinal reinforcement strands 15 through which the later

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Distribution of the longitudinal reinforcements within the workpiece wall 17 is determined. From the top half of the FIG. 3 shows, among other things, that the tubes 14 in the extrusion direction over the confluence of the annular gap 13 in the Nozzle cavity are also extended.

In Figure 4, the preliminary process is shown schematically, by means of which the further reinforcing inserts in the form of fibers or sections mixed with the plastic made of fibers, textile-processed fibers, wires 16 or the like, aligned transversely to the longitudinal axis 20-20 of the workpiece Unless endless, additional reinforcement inserts are used. Those in channel 11 more or further reinforcement inserts 16 that are less randomly embedded in the plastic are due to the damming effect, which is generated at the transition into the narrow annular gap 12 concentric to the workpiece axis, forced, adjust in the flow direction of the plastic. The reinforcement inserts keep this position in the direction of flow 16 also after the transition into section 13 of the annular gap. As explained earlier, there is one peripheral arrangement of the reinforcing inserts 16 in the workpiece, transverse to the axis 20-20, and thus to one overall helical position of the same with arbitrary adjustable pitch of the screw thread, the direction of the endless reinforcing inserts in each Trap is crossed.

Since this strand-like, fed in the longitudinal direction and laid reinforcement inserts 15 in the area of the confluence of the annular gap 13 in the cavity of the nozzle 10 through the Pipes 14 are protected, the further reinforcing inserts 16 are located between the pipes 14 positions relocated.

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In FIG. 5, there are cross-sections of two finished plastic pipes produced by the method according to the invention reproduced. Between the endless, strand-like reinforcement inserts 15 running in the longitudinal direction are the generally shorter to be held, further reinforcing inserts 16 in a transverse direction, that is to say throughout occur as fibers or as fiber sections, raw or textile processed. The arrangement in the right half eier Fig. 5 differs only in the two-row arrangement of the longitudinal strands 15 opposite the illustration of the left half, in which the reinforcement inserts on a single circular line, distributed over their Length, occur.

according to the method proposed according to the invention Workpieces of the most varied cross-sections are produced, which, with the simplest production, are considerably improved, have mechanical properties. There is here both with regard to the shape and the arrangement of the longitudinal reinforcements and the greatest freedom in the choice of materials. The reinforcement inserts, fibers and fiber strands can be made from any material suitable for this purpose, whereby asbestos, glass fibers, glass silk, glass wool, slag wool, textile fibers, strand-like textile goods in the form of threads, yarns ,. Twists, cords, ropes, ribbons, etc. made from natural ones and / or synthetic fibers or fiber blends, in the form of wires, twisted wires, twisted metal strips or untwisted or the like. It is advisable here to use the fiber strands that form the longitudinal reinforcement to keep under tension. This ensures that the for filling the extrusion tool with the to be processed plastic can build up the required back pressure. This back pressure is for a flawless surface of the finished workpiece as well as for complete filling,

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which will force any air out of the device.

If the reinforcements running in the longitudinal direction consist of rovings, these can be removed before entering the extruder be drawn through a bath of viscous resin and thus pre-soaked. In this case the resin is which soaks the rovings, generally in the so-called Α state. But it is also possible to use rovings, in which the resin that impregnates them is in the B-state, i.e. the resin is on thermal and / or chemical wege is already in a pre-hardened, but in any case almost dry or completely dry state. In The same can be said for the plastic mixture to be processed with short reinforcing inserts be an A or B state. The reinforcement inserts and / or the further reinforcement inserts do not need to be made of the same material; Likewise, different types of resin can be used, of course, with each other must be compatible, find use. The advance of the finished workpiece in the extrusion press can either by the pressure with which the plastic compound is introduced, or by a pulling device or by both measures take place together. The length of the workpiece produced in a continuous process corresponds to that of available rovings, generally up to about two thousand meters.

In short, the essence of the invention is to be seen in the fact that in a plastic, in particular synthetic resin, flow more or less randomly distributed reinforcing strand sections initially with a stream of synthetic resin (Premix) fed radially to the longitudinal axis of the workpiece, then over a cross-section that is larger than the workpiece transverse

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cut and preferably kept congruent to this, distributed as evenly as possible, then in the Axialrichtimg deflected, guided parallel to the workpiece axis up to the axial alignment of the reinforcement strand sections, transversely towards the workpiece axis, i.e. deflected radially on all sides, centripetal to a cavity of the V / part cross-section to be realized B. supplied, peripheral there from the radial-centripetal direction, i.e. equidistant from the workpiece surface deflected and then filling the workpiece cross-section with plastic, reinforcing strand sections and hovings are used for workpiece production will. Insofar as heat treatments are required here and / or on the further path of the workpiece, are required they, as known per se, are not presented in detail; heating windings required for this purpose are, for example, in Figure 1 at 26 to 29 indicated.

The overall arrangement is shown in FIG. 6. The arrangement shown in FIGS. 1 and 2 can be seen at 21, which is wound up Rovings at 22 and a double acting, i.e. synthetic resin or plastic continuously replenishing Piston press 23. Lovely, well-known facilities, For example, a saw arrangement 30 for cutting the finished workpiece 17 into desired lengths, Cooling beds 31, strand carriers in the form of rolls 32, etc., complete the system.

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Claims (1)

Sponsorship claims Process for the production of workpieces made of plastics with at least longitudinal reinforcement inserts by means of extrusion, whereby the longitudinal reinforcement inserts are parallel to the longitudinal direction of the workpiece and in relation to each other parallel pipes are supplied and the plastic is supplied via an annular space surrounding a press nozzle, characterized in that that further reinforcement inserts are added to the plastic before it is fed to the press nozzle and that the Plastic and these further reinforcement inserts initially one to the longitudinal axis of the workpiece to be produced parallel and then a radial direction is issued up to the introduction into the press nozzle. 2. The method according to claim 1, characterized in that the further reinforcing inserts having plastic over such a distance in the direction parallel to the workpiece axis is moved so that the further reinforcement inserts a parallel or approximately parallel to the flow direction Take position 3. The method according to any one of claims 1 to 2, characterized in that the other Reinforcing inserts having plastic from a workpiece cross-section surrounding at a distance, for Workpiece axis parallel annular gap initially in the centripetal direction towards the workpiece axis towards the latter and then both axially and equidistantly is deflected to the workpiece circumference, so that the other 909829/1392 Reinforcement inserts run transversely to the longitudinal axis of the workpiece 4 · Method according to one of Claims 1 to 3> characterized in that endless reinforcing inserts are kept under pretension. 5 · Device for carrying out methods according to a of claims 1 to 4 with a compression nozzle to which the plastic is fed via an annular channel and in which pipes arranged parallel to the longitudinal axis of the workpiece and to one another open out for guiding endless reinforcing inserts, characterized in that the annular channel (11) a narrow section parallel to the workpiece axis (12) and has a radial, inwardly extending section (13) which adjoins in the flow direction of the plastic and which is inserted into a press nozzle (10) joins. 6. Apparatus according to claim 5, characterized in that in the region of the confluence of the radially directed section (13) of the annular channel (12) in the cavity of the nozzle (10) axially parallel Guides (14) for longitudinal, continuous strands are arranged from reinforcing fiber layers (15). 323 d / 26. 909829/1392 Blank page