DE2137778A1 - Method and apparatus for making fiber reinforced resin articles - Google Patents

Description

34 359

Frede Hilmar Drostholm
in Vedbaek (Denmark)

Method and device for the production of fiber-reinforced

Resin objects

The invention relates to a method and a device for extruding fiber-reinforced profiles, rods or tubes made of thermosetting plastics, e.g. polyester or epoxy resins, the device having a head or nozzle body with an or has a plurality of inner shaping surfaces defining a shaping passage through which resin and fiber reinforcement means a pulling mechanism.

The known devices for this type of extrusion or "pultrusion" of profiles and tubes have the disadvantage that the The surface of the product is scratched during the pull-through process, because gelation occurs in the value of the heat transfer and to the Hardening of the plastic material in the product. The hardened parts of the product create a trace or streak in the soft parts, as the hardened parts tend to adhere to the shaping surfaces of the passage. This often makes it necessary sanding or painting the products after extrusion, which is costly. Such a treatment is e.g. at the production of fiberglass-reinforced rods such as fishing rods

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conducive. Bars and tubes with streaky, uneven surfaces have poorer chemical resistance.

The invention aims to eliminate the above disadvantages; it provides improvements both in terms of device and the process and also enables the manufacture of improved products.

In particular, according to the invention, there is an improvement in the product allows, in which not only undesired surface defects are avoided, but also provided a protective coating is. If desired, the coating can also be used to to color the product.

Regarding the method the invention enables the production of objects according to the "pultrusion" method using smaller tensile forces than heretofore required, and a w decreased wear of the nozzle.

According to the invention, the nozzle device is through channels for the delivery of a liquid coating resin material to one or more surfaces of the article during the molding process marked. These channels preferably extend through the device and have openings through which the resin material on the surfaces surrounding the molding passage in a zone between the inlet and outlet ends of the passage is applied.

The molding passage is in the zone where the resin material is discharged and radially expanded downstream thereof compared to the K zone of the passage upstream thereof or towards the entrance. In this way, the rod or the tube can be coated with the coating resin supplied through the channels as it passes through the device. As a result of the widening of the molding passage, there is enough space for the coating material and, since the latter is uncured, it acts as a lubricant between the article being molded and the nozzle body. The coating layer first hardens until it leaves the outlet opening of the device. To this end, the

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Use of a coating resin material provided under the conditions prevailing in the molding passage is liquid and only hardened and solidified after exiting the passage again. The resulting surface of the product is smooth and therefore more chemically resistant. Sanding and painting are thus superfluous, and the reinforcement is safely protected by a well-defined plastic layer of a predetermined thickness.

For the production of the pipes or other shaped bodies according to the invention, thermosetting resins such as polyester or resin are generally used Epoxy resin materials provided. These resins are used in liquid form, the reinforcing fibers with the liquid Resin impregnated and then through the molding passage of the nozzle device to be pulled.

The coating resin material used in the present invention is Applied to the surface of the objects during molding in liquid form and remains liquid as long as the object passes through the Forming passage is pulled through and out of this, but must be able to solidify after exiting the nozzle. For example For this purpose, thermosetting resin materials such as polyester or epoxy resin materials can be used, which are composed in this way

are that they have a higher solidification temperature or a longer one Have setting time than that for impregnation of the reinforcing fibers used resins. These resins can then either after the article has left the molding passage the heat generated by the exothermic reaction of the solidifying impregnation resin is developed, or by external heat supply, e.g. by means of a heating lamp, which is directed at the object in a zone directed beyond the exit end of the molding passage.

According to the invention, the widened part of the molding passage a constant diameter or constant cross-sectional dimensions from the openings of the channels to the outlet of the molding passage. In this way the production takes place the nozzle setup very easily.

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■ V 213777a

In a preferred embodiment of the device according to the invention the enlarged part of the molding passage begins immediately before the point where the reinforced resin material passes through begins to harden or gel. In this way, the lubricating effect of the coating material is best used.

The device according to the invention for the production of pipes, which has an outer matrix and a mandrel is preferably designed so that the widening of the passage between These two parts are achieved by having the inner diameter the die is enlarged and the outside diameter of the mandrel is reduced. Thereby the manufacture of the nozzle device simplified.

In order to simplify the production of the channels, the channels in the die can mainly run radially and to an auxiliary extruder be connected to the preparation and supply of the coating resin material, while the channels in the mandrel radially to a simple Guide channel in the axis of the mandrel, which channel is also connected to an auxiliary extruder.

When a thermosetting resin is used as the coating resin material the controlled curing of the coating can be brought about by heating lamps that go beyond letting out the Forming passage arranged and directed against the extruded product.

Furthermore, the non-widened part of the passage can merge into the widened part via an inclined surface, as a result of which a more uniform extrusion from the device is achieved. P It is also possible according to the invention that the widened part of the molding passage in a special, annular Die is arranged, which is connected to the outlet end of the nozzle device. In this way the manufacture of the device, since this part of the passage can easily be created in the die.

In a typical embodiment of the method according to the invention To produce a solid molded body or tube, at least two layers of rovings or other elongated ones are required fibrous reinforcements transported or pulled through the passage in the device after being coated with a liquid resin material, e.g. a polyester or epoxy resin, and these layers become continuously a liquid, however

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heat-curable resin material including curing-triggering additives fed to an auxiliary extruder. This procedure has the special Advantage that a coating layer made of uncured resin formed on the outside of the profile or on the outside and inside of the tube, which resin material compared to the reinforced Resin has such thermosetting properties that it does not harden before it has passed the nozzle and can therefore act as a lubricant. In this way it will be extremely easy and in an economical way to obtain extruded products with smooth and chemically resistant surfaces.

A modification of the method according to the invention is characterized in that the feed for the coating or coatings is selected so that the hardening of this layer or layers only begins until additional heat is supplied beyond the outlet end of the molding passage, e.g. by means of outside the nozzle end arranged heating devices or by ultraviolet irradiation of the outer layer. This ensures that the coating resin material is outside the 'at the right time. Passage hardened.

The coating resins used in the process according to the invention can consist of polyester or epoxy resin to which accelerators and catalysts are added to ensure satisfactory control to achieve hardening.

The invention is explained in more detail with reference to the drawing, in which 1 shows a schematic side view of a device according to the invention System; FIG. 2 shows an enlarged axial section through a nozzle device according to the invention, and FIG. 3 shows a similar one Representation like that of FIG. 2 of a modified nozzle device. .

In the system according to Fig. List *: the nozzle device in general marked with D and for the production of a pipe or hose set up. Reinforcing fiber materials F are fed into and through a liquid resin bath R, in which they are impregnated and from WQ they reached the nozzle inlet in an impregnated state and through the nozzle with the help of a pulling mechanism indicated by P. through and out of the nozzle. The finished tube is labeled A.

The nozzle device can be heated, e.g. with the help of heating elements H which are arranged around the outside of the nozzle device. This heating serves to harden and solidify the

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of the impregnating resin, while the article through the nozzle device is pulled.

The coating resin is fed in through a schematic shown auxiliary extruder E, from the supply lines 11a and 12a, which are connected to channels in the nozzle device, as described in more detail in connection with FIG will.

The liquid coating resin applied to the inside and outside of the pipe being formed is after exiting of the object solidified from the nozzle device, and for this purpose, depending on the type of resin material used for coating, an additional heat source, e.g. heating lamps, schematically labeled L, is provided.

The nozzle device consists of an outer mattress 1 and a mandrel 2 cooperating with this, so that a tubular Molding passage is formed with an enlarged part 3a and a non-enlarged part 3b, which parts through the molding Surfaces 4 and 5 are limited. In Fig. 2 the passage 3a, 3b ring-shaped, but it can also have any other desired shape. With 6 is the outlet end of the passage and with 7 the upstream end is indicated.

Outside the widened passage 3a in the annular part, radially arranged channels 10a are drilled. These channels are distributed all around the ring-shaped part 1. The mandrel 2 is also provided with channels 10b which extend in several radial directions. The channels 10a are longitudinally connected. running channels connected and the channels 10b to a central * channel 12; the channels 11 and 12 are connected via lines 11a and 12a to the auxiliary extruder E (Fig.l) for the preparation and supply of the coating material. This extruder can be of the screw or piston type. The section of the widened passage 3> a which lies between the channels 10a and the outlet end 6 has a constant diameter, while the cross section of the section lying between the passages and the non-widened part of the passage is reduced.

Beyond the outlet end 6 of the nozzle are those against the extru-

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Dated product directional heating lamps L arranged.

The arrangement described above can be operated in the following way:

Fibrous reinforcement material, e.g. in the form of glass rovings and / or glass fiber mats or strips, are impregnated with a liquid polyester resin in the resin container R, then conveyed lengthwise to the annular forming passage between the die 1 and the mandrel 2 of the nozzle device D and guided through this. During the passage through the nozzle device, the resin material is solidified under the action of the heating elements H and the solidified object is pulled out of the nozzle device by the pulling mechanism P. A coating resin material such as a liquid polyester resin having a higher solidification temperature or a lower solidification rate is incorporated. The inside and outside of the pipe formed is coated with a resin layer, the coating material acting as a lubricant on the way from the channels to the outlet of the nozzle device, so that the resin material hardening inside the pipe does not adhere to the surfaces U and 5. By widening the passage at 3a, the sliding of the tube along surfaces U and 5 is facilitated. When the now fully formed pipe emerges from the nozzle, the exothermic heat is transferred from the pipe material to the coating layer. The exothermic temperature can ^{rise to 180 °} C., for example, and the coating hardens. Additional heat can be supplied through the heating elements marked L to control or accelerate the hardening process. The finished pipe has a completely smooth surface, and the post-processing treatments mentioned earlier, such as grinding and painting, are unnecessary.

In FIG. 3, the nozzle device consists of a die 13 and a core 14, the die being provided with an enlarged extension which forms a continuation of the outer wall delimiting the tubular molding passage. The extension 15 is provided with radially extending channels 20a with which _y brakeline, zv perform an auxiliary extruder for supplying the liquid coating resin, are connected. When the nozzle device of FIG. 2 is used, the outside of the profile achieves the required smooth surface.

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If desired, the coating resin can be fed through channels which are only provided in the mandrel, with a coating or lining is produced inside a pipe.

For the production of bars, the die 1 or 13 can be used alone can be used without a mandrel.

It should again be pointed out that any general-purpose polyester resin for impregnating the fiber reinforcements can be used as resin materials according to the invention, for example a polyester resin catalyzed with 1% benzoyl peroxide, which starts to activate at about 82 ° or higher. In such an impregnation resin, a bisphenol-A epoxy acrylate such as EPOCRYL-12 (manufactured by Shell Chemical Company) can be used as a suitable coating resin. A suitable mixture consists, for example, of 100 parts by weight of the resin and 1 part by weight of tert. Butyl perbenzoate and finely divided silicon oxide powder (Cab-0-Sil). This resin mixture is activated at a temperature of about ⁰ C 138-1UO.

When using this or various other resin mixtures with appropriate control of the heating of the nozzle device and at the rate of draw-through, the coating resin remains in a substantially liquid state until the article exits the nozzle. Curing then takes place easily with the aid of additional heating devices.

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Claims (8)

Patent claims: 1.) Process for the production of fiber-reinforced resin articles, Be it a fibrous reinforcement material with a thermosetting one liquid resin material impregnated and the impregnated reinforcing material through the molding passage of a nozzle device pulled through and thereby on the solidification of the liquid resin material during the passage through the Nozzle device causing temperature is heated, characterized in that in the molding passage in a zone between the inlet and outlet ends of which a liquid coating sharζ is introduced, which is curable, under the conditions prevailing in the molding passage, however, remains essentially liquid and over at least one surface of the article is distributed during its molding, and that the solidification of the coating resin material on this surface of the article is effected after the article exits the molding passage. 2. The method according to claim 1, characterized in "that a thermosetting coating resin material having such Curing temperature and / or time is used that the coating resin remains liquid as long as the. Subject in Forming passage of the nozzle device is located; and that the coating resin after the article emerges from the nozzle is hot hardened. 3. The method according to claim 2, characterized in that a thermosetting coating resin material with a higher curing temperature is used as that of the impregnation resin and the coating resin material is used for solidification is heated to this higher temperature after the article has emerged from the molding passage. 109886/1358 $ 1 4. The method of claim 1 using a tubular A forming passage for making a tubular article, characterized in that the Coating resin material is spread over the inside of the tubular article as it is molded. 5. The method of claim 1 using a tubular Molding passage for the manufacture of a tubular object, characterized in that the loading " coating resin material distributed over the inside and outside of the tubular article as it is molded will. k 6. Device for performing the method according to the Claims 1 to 5, consisting of a nozzle device with a molding passage, a device for conveying with a liquid, thermosetting resin impregnated fibrous Reinforcement material in and through the molding passage, a means for heating the resin material to solidify of the object as it passes through the vault and a pulling mechanism for picking up spaced a distance behind the exit end of the molding passage and withdrawing the molded article from the molding passage, characterized in that means for Application of a curable coating resin material from im _{h being} substantially liquid on a surface of the article formed in the molding passage, and that means for curing the coating resin material is disposed between the exit end of the molding passage and the pulling mechanism. 7. Apparatus according to claim 6, for the manufacture of tubular Articles, having a nozzle device with an outer and a tubular forming passage defining inner part, characterized in that the inner part 109886/1358 - ίο - Allow for the application of a liquid, but curable, coating resin material on the inside of the tubular article during its manufacture. 8. Apparatus according to claim 6, characterized in that the molding passage has a portion of enlarged cross-section near its exit end and passages in the nozzle body for supplying the coating resin material into the molding passage at the beginning of this expansion are provided to coat a surface of the article during its molding in the enlarged portion of the molding passage. Frede Hilmar Drostholm The representative 129886/1358 - 11 - Blank page