DE19852159C1 - Manufacture of fiber-reinforced, optionally non-rotationally-symmetrical hollow composites with thermoplastic matrix, employs integrated extrusion-pultrusion winding plant - Google Patents

Abstract

The manufacture of fiber-reinforced optionally non-rotationally symmetrical hollow composites with a thermoplastic matrix comprises using an integrated extrusion pultrusion winding plant in which fiber and plastic are preconsolidated together inside a nozzle taper and the fiber is laid down onto the rotating mold core. Direct fiber impregnation is effected in a filament winding plant by an extruder (2). Plastic is supplied to the extruder through a filling funnel (3). It is forced as a melt from the extruder, through the encasing-nozzle (6). The nozzle encases and impregnates a filament or fibers with the molten plastic. Fiber and plastic are preconsolidated together, inside a nozzle taper. Having been impregnated, the fiber is laid down onto the rotating mold core (4). Preferred features: Various reinforcing systems can be used, in the form of e.g. band, tape, yarn, flyer frame- and/or hybrid flyer yarn, rovings or other raw textile form, such as fabric or mat. Fiber is continuous or interrupted, of single or mixed composition, being e.g. glass, carbon, flax, hemp, nettle, jute or sisal. The plastic is supplied as granules, for melting by an extruder (exemplified here) or otherwise. The nozzle is adapted suitably for the purpose. The extruder is held on the filament winding plant support (5). Defined core (4) rotation and support movement, establish a predefined winding pattern. The core onto which the impregnated fiber is laid down, is a positive or negative mold.

Description

The invention relates to a method for fiber impregnation and manufacture of fiber-reinforced hollow bodies with thermoplastic scher matrix, the fiber impregnation over a to Filament winding system applied extruder with nachge switched jacket nozzle.

It is known that the winding of fiber reinforced Connected to thermosetting matrix materials in the front due to the industrial manufacture of bobbins. By the von Funck (development of innovative manufacturing tech techniques for processing continuously fiber-reinforced therm moplastics in the winding process, VDI progress reports, series 2: Manufacturing technology, no .: 393) as well as Michaeli, Rau and Jürss (Production of components using the pultrusion and winding process, Kunststoffberater 6/1995, pp. 29-33) described advantages the possible cost reduction of approx. 20%, the good mechani eternals and chemical resistance, the how usability and the elimination of the time-consuming out hardening there are increasing applications for wound Components with thermoplastic matrix in electrical engineering, the building industry, the automotive industry as well as plant and mechanical engineering. Application examples are pipes, shafts, Tanks or pressure vessels, so that the implementation of the Winding process with thermoplastic matrix components since is followed for some time.

An industrial and economic implementation is currently under way not yet solved satisfactorily, so that on the one hand Be efforts to improve the impregnation properties of the Fiber material carried out with the matrix component and  on the other hand the qualities of the consolidation of the association can be increased by using suitable heating systems.

The known material modifications include impregnation or powder-impregnated fiber rovings (e.g. FIT material Glass fiber / polypropylene) as well as wound or twisted Hybrid yarns (e.g. Vetrotex Twintex roving).

At the same time, there is extensive information in the literature on the Wrap with an open flame from Funck, Neitzel and hausmann (Manufacturing of thermoplastic pressure vessels in the fiber winding process driving, lecture 27th AVK conference Baden-Baden, 10/1996; Ther moplast winding process for bicycle frames, plastics 3/1995, pp. 372-374). B. cellulose or also natural fibers using this technological variant cannot be processed. Rosbach explains the Kon design and implementation of a thermoplastic winding process based on an infrared heater system (thesis, ETH Zurich, 1995) and contact heating. The latter leads to adhere the melt and to glue the lead elements of consolidation. About melting the matrix by contact, infrared or hot air heaters report Born et al (fibers impregnated with thermoplastics wrap, plastic processor 5/1990, pp. 18-25) and Neitzel et al (Filament winding with thermoplastic matrices - current development & equipment, Japan International SAMPE Technical Seminar '94, Kyoto 14./15. 07. 1994).

These energy transfers are due to the regulation, esp especially with rapid changes in the fiber winding speed speed z. B. in the turning zones, limited.

The following patents only describe devices for Sheath of a twisted cable (DE 40 03 735 A1), method  and devices for crosslinking polymers in the form of elongated winding material (DE 44 25 593 A1) and devices to manufacture a tube by helical Wind up (DE 31 45 122 A1).

The aim of the invention is to find a suitable, simple and economical process for fiber impregnation and wick development in the production of fiber-reinforced, also natural fiber reinforced hollow bodies with thermoplastic matrix to develop high product quality.

The object of the invention is achieved by the measures of Claim 1 solved. This is essentially done by the combination of filament winding technology with the extrusi ons and pultrusion technology, a process variant for On-line impregnation is continuous but not necessary continuous, windable, textile reinforcement semi-finished products with thermoplastic matrices and thus the Manufacture of wound, thermoplastic fiber Plastic composite. The manufacturing process wound hollow body with thermoplastic matrix Task, textile thread half that can be processed in the winding process witness (roving, yarn, filament, ribbon, fabric etc.) from one Pull off the coil in a sheathing nozzle with through a Melt extruder supplied thermoplastic melt impregnate and place on a rotating mandrel.

The semi-finished reinforcement is impregnated in the process according to the invention for the production of fiber-reinforced thermoplastic fiber composite plastics by the fact that the semi-finished reinforcement is fed to a sheathing nozzle working according to the pultrusion principle ( Figure 1, position 6), and at the same time the sheathing nozzle adapted to a melting extruder ( 2 ) 6 ) is fed by this with the thermoplastic melt and brings the melt and reinforcing fiber or semi-finished product together. In addition to the mixing of fiber and matrix and / or the sheathing of the fiber by the matrix, an on-line impregnation or preconsolidation takes place via the pultrusion technique, in which the sheathing nozzle ( 6 ), which preferably tapers in the direction of production, so that the after ver manufactured fiber-plastic composites according to the invention, in comparison to previously used heater systems, have a high composite quality. The nozzle outlet is designed so that the thermoplastic impregnated reinforcing semi-finished product can be deposited on the rotating mandrel and further energy input by additional heating systems is not necessary.

The method thus represents a suitable, simple as well economic method to achieve the used semi-finished reinforcement with the thermoplastic Impregnate matrix and the defined shelf on one to enable rotating mold core. The procedure described ren is particularly characterized by the production of a wound with thermoplastic fiber-plastic composite high composite quality due to excellent impregnation from reinforcement with the matrix system.

The invention is appended below in the drawing illustrated embodiment described in more detail and explained.

The pultrusion winding system shown in Figure 1 for on-line impregnation of windable reinforcement semi-finished products with a thermoplastic matrix, consisting of a melting extruder ( 2 ) with a filling funnel ( 3 ) located on the support ( 5 ) of a filament winding system ( 1 ) with a winding core ( 4 ). and sheathing nozzle ( 6 ), is characterized by the defined and economical impregnation of high quality reinforcing materials with the melt fed through the melting extruder ( 2 ) to the sheathing nozzle ( 6 , Fig. 2) as well as by the specified fiber winding speed and the feed of the support ( 5 ) predefined storage on the rotating winding core ( 4 ) of the filament winding system ( 1 ).

The amplifier system can with the Pultrusi according to the invention ons winding process in tape, yarn, flyer or hybrid flyer yarn and roving are used. Also the use of textile fabrics and semi-finished mat products possible, where as fiber materials such. B. glass, carbon, Aramid, carbon and / or natural fibers can be used can.

example 1

To develop a new process technology by Combination of winding and extrusion process for manufacturing of rotationally symmetrical bobbins was introduced the matrix component in the composite in a first process a hybrid flyer yarn made of 50 with an open structure % Thermoplastic and 50% natural fiber.

For this, flax and polypropylene staple fibers were used det, the production of the hybrid flyer yarn for stretch and flyer after the cotton spinning process with modified Carded cotton technology was done.

The fiber compo was used to apply the fiber mixtures nenten placed in the mixed bed, mixed on an opener and  then added a card. Subsequently came the fiber pile produced in this way can be switched on flexibly Jug stick in a spinning jug for storage, before one Another process step is a deformation to the tape Press roll pair was made. With the help of an additional used cotton stretch, the band was still more doubled and warped. The route band thus generated was finally an extra Coarse flyer with integrated 3-roll drafting system fed, twisted and stretched into a hybrid flyer yarn.

The hybrid yarn produced in this way could then be drawn off from a bobbin holder with bobbin and fed to the sheathing nozzle ( 6 ) located on the extruder ( 2 ). The polypropylene part of the hybrid flyer yarn was melted in the heated jacket nozzle ( 6 ). At the same time, further polypropylene (approx. 20%) in granular form was added via the filling funnel ( 2 ) of the melt extruder ( 2 ) applied to the filament winding system ( 1 ) via a filling funnel ( 3 ), melted and fed to the sheathing nozzle ( 6 ) leads. Here, on the one hand, the two polypropylene components (fiber / granulate) were mixed and, on the other hand, the flax fiber was mixed or coated with polypropylene melt.

This process was intensified by the sheathing nozzle ( 6 ) tapering in the direction of production, so that the thermoplastic-impregnated natural fibers could be deposited on the winding core ( 4 ) via the nozzle outlet. By setting the fiber winding and support speed in the range from 2 to 50 m / min, winding bodies with a predefined pattern could be produced. Furthermore, the fiber content could be varied from 10 to about 70% by mass of the wound hollow body through the throughput of the melt extruder ( 2 ).

The pultrusion winding process was then carried out put tubular test specimens of a mechanical test subjected to pressure testing. The determined values for the Compressive stress was measured with samples of the same starting materials, Flax as a reinforcing fiber and polypropylene as a matrix wrapped at room temperature and then in one press were consolidated, compared. This procedure var ante in thermoplastic winding technology enables due to the precise temperature control and the high forces that can be applied optimal network consolidation. The carried out in conclusion te comparison of properties of the pultrusion according to the invention winding process with fiber winding at room temperature Subsequent consolidation of the network using press technology Technology showed no significant difference in the association properties in printing tests.

Claims (7)

1. A process for the production of fiber-reinforced rotation but not necessarily rotationally symmetrical hollow bodies in the primary molding process with a thermoplastic matrix in a pultrusion winding system, characterized in that the fiber impregnation is applied via a melting extruder ( 2 ) to a filament winding system ( 1 ) with a downstream coating nozzle ( 6 ) takes place, the semi-finished reinforcement being fed to the sheathing nozzle ( 6 ), which is connected to the extruder ( 2 ) applied to the filament winding system ( 1 ), and to the one which is melted via the extruder ( 2 ) with feed hopper ( 3 ) Plastic are encased that by a tapering of the sheathing nozzle ( 6 ) in the production direction, the reinforcement semi-finished product and the melted plastic are pre-solidified and that the thermoplastic impregnated reinforcement semi-finished product is then deposited on the ro-forming mandrel ( 4 ). 2. The method according to claim 1, characterized in that Different types of reinforcement systems in tape, tape, Yarn, flyer and / or hybrid flyer yarn as well as in roving form or in a different type of textile presentation or Semi-finished form, such as woven or semi-finished mat, used become. 3. The method according to claims 1 and 2 characterized thereby records that continuous and / or discontinuous fiber materials such as B. glass, carbon, aramid or carbon fibers and z. B. flax, hemp, nettle, Jute and sisal fibers, used individually or in a mixture become.   4. The method according to claims 1 to 3, characterized in that the melting extruder ( 2 ) with a funnel ( 3 ) or another melting unit ther thermoplastic plastics are preferably performed in granular form and melted. 5. The method according to claims 1 to 4 characterized in that the merging melt and Ver reinforcing semifinished product, the sheathing nozzle ( 6 ) on the melt extruder ( 2 ) or another melting unit is adapted. 6. The method according to claims 1 to 5, characterized in that the melting extruder ( 2 ) or the other melting unit with an adapted sheathing nozzle ( 6 ) on the support ( 5 ) of the filament winding system ( 1 ) is applied and via a defined Rotation of the wic kelkerns ( 4 ) and the method of support ( 5 ) a predefined winding pattern is generated. 7. The method according to claims 1 to 6, characterized in that the impregnated, pre-consolidated semi-finished product is deposited in the molten state on a rotating positive or negative winding core ( 4 ).