Film Insert Molding Research Articles

Study on the Influence of Process Parameters on Interface Strength of Film-insert Molding

By the controlling of variable, the influences on the film interface strength that filmline molding process had were investigated. The interfacial bonding strength under the circumstance where various of processing parameters (temperature, film thickness, injecting speed) were combined was measured through a normalized 90° peel test. And we used Superhigh magnification lens zoom 3D microscope to observe the Interface structure around the interface and the section of interface was observed too. To profoundly study the interfacial bonding strength mechanism, using the numerical simulation method, we analysed the temperature changes of the interface. And the crystallinities in different processing parameters combination situations were monitored by thermal characterization DSC. And then we calculated the crystallinities of the melt at the interface, drawing a conclusion about the relations between crystallinity and interface strength. The results show that the process conditions are favorable for improving the crystallinity of the interface and have obvious effects on the strength of the interface.

68.3: Curved Mobile Phone Cover with Carbon NanoBud Touch

A touch‐integrated mobile phone cover lens has been developed using Carbon NanoBud material. This product is a new curved edge cover lens with high optical quality touch, a light‐weight, unbreakable and hard‐coated all‐plastic design, and cost effective manufacturing by Film Insert Molding.

열진공성형에서 적층필름 두께변화에 대한 수치 및 실험적 해석

Vacuum-assisted thermoforming is one of the critical steps for successful application of film insert molding (FIM) to make parts of complex shape. If the thickness distribution of the formed film is non-uniform, then cracking, deformation, warpage, and wrinkling can easily occur at the injection molding stage. In this study, the simulation of thermoforming was performed to predict the film thickness distribution, and the results were compared with experiments. Uniaxial tensile tests with a constant crosshead speed for various high temperatures were conducted to investigate the stress-strain behavior. An instance of yielding occurred at the film temperature of , and the film stiffness increased with increasing crosshead speed. Two types of viscoelastic models, G`Sell model, K-BKZ model, were used to describe the measured stress-strain relationship. The predicted film thickness distributions were in good agreement with the experimental results.

유리섬유가 강화된 필름 삽입 사출품의 섬유배향 및 휨

필름 삽입 사출 시편의 휨은 비대칭적인 잔류응력 분포에 기인한다. 비대칭적 잔류응력과 온도 분포는 삽입된 필름 표면의 수직방향으로 지연되는 열 전달에 의해 발생한다. 사출 공정조건 최적화를 통해 필름 삽입 사출 시편의 휨을 억제할 수 없었기 때문에, 필름 삽입 사출 시편의 휨을 최소화하기 위해서 유리 섬유가 강화된 복합재료를 기판으로 사용하였다. 유리 단섬유의 분포를 마이크로 CT 장비를 이용하여 평가하였다. 복합재료로 구성된 기판을 이용한 필름 삽입 사출 시편의 배향 텐서와 휨을 계산하기 위해서는 적절한 마이크로 역학, 이방적 열팽창계수 및 닫힌 어림법 모델이 선택되어야만 한다. 여섯 종류의 마이크로 역학모델, 세 종류의 열 팽창 계수 모델 및 다섯 종류의 닫힌 어림법 모델을 고려한 후, Mori-Tanaka 모델, Rosen and Hashin 모델 및 third orthotropic 닫힌 어림법 모델을 선택하였다. 수치적으로 계산된 섬유 배향 텐서와 휨에 관한 결과들은 실험결과와 잘 일치하였고, 유리 섬유의 보강효과가 필름 삽입 사출 복합 재료 시편의 휨에 미치는 영향을 파악하였다. Warpage of the film insert molded (FIM) part is caused by an asymmetric residual stress distribution. Asymmetric residual stress and temperature distribution is generated by the retarded heat transfer in the perpendicular direction to the attached film surface. Since warpage was not prevented by controlling injection molding conditions, glass fiber (GF) filled composites were employed as substrates for film insert molding to minimize the warpage. Distribution of short GFs was evaluated by using micro-CT equipment. Proper models for micro mechanics, anisotropic thermal expansion coefficients, and closure approximation should be selected in order to calculate fiber orientation tensor and warpage of the FIM part with the composite substrate. After six kinds of micro mechanics models, three models of the thermal expansion coefficient and five models of the closure approximation had been considered, the Mori-Tanaka model, the Rosen and Hashin model, and the third orthotropic closure approximation were selected in this study. The numerically predicted results on fiber orientation tensor and warpage were in good agreement with experimental results and effects of GF reinforcement on warpage of the FIM composite specimen were identified by the numerical results.

필름 인서트 사출성형 평판의 휨 변형에 관한 실험적 연구

FIM(Film Insert Molding) is an innovative method of producing decorated parts for a wide range of products. Because it requires fewer steps when compared to conventional production methods, the time and cost of manufacturing high quality components can be reduced considerably. In this paper, the effects of processing conditions on the warpage of film-insert molded plate were investigated by using a design of experiments. The dominant factors affecting warpage were mold temperature and holding pressure. Warpage increased with the temperature difference between stationary mold and fixed one. Even when the mold temperature difference was zero, the plate with a film was bent after ejection such that the film side protruded. As holding pressure increased, warpage decreased significantly. In addition warpage increased with time increment for the film-insert molded plates.

열진공성형 공형조건이 적층필름의 두께분포에 미치는 영향

Vacuum-assisted thermoforming is one of the critical steps for the successful application of film insert molding(FIM) to parts of complex shapes. If the thickness distribution of the formed film is non-uniform, cracking, deformation, warping, and wrinkling can easily occur at the injection molding stage. In this study, the effects of processing parameters, which include the film heating time, plug depth, plug speed and vacuum delay time, on film thickness distribution were investigated. It was found that the film thickness at the part sidewall decreases with increasing the film heating time and plug depth, but the thickness at the bottom was found to exhibit the opposite behavior. The film thickness of the sidewall was observed to increase at higher plug speed and vacuum delay time of 0 ~ 0.3sec.

Fluid-structure interaction analysis on the film wrinkling problem of a film insert molded part

Back-injection of polymeric liquid to preformed films, also known as film insert molding (FIM), provides the surface quality of polymeric parts. The back-injection material is responsible for mechanical and thermal properties of the part, especially such as stiffness and thermal expansion. In the back-injection molding it is important to ensure that the inserted films are not wrinkled by the injection of molten polymers. In this study, FIM was carried out with utilizing polycarbonate/acrylonitrile butadiene styrene (PC/ABS) alloy and polymethyl methacrylate/acrylonitrile butadiene styrene (PMMA/ABS) film. The wrinkling of films was observed by the atomic force microscope (AFM). Numerical simulations were performed to understand the mechanism of the film wrinkling and optimize the processing conditions of FIM for high precision parts by using commercial packages including Hypermesh™, Moldflow™, and COMSOL™. A critical shear rate for the film wrinkling of a center garnish part was determined based on the deformation energy of plate. It was found that the critical shear rate calculated numerically was in good agreement with that of the film insert molded parts. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers

Prediction of the film thickness distribution and pattern change during film insert thermoforming

AbstractVarious surface process methods have been developed to decorate plastic or metallic products. Film insert molding (FIM) is one of the methods that enhance the functional and/or aesthetic qualities of a product's surface. However, the drawbacks of FIM are that the thickness of the film can change, depending on the product configuration, and further, the pattern of the decorated film may change. Therefore, this article attempts to quantify the changes in the thickness and in the pattern of the decorated film during the FIM process. G'Sell's viscoelastic constitutive law was adopted to describe the rheological behavior of polymer film. A constant‐velocity uniaxial tensile test at high temperature, which is a new method proposed in this research, was used to obtain the rheological parameters. We also suggested a visual method for predicting pattern change, which was validated by comparing analytical results with those of real products. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers

Film insert molding as a novel weld‐line inhibition and strengthening technique

AbstractSpecimens with weld lines were produced via conventional and film insert molding techniques using two types of materials as the substrate resin, i.e. a polycarbonate/acrylonitrile‐butadiene‐styrene (PC/ABS) blend and glass fiber‐filled polycarbonate (PC‐gf). The formation and morphology of the weld line region was assessed with and without the presence of 0.5‐mm‐thick PC film inserts. The weld line formation and characteristics were found to be dependent on the extent of interaction between the injected resin and the mold surface or the film insert. Better interfacial interaction between the substrate and film led to the distortion of the weld line orientation, which significantly enhanced the mechanical properties of the weld line. The incorporation of glass fibers into the substrate resin would usually reduce the resistance of the weld line towards tensile, flexural and impact loadings. However, with the attachment of film inserts, the mechanical properties of the weld line region have significantly improved, even with the presence of rigid fibers. Upon examination of tensile and impact fracture surfaces of film insert specimens, a unique orientation of fibers across the weld line (parallel to the flow direction and perpendicular to the weld line) could be observed at regions directly under the film. The combination of favorable properties from the unique fiber orientation and distortion of the weld line, as well as the ability of the film to effectively dissipate forces towards a larger area, have synergistically contributed towards the mechanical property enhancement of the weld line region in film insert moldings. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers

Effects of Molding Conditions on Interfacial Structure and Properties of Film Insert Molding

Effects of Molding Conditions on Interfacial Structure and Properties of Film Insert Molding