scholarly journals Feasibility Study of Soft Tooling Inserts for Injection Molding with Integrated Automated Slides

Micromachines ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 730
Author(s):  
Tobias Vieten ◽  
Dennis Stahl ◽  
Peter Schilling ◽  
Faruk Civelek ◽  
André Zimmermann
Keyword(s):  
Injection Molding ◽  
Glass Fiber ◽  
Feasibility Study ◽  
Digital Light Processing ◽  
Injection Molded ◽  
Molded Interconnect Devices ◽  
Complex Parts

The production of injection-molding prototypes, e.g., molded interconnect devices (MID) prototypes, can be costly and time-consuming due to the process-specific inability to replace durable steel tooling with quicker fabricated aluminum tooling. Instead, additively manufactured soft tooling is a solution for the production of small quantities and prototypes, but producing complex parts with, e.g., undercuts, is avoided due to the necessity of additional soft tooling components. The integration of automated soft slides into soft tooling has not yet been investigated and poses a challenge for the design and endurance of the tooling. The presented study covers the design and injection-molding trial of soft tooling with integrated automated slides for the production of a complex MID prototype. The design further addresses issues like the alignment of the mold components and the sealing of the complex parting plane. The soft tooling was additively manufactured via digital light processing from a silica-filled photopolymer, and 10 proper parts were injection-molded from a laser-direct structurable glass fiber-filled PET+PBT material before the first damage on the tooling occurred. Although improvements are suggested to enhance the soft tooling durability, the designed features worked as intended and are generally transferable to other part geometries.

Fracture Toughness of Discontinuous Long Glass Fiber Reinforced Polypropylene: An Approach Based on a Numerical Prediction of Fiber Orientation in Injection Molding

2005 ◽  
Vol 13 (2) ◽  
pp. 121-130 ◽  
Author(s):  
V. Rizov ◽  
T. Harmia ◽  
A. Reinhardt ◽  
K. Friedrich
Keyword(s):  
Fracture Toughness ◽  
Injection Molding ◽  
Glass Fiber ◽  
Fiber Orientation ◽  
Numerical Prediction ◽  
Fiber Reinforced ◽  
Local Fracture ◽  
Glass Fiber Reinforced ◽  
Long Glass Fiber ◽  
Injection Molded

The fracture toughness of discontinuous long glass fiber reinforced injection-molded polypropylene has been characterized by using the microstructural efficiency concept in combination with a numerical prediction of the fiber orientation during injection molding. The latter was performed by using the SIGMASOFT commercial software. In a three-dimensional numerical scheme, input data such as fiber volume fractions, shear viscosity and mean fiber aspect ratio have been used in order to perform the mold filling analysis. The resulted local fiber orientation parameters for injection molded square plates of long glass fiber reinforced polypropylene allowed to calculate the local fracture toughness with microstructural efficiency concept. The latter were compared with the experimental toughness values obtained by the use of compact tension test specimens. The good correlation between the calculated fracture toughness data and the measured ones shows that a fiber orientation prediction by the SIGMASOFT finite element computer code can be used in combination with the microstructural efficiency concept for the determination of local fracture toughness values in injection molded long glass fiber reinforced thermoplastics. The combined approach opens good opportunities for optimization of a thermoplastic workpiece in its design with respect to local fracture resistance. This will enable the material performance levels to be significantly extended, with consequent increases in engineering applicability.

Two-Component Injection Molding of Molded Interconnect Devices

2012 ◽  
Vol 628 ◽  
pp. 78-82 ◽  
Author(s):  
Jyun Yi Chen ◽  
Wen Bin Young
Keyword(s):  
Injection Molding ◽  
Thickness Variation ◽  
Injection Molding Process ◽  
Molding Process ◽  
Micro Injection Molding ◽  
Two Component ◽  
Injection Molded ◽  
Channel Patterns ◽  
Injection Molded Plastic ◽  
Molded Interconnect Devices

Molded Interconnect Device (MID) can be defined as that an injection-molded plastic part combining with electrical and mechanical functions in a single device. This study is to examine the application of micro injection molding technology to the two-component molding process for the MID fabrication. The process involves the first shot of a plastic component with channel patterns on the surface. A second shot by micro injection molding technology is applied to fill the channel with the plateable plastics. The effects of the micro injection molding process parameters on filled line width of the two-component MID will be investigated. It is concluded that, for a MID component, the molding conditions must be designed carefully to keep the thickness variation below the allowable value. It is also found from the experiments that the thickness interference may in the range from 92 m to 196 m to have adequate molding at the second shot.

scholarly journals Porosity distribution in metal injection molded parts

2021 ◽  
Vol 46 (1) ◽  
pp. 7-10
Author(s):  
Samir Butković ◽  
Emir Šarić ◽  
Muhamed Mehmedović
Keyword(s):  
Injection Molding ◽  
Cross Section ◽  
Density Variation ◽  
Residual Porosity ◽  
Metal Injection Molding ◽  
Green Density ◽  
Shaped Part ◽  
Molded Parts ◽  
Injection Molded ◽  
Complex Parts

Metal injection molding technology is commonly used in production of small and very complex parts. Residual porosity is unavoidable characteristic of P/M parts, affecting their final properties. During injection molding phase powder-binder separation can occur, causing green density variation through cross section of the part. This behaviour is particularly pronounced as complexity of the parts increases. As a consequence, zones with different density and residual porosity can be seen after sintering. In this regard, porosity and hardness distribution of the sintered ring-shaped part is analysed and presented in the paper.

scholarly journals Are We Able to Print Components as Strong as Injection Molded?—Comparing the Properties of 3D Printed and Injection Molded Components Made from ABS Thermoplastic

2021 ◽  
Vol 11 (15) ◽  
pp. 6946
Author(s):  
Bartłomiej Podsiadły ◽  
Andrzej Skalski ◽  
Wiktor Rozpiórski ◽  
Marcin Słoma
Keyword(s):  
Tensile Strength ◽  
Injection Molding ◽  
Mechanical Strength ◽  
Cross Section ◽  
Fused Deposition Modeling ◽  
High Strength ◽  
Large Cross Section ◽  
Fused Deposition ◽  
Injection Molded ◽  
The Cross

In this paper, we are focusing on comparing results obtained for polymer elements manufactured with injection molding and additive manufacturing techniques. The analysis was performed for fused deposition modeling (FDM) and single screw injection molding with regards to the standards used in thermoplastics processing technology. We argue that the cross-section structure of the sample obtained via FDM is the key factor in the fabrication of high-strength components and that the dimensions of the samples have a strong influence on the mechanical properties. Large cross-section samples, 4 × 10 mm2, with three perimeter layers and 50% infill, have lower mechanical strength than injection molded reference samples—less than 60% of the strength. However, if we reduce the cross-section dimensions down to 2 × 4 mm2, the samples will be more durable, reaching up to 110% of the tensile strength observed for the injection molded samples. In the case of large cross-section samples, strength increases with the number of contour layers, leading to an increase of up to 97% of the tensile strength value for 11 perimeter layer samples. The mechanical strength of the printed components can also be improved by using lower values of the thickness of the deposited layers.

scholarly journals Constant Temperature Approach for the Assessment of Injection Molding Parameter Influence on the Fatigue Behavior of Short Glass Fiber Reinforced Polyamide 6

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1569
Author(s):  
Selim Mrzljak ◽  
Alexander Delp ◽  
André Schlink ◽  
Jan-Christoph Zarges ◽  
Daniel Hülsbusch ◽  
...  
Keyword(s):  
Injection Molding ◽  
Glass Fiber ◽  
Process Parameters ◽  
Fatigue Properties ◽  
Injection Molding Process ◽  
Molding Process ◽  
Short Glass Fiber ◽  
Glass Fiber Reinforced ◽  
Molding Parameter ◽  
Short Glass

Short glass fiber reinforced plastics (SGFRP) offer superior mechanical properties compared to polymers, while still also enabling almost unlimited geometric variations of components at large-scale production. PA6-GF30 represents one of the most used SGFRP for series components, but the impact of injection molding process parameters on the fatigue properties is still insufficiently investigated. In this study, various injection molding parameter configurations were investigated on PA6-GF30. To take the significant frequency dependency into account, tension–tension fatigue tests were performed using multiple amplitude tests, considering surface temperature-adjusted frequency to limit self-heating. The frequency adjustment leads to shorter testing durations as well as up to 20% higher lifetime under fatigue loading. A higher melt temperature and volume flow rate during injection molding lead to an increase of 16% regarding fatigue life. In situ Xray microtomography analysis revealed that this result was attributed to a stronger fiber alignment with larger fiber lengths in the flow direction. Using digital volume correlation, differences of up to 100% in local strain values at the same stress level for different injection molding process parameters were identified. The results prove that the injection molding parameters have a high influence on the fatigue properties and thus offer a large optimization potential, e.g., with regard to the component design.

scholarly journals Ultrasonic injection molding of glass fiber reinforced polypropylene parts using tungsten carbide-cobalt mold core

2021 ◽  
pp. 109771
Author(s):  
Xiong Liang ◽  
Yongjing Liu ◽  
Zehang Liu ◽  
Jiang Ma ◽  
Zhenxuan Zhang ◽  
...  
Keyword(s):  
Injection Molding ◽  
Tungsten Carbide ◽  
Glass Fiber ◽  
Fiber Reinforced ◽  
Glass Fiber Reinforced

scholarly journals A Practical Numerical Approach to Characterizing Non-Linear Shrinkage and Optimizing Dimensional Deviation of Injection-Molded Small Module Plastic Gears

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2092
Author(s):  
Xiansong He ◽  
Wangqing Wu
Keyword(s):  
Injection Molding ◽  
High Speed ◽  
Numerical Approach ◽  
Linear Shrinkage ◽  
Influential Factor ◽  
Dimensional Deviation ◽  
Non Linear ◽  
Injection Molded ◽  
Plastic Gears ◽  
Circle Diameter

This paper was aimed at finding out the solution to the problem of insufficient dimensional accuracy caused by non-linear shrinkage deformation during injection molding of small module plastic gears. A practical numerical approach was proposed to characterize the non-linear shrinkage and optimize the dimensional deviation of the small module plastic gears. Specifically, Moldflow analysis was applied to visually simulate the shrinkage process of small module plastic gears during injection molding. A 3D shrinkage gear model was obtained and exported to compare with the designed gear model. After analyzing the non-linear shrinkage characteristics, the dimensional deviation of the addendum circle diameter and root circle diameter was investigated by orthogonal experiments. In the end, a high-speed cooling concept for the mold plate and the gear cavity was proposed to optimize the dimensional deviation. It was confirmed that the cooling rate is the most influential factor on the non-linear shrinkage of the injection-molded small module plastic gears. The dimensional deviation of the addendum circle diameter and the root circle diameter can be reduced by 22.79% and 22.99% with the proposed high-speed cooling concept, respectively.

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.

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.

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