Effect of processing conditions on warpage of film insert molded parts

Baek, Soo Jin; Kim, Seong Yun; Lee, Seung Hwan; Youn, Jae Ryoun; Lee, Sung Hee

doi:10.1007/s12221-008-0117-y

Cited by 33 publications

(7 citation statements)

References 24 publications

(21 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This in turn leads to greater shrinkage of the polymeric materials and warpages of the molded part. However, the warpage increases again as the melt temperature is above 275 8 C. This matches with the results of Baek et al (2008) with a \ bell-shaped" tendency of part warpage. This can be explained by the fact that ah igher melt temperature keeps the polymeric melt hot for alonger time.…”

Section: Numerical Simulation Of Temperature and Part Warpagesupporting

confidence: 88%

See 1 more Smart Citation

Factors Influencing the Warpage in In-Mold Decoration Injection Molded Composites

Lee

Chen

Huang

et al. 2013

International Polymer Processing

View full text Add to dashboard Cite

This report studied, both experimentally and numerically, the factors affecting the warpage in in-mold decoration (IMD) injection molded parts. All experiments were conducted on an 80-ton injection-molding machine. The materials used in the experiments included poly(ethylene terephthalate) (PET) films and 30 %g lass fiber-filled PET resins. U-shaped plate parts with three different angles (908 ,1 358 ,a nd 1508)a tt he corners were molded. The influence of various processing parameters on part warpage was investigated using an experimental matrix, with its design based on the experimental-parameterdesign method developed by Taguchi. The experimental results suggested that all molded parts warped toward the side of the decoration film. For the parameters selected in the experiments, the corner angle and the melt injection pressure were found to be the principal factors affecting the warpage of IMD injection molded parts. The 908 angled parts exhibited the greatest amount of warpage, while the 1508 angled parts showed the least amount of warpage. Additionally, acommercially available code (Moldex 3-D) was used to simulate the temperature distribution during the filling process and the molded part warpage. Calculated warpage satisfactorily matched with the experimental data. It has been shown that the warpage of IMD injection molded parts is mainly caused by the imbalanced temperature distributiond uring cooling, due to the part geometry and the decoration films.

show abstract

Section: Numerical Simulation Of Temperature and Part Warpagesupporting

confidence: 88%

“…The research efforts on IMD molded warpage, however, have been limited. Baek et al (2008) studied the effect of processing conditions on the warpage of the film insert's molded parts. They found that the warpage decreased monotonically with increasing injection speed and exhibited ab ell-shaped curve as af unction of melt temperature.…”

Section: Introductionmentioning

confidence: 99%

Factors Influencing the Warpage in In-Mold Decoration Injection Molded Composites

Lee

Chen

Huang

et al. 2013

International Polymer Processing

View full text Add to dashboard Cite

show abstract

“…It is assumed that the occurrence of the blisters is related to the shrinkage of the substrate material. If the shrinkage in the substrate is higher than the contraction of the film insert during the cooling phase of the process, a delamination between the film insert and the substrate material can occur [23]. For that reason, the average volumetric shrinkage of the substrate under the film insert was investigated in the simulations.…”

Section: Simulationsmentioning

confidence: 99%

Blister Formation in Film Insert Moulding

et al. 2020

View full text Add to dashboard Cite

The formation of blister in the injection moulded parts, especially in the film insert moulded parts, is one of most significant causes of part rejection due to cosmetic requirements or functionality issues. The mechanism and physics of blister formation for molded parts are not well-understood by the state-of-the-art literature. The current paper increases the fundamental understanding of the causes for blister formation. In the experiment, a membrane strip of 5 mm in width was overmoulded with Polypropylene (PP), which formed a disc-shaped part with a diameter of 17.25 mm and a thickness of 500 µm. To investigate the influence of the processing parameters, a full factorial design of experiments (DoE) setup was conducted, including mould temperature (Tm), barrel temperature (Tb), injection speed (Vi) and packing pressure (Pp) as variables. The degree of blistering at the surface was characterized by the areal surface roughness parameters Spk and Smr1, measured with a confocal laser microscope. The measurements were taken on the 10 mm long section of the membrane surface in the centre of the moulded part across the entire width of the film. In addition, the film insert moulding (FIM)-process was simulated and the average shrinkage of the substrate material under the membrane was investigated. Eventually, a method and processing window could be defined that could produce blister-free parts.

show abstract

“…We confirmed that the warpage was exacerbated when glass fiber was added and experiments were conducted in an attempt to improve the warpage of the specimen by utilizing the MCP. In a previous investigation on warpage, Baek and Lee [16] studied the warpage characteristics of film insert molded parts according to the injection molding process conditions. Their research investigated warpage characteristics according to process conditions such as temperature, speed, and pressure, and it corresponds to insert injection process without the MCP.…”

Section: Introductionmentioning

confidence: 99%

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

et al. 2019

View full text Add to dashboard Cite

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.

show abstract

Effect of processing conditions on warpage of film insert molded parts

Cited by 33 publications

References 24 publications

Factors Influencing the Warpage in In-Mold Decoration Injection Molded Composites

Factors Influencing the Warpage in In-Mold Decoration Injection Molded Composites

Blister Formation in Film Insert Moulding

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

Contact Info

Product

Resources

About