Injection Molding, Closures, Rotational Molding, Compression Molding, and Tubes

Abstract This article discusses technologies focused on processing plastic materials or producing direct tools used in plastics processing. The article focuses on extrusion and injection molding, covering applications, materials and their properties, equipment, processing details, part design guidelines, and special processes. It also covers the functions of the extruder, webline handling, mixing and compounding operations, and process troubleshooting. Thermoforming and mold design are covered. Various other technologies for polymer processing covered in this article are blow molding, rotational molding, compression molding, transfer molding, hand lay-up process, casting, and additive manufacturing.

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

Materials Science Forum ◽

10.4028/www.scientific.net/msf.505-507.229 ◽

2006 ◽

Vol 505-507 ◽

pp. 229-234 ◽

Cited By ~ 5

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.

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Injection Molding and Compression Molding of Polyamide 10.10

Proceedings ◽

10.3390/proceedings2020057051 ◽

2020 ◽

Vol 57 (1) ◽

pp. 51

Author(s):

George Mihail Teodorescu ◽

Zina Vuluga ◽

Mariana Osiac ◽

Nicoleta Levinta ◽

Cristian Andi Nicolae ◽

...

Keyword(s):

Injection Molding ◽

Compression Molding ◽

Common Process

In today’s industry, molding is a common process used to manufacture a product or a component with the use of heat and pressure. [...]

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Effect of Oil and Black on the Injection Molding of EPDM Compounds, II, Molding Studies

Rubber Chemistry and Technology ◽

10.5254/1.3539302 ◽

1969 ◽

Vol 42 (5) ◽

pp. 1336-1349

Author(s):

W. G. DePierri

Keyword(s):

Injection Molding ◽

Physical Properties ◽

Elevated Temperatures ◽

Compression Molding ◽

Lower State ◽

Flow Properties ◽

Flow Rates ◽

Injection Molded ◽

Lower Temperature ◽

Commercial Equipment

Abstract The results which we discussed in this paper show that the demands made on the compound in an injection molding operation are more severe than those made by compression molding. The flow properties of the compound are much more critical in injection molding because of the high flow rates which are encountered. Compounds must have viscosities which are low enough to allow the mold to fill completely in the injection step. The level of oil and black in the compound are very important factors in controlling compound viscosity. The cure system is more critical, for it must give good physical properties at the elevated temperatures used in injection molding. The ability to attain good physical properties at low cure temperatures does not necessarily mean that good properties will be achieved at elevated cure temperatures as was shown by the comparison of physical properties of specimens prepared by high temperature injection and low temperature compression molding. The physical properties of injection molded specimens made from some compounds cured at high temperatures indicated a lower state of cure at optimum cure than compression molded specimens cured at lower temperature. Much of this effect can be explained by changes in state of cure caused by the increased temperature. The oil type used in the compound did not appear to be especially important in determining the physical properties of molded items. Oil level, however, is an important factor in determining both the processability of a compound and the physical properties of the finished product. Some of the problems associated with injection molding of EPDM compounds encountered in this work may result from the experimental injection molding equipment used in the study and may not be evident when commercial equipment is employed. Other of the problems could be solved by compounding, especially by changes in the cure system.

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Injection molding and injection compression molding of three-beam grating of DVD pickup lens

Sensors and Actuators A Physical ◽

10.1016/j.sna.2005.07.025 ◽

2006 ◽

Vol 125 (2) ◽

pp. 367-375 ◽

Cited By ~ 55

Author(s):

Cheng-Hsien Wu ◽

Wei-Shiu Chen

Keyword(s):

Injection Molding ◽

Compression Molding ◽

Injection Compression Molding

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

Materials Science Forum - Progress on Advanced Manufacture for Micro/Nano Technology 2005 ◽

10.4028/0-87849-990-3.229 ◽

2006 ◽

pp. 229-234

Author(s):

Yung Kang Shen ◽

H.J. Chang ◽

C.T. Lin

Keyword(s):

Optical Properties ◽

Injection Molding ◽

Compression Molding ◽

Micro Injection Molding ◽

Injection Compression Molding

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

International Journal of Automation Technology ◽

10.20965/ijat.2018.p0930 ◽

2018 ◽

Vol 12 (6) ◽

pp. 930-939 ◽

Cited By ~ 1

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.

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Thermal and Mechanical Analysis of Polyethylene Homo-Composites Processed by Rotational Molding

Polymers ◽

10.3390/polym11030528 ◽

2019 ◽

Vol 11 (3) ◽

pp. 528 ◽

Cited By ~ 7

Author(s):

Antonio Greco ◽

Francesca Ferrari ◽

Maria Grazia Buccoliero ◽

Greta Trono

Keyword(s):

Mechanical Properties ◽

Compression Molding ◽

Mechanical Analysis ◽

Rotational Molding ◽

Reinforcing Bars ◽

Molding Process ◽

Bending Tests ◽

Fiber Placement ◽

A Value ◽

Uhmwpe Fibers

This work is aimed at studying the suitability of ultra-high molecular weight polyethylene (UHMWPE) fibers for the production of polyethylene homo-composites processed by rotational molding. Initially pre-impregnated bars were produced by co-extrusion and compression molding of UHMWPE fibers and linear low-density polyethylene (LLDPE). A preliminary screening of different processing routes for the production of homo-composite reinforcing bars was performed, highlighting the relevance of fiber impregnation and crystalline structure on the mechanical properties. A combination of co-extrusion and compression molding was found to optimize the mechanical properties of the reinforcing bars, which were incorporated in the LLDPE matrix during a standard rotational molding process. Apart from fiber placement and an increase in processing time, processing of homo-composites did not require any modification of the existing production procedures. Plate bending tests performed on rotational molded homo-composites showed a modulus increase to a value three times higher than that of neat LLDPE. This increase was obtained by the addition of 4% of UHWMPE fibers and a negligible increase of the weight of the component. Dart impact tests also showed an increased toughness compared to neat LLPDE.

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