scholarly journals On short glass fiber reinforced thermoplastics with high fiber orientation and the influence of surface roughness on mechanical parameters

2021 ◽  
pp. 073168442110517
Author(s):  
Tamara van Roo ◽  
Stefan Kolling ◽  
Felix B Dillenberger ◽  
Joachim Amberg
Keyword(s):  
Fiber Orientation ◽  
Glass Fibers ◽  
Fiber Direction ◽  
Fiber Reinforced ◽  
Polybutylene Terephthalate ◽  
Structural Simulation ◽  
Fiber Reinforced Materials ◽  
Molded Parts ◽  
Injection Molded ◽  
Short Glass

Injection molding is a common process for manufacturing thermoplastic polymers. Preconnected to fabrication, mechanically loaded parts are examined in structural simulation. A crucial prerequisite for a valid structural simulation for any material is the underlying material data. To determine this data, different phenomena must be considered such as influences of load type, strain rate, environmental conditions and in case of fiber reinforced materials the fiber orientation (FO) in the considered area. Because of rheological effects, injection molded parts often possess a non-homogeneous FO distribution. This makes it challenging to create testing plates for specimen extraction with a well-defined FO over thickness and width in the considered area. In this paper, a novel testing part is introduced with an unidirectionally oriented testable area. It shows a FO degree of more than 0.75, which has been validated with μ-CT measurement and two thermoplastic materials: polyamide and polybutylene terephthalate, both reinforced with 30 weight percent of short glass fibers. In order to resolve influences of the already addressed FO distribution in injection molded parts, tensile test specimens need to be extracted out of specially designed plates via milling and cannot be injection molded directly. Experiments were carried out to study possible effects of preparation on the mechanical properties of specimens with both materials and two milling parameter sets. The first milling parameter set creates reproducible surface roughnesses, whereas the second parameter set shows a correlation between FO and roughness value: when milling perpendicularly to the main FO lower roughnesses are reached than milling in fiber direction. Uncertainties of the normalized rupture strain from orthogonally extracted specimens seem to be larger than the values from those extracted in fiber direction.

Fiber Orientation in Injection-Compression Molded Short-Fiber-Reinforced Polypropylene Parts

2009 ◽  
Author(s):  
Han-Xiong Huang ◽  
Can Yang ◽  
Kun Li
Keyword(s):  
Fiber Orientation ◽  
Flow Direction ◽  
Processing Parameters ◽  
Short Fiber ◽  
Fiber Reinforced ◽  
Compression Force ◽  
Time Compression ◽  
Compression Time ◽  
Molded Parts ◽  
Injection Molded

Four processing parameters, including compression force, compression time, compression distance, and delay time, were investigated in terms of their effects on the fiber orientation in injection-compression molded (ICM) short-fiber-reinforced polypropylene parts. The results reveal that the fiber orientation pattern in ICM parts is different from that in conventional injection molded parts. Compression force plays an important role in determining the fiber orientation, whereas the effect of compression time can be neglected. Moreover, the fiber orientation changes obviously in the width direction, with most fibers arranging orderly in the flow direction at positions near the mold cavity wall.

Prediction of fiber orientation in injection molded parts of short-fiber-reinforced thermoplastics

1990 ◽  
Vol 30 (16) ◽  
pp. 957-966 ◽  
Author(s):  
Takaaki Matsuoka ◽  
Jun-Ichi Takabatake ◽  
Yoshinori Inoue ◽  
Hideroh Takahashi
Keyword(s):  
Fiber Orientation ◽  
Short Fiber ◽  
Fiber Reinforced ◽  
Molded Parts ◽  
Injection Molded ◽  
Reinforced Thermoplastics ◽  
Fiber Reinforced Thermoplastics

Effects of hybridization and fiber orientation on flexural properties of hybrid short glass fiber– and short carbon fiber–reinforced vinyl ester composites

2018 ◽  
Vol 26 (5-6) ◽  
pp. 371-379 ◽  
Author(s):  
Muhammad Shafiq Irfan ◽  
Farhan Saeed ◽  
Yasir Qayyum Gill ◽  
Asif Ali Qaiser
Keyword(s):  
Fiber Orientation ◽  
Vinyl Ester ◽  
Hybrid Composites ◽  
Glass Fibers ◽  
Fiber Composites ◽  
Short Fiber ◽  
Flexural Properties ◽  
Fiber Reinforced ◽  
Short Carbon ◽  
Short Glass

Short fiber–reinforced hybrid polymer (SFRHP) composites were prepared using short glass fibers (SGFs) and short carbon fibers (SCFs) as the reinforcements and vinyl ester resin as the matrix. The flexural properties of all-SGF, all-SCF, and SGF-SCF hybrid composites with controlled fiber orientation were found out experimentally and also predicted using rule of hybrid mixtures. Hand layup technique was used for the preparation of the composites. Composites with different patterns of fiber alignment were prepared and their properties were compared with randomly oriented short fiber composites. The results showed that the flexural performance of samples with longitudinal orientation of the fibers was significantly better than randomly oriented samples for all composites. Synergistic effect of hybridization (positive hybridization) with respect to flexural properties of SFRHP composites was obtained by controlling the orientation of the fibers. It was shown that the hybridization of fibers in the short fiber composites can provide economic savings.

scholarly journals Comparison of Real and Simulated Fiber Orientations in Injection Molded Short Glass Fiber Reinforced Polyamide by X‑ray Microtomography

Polymers ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 29
Author(s):  
Rafał Żurawik ◽  
Julia Volke ◽  
Jan-Christoph Zarges ◽  
Hans-Peter Heim
Keyword(s):  
Glass Fiber ◽  
Process Parameters ◽  
Fiber Orientation ◽  
Fiber Reinforced ◽  
X Ray ◽  
The Real ◽  
Short Glass Fiber ◽  
Glass Fiber Reinforced ◽  
Injection Molded ◽  
Short Glass

During injection molding of short glass fiber reinforced composites, a complex structure is formed due to the fiber movement. The resulting fiber orientation can be predicted using various simulation models. However, the models are known to have inadequacies andthe influence of process and model parameters is not clearly and comprehensively described. In this study, the aforementioned model and process parameters are investigated to determine the dependencies of the individual influences on the real and simulated fiber orientation. For this purpose, specimens are injection molded at different process parameters. Representative regions of the specimens are measured using X-ray microtomography and dynamic image analysis to determine the geometric properties of the fibers as well as their orientations. Furthermore, simulations are performed with the simulation software Moldflow® using different mesh types and densities as well as varying parameters of the MRD model to represent the real fiber orientations. The results show that different orientation areas arise in the samples, which cannot be represented with a simulation varying only one parameter. Several simulations must be carried out in order to represent flow regions occurring in the specimen as realistically as possible.

scholarly journals A Fatigue Damage Model for Life Prediction of Injection-Molded Short Glass Fiber-Reinforced Thermoplastic Composites

Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2250
Author(s):  
Mohammad Amjadi ◽  
Ali Fatemi
Keyword(s):  
Injection Molding ◽  
Glass Fiber ◽  
Fatigue Damage ◽  
Life Prediction ◽  
Glass Fibers ◽  
Damage Model ◽  
Fiber Reinforced ◽  
Short Glass Fiber ◽  
Glass Fiber Reinforced ◽  
Short Glass

Short glass fiber-reinforced (SGFR) thermoplastics are used in many industries manufactured by injection molding which is the most common technique for polymeric parts production. Glass fibers are commonly used as the reinforced material with thermoplastics and injection molding. In this paper, a critical plane-based fatigue damage model is proposed for tension–tension or tension–compression fatigue life prediction of SGFR thermoplastics considering fiber orientation and mean stress effects. Temperature and frequency effects were also included by applying the proposed damage model into a general fatigue model. Model predictions are presented and discussed by comparing with the experimental data from the literature.

Elastic properties of injection molded short glass fiber reinforced thermoplastic composites

2020 ◽  
Vol 254 ◽  
pp. 112850
Author(s):  
Yucheng Zhong ◽  
Ping Liu ◽  
Qingxiang Pei ◽  
Viacheslav Sorkin ◽  
Athanasius Louis Commillus ◽  
...  
Keyword(s):  
Glass Fiber ◽  
Elastic Properties ◽  
Thermoplastic Composites ◽  
Fiber Reinforced ◽  
Short Glass Fiber ◽  
Glass Fiber Reinforced ◽  
Injection Molded ◽  
Short Glass

scholarly journals Measuring Fiber Length in the Core and Shell Regions of Injection Molded Long Fiber-Reinforced Thermoplastic Plaques

2020 ◽  
Vol 4 (3) ◽  
pp. 104
Author(s):  
Abrahán Bechara Senior ◽  
Tim Osswald
Keyword(s):  
Fiber Length ◽  
Fiber Reinforced ◽  
Characterization Methods ◽  
The Core ◽  
Glass Fiber Reinforced ◽  
Molded Parts ◽  
Concentration Changes ◽  
Injection Molded ◽  
Fibers Orientation ◽  
Reinforced Thermoplastics

Long fiber-reinforced thermoplastics are an attractive design option for many industries due to their excellent mechanical properties and processability. Processing of these materials has a significant influence on their microstructure, which controls the properties of the final part. The microstructure is characterized by the fibers’ orientation, length, and concentration. Many characterization methods can capture the fiber orientation and concentration changes through the thickness in injection molded parts, but not the changes in fiber length. In this study, a technique for measuring fiber length in the core and shell regions of molded parts was proposed, experimentally verified, and used on injection molded 20 wt.% glass fiber-reinforced polypropylene plaques. The measured fiber length in the core was 50% higher than in the shell region. Comparison with simulation results shows disagreement in the shape of the through-thickness fiber length profile. Stiffness predictions show that the through-thickness changes in fiber length have little impact on the longitudinal and transverse Young’s modulus.

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