Low Warpage Nanophase-Separated Polypropylene/Olefinic Elastomer Reactor Blend Composites with Digitally Tuned Glass Fiber Orientation by Extrusion-Based Additive Manufacturing

2021 ◽  
Vol 3 (4) ◽  
pp. 2070-2081
Author(s):  
Carl G. Schirmeister ◽  
Sebastian Schächtele ◽  
Yannic Keßler ◽  
Timo Hees ◽  
Rainer Köhler ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Glass Fiber ◽  
Fiber Orientation ◽  
Reactor Blend

scholarly journals Warpage Reduction of Glass Fiber Reinforced Plastic Using Microcellular Foaming Process Applied Injection Molding

Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 360 ◽  
Author(s):  
Hyun Kim ◽  
Joo Sohn ◽  
Youngjae Ryu ◽  
Shin Kim ◽  
Sung Cha
Keyword(s):  
Injection Molding ◽  
Glass Fiber ◽  
Fiber Orientation ◽  
Mechanical And Thermal Properties ◽  
Micro Ct ◽  
Fiber Reinforced ◽  
Foaming Process ◽  
Microcellular Foaming ◽  
Glass Fiber Reinforced ◽  
The Impact

This study analyzes the fundamental principles and characteristics of the microcellular foaming process (MCP) to minimize warpage in glass fiber reinforced polymer (GFRP), which is typically worse than that of a solid polymer. In order to confirm the tendency for warpage and the improvement of this phenomenon according to the glass fiber content (GFC), two factors associated with the reduction of the shrinkage difference and the non-directionalized fiber orientation were set as variables. The shrinkage was measured in the flow direction and transverse direction, and it was confirmed that the shrinkage difference between these two directions is the cause of warpage of GFRP specimens. In addition, by applying the MCP to injection molding, it was confirmed that warpage was improved by reducing the shrinkage difference. To further confirm these results, the effects of cell formation on shrinkage and fiber orientation were investigated using scanning electron microscopy, micro-CT observation, and cell morphology analysis. The micro-CT observations revealed that the fiber orientation was non-directional for the MCP. Moreover, it was determined that the mechanical and thermal properties were improved, based on measurements of the impact strength, tensile strength, flexural strength, and deflection temperature for the MCP.

Development of the layered structure in a double-gated glass fiber-reinforced polypropylene injection molding: Experimental and simulated results

2018 ◽  
Vol 37 (14) ◽  
pp. 945-959 ◽  
Author(s):  
MC Quintana ◽  
MP Frontini
Keyword(s):  
Glass Fiber ◽  
Layered Structure ◽  
Fiber Orientation ◽  
Flow Direction ◽  
Weld Line ◽  
Orientation Distribution ◽  
Simulation Software ◽  
Distribution Data ◽  
Melt Temperature ◽  
Fiber Orientation Distribution

The present study aims to experimentally validate numerical simulation of fiber orientation distribution performed by molding simulation software Moldex3D in a double-gated injection-molded glass fiber-filled (40 wt%) polypropylene box, by making a detailed comparison of predicted and experimentally measured fiber orientation distribution data. The modeling approach evaluated in this work consists in the implementation of the Folgar–Tucker rotary diffusion model with the invariant-based optimal fitting closure approximation for the fourth-order orientation tensor. The specimen used has a weld line in the center and sharp corners. This investigation characterizes in detail the development of the through-thickness layered structure at distinctive locations of the specimen. The sensitivity of fiber orientation distribution and the layered structure to changes upon injection time and melt temperature is also evaluated. The boxes display the typical layered laminate structure, with fibers aligned in the main flow direction near the walls (shell layer) and less oriented in the middle plane (core layer). The boxes injected at the lowest melt temperature display an additional skin layer. Unfortunately, simulation fails in predicting the five layers structure developed under these latter conditions. The grade of fiber orientation is deemed to be independent of process parameters but not the layered structure.

scholarly journals Influence of the Initial Fiber Orientation on the Weld Strength in Welding of Glass Fiber Reinforced Thermoplastics

2016 ◽  
Vol 2016 ◽  
pp. 1-16 ◽  
Author(s):  
Isabel Fiebig ◽  
Volker Schoeppner
Keyword(s):  
Glass Fiber ◽  
Fiber Orientation ◽  
Weld Strength ◽  
Fiber Reinforced ◽  
Hot Plate ◽  
Glass Fiber Reinforced ◽  
Vibration Welding ◽  
Reinforced Thermoplastics ◽  
Fiber Reinforced Thermoplastics ◽  
Initial Fiber

The welding factors are significantly lower in welding of fiber reinforced thermoplastics than in welding of unreinforced thermoplastics due to the fiber orientation in the weld. This paper presents results from investigations on the influence of the initial fiber orientation on the weld strength in hot plate and vibration welding for glass fiber reinforced polypropylene and polyamide 6. Injection molded specimens are compared to specimens with main initial fiber orientation being longitudinal and transverse to the joining direction. The results of CT analysis of the fiber orientation in the weld show the opportunity to achieve a higher weld strength by using specimens with fibers being initially oriented longitudinally to the joining direction. The influence of the initial fiber orientation in the parts to be welded on the weld strength in hot plate welding is more distinct than in vibration welding.

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