Plastic product, final

Coloiants can and do have a measuiable effect on myriad physical and chemical properties of final plastic products. Often, this is ovedooked both by... 

Rotational molding creates a wide variety of plastic products that cannot be made effectively, efficiently, or economically by other means. What sets this method apart from others is that it can create thin-walled, hollow parts that exhibit no weld lines or scarring from ejector pins and from the process itself. It also has the advantage of having little scrap and minimal molded-in stresses, due to the low pressure and low shear rate characteristics of the process. Finally, it can be used to make parts that are very large which would be impossible to manufacture by other methods. 

There are three principal families of styrene containing polymers, which are used to make commercial plastic products. The first family is pure polystyrene, the second family comprises random copolymers, and the final family consists of polystyrene chains grafted to blocks of rubbery polymers. There are also synthetic rubbers that contain significant concentrations of styrene, but these are outside the scope of this book. 

Beyond this initial theoretical drawing-board-and-slide-rule approach, of course, lies the critical need for experimental proof in actual process machinery and prototype field trials, which should be included as a 4th dimension in such a schematic diagram, and is the final pragmatic judgment to determine technical success of any plastic product. This is the direction in which applications research and product design must grow in the future, in order to convert plastics art into plastic science. 

Thermoplastics are delivered in the form of granules and powders to production sites that are separate from the plastic synthesis. The raw plastic materials are often referred to as polymers. After addition of the necessary additives, e.g. plasticizers, the final material is referred to as a plastic. 

Filament-Winding. This requires a mandrel to shape the desired finished product. Continuous filament or woven tape is fed through a liquid resin bath to impregnate it, and then wound onto the mandrel in a calculated pattern to optimize the final properties (Table 15.27). The assembly is oven-cured. A collapsible mandrel can then be removed from the plastic product or the mandrel can be left as a part of the finished product. These are the strongest plastic products ever made. Typical products are pipes, tanks, and pressure bottles. Other suggested products... 

These plastics, after final processing into products, are substantially infusible and insoluble. Examples of their properties are reviewed in Table 2.5. 

The requirements in 16 CFR Parts 1000-1799 contain the provisions of the Consumer Product Safety Act and the Hazardous Substances Act that are designed to ensure consumer safety. Although these regulations primarily concern the final plastic products to customers, colorant and additive formulators are required to ensure these products, when used in the customer s final commercial product, will meet these regulatory requirements. Among these requirements are constituency limits for certain hazardous ingredients (such as toxic metals) and product flammability criteria. 

Tn many applications of plastics, when products finally fail, they fail because of brittle fracture. Plastics are not unique in this respect products made of metals, ceramics, and wood also sometimes fail by brittle fracture. Thus the mechanism and understanding of brittle fracture are a major concern of materials scientists and materials engineers. 

The need for developing methods of analysis for additives in plastics materials is increasing day by day because of several aspects. First, as toxicological studies are developed, there is the presence of some substances which have been banned in specific products. Second, in production, it is necessary to carry out a quality control for additive levels. It is also necessary to determine the stability of the additives when the polymer is processed. In this case, some additional compounds, often undesirable, can be generated and their control becomes necessary. Finally, the analysis will let us know the composition of a plastic product. 

In the manufacture of bonded insulating materials, the fibers in the fleece shaft or on the conveyor belt are sprayed with an aqueous binder, generally a phenol-formaldehyde resin. The binder content in the bonded insulating material is 3 to 4%. Compaction to the desired density and hardening of the resin binder occurs in a tunnel kiln, through which the fibers are continuously transported on a conveyor belt. The compaction is achieved with a second belt which exerts the required pressure on the upper surface of the continuous sheet. This is often followed by laminating the sheet with e.g. paper, aluminum or plastic foil. Finally the product is rolled up or cut into sheets. 

Table 1.1 summarizes the changes in total plastic consumption in Western Europe from 1992 to 1996.2 These data refer to the final market for plastic products consumed by end-users but they do not include sectors such as textile fibres, elastomers, coatings, or products in which plastics are present in small quantities, because these are not considered as plastic products. If non-plastic applications are also taken into account, the total plastic consumption in Western Europe in 1996 increases up to 33.4 million tonnes. By comparison, the consumption of plastics in the USA and Japan in 1995 were 33.9 and 11.3 million tonnes, respectively.3... 

The method of hydrolysis used in the CUT-method offers an efficient and economical way of processing plastic waste, both post-consumer municipal waste and industrial waste, contaminated with a cellulose component. The presence of cellulose gives a desired stiffness to the final product, as studies have shown [4,5]. Such plastics product can be used in several applications, such as artificial wood. 

Additives which change chemical properties during processing and in the final plastic product include anti-ageing additives in the form of antioxidants, heat stabilizers, light stabilizers and flame retardants. 

The enterprise that plastics and the plastics industry have formed is nothing short of phenomenal. An entirely new industry emerged creating employment for an estimated 5 million people worldwide. The plastic products produced and used worldwide have made a major contribution to the progress of materials and civilization. The industry is too young to begin to surmise its final direction. 

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