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Nanosensor Laboratory
Published in Vinod Kumar Khanna, Nanosensors, 2021
This is a widely adopted procedure for fabrication of micro-parts or micro-structured components from plastics, ceramics, or metals. The molding mass is melted in the injection molding machine and then injected into a heated and frequently evacuated tool, where it cools and solidifies into the final part. This tool is equipped with micro-structured mold inserts, manufactured by mechanical micromachining (micro-cutting), laser micromachining, X-ray or UV lithography, based on the LIGA process, or by a combination of these and other processes. Depending on the component to be molded, the injection molding process is conducted either isothermally or with heating, prior to injection, and cooling, prior to demolding. After cooling and opening of the tool, the injection-molded components are removed. This is done mostly by a handling device or robot. Nearly all thermoplastics (also known as thermo-softening plastics, are those which become soft when heated and hard when cooled), as well as thermoplastic elastomers (polymers having the elastic properties of natural rubber: ELAST(IC)+[(POLY]MER) are suitable for micro-injection molding.
Kenaf Fiber-Reinforced Thermoplastic Composites
Published in S.M. Sapuan, J. Sahari, M.R. Ishak, M.L. Sanyang, Kenaf Fibers and Composites, 2018
Injection molding is by far the most used processing technique of producing parts from thermoplastic materials due to its high productivity. Injection molding machines and molds are very expensive because of the high pressures required and complexity of the process control. However, the shortcomings of this technique are balanced by its ability to produce a complex finished part in a single and rapid operation. The principle of injection molding is very simple. The plastic material is fed into the injection barrel by gravity through the hopper. Upon entrance into the barrel, the polymer is heated to the melting temperature. It is then forced into a closed mold that defined by the shape of the article to be produced. The mold is cooled constantly to a temperature that allows the molten to solidify; when the mold is opened, the finished product is ejected and the process continues.
Introduction to Polyurethanes
Published in I.R. Clemitson, Castable Polyurethane Elastomers, 2015
Depending on the ratios of the reacting agents, the final product can vary from a thermoplastic polymer through being a pseudo thermoset to a thermoset polymer. If the ratio of polyol to diisocyanate is designed to give a material that is hydroxyl ended, a thermoplastic material is obtained. These polymers can be processed in the same type of extrusion and injection molding machines as other thermoplastics such as polyethylene, polypropylene, PVC, etc. The formation of hydrogen bonding between the polymer chains gives the final product its mechanical strength.
Evaluation of various standards of adhesion properties between fused-layer-modeling parts and injection molded parts
Published in The Journal of Adhesion, 2020
A. Richter, F. Fischer, K. Dilger
According to DIN 8580, the injection molding process belongs to the first main group of primary forming processes and is mainly used in the manufacturing of plastic components. The primary forming process is characterized by the creation of components from shapeless material by creating a bond between the individual material particles. A shaping tool is required. This tool consists of cavities. The cavity contains the geometry of the component to be produced. Injection molding is categorized as plastics technology because it is mainly plastics that are processed with this manufacturing process. Within plastics technology, injection molding is the most important manufacturing process, since components can usually be manufactured directly as finished parts in large quantities and the manufacturing time is often only a few seconds so that it can be offered at a very reasonable price per piece. Molded parts can vary in size. The properties of injection molds making it quite expensive, so that it is only worthwhile to use it as a series process in large quantities. For the production of plastic parts by injection molding, an injection molding machine, a corresponding injection mold with shaping cavity and plastic granulate are required.[8,9]
Transients in flexible manufacturing systems with setups and batch operations: Modeling, analysis, and design
Published in IISE Transactions, 2021
Mengyue Wang, Hongxuan Huang, Jingshan Li
To respond to dynamic changing markets and diverse customer demands, manufacturing systems have become more and more flexible. Multiple types of products can be made on the same production facility. For instance, vehicles with mixed models, styles, and different options are assembled on the same production line. An injection molding machine can fabricate multiple types of parts with different shapes or geometries. Various machining operations can be carried out on one numerical control lathe or cell. Due to its prevalence, the flexible manufacturing systems approach has received considerable research attention to improve production responsiveness and robustness.