Zeitschrift Kunststofftechnik Journal of Plastics Technology€¦ · fiber-reinforcement in one shot has been developed. “Dry” textiles or continuous fibers are inserted into

4Autor Titel (gegebenenfalls gekürzt)

© Carl Hanser Verlag Zeitschrift Kunststofftechnik / Journal of Plastics Technology 15 (2019) 2

15 (2019) 2

eingereicht/handed in: 24.09.2018 angenommen/accepted: 15.01.2019

Tim Deringer, M.Sc., Dipl.-Ing. Tobias Kleffel, Prof. Dr.-Ing. Dietmar Drummer Lehrstuhl für Kunststofftechnik, Friedrich-Alexander Universität Erlangen-Nürnberg

Integrative manufacturing of thermoset injec-tion molding components with continuous fi-ber-reinforcement

A new process for the manufacturing of thermoset injection molding components with local continuous fiber-reinforcement in one shot has been developed. “Dry” textiles or continuous fibers are inserted into the cavity of an injection mold. Subsequently, the continuous fibers are impregnated and embed-ded into a short-fiber-reinforced thermoset molding compound by the following injection molding pro-cess. In this paper, the technical feasibility of the process is proven by the analyses of the wettability and impregnability of dry carbon-rovings depending on the mold temperature. Furthermore, mechani-cal tests show that by this new process the integration of continuous fibers into injection molded com-ponents improves the mechanical properties if they are impregnated completely.

Integrative Herstellung von endlosfaserver-stärkten Duroplastbauteilen im Spritzguss

Es wird ein neuer Prozess zur Herstellung von duroplastischen Spritzgussteilen mit lokaler Endlosfa-serverstärkung in einem Spritzgießzyklus entwickelt. Hierfür werden "trockene" Textilien oder Endlos-fasern in die Kavität eines Spritzgießwerkzeuges eingelegt. Anschließend werden die Endlosfasern mittels einer kurzfaserverstärkten duroplastischen Formmasse imprägniert und eingebettet. In dieser Veröffentlichung wird die technische Machbarkeit des Verfahrens durch die Analyse der Benetzbarkeit und Imprägnierbarkeit von trockenen Carbon-Rovings in Abhängigkeit der Werkzeugtemperatur nachgewiesen. Darüber hinaus zeigen mechanische Tests, dass durch dieses neue Verfahren, dass die Integration von Endlosfasern in Spritzgussteilen deren mechanische Eigenschaften verbessern, sofern diese vollständig imprägniert sind.

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Zeitschrift Kunststofftechnik

Journal of Plastics Technology

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Deringer, Kleffel, Drummer Thermoset injection molding with CFR

Journal of Plastics Technology 15 (2019) 2 170

Integrative manufacturing of thermoset injection molding components with continuous fiber-reinforcement

T. Deringer, T. Kleffel, D. Drummer

1 INTRODUCTION

Continuous fiber-reinforced plastics (CFRP) feature excellent weight-specific mechanical properties. Hence, CFRP are used with increasing frequency to substitute metal for weight reduction [1]. Usually, CFRP are expensive and are thus primarily used in fields where costs are of less importance, such as the aerospace industry. According to a market report of 2017 [2], it is predicted that the automotive industry will have replaced the aerospace industry as biggest processor of CFRP until 2022. However, the automotive industry is more fo-cused on cost efficiency. Therefore, CFRP components with low costs are re-quired. The most common processes for manufacturing CFRP components, based on thermosets, are Liquid Composite Molding Technologies (LCM), auto-clave processes, Prepreg Compression Molding (PCM) and Compression Mold-ing of Sheet Molding Compounds (SMC) [3].

LCM Technologies, especially the Resin Transfer Molding (RTM), allow the production of CFRP components with a small effort to post processing. In the process, uncured resin is injected into a mold which contains a preform and cured subsequently [4]. The preform consists of continuous fibers and is the limiting factor of RTM, as the process and component costs rise with increasing complexity of the preform geometry. Typical cycle times of RTM are between 3 and 25 min [3, 5]. Another LCM Technology is the wet pressing, in which the resin is poured in the mold before the mold is closed [6]. The impregnation of the reinforcing structure by resin takes place at the closing movement of the mold and the resulting pressure. In comparison to RTM, the molds are cheaper and less complex, but the cycle times are similar long and the preforms are ex-pensive, too [7, 8].

A widespread process for the manufacturing of CFRP parts is the autoclave process that enables a constant consolidation pressure to the entire component surface regardless of the component geometry. In this process, prepregs, i.e. pre-impregnated fiber-reinforced semi-finished materials are placed in a vacu-um bag in an autoclave and are cured under high pressure. The disadvantages of this technology are long process cycles of several hours and high process costs [9, 10].

PCM enables fast manufacturing of CFRP components in a compression mold-ing press [11]. Here, the part geometry is limited to shelllike or flat structures

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[12]. For higher design freedom, SMC can be used for compression molding. However, SMC usually use nonoriented fibers with fiber lengths between 10 mm and 50 mm [3]. Due to the lack of orientation and fiber length, compo-nents manufactured by SMC have limited mechanical properties [13].

According to the state of the art, there is no known technology for the manufac-turing CFRP components with complex threedimensional geometries based on thermosets with continuous fibers in load direction and low manufacturing costs. For thermoplastic composites, the Fraunhofer ICT developed the Tailored Injec-tion Molding process [14], which allows the reinforcement of injection molded components with preimpregnated continuous fiber-reinforced semi-finished ma-terials. In [15], an unreinforced polypropylene (PP) is used as matrix material, whereas semi-finished materials like unidirectional-tape or hybrid rovings based on PP were used as reinforcement materials. In regard to the mechanical prop-erties, a short-fiber-reinforced component with 30 wt.-% fiber content shows the same tensile strength as a roving-reinforced component with only 6.6 wt.-% fi-ber content [16]. However, CFRP based on thermosets have higher tempera-ture stability, chemical resistance and lower creep tendency compared to com-posites based on thermoplastics [17]. In addition, thermosets are at a lower price level compared to thermoplastic materials with comparable mechanical and thermal characteristics such as polyetheretherketone (PEEK).

For the manufacturing of favorable thermoset CFRP components, a new ap-proach is the insertion of a “dry” continuous fiber-reinforcement material into a standard thermoset injection molding process, Figure 1. At the beginning of the process, continuous fiber-reinforcements are placed and fixed in the cavity of the mold. The continuous fiber-reinforcements are positioned in load direction of the component. Afterwards, the continuous fiber reinforcements are impregnat-ed by injecting a short-fiber-reinforced thermoset molding compound. Once the material is fully cured, the finished component exhibits a local continuous fiber-reinforcement in load direction and a short-fiber-reinforcement in the residual sections. The design freedom of such a component is high due to the injection molding process. Furthermore, the whole cycle time, including curing time, ranges only from 1 to 3 min. In addition to the short cycle times, the use of ex-pensive continuous fibers can be reduced. However, a challenge of the new process is the fiber position control in complex geometries, which include e.g. radii or beads. Further restrictions are possible fiber displacements during injec-tion molding.

The in-mold impregnation of dry continuous fiber-reinforcements with thermo-plastics is already state of the art [18]. However, the thermoplastic molding compound is not fiber-reinforced and needs a complex mold technology.

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Figure 1: Schematic process sequence of the thermoset injection molding di-rect impregnation

The CFRP manufacturing process defines the geometrical structure of the com-ponents and influences its material properties. To achieve the best properties, the fibers have to be completely integrated in the polymeric matrix and com-pletely wetted. In consequence, the core of the manufacturing process of CFRP components is the impregnation process. The impregnation is defined as the flow of a liquid through a porous medium [19, 20]. Derived from the work of Henry D’Arcy [21], in the two-dimensional view, the flow path of the liquid and thus the impregnability is proportional to the viscosity of the liquid, permeability of the porous medium, impregnation time and processing pressure. All influ-ences on the flow path in the conventional process are equally adaptable for the thermoset injection molding process. The only exception constitutes the viscosi-ty of the liquid, here the thermoset melt. In theory, the viscosity of the pure thermoset melt in a molding compound should be as low as the used liquid thermoset in a process such as LCM. However, for the process capability it is necessary that the molding compound contains a certain level of filler [22]. Through the variation of the filler concentration, the rheological behavior is in-fluenced, which leads to an increasing viscosity [23, 24]. Further factors that influence the viscosity of a thermoset melt are the temperature and the degree of cure [25, 26]. If the temperature increases, the kinetic energy will rise, which leads to a higher agility of the molecules and to a decrease of the viscosity. However, a higher temperature also implies a higher amount of activation ener-gy, which accelerates the chemical reaction. Through the accelerated chemical reaction, higher curing degrees and intrinsic viscosities can be reached in

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shorter times [17]. Thus, the intrinsic viscosity is the limit of the processing vis-cosity in the new process, depending on the curing degree [27]. The result is a small processing window for impregnation, which can be computed from the time dependent viscosity and the impregnation time. Simultaneously to the im-pregnation, the consolidation is taking place. Hence, the air in the dry continu-ous fiber reinforcement is displaced. The consolidation determines the setting of defined fiber volume content [28, 29] and as a result the mechanical properties.

In this study, the feasibility of the new thermoset injection molding direct im-pregnation process is shown. The integration, wetting and impregnation of a “dry” continuous fiber-reinforcement in a short-fiber-reinforced thermoset injec-tion molding compound depending on the mold temperature is shown by micro-graphs. Furthermore, the potential of the new process is demonstrated by ten-sion tests.

2 MATERIALS AND METHODS

2.1 Materials

For the experiments, a standard commercial thermoset molding grade was used to generate a compound by adding a short-fiber-reinforcement. The base of the compound is an epoxy resin blackbox EP 3585 from Raschig GmbH (Germany, Ludwigshafen) without any filler materials. During the compounding process, the blackbox was mixed with 5 wt.-% talcum of the type Plustalc H50 from Mon-do Minerals B.V. (Netherlands, Amsterdam) and 20 wt.-% of 3 mm short-glass-fibers of the type FGCS 316 from Schwarzwälder Textil-Werke GmbH (Germa-ny, Schenkenzell). The compound was manufactured on a co-rotating twin-screw extruder of the type ZSE25Ax45D from KraussMaffei GmbH (Germany, Berstorff) and was granulated using a granulator of the type 150 Deltatech from Rapid GmbH (Germany, Griesheim). For the dry continuous fiber-reinforcement, 3 K-carbon rovings of the type HTS 40 from Toho Tenax GmbH (Germany, Wuppertal) were used.

For rotational viscometry tests the epoxy resin blackbox EP 3585 From Raschig GmbH without catalyst was used additionally.

2.2 Test specimen

For the investigations, a tension bar, Figure 2, with a length-to-width ratio of 140 mm x 20 mm and a thickness of 4 mm was used, according to DIN EN ISO 10724-1. All test specimen were manufactured by a standard thermoset injec-tion molding machine of the type KM 80 CX SP 180 from KrausMaffei GmbH (Germany, Munich) with an injection velocity of 10 mm/s and a holding pressure of 300 bar. The injection molding unit had a temperature of 65 °C in the feed

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section and 85 °C in the injector section. In total, three test specimen variants were manufactured, which differentiated by the used mold temperature. Due to the assumption that the viscosity of the matrix is lowest for the highest possible temperature the maximum mold temperature of 200 °C was used as starting point. From this point the mold temperature was reduced in 20 °C steps to 180 °C and 160 °C. The total processing time was 60 s, including a heating time / curing time of 45 s. Before the injection molding of a tension bar, six rovings were fixed inside the mold cavity in length direction. In order to ensure a sym-metrical layout of the specimen, three rovings were placed on each side inside the mold cavity with temperature-resistant tape in the shoulder sections of the tension bar, Figure 2. In addition to these tension bars, tension bars without rovings were manufactured as a reference to validate the effects of the continu-ous fiber reinforcement.

Figure 2: Schematic view of the test specimen with position information of the continuous fiber-reinforcement

2.3 Microscopy

The wetting and impregnation of the rovings in the test specimen were analyzed on cross sections with an optical microscope of the type Axiophot from Carl Zeiss AG (Germany, Oberkochen). For the manufacturing of the cross sections, the test specimens were cut with a water-cooled saw, Figure 3, and embedded in cold-curing epoxy resin. Finally, the cross sections were grinded down and polished.

Figure 3: Position of the cross sections for the microscopy analyses

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2.4 Rotational viscometry (rotvis)

For the investigation of the viscosity, a rotational viscometer of the type AR 2000 from TA-Instruments Inc. (USA, New Castle) was used with a plate-plate (∅ 8 mm) measurement system. All measurements were executed according to DIN 53019-1 with a frequency amounted to 1 Hz and a strain of 0.2 %. The heating rate of the dynamic measurement was 10 K/min, which was the maxi-mum possible heating rate. For the isothermal measurement, the sample chamber was preheated to the respective test temperature. The sample was immediately inserted and the measurement started. The first recording was made with a time delay of 6 seconds.

The curing without catalyst takes place at much higher temperatures compared to conventional measurements.

2.5 Tension test

All test specimens were tested according to DIN ISO 527-4 with a test speed of 5 mm/min. The tests were performed under standard atmosphere conditions (23 °C and 50 % humidity) according to DIN EN ISO 291.

3 RESULTS AND DISCUSSION

3.1 Integration, wetting and impregnation

The basic feasibility of the new thermoset injection molding direct impregnation process is shown in Figure 4 for a mold temperature of 200 °C. The characteris-tic test specimen shows no warpage. In addition, the dimensions of the continu-ous fiber-reinforced test specimen do not differ from the reference. The continu-ous fiber reinforcements are integrated in the short-fiber-reinforced thermoset matrix. There are no visible dry fibers on the surface. Furthermore, the surfaces of the test specimens are smooth without any holes, neither haptic nor optical differences between continuous and short-fiber-reinforced sections can be iden-tified. Only at the shoulder sections, the continuous fibers were not fully inte-grated. This is caused by using temperature resisted tape, which locally barred the thermoset melt from the rovings during the injection molding.

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Figure 4: Characteristic tension bar, manufactured by thermoset injection molding direct impregnation at a mold temperature of 200 °C

Figure 5 shows characteristic micrographs of cross sections for different mold temperatures. For 200 °C and 180 °C can be seen a complete integration of the continuous fibers in the thermoset matrix. At the edge, the fibers are nearly on one level and the thermoset matrix forms a thin layer between the surface (bro-ken white line) and the continuous fibers, excluding air. Thus, the wetting of the rovings is good. Furthermore, all single fibers of the roving are surrounded by thermoset matrix, which indicates also a good micro impregnation. At a mold temperature of 160 °C there are dry fibers can be seen at the surface of the test specimen. In addition, due to the lack of wetting, indentations can be detected on the test specimen surface. In the middle of the roving, there are several air pockets between the continuous fibers, which indicates an incomplete micro impregnation. Thus, a dependence between mold temperature and impregna-tion capability of the matrix can be assumed.

Figure 5: Detailed-micrographs of wetting of continuous fibers on the surface (edge is at the top) depending on the mold temperature, polished to 1 µm Left: Mold temperature of 200 °C Middle: Mold temperature of 180 °C Right: Mold temperature of 160 °C

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In addition to Figure 5, micrographs of the roving arranged in the middle can be seen close to the sprue, in the middle of the sample and far from the sprue. Figure 6 shows a fully integrated roving in the thermoset matrix for 200 °C and 180 °C independent of the investigated position in the component. There are no gaps or air pockets next to the rovings. Thus, the macro impregnation was suc-cessful. All fibers are surrounded by thermoset matrix without gaps or air pock-ets.

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Due to the fine polishing particle size of 1 µm, the transparent short-glass-fibers in the thermoset matrix are optically not recognizable in Figure 6. In order to change this, the cross sections are polished to 3 µm particle size which leads to recognizable height differences between the glass-fibers and the thermoset ma-trix, Figure 7. The effect is only shown for 200 °C, because there was no visible difference between the varied mold temperatures. Considering Figure 7 (left), the short-glass-fibers are orientated parallel to the carbon-fibers, which resem-bles an orientation in flow direction. This corresponds to the state of the art of the injection molding of short-fiber-reinforced polymers [30, 31]. Meier et al. shows that for LCM processes, parts without reinforcement are filled first due to the fact that the liquid thermoset follows the path of lowest resistance [32]. After the complete filling of the non-reinforced parts, the rovings get impregnated by the thermoset flow in thickness direction. The glass-fibers are squeezed be-tween the carbon-fibers without changing their orientation, Figure 7 (left). How-ever, short-glass-fibers can only be found between the continuous carbon-fibers in the edge area of the roving, Figure 7 (right). The rest of the roving is impreg-nated by the thermoset matrix without recognizable fillers. Thus, the glass-fibers have no direct influence on the viscosity of the thermoset melt and the impreg-nation behavior inside a single roving. However, this sieve-effect leads to a junction area with an accumulation of short-glass-fibers at the edge of the rov-ing, which could influence the flow of the thermoset melt. Jordan [33] shows the influence from such sieve effect for an aerosol and a fiber filter. With increasing particle loading, the flow is affected by a pressure drop in the fiber filter from in-to outlet [33].

Figure 7: Characteristic micrograph of a cross section of a centrally positioned roving of a continuous fiber-reinforced test specimen, which was manufactured with a mold temperature of 200 °C, polished to 3 µm

Left: Overview of the whole roving Right: Detail view of the roving on the transition to the core of the test spec-imen

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3.2 Viscosity

According to the previous results, the sieve-effect enables an impregnation of the rovings by the thermoset melt without fillers. The viscosity of the pure ther-moset melt with and without catalyst is shown in Figure 8-a) for a dynamic measurement with a heating rate of 10 K/min. The thermoset melt with catalyst has a viscosity minimum of 3,3*103 Pa*s at a temperature of 115 °C. However, through the lower activation energy caused by the catalyst and the low heating rate, the thermoset is cured before the minimum viscosity and the target tem-perature is reached [34]. In consequence, the measured viscosity differs signifi-cantly from the viscosity in the real process. In contrast, there are different re-sults for the thermoset without catalyst. The viscosity minimum of the thermoset without catalyst is approximately 3 Pa*s from a mold temperature of 160 °C to 170 °C. Above a temperature of 170 °C, the viscosity is superimposed by the crosslinking reaction. Hence, the required temperature to initiate the curing re-action is significantly higher compared to the thermoset melt with catalyst. Ac-cording to Frutiger in [35], the difference between the mold and thermoset melt (next to the mold surface) is at the begin of the flow about 50 °C and at end of flow about 25 °C for a mold temperature of 200 °C. In the present study, the continuous fibers were fixed on the cavity surface, it can be assumed that the relevant melt temperature is about 25 °C below the mold, too. Thus, in the real process at a mold temperature of 200 °C and 180 °C, the viscosity would be one-third lower than at 160 °C.

In addition, the isothermal measurement of the thermoset melt without catalyst is shown in Figure 8-b). Measurements above 140 °C were not possible with the isothermal measurement, since the high heating rate of the material without catalyst caused individual resin components to foam up and thus falsified the measurement. A thermogravimetric analysis confirmed that this is not water but a resin component in the material. Furthermore, it can be seen that the viscosity changes only slightly at the respective temperatures over the entire measuring time, since there are no crosslinking reactions without a catalyst. Dynamic dif-ferential calorimetry measurements confirm that no cross-linking occurs. The isothermal measurements once again show that the viscosity decreases with increasing temperature. Figure 8-c) compares the results of the isothermal measurement with those of the dynamic measurement. From 120 °C to 140 °C, the viscosity values determined are approximately the same. A hypothesis should show a further decrease in viscosity at higher temperature without su-perimposition of the curing reaction.

Due to higher heating rates in the real process, even lower viscosity values of the thermoset melt are likely. In comparison to the direct impregnation with the thermoplastic PA6 in [18], the viscosity minimum of the thermoset without cata-lyst is in the rotvis measurements approximately ten times lower. Hence, a good impregnability and high potential of the new process could be concluded.

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Figure 8: Viscosity of the thermoset melt EP3585 without fillers; a) dynamic measurement with a heating rate of 10 K/min for Resin with and without catalyst b) Isothermal measurement without catalyst c) Hypothesis based on a) and b)

3.3 Mechanical tests

Figure 9 shows the tensile strength and elastic modulus of the test specimen series with continuous fiber-reinforcement with different mold temperatures. At the mold temperature of 180 °C the sample size was two, because one speci-men could not be considered due to a fiber shift. The mechanical properties of the continuous fiber-reinforced test specimens at 200 °C and 180 °C are nearly on the same level and much higher than those at 160 °C. The test specimens of these both temperatures were impregnated completely and can absorb the oc-curring tensile stresses as a composite. The difference in mechanical properties for 200 °C and 180 °C could result from the different crosslinking states. In [30]

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it is shown that different degrees of curing can result from processing epoxy resin at different mold temperatures, which have a direct influence on the me-chanical properties. However, at 160 °C the complete wetting and impregnation of the rovings wasn’t possible. The resulting indentations and air pockets have a negative effect on the notch-sensitive thermoset matrix and lead to premature failure.

The comparison between test specimens without and with continuous fiber rein-forcement at a mold temperature of 200 °C illustrates the improvement of the tensile strength of approximately 48 %, Figure 9. In addition, the elastic modu-lus is increased by 38 % compared to the unreinforced reference. In this con-text, it should be noted that the six 3 K-rovings conform only 1.5 wt.-% of the total weight and 1.7 % of the cross sectional area in the narrow section of the test specimen. The high standard deviation of the continuous carbon fiber rein-forced specimens is caused by an outlier, which had a tensile strength of 120 MPa. The average of the tensile strength without this outlier was 72 ± 7.8 MPa. Further investigations to show the full potential are in progress, which in-clude an optimization of the interface between fibers and thermoset melt.

Figure 9: Tensile strength and elastic modulus of the test specimen series without roving and with continuous-fiber reinforcement produced with different mold temperatures

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4 CONCLUSION

The basic feasibility of a new process for producing thermoset injection molding components with local continuous fiber-reinforcements in one shot using dry fiber semi-finished materials was confirmed for a tension bar. Carbon-rovings were inserted into an injection mold and overmolded by a short-fiber-reinforced compound, based on epoxy. The variation of the mold temperature shows a dependency between viscosity and impregnability. Micrographs illustrate that the inserted carbon-rovings were completely integrated, wetted and impregnat-ed in the test specimen during the injection molding at the mold temperatures of 200 °C and 180 °C. At a mold temperature of 160 °C the rovings were not im-pregnated completely. Furthermore, a sieve effect at the edge of each single roving was detected independent of the mold temperature. Thus, the short-glass-fibers of the used compound penetrated only a small volume at the boundary area of the carbon-rovings. The rest of the roving was impregnated only by the pure thermoset melt. Measurements showed that the viscosity of the pure thermoset melt is lower compared to the viscosity of a thermoplastic mate-rial used in a comparable in-mold impregnation process. Mechanical tests show that a complete impregnation is necessary. Compared to test specimen without a continuous fiber-reinforcement, the tensile strength and elastic modulus were improved by more than 40 % using a continuous carbon-fiber- reinforcement with a content of only 1.7 % in the cross sectional area in the middle part of the used test specimen. One of the main challenges is proper fiber alignment in complex geometries. Further investigations will cover the influence of further processing parameters, the fiber guidance in cavity and the sieve effect on the impregnation behavior and component properties.

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Stichworte: Duroplast, Duroplastspritzgießen, Endlosfaserverstärkte Verbundwerkstoffe, Duropalstspritzguss Direktimprägnierung, duroplastische Verbundwerkstoffe.

Keywords: Thermoset, In-mold impregnation, thermoset injection molding, continuous fiber-reinforced composites, direct impregnation, thermoset composites, thermoset injection molding direct impregnation

Autor / author:

Tim Deringer, M.Sc. (1. Autor) Dipl.-Ing. Tobias Kleffel (2. Autor) Prof. Dr.-Ing. Dietmar Drummer Lehrstuhl für Kunststofftechnik (LKT) Friedrich-Alexander Universität Erlangen-Nürnberg Am Weichselgarten 9 91058 Erlangen

E-Mail: [email protected] Webseite: www.lkt.fau.de Tel.: +49 (0)9131/85-29706 Fax: +49 (0)9131/85-29709

Herausgeber / Editors:

Editor-in-Chief Prof. em. Dr.-Ing. Dr. h.c. Gottfried W. Ehrenstein Lehrstuhl für Kunststofftechnik Universität Erlangen-Nürnberg Am Weichselgarten 9 91058 Erlangen Deutschland Tel.: +49 (0)9131/85 - 29703 Fax: +49 (0)9131/85 - 29709 E-Mail: [email protected] Europa / Europe Prof. Dr.-Ing. Dietmar Drummer, verantwortlich Lehrstuhl für Kunststofftechnik Universität Erlangen-Nürnberg Am Weichselgarten 9 91058 Erlangen Deutschland Tel.: +49 (0)9131/85 - 29700 Fax: +49 (0)9131/85 - 29709 E-Mail: [email protected]

Amerika / The Americas Prof. Prof. hon. Dr. Tim A. Osswald, verantwortlich Polymer Engineering Center, Director University of Wisconsin-Madison 1513 University Avenue Madison, WI 53706 USA Tel.: +1 608/263 9538 Fax: +1 608/265 2316 E-Mail: [email protected]

Verlag / Publisher:

Carl-Hanser-Verlag GmbH & Co. KG Wolfgang Beisler Geschäftsführer Kolbergerstraße 22 D-81679 München Tel.: +49 (0)89/99830-0 Fax: +49 (0)89/98480-9 E-Mail: [email protected]

Redaktion / Editorial Office:

Dr.-Ing. Eva Bittmann Jannik Werner, M.Sc. E-Mail: [email protected] Beirat / Advisory Board:

Experten aus Forschung und Industrie, gelistet unter www.kunststofftech.com

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Documents

Zeitschrift Kunststofftechnik Journal of Plastics Technology€¦ · fiber-reinforcement in one shot has been developed. “Dry” textiles or continuous fibers are inserted into