Product-Resin-Process Performances

In order to understand potential problems and solutions of design, it is helpful to consider the relationships of machine capabilities, plastics processing variables, and part performance (see Fig. 1-49). A distinction has to be made here between machine conditions and processing variables. For example, machine conditions include the operating temperature and pressure, mold and die temperature, machine output rate, and so on. Processing variables are more specific, such as the melt condition in the mold or die, the flow rate versus temperature, and so on (see Chapter 7). 

Those familiar with processing can detect and correct visible problems or readily measure factors such as color, surface conditions, and dimensions. However, less-apparent property changes are another matter. These may not show up until the parts are in service, unless extensive testing and quality control are used (see Chapters 9 and 11). 

Become aware that for any gain there couid be a loss not originally included in the design performance. 

When you gain something there will be a loss.does 

In the United States, about 20 percent or 81,0001 (90,000 tons) of plastic (polyethylene terephthalate PET) soft-drink bottles are being recycled. The high-density polyethylene (HDPE) milk bottles recycled amount to 36,000 t (40,000 tons) per year. See Chapter 12 for more details on the waste problem. 

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Figure 1-49. Interrelating product-resin-process performance.

Plasticizers seem to have an importance equal to plasticized resins and should be considered as a spouse rather than as servant. This couple, resin plus plasticizer, is equally responsible for the physical properties of the plasticized product, its processing performance, and its cost. In selecting a plasticizer, one must consider compatibility, efficiency, permanence, and economy. Compatibility depends upon polarity, structural configuration, and size of molecule. Efficiency depends upon the solvating effect. Permanence depends upon volatility and susceptibility to extraction. And economy depends upon raw materials and conversion costs. 

Progress in research and development in the wood-based industry and in the adhesive industry has shown many successes during the last decades. On the other hand, many industrial requirements still require considerable and important developments in this area. The main driving forces today are cheaper , quicker and more complex . The first two are caused by the heightened competition in the above-mentioned industries and the attempt to minimize costs while maintaining a certain level of product quality and performance. The key word more complex stands for new and specialized products and processes. Adhesives play a central role in wood-based panel production. The quality of bonding, and hence the properties of the wood-based panels, are determined mainly by the type and quality of the adhesive. Development in wood-based panels, therefore, is always linked to development in adhesives and resins. 

The various processes reviewed in this book are used to fabricate all types and shapes of plastic products, ranging from household convenience packages to electronic devices and many others—including the strongest products in the world, used in space vehicles, aircraft, building structures, and so on. Proper process selection depends upon the nature and requirements of the plastic, the properties desired in the final product, the cost of the process, its speed, and product volume. (Note that a plastic also may be called a polymer or a resin.) Some materials can be used with many kinds of processes others require a specific or specialized machine. Numerous fabrication process variables play an important role and can markedly influence a product s aesthetics, performance, and cost. 

Emulsion polymerization processes are generally used in industrial processes focused on adhesives, resins, paints, nanocomposites, thermoplastics, and thermosets. These productions are primarily performed in pharmaceutical segments and military, automotive, medical, and chemical settings [2,16-18]. 

The characterization of the final product shows that the resins prepared by the microwave and conventional methods have comparable properties. In particular, GPC analysis showed that all the E-M epoxy resins have a similar molecular weight and molecular weight distribution. The main advantage of such a process performed in the microwave reactor was the reduction of the reaction time under microwave conditions (40 min, 160 °C) in comparison to thermal heating (80 min, 160 °C) [117]. 

As the fundamental building block for printed circuits, base materials must meet the needs of the printed circuit board (PCB) manufacturer, the circuit assembler, and the original equipment manufacturer (OEM). A balance of properties must be achieved that satisfies each member of the supply chain. In some cases, the desires of one member of the supply chain conflict with another. For example, the need for improved electrical performance by the OEM, or improved thermal performance by the assembler, may necessitate the use of resin systems that require longer multilayer press cycles or less productive drilling processes, or both. 

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