Processing methods for plastics

One of the most cotrunon processing methods for plastics is injection moulding. Nowadays every home, every vehicle, every office, every factory contains a multitude of different types of articles which have been injection moulded. These include such things as electric drill casings, yoghurt cartons, television... 

There are mainly three methods for pyrolysis of plastics, namely thermal cracking, catalytic cracking, and cracking-catalytic reforming [62]. Each has its own suitable process, as shown in Figure 28.2. Other methods for plastics pyrolysis include hydrogenation... 

Corona process Method for surface pretreatment of plastics, based on the entrapment of reactive atoms from the gas phase in the surface of plastics by high-voltage discharge. 

This book is intended to provide a basic understanding of piastic packaging mate-riais. It covers the properties of common packaging plastics, and relates these properties to the chemical structure of the polymers. Common processing methods for transforming plastic resins into packages are covered. 

In recent years, the diversity of properties of plastic lumber produced from different mixes of materials, by different processes, has resulted in calls for development of standards. In late 1997, the American Society for Testing and Materials (ASTM) issued five new test methods for plastic lumber intended to help establish a benchmark for minimum plastic lumber performance. The standards include tests for compressive properties, flexural properties, bulk density and specific gravity, compressive and flexural creep and creep rupture, and tests for performance of mechanical fasteners. ... 

Lower-cost processing methods for thermosetting plastics have been developed, especially the screw-injection molding technology. 

Rotational moulding is one of the plastic processing methods for the production of hollow plastic products. Plastic powder is charged and subjected to biaxial rotation in an oven at a temperature of 200- 00 °C. The plastic powder melts inside the mould by heat transferred via convection through the mould wall. All the powder melts and the mould is moved out of the oven while maintaining the biaxial orientation. Exposure to air, or using a fan or water shower are usually employed to cool the mould. 

The basic processing method for all MCPs is the use of thermod5mamic in-stabihty phenomena. A large amount of gas, typically CO2 or N2, is dissolved in the plastics under high pressure at the processing temperatin-e so as to create a driving force for phase separation when the pressure is suddenly lowered. 

Post-consumer recycling process occurs when plastics are made into products, for example, bottles, bags, film, packaging, used by a consumer, collected by a waste disposal company, processed into recycled pellets at an MRE, and then sold to plastic companies. Mechanical recycling is the most common recycling method for plastics. 

Injection molding is one of the most widely used material processing methods for mass-production of plastic parts with complex geometry. Thus, it lends itself as a perfect process for producing nanocomposite components. However, various process parameters used in the injection molding process would significantly affect the performance of the molded parts, and to the best of... 

---