The effect of fiber concentration on fiber orientation in injection molded film gated rectangular plates

Jørgensen, Jens Kjær; Andreassen, Erik; Salaberger, Dietmar

doi:10.1002/pc.24698

Cited by 32 publications

(7 citation statements)

References 29 publications

(57 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In particular when one sets N p = 0, we retrieve the uncoupled scalar viscosity model, completely independent of fiber evolutions during the injection process. Since traditional linear dependence of N p on volume fraction may not be suitable for concentrated fiber-reinforced suspensions, see Jørgensen et al (2017), in this paper we adopt the nonlinear functional dependence of N p on fiber aspect ratio and volume fraction proposed by Phan-Thien and Graham (1991). Its dependence on mass fraction is illustrated in Fig.…”

Section: Anisotropic Fiber-induced Rheological Equationsmentioning

confidence: 99%

“…Since the core region is in general dominated by extensional flows transverse to the filling direction, it can be argued that these elongational deformations are not correctly taken into account in current models and a flow-fiber coupled simulation with fiber-dependent rheological properties may be more appropriate, cf. Tucker III (1991); Jørgensen et al (2017).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Flow-Fiber Coupled Viscosity in Injection Molding Simulations of Short Fiber Reinforced Thermoplastics

Li¹,

Luyé²

2019

International Polymer Processing

View full text Add to dashboard Cite

The main objective of this paper is to numerically investigate the use of fiber-dependent viscosity models in injection molding simulations of short fiber reinforced thermoplastics with a latest commercial software. We propose to use the homogenization-based anisotropic rheological model to take into account flowfiber coupling effects. The 4th-order viscosity tensor is approximated by an optimal scalar model and then implemented in the Moldflow Insight API framework. Numerical simulations are performed for a test-case rectangular plate with three fiber orientation models. The resulting coupled flow kinematics and fiber evolutions are then compared to the standard uncoupled simulations. Interpretations are given based on detailed post-processing of the field results. Certain deformation conditions are expected to be better taken into account, which may also in return lead to an improved fiber orientation prediction. Preliminary confrontation between flow-fiber coupled simulations and existing experimental data is then presented at the end of the paper.

show abstract

Section: Anisotropic Fiber-induced Rheological Equationsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Flow-Fiber Coupled Viscosity in Injection Molding Simulations of Short Fiber Reinforced Thermoplastics

Li¹,

Luyé²

2019

International Polymer Processing

View full text Add to dashboard Cite

show abstract

“…The fiber content also influences the ductility. A higher fiber content will lead to a decrease in ductility, with an increase in rigidity and strength 3,6 …”

Section: Resultsmentioning

confidence: 99%

“…The principal factor that affects the mechanical properties of SFRP is the fiber orientation. There are many factors that affect the fiber orientation such as injection point position, injection speed, injection pressure, mold temperature, fiber content, part geometry, and overall thickness 1–4 . Many studies are conducted to present the effects of fiber orientation on to the mechanical response of composite materials 5–21 …”

Section: Introductionmentioning

confidence: 99%

Experimental testing of two short‐fiber reinforced composites: PPA‐GF33 and PPS‐GF40

Micota

Isaincu

Marșavina

2021

Mat Design & Process Comms

View full text Add to dashboard Cite

This paper presents an experimental testing of two short‐fiber reinforced composites (SFRC). The two materials are a polyphthalamide with 33% glass fiber inclusion (PPA‐GF33) and a polyphenylene sulfide with 40% glass fiber inclusion. Rectangular plates were obtained from these two materials by injection molding. Specimens, type 1BA, according to ISO 527‐2, were cut out with orientations of 0°, 15°, 30°, 45°, 60°, and 90°, with respect to the longitudinal direction of the plate. The cutting was conducted using a CNC water jet machine. Tension tests were performed at room temperature, in order to determine the mechanical behavior. Results are presented in the form of stress–strain curves, considering different orientations of the specimens. The experimental results were processed in order to assess the differences that appear due to fiber orientation. A comparison between the two materials was performed in terms of Young's modulus, tensile strength, and tensile strain. The experimental data were used to calibrate the Tsai–Hill fracture criterion.

show abstract

“…Using X‐ray computed tomography (X‐CT) removes the directional ambiguity arising from fiber orientation measurements performed using two‐dimensional techniques . Measurements of shell–core fiber orientation development in injection molded parts have already been performed using X‐CT for studies on mechanical properties . Recently, X‐CT study was shown as a viable technique for tracking 3D fiber orientation evolution during simple shear .…”

Section: Introductionmentioning

confidence: 99%

Fiber migration in shear flow: Model predictions and experimental validation

et al. 2019

View full text Add to dashboard Cite

Understanding transient flow behavior of polymer composites is crucial for improving the predictions of final composite properties in polymer processing operations. This work is aimed at measuring concentration migration of fiber reinforcing particles in addition to fiber orientation evolution during simple shear flow. Center-gate injection molded samples using Nylon-6 containing 33 wt% short glass fibers (PA6-33GF) were prepared. Samples were imaged using X-ray computed tomography (X-CT) to obtain fiber orientation tensors and fiber volume fraction distributions after different strain units were imposed. With higher applied strains, the orientation of fibers evolved from a shell-core structure typical of injection molded composites to a preferential alignment in the shearing direction. As for fiber concentration, an initial shell-core concentration profile established during injection molding was found to diminish towards a uniform concentration distribution upon shearing. This experimentally observed concentration migration was modeled using the suspension balance model (SBM) which predicts concentration changes based on changes in particle stress contributions. The SBM uses a particle stress contribution model that is designed for spherical particles. Predictions from this model gave reasonably accurate steady state results and the evolution of the concentration profile. A modified fiber stress model that incorporates fiber orientation effects was also tested for its applicability for fiber-filled systems. Predictions from this model yielded reasonable agreement with measured concentration evolution data but with a slower attainment of a uniform concentration profile. Further investigation on the empirical constants used in the fiber stress model warrants a rheological assessment to improve concentration evolution predictions for use in constitutive rheological modeling. POLYM. COMPOS., 40:3573-3581, 2019.

show abstract

The effect of fiber concentration on fiber orientation in injection molded film gated rectangular plates

Cited by 32 publications

References 29 publications

Flow-Fiber Coupled Viscosity in Injection Molding Simulations of Short Fiber Reinforced Thermoplastics

Flow-Fiber Coupled Viscosity in Injection Molding Simulations of Short Fiber Reinforced Thermoplastics

Experimental testing of two short‐fiber reinforced composites: PPA‐GF33 and PPS‐GF40

Fiber migration in shear flow: Model predictions and experimental validation

Contact Info

Product

Resources

About