Plastic material, versatility

Compared to other material-based industries, plastics have enjoyed an impressive growth rate over a century since their inception, but particularly since about 1940. Hie product-design community was quick to recognize the design freedom and great versatility that plastics materials and pro-... 

The versatility of the plastic materials permits them to be varied to perform special functions. By applying ingenuity to these amazingly adaptable materials, we can produce products that add to the worldwide survival capability of life under severe environments and improve the quality of life under normal environments. The designer s role in fitting the possibilities to the needs is one that is increasingly important. 

To understand this dramatic increase in the use of PVC in competition with dozens of other plastic materials, we must look beyond the initial assumption that it has been solely a result of the Reclining price of the polymer. The spiraling consumption is primarily the result of the usefulness of the product. The declining price is the result of technological advances, mostly in the field of monomer production, plus increasing competition in polymer marketing. For example, in the United States the number of polymer producers has increased from six to 26 during the last 20 years. In other words, PVC is popular because of its versatility. 

The extraordinary versatility of this polymeric plastic material, which has made it one of the most widely used of the myriad of polymers and copolymers available today, is demonstrated by its range of end uses. PVC products have properties that combine strength, lightness, and inertness with a wide range of resilience, excellent color acceptance, electrical insulating properties, crystal-like clarity, and the ability to be processed easily by many methods into a tremendous variety of forms. 

The organic cellulose ester plastics are versatile materials and can be processed by almost any hot-processing technique used for thermoplastics. The principal techniques for all three plastics are injection molding and extrusion. Blow molding is also possible. Butyrate and propionate powder are used in tluidized-bed and electrostatic coating processes, as well as in the rotational molding process. 

Figure 1.2 illustrates plastic consumption in Western Europe by product for 1995,4 confirming that plastics are versatile materials which can be found in a wide range of products. The production and consumption of plastics have continuously increased over recent decades. The plastic consumption per capita in Western Europe has increased from 1 kg per inhabitant in 1960 to about 65 kg per inhabitant in 1995. 

The blow molding process therefore involves essentially two properly synchronized operations parison formation from the plastic material and blowing the parison into the shape of the desired part. There are two techniques for plasticizing the resin for parison formation. These are extrusion blow molding (which is the most common method and which is characterized by scrap production) and injection blow molding. The latter process is versatile and scrap free and is beginning to be more understood and accepted by processors. 

Today, there are products that satisfy the technical requirements and have an acceptable market price. One commercial success story is represented by Mater-bi , a plastic material based on TPS and other polymers that is very versatile and suitable for applications such as composting bags, mulch film, disposable cutlery, etc. However, due to the complexity of its production, its cost is higher than conventional polyethylene or polypropylene, and it is generally sold for applications where biodegradability is mandatory. 

Foams are versatile both in their applications and in the way in which the materials are made. These include the production of various shapes by casting, extruding, injection molding, thermoforming, and reaction injection molding. Foam versatihty also includes the fact that any plastic material, thermoplastic or thermoset, may be produced in cellular form. 

The family as a whole is very versatile. While performance on some plastics is only modest, the group may be used with advantage, on plastics materials sensitive to stress cracking. The polyolefins and other low surface-energy plastics (such as PTFE and some rubbers) present major difficulties unless specially prepared. 

PVC is one of the world s oldest plastics, and it is the most dominant in building and construction. PVC is a tough, strong thermoplastic material which has an excellent combination of physical and electrical properties. PVC is a major plastic material which is commonly used in building (55% of plastics used in construction are PVC), mainly because of its excellent fire performance [49]. PVC is replacing traditional building materials like wood, concrete and even clay. PVC and its copolymers are one of the most versatile and widely used resins in building product applications. The uses of PVC are... 

Reactive type fire retardants appear to be most versatile in thermosetting plastic materials, in which substitution of compounds can be effected at a stage much closer to end-use than might be the case with thermoplastics. Additive type fire retardants appear to be most versatile in thermoplastics. 

Plastic materials are the most versatile material and contribute in several aspects and in their initial stage as powder or granules. Plastic processing techniques are used to utilize the powder or granules for finished parts. The ability of thermoplastics to melt and re-harden has been exploited in many different processing methods [3-5]. 

As mentioned previously, the versatility of PVC is rooted in its ability to be compounded with a wide spectrum of additives to produce plastic materials having a very diverse performance range. In order to achieve this goal the additives must be properly blended with the PVC in a process that is tailored to the type of formulation and components that are to be used. 

All other chapters in the book have been updated with the latest information, diagrams, and photographs of the test equipment. The Appendix section has been updated. Appendix I, which listed the properties of the most common plastics, elastomers, and rubbers in the early edition, has been replaced with information about four major electronic databases for plastic materials. In order to increase the versatility of the book, numerous color photographs depicting photoelastic analysis and color theory along with various animations have been added on to the compact disk that is included with the book. More importantly, a virtual tour of a prominent Plastics Testing Laboratory is included to give the reader an... 

---