Cost-effective glass-reinforced thermoplastic matrix towpregs produced by a powder coating line that were used to manufacture composite pipes by filament winding. A conventional 6 axes filament-winding equipment was adapted for processing such structures. The influence of the filament winding speed and mandrel temperature on the composite final properties was studied in the present work. An optimized processing window was established by comparing the composite theoretical expected mechanical properties with the experimentally obtained
ones. The final properties determined on the produced pipes and structures and the technological changes introduced to the conventional filament-winding equipment will be presented and discussed. Besides the processing description and conditions, it will be presented the relationship between processing conditions and mechanical properties.(undefined

Marques, A. T.

Nunes, J. P.

Silva, J. F.

Universidade do Minho: RepositoriUM

ECCM15 - 15TH EUROPEAN CONFERENCE ON COMPOSITE MATERIALS, Venice, Italy, 24-28 June 2012  1     FILAMENT WOUND PRODUCTS MADE WITH THERMOPLASTIC MATRIX TOWPREGS   J. F. Silva 1*, J. P. Nunes 2, A. T. Marques3  1 ISEP, Dept. of Mechanical Engineering, R. Dr. Antonio B. Almeida 431, 4200-072 Porto, Portugal 2 Institute for Polymers and Composites/I3N, Minho University, Campus de Azurem, 4800-058 Guimaraes, Portugal 3 FEUP, Porto University, R. Dr. Roberto Frias, 4200-465 Porto, Portugal *e-mail: jfs@isep.ipp.pt  Keywords: Towpreg, Filament winding, Thermoplastic matrix composites, Processing    Abstract Cost-effective glass-reinforced thermoplastic matrix towpregs produced by a powder coating line were used to manufacture composite pipes by filament winding. A conventional 6 axes filament-winding equipment was adapted for processing such structures. The influence of the filament winding speed and mandrel temperature on the composite final properties was studied in the present work. An optimized processing window was established by comparing the composite theoretical expected mechanical properties with the experimentally obtained ones. The final properties determined on the produced pipes and structures and the technological changes introduced to the conventional filament-winding equipment will be presented and discussed. Besides the processing description and conditions, it will be presented the relationship between processing conditions and mechanical properties.   1 Introduction A purposely-built powder-coating process was used to produce thermoplastic matrix towpregs based on a polypropylene reinforced with continuous glass fiber (GF/PP) [1, 2]. A conventional filament winding equipment used to produce thermosetting matrix composites was modified to process the towpregs into 80 mm diameter pipes [3, 4] using a new developed heated mandrel. The concept can be seen in the schema shown in Figure 1.   Towpreg advantages Fabrication Processing Products • cheap and continuous • no melting nor solvents • almost all plastics and fibres • wide range of fibre contents • major thermoset processing methods   • environmentally clean  • unidirectional or woven fibres • variable anisotropy and fiber contents • braided 3-D structures  Figure 1. Schematic proposal of the work carried out  ECCM15 - 15TH EUROPEAN CONFERENCE ON COMPOSITE MATERIALS, Venice, Italy, 24-28 June 2012  2  The influence of filament winding speed on the final composite properties was studied at different mandrel temperatures. This work discusses the results obtained and compares them with those already achieved using a mandrel at room temperature [4]. The results obtained from the interlaminar shear tests made to verify the consolidation quality proven that the pipe interlaminar shear strength is more sensitive to the mandrel temperature and winding speed than the tensile strength or the initial specific ring stiffness.   2 Experimental 2.1 Raw materials A polypropylene powder (ICORENE 9184B P from ICO Polymers France) having a powder size between 60 and 850 (µm) and a 2400 Tex glass fibers (357D-AA from Owens Corning) were used to process towpregs in the powder-coating line. Table 1 shows the properties of the raw materials used in this work.  Property Units Glass fibres Polypropylene Density Mg/m3 2.56 0.91 Tensile strength MPa 3500 30 Tensile modulus GPa 76 1.3 Linear roving weight Tex 2400 - Table 1. Raw materials properties   2.2 Production of the GF/PP Towpregs The GF/PP towpregs used in this work were produced using the typical powder coating line processing conditions shown in Table 2.  Variable Units Value Linear fibre pull speed m/min 2-6 Furnace temperature ºC 400-420 Spreader pressure kPa 500 Table 2. Typical coating line operational conditions   2.2 Filament wound system GF/PP pipes with dimensions of φ80×4 mm were processed from the towpregs on the modified CNC 6 axes conventional PULTREX machine shown in Figure 2.  As can be seen in the Figure, a pre-heating furnace, a hot-air heater and a 30 mm diameter consolidation roll were mounted in the machine. In respect to the system used in a previous work and described elsewhere [3, 4], a new mandrel internally heated by hot air was employed here. Furthermore, the mandrel and consolidation temperatures were measured and controlled by two thermocouples, one mounted in contact with the mandrel surface and the other near the consolidation roll contact area, respectively. Using this system, the GF/PP composite pipes were made in the different filament winding conditions shown in Table 3. As can be seen, two different mandrel temperatures were used to produce the composite pipes at three different mandrel rotational speeds.  ECCM15 - 15TH EUROPEAN CONFERENCE ON COMPOSITE MATERIALS, Venice, Italy, 24-28 June 2012  3   a) Schematic layout  b) Photograph showing a detail of the heated mandrel. Figure 2. Filament winding system   Variable Units Values Mandrel rotational speed rpm 6 8 10 Mandrel temperature ºC 150 200 150 200 150 200 Consolidation pressure kPa 200 Pre-heating temperature ºC 260 Consolidation temperature ºC 300 Tow tension N 10 Table 3. Filament winding operational conditions   2.3 Testing procedure Each produced pipe was tested in order to determine the initial specific ring stiffness, apparent circumferential tensile strength and fiber mass fraction according to EN 1228, ASTM 2290 and EN 60, respectively. Furthermore, specimens with dimensions of 12 × 7 × 4 mm3 were cut from the filament wound pipes and submitted to interlaminar shear tests to evaluate the consolidation quality. In order to do this the interlaminar shear strength was determined in a new developed testing device (see Figure 2) based on the one described elsewhere [5]. After mounting this device in a universal testing machine Instron 4505, simple supported specimens were submitted to shear tests using a cross-head speed of 1 mm/min. The interlaminar shear strength, τ, was then calculated by:   ( )baSbF+⋅⋅=τ  (1) where: F is the testing machine force S is the specimen cross-section and, a, b are the dimensions shown in Fig. 3 ECCM15 - 15TH EUROPEAN CONFERENCE ON COMPOSITE MATERIALS  Test specimenFigure 3.  2.4 Results Table 4 shows the dependence of the composites mechanical properties on the mandrel temperature and compares them with the theoretical expected ones calculated from the properties determined experimentally on the glass Classical Lamination Theory (CLT) and the micromechanical lamina approach [6,7]. Property Tensile strength ExperimentalTheoreticalInterlaminar shear strength ExperimentalTheoreticalCircumferential modulus ExperimentalTheoreticalFiber mass fraction ExperimentalFiber volume fraction CalculatedTable 4. As can be seen, the obtained mechanical properties are lower than the theoretical expected ones but already enough competitive for a large number of commercial applications of composite pipes/vessels. As the poorest values of the interlaminar shear strengtseems to be related with the difficulties found in consolidate well the composite pipe wall structure during the very short consolidation time achieved in the filament winding process., Venice, Italy4  a) Photo of the device   a) Device drawing  Interlaminar shear testing device. fibers and polypropylene [2] using the Units Mandrel temperature (ºC)150 200  MPa 375.3 ± 53.9 281.9 ± 18.3 693.7 ± 229 MPa 1.76 ± 0.51 2.28 ± 2.19 8.93 ± 0.37 GPa 15.1 ± 0.52 15.4 ± 0.75 37.3 ± 7.7 % 80.2 ± 1,5 59.0 ± 2,8 Mechanical properties determined on composites , 24-28 June 2012   Room Temperature  431.0 ± 37.6   2.82 ± 1.06   17.8 0.45    h suggest, this  ECCM15 - 15TH EUROPEAN CONFERENCE ON COMPOSITE MATERIALS, Venice, Italy, 24-28 June 2012  5  In order to try improving the composite consolidation the dependence of the interlaminar shear strength on the mandrel surface temperature and rotational speed was investigated. The results obtained are summarized in Table 5. It shows that the composite consolidation is deeply affected by both parameters under study. The highest interlaminar strength was achieved by combining a mandrel surface temperature of 200ºC with a 8 rpm rotational speed.  Property Units  Mandrel rotational speed (rpm) 6 8 10 Mandrel temperature ºC  150 200 150 200 150 200 Interlaminar shear strength MPa Average 2.12  1.58 1.97 4.73 1.18 0.53 St. Dev. 0.99 0.02 0.40 0.59 0.05 0.03 Table 5. Dependence of the interlaminar shear strength on the mandrel temperature and rotational speed   3 Conclusions A new low-cost filament wound technology was developed to produce thermoplastic matrix composites with mechanical properties compatible with the major commercial applications. It was found that the mandrel surface temperature and rotational have a major role on the composite consolidation quality. This work shows that interlaminar shear tests can be used in the optimization of these parameters. Such optimization could be useful to enlarge the application of filament wound composite structures on more demanding markets.  References [1] Silva, R. F., Silva, J. F. , Nunes, J. P., Bernardo, C. A., Marques, A. T., New Powder Coating Equipment to Produce Continuous Fibre Thermoplastic Matrix Towpregs, in “Materials Science Forum”, Trans Tech Publications, Vol. 587-588, pp. 246-250, (2008). [2] Silva, J. F., Nunes, J. P., Bernardo, C. A., Determining The Final Properties Of Thermoplastic Matrix Composites Produced From Towpregs, 14th European Conference on Composite Materials – ECCM 14, 7-10 June, Budapest, Hungry, (2010). [3] Nunes, J.P., Silva, J.F., Vieira, P., Marques, A.T., Implementation of an Industrial Process to Produce Filament Wound Composites from Thermoplastic Towpregs and Coated Tapes, Proceedings of the 8th World Conference of the Polymer Processing Society - PPS 18, Guimaraes, Portugal (2002). [4] Nunes, J. P., Silva, J. F., Marques, A. T., Van Hattum; F. W. J. Bernardo, C. A., Advances In Thermoplastic Matrix Towpreg Processing, Journal of Thermoplastic Composite Materials, Vol. 17 (6), pp. 523-544, USA (2004). [5] Lauke, B., Schneider, K and Friedrich, K, Interlaminar shear Measurement of Thin Composite Rings Fabricated by Filament Winding, Proceedings of ECCM 5, Bordeaux, France, pp. 313-318 (1992). [6]  Nunes, J.P., Bernardo, C.A., Pouzada, A.S., Edie, D.D., Formation and Characterisation of Carbon/Polycarbonate Towpregs and Composites, J. of Composite Materials, 31:17, 1758-1777 (1997). [7] Jones, R.M., Mechanics of Composite Materials, Washington, Scripta Book Company (1975). 

Filament wound products made with thermoplastic matrix towpregs

Cost-effective glass-reinforced thermoplastic matri
x towpregs produced by a powder coating
line were used to manufacture composite pipes by fi
lament winding. A conventional 6 axes
filament-winding equipment was adapted for processi
ng such structures. The influence of the
filament winding speed and mandrel temperature on t
he composite final properties was
studied in the present work. An optimized processin
g window was established by comparing
the composite theoretical expected mechanical prope
rties with the experimentally obtained
ones. The final properties determined on the produc
ed pipes and structures and the
technological changes introduced to the conventiona
l filament-winding equipment will be
presented and discussed. Besides the processing des
cription and conditions, it will be
presented the relationship between processing condi
tions and mechanical properties

Scientific Repository of the Polytechnic Institute of Porto

English

Filament wound products made with thermoplastic  matrix towpregs

ECCM15 - 15TH EUROPEAN CONFERENCE ON COMPOSITE MATERIALS, Venice, Italy, 24-28 June 2012Cost-effective glass-reinforced thermoplastic matri
x towpregs produced by a powder coating
line were used to manufacture composite pipes by fi
lament winding. A conventional 6 axes
filament-winding equipment was adapted for processi
ng such structures. The influence of the
filament winding speed and mandrel temperature on t
he composite final properties was
studied in the present work. An optimized processin
g window was established by comparing
the composite theoretical expected mechanical prope
rties with the experimentally obtained
ones. The final properties determined on the produc
ed pipes and structures and the
technological changes introduced to the conventiona
l filament-winding equipment will be
presented and discussed. Besides the processing des
cription and conditions, it will be
presented the relationship between processing condi
tions and mechanical properties

Repositório Científico do Instituto Politécnico do Porto

http://repositorium.sdum.uminho.pt/bitstream/1822/20520/1/ECCM15_Paper437_final.pdf

Filament wound products made with thermoplastic matrix towpregs

Abstract

Similar works

Full text

Available Versions

Universidade do Minho: RepositoriUM

Scientific Repository of the Polytechnic Institute of Porto

Repositório Científico do Instituto Politécnico do Porto