Prediction of the consolidation of woven fibre-reinforced thermoplastic composites. Part I. Isothermal case

Phillips, Richard; Akyüz, D.

doi:10.1016/s1359-835x(97)00099-7

Cited by 27 publications

(21 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Among others, a key drawback of thermoplastic matrix composite is the high viscosity of the molten thermoplastic resin compared to thermosetting, which can determine a poor impregnation of fibers. The use of commingled fabrics can overcome this problem, thanks to the intimate physical blending of reinforcing and matrix fibers directly into the bundles [4–6].…”

Section: Introductionmentioning

confidence: 99%

Assessment of the relevance of sintering in thermoplastic commingled yarn consolidation

et al. 2011

View full text Add to dashboard Cite

The aim of the present article is to study the different phenomena which are at the basis of the consolidation of commingled thermoplastic semi‐pregs made of amorphous polyester fibers and E‐glass reinforcement. The evolution of the void fraction during the consolidation of the composite was monitored by a dynamometer, equipped with parallel plates and a forced convection oven. Different physical changes were associated to the consolidation temperature. Scanning electron microscopy (SEM) and thermomecahnical analysis (TMA) showed that at low temperature, matrix fiber deformation and sintering are responsible of the initial void reduction. At a temperature higher than the onset of the flow region, reinforcement impregnation is responsible of the further void reduction. Dimensionless analysis confirmed that at lower temperatures, corresponding to higher viscosities, consolidation due to viscous flow of the polymer matrix is negligible compared to consolidation due to sintering of matrix fibers. The results indicate that the Darcy law can efficiently represent the consolidation during the microscale impregnation of the reinforcement, but cannot account for the initial stages of consolidation. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers

show abstract

Section: Introductionmentioning

confidence: 99%

Assessment of the relevance of sintering in thermoplastic commingled yarn consolidation

et al. 2011

View full text Add to dashboard Cite

show abstract

“…The flow of the molten material is governed by Darcy's law, 11,12 which implies that low viscosities and low migration distance of the polymer matrix are required for complete consolidation. For this reason, commingled yarn pre-pregs, or semi-pregs, are used for this purpose, allowing composites to be processed at low pressures.…”

mentioning

confidence: 99%

A preliminary study on bladder‐assisted rotomolding of thermoplastic polymer composites

Salomi

Greco

Felline³

et al. 2007

Adv Polym Technol

View full text Add to dashboard Cite

ABSTRACT:In this preliminary work, a new process is examined for manufacturing hollow parts from continuous fiber-reinforced thermoplastic polymer. The new process combines the basic idea of bag forming (or bladder-assisted forming) with the rotation of the mold for the processing of thermoplastic matrix composites. A pressurized membrane is used to compact the composite on the inner wall of a mold, which is placed inside a forced convection oven. The mold is removed from the oven for the cooling stage. The process was initially developed by using a thermoplastic pre-preg obtained using yarns of commingled E-glass fibers with isotactic polypropylene (iPP). A preliminary characterization of the thermoplastic composite showed that the material can be consolidated with pressures as low as 0.01 MPa, which is readily ROTOMOLDING OF THERMOPLASTIC POLYMER COMPOSITESachievable with the process of this study. The design of the mold and membrane was carried out on the basis of both structural analysis of the aluminum shell and thermal analysis of the mold. The mold thickness is of great importance with respect to both the maximum pressure allowed in the process and the overall cycle time. Molding was performed on stacks of three and six layers of yarn, varying the applied pressure between 0.01 and 0.05 MPa and maximum temperature of the internal air between 185• C and 215• C. The composite shells obtained under different processing conditions were characterized in terms of physical and mechanical properties. Mechanical properties comparable with those obtained by compression molding and vacuum bagging were obtained. The maximum values obtained are 12.1 GPa and 290 MPa for the flexural modulus and the flexural strength, respectively. Furthermore, the results obtained show that mechanical properties improve with increasing the pressure during the cycle and with the maximum temperature used in the process.

show abstract

“…The theoretical flexural stiffness was therefore calculated by Eqs. (2) and (3) using E LLDPE = 0.480 GPa. The comparison of theoretical and measured flexural stiffness, as reported in Table I, shows a good correspondence, which is indicative of good adhesion between the two layers.…”

Section: Processing Cyclementioning

confidence: 99%

“…This is usually pursued by using commingled yarn composites, which can be processed at very low pressures. 2,3 Processing techniques typically fall into two categories: consolidation between matched dies (matched die forming, hydro forming, rubber block forming, and shaped rubber tool forming) and those where the consolidation force is provided by a diaphragm, membrane, or film (double diaphragm forming, vacuum bag consolidation, and autoclave processing). 4−8 In a previous work, 9 it was shown that hollow articles can be produced by a bladdermolding technique, where a composite preform is placed between a silicone bladder and a hollow metallic mold.…”

Section: Introductionmentioning

confidence: 99%

Processing and Properties of a Polymer/Composite Double‐Layer Laminate

Salomi¹,

Greco

Pacifico³

et al. 2011

Adv Polym Technol

View full text Add to dashboard Cite

Coupled polymer/composite parts were obtained for adapting a bladder-molding technique previously developed for the production of hollow components with continuous fiber-reinforced thermoplastic matrix composites.The internal layer (bladder side) is made up of an unreinforced thermoplastic polymer, linear low-density polyethylene (LLDPE), and the external one (mold side) is made up of a thermoplastic matrix composite based on isotactic polypropylene (PP) and E-glass fabric. The adhesion between the two layers is achieved by applying pressure (<1 bar) through a silicone bladder. The composite/polymer interface was characterized by the evaluation of the interfacial shear strength (IFSS) (between composite and unreinforced polymer), flexural stiffness, and short-beam strength analysis. The experimental mechanical properties were compared with model results, derived on the assumption that perfect adhesion exists between the two layers. A good agreement between the predicted and experimental mechanical properties was observed. As indicated by double notch shear tests used for the IFSS evaluation, good adhesion between LLDPE and PP matrix composite was achieved during processing. The results reported confirm the suitability of the method for a double-layer structure fabrication. C 2011 Wiley Periodicals, Inc. Adv Polym Techn 00: 1-12, 2011; View this article online at wileyonlinelibrary.com.

show abstract

Prediction of the consolidation of woven fibre-reinforced thermoplastic composites. Part I. Isothermal case

Cited by 27 publications

References 17 publications

Assessment of the relevance of sintering in thermoplastic commingled yarn consolidation

Assessment of the relevance of sintering in thermoplastic commingled yarn consolidation

A preliminary study on bladder‐assisted rotomolding of thermoplastic polymer composites

Processing and Properties of a Polymer/Composite Double‐Layer Laminate

Contact Info

Product

Resources

About