Comparison of injection molding and injection/compression molding for the replication of microstructure

2015 ◽  
Vol 27 (4) ◽  
pp. 309-317 ◽  
Author(s):  
Seokkwan Hong ◽  
Jeongho Hwang ◽  
Jeongjin Kang ◽  
Kyunghwan Yoon
Keyword(s):  
Injection Molding ◽  
Compression Molding ◽  
Injection Compression Molding

Study on Optical Properties of Microstructure of Lightguiding Plate for Micro Injection Molding and Micro Injection-Compression Molding

2006 ◽  
Vol 505-507 ◽  
pp. 229-234 ◽  
Author(s):  
Yung Kang Shen ◽  
H.J. Chang ◽  
C.T. Lin
Keyword(s):  
Optical Properties ◽  
Injection Molding ◽  
Digital Camera ◽  
Mold Temperature ◽  
Compression Molding ◽  
Micro Injection Molding ◽  
Melt Temperature ◽  
Packing Pressure ◽  
Injection Compression Molding ◽  
Better Than

The purpose of this paper presents the optical properties of microstructure of lightguiding plate for micro injection molding (MIM) and micro injection-compression molding (MICM). The lightguiding plate is applied on LCD of two inch of digital camera. Its radius of microstructure is from 100μm to 300μm by linearity expansion. The material of lightguiding plate uses the PMMA plastic. This paper uses the luminance distribution to make a comparison between MIM and MICM for the optical properties of lightguiding plate. The important parameters of process for optical properties are the mold temperature, melt temperature and packing pressure in micro injection molding. The important parameters of process for optical properties are the compression distance, mold temperature and compression speed in micro injection-compression molding. The process of micro injection-compression molding is better than micro injection molding for optical properties.

Restraint of Voids Generated Inside Injection Molded Products by In-Mold Pressing Method

2018 ◽  
Vol 12 (6) ◽  
pp. 930-939 ◽  
Author(s):  
Atsushi Motegi ◽  
Tomohiro Hishida ◽  
Yasuhiko Murata ◽  
◽  
Keyword(s):  
Injection Molding ◽  
High Strength ◽  
Compression Molding ◽  
Fiber Reinforced ◽  
Pressing Method ◽  
Glass Fiber Reinforced Plastic ◽  
Fiber Reinforced Plastic ◽  
Reinforced Plastic ◽  
Injection Molded ◽  
Injection Compression Molding

In recent years, long glass fiber reinforced plastic and carbon fiber reinforced plastic have begun to be used for structural components that require high strength. As a result, thick-walled injection molded products are being manufactured. However, defects, known as voids, are generated inside the molded product and decrease the strength of the molded product, posing a significant problem at molding production sites. The partial compression method, which is a type of injection compression molding, is effective in preventing voids in thick-walled injection molding. However, there have been limited studies that comprehensively investigated the effects of the compression conditions on void prevention in thick-walled injection molding products or the shape and dimension of the molded product, or the issues in the molded product produced by applying compression. The authors have previously proposed the in-mold pressing (IMP) method, which allows the application of partial compression without the use of an injection compression molding machine and verified its validity. In this study, we proposed a compression device in which a servomotor-driven hydraulic pump actuator is used to propel a movable rod to apply compression to the melt inside the mold cavity. The IMP method using this device was applied to mold thick-walled products with thicknesses of 10 mm and greater, and the effects of compression on the generation of voids inside the molded product and the shape and dimensions of the product were investigated. The results indicate that the generation of voids can be prevented by application of this method. In addition, it was found that marginal deformations, which can pose issues, occur in the molded product when compressive stresses generated inside the molded product by compression are released after demolding.

Moldability and Quality of Polylactic Acid (PLA) Packaging Produced by Injection Molding and Injection Compression Molding

2013 ◽  
Vol 19 (2) ◽  
pp. 583-586
Author(s):  
Patcharee Larpsuriyakul ◽  
Natcha Prakymoramas ◽  
Dumrong Thanomjitr ◽  
Suparada Santanipat ◽  
Jitphisut Kitpaiboonvong ◽  
...  
Keyword(s):  
Injection Molding ◽  
Polylactic Acid ◽  
Compression Molding ◽  
Injection Compression Molding

scholarly journals Manufacturing Signatures of Injection Molding and Injection Compression Molding for Micro-Structured Polymer Fresnel Lens Production

Micromachines ◽  
2018 ◽  
Vol 9 (12) ◽  
pp. 653 ◽  
Author(s):  
Dario Loaldi ◽  
Danilo Quagliotti ◽  
Matteo Calaon ◽  
Paolo Parenti ◽  
Massimiliano Annoni ◽  
...  
Keyword(s):  
Injection Molding ◽  
Laser Scanning ◽  
Injection Pressure ◽  
Fresnel Lens ◽  
Uncertainty Budget ◽  
Compression Molding ◽  
Process Conditions ◽  
Dimensional Measurements ◽  
Micro Features ◽  
Injection Compression Molding

Injection compression molding (ICM) provides enhanced optical performances of molded polymer optics in terms of birefringence and transmission of light compared to Injection molding (IM). Nevertheless, ICM requires case-dedicated process optimization to ensure that the required high accuracy geometrical replication is achieved, particularly especially in the case of surface micro-features. In this study, two factorial designs of experiments (DOE) were carried out to investigate the replication capability of IM and ICM on a micro structured Fresnel lens. A laser scanning confocal microscope was employed for the quality control of the optical components. Thus, a detailed uncertainty budget was established for the dimensional measurements of the replicated Fresnel lenses, considering specifically peak-to-valley (PV) step height and the pitch of the grooves. Additional monitoring of injection pressure allowed for the definition of a manufacturing signature, namely, the process fingerprint for the evaluation of the replication fidelity under different process conditions. Moreover, considerations on the warpage of parts were related to a manufacturing signature of the molding processes. At last, the global part mass average and standard deviation were measured to correlate local geometrical replication performances with global part quality trends.

SURFACE REPLICATION OF MOLDED PRODUCTS WITH MICRONEEDLE FEATURES IN INJECTION MOLDING

2012 ◽  
Vol 06 ◽  
pp. 166-171 ◽  
Author(s):  
KAZUYASU UCHIUMI ◽  
TETSUO TAKAYAMA ◽  
HIROSHI ITO ◽  
AKINORI INOU
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
Injection Molding ◽  
Compression Molding ◽  
Mold Cavity ◽  
Molded Parts ◽  
Vacuum Processing ◽  
Cavity Effects ◽  
Injection Compression Molding ◽  
Supercritical Carbon

Micro-molding of microneedle features was conducted using several injection-molding techniques. Injection compression molding and injection molding were performed with supercritical carbon dioxide fluid and with or without vacuum processing inside the mold cavity. Effects of process parameters on processability and surface replication of the molded parts were evaluated. The height replication ratio for microneedles was improved using injection compression molding. At a shorter compression stroke, the needle height was improved, and the influence of compression delay time was also small. Moreover, the effects of vacuum processing inside the mold cavity under the filling process were slight. The height replication ratio for microneedles showed the highest values using injection molding using supercritical carbon dioxide fluid with vacuum inside the mold cavity.

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