Product performance requirements

There are conditions during the fabrication of plastic products that ensure meeting product performance requirements. However there are also constraints as reviewed in Chapter 8. 

There are other types of impact tests for shock loading where energy is required to cause complete failure is reported. Each has their specific behaviors that can be related to specific product performance requirements. Tests include ball burst, ball or falling dart using different weights and heights, bag drop, bullet-type instantaneous impact, Charpy, dart drop, Mullen burst, tear resistance, and tub (2). 

All these thermal properties relate to how to determine the best useful processing conditions to meet product performance requirements. There is a maximum temperature or, to be more precise, a maximum time-to-temperature relationship for all materials preceding loss of performance or decomposition. Figure 7-13 provides a temperature guide for continuous heating of plastics. 

Specifying the proper plastic material that meet product performance requirements after being processed ... 

The two types of models that are developed are the design and process models. Design models are cause-and-effect quantitative models that translate product-performance requirements to process requirements. The design model identifies key in-process output parameters and associated tolerances. For example ... 

There is no such thing as a typical feedstock that should be used to manufacture a specific WPC and the materials selected depend very much on cost, availability, market value of the product (i.e., low-cost or high-value end of the market) and product performance requirements. 

Fabricating productivity depends on factors such as production quantities and product-performance requirements interrelated to cost. These factors include (1) research and development, (2) new technologies, (3) update on equipment, (4) automated systems, (5) modem facilities, (6) certification, and (7) new plastic materials. Properly trained people are required for efficient fabricating. Optimum use... 

The nature of design analysis obviously depends on having product-performance requirements. The product s level of technical sophistication and the consequent level of analysis that can be justified costwise basically control these requirements. The analysis also depends on the... 

A designer sometimes has an opportunity to use a material that provides no problem in the solid-waste stream or to use a design that lets lower-cost recycled plastics be used. In fact, blends of virgin (not previously processed) plastics with recycled plastics could permit the meeting of required product performance requirements. This approach has been used for the past century. However, the designer must take into account the possible lower performances that will occur with recycled plastics (Chapter 3). 

When polyethylene was first produced during the late 1930s, physicists in England, USA, and Germany predicted a tremendous potential for it. At that time, the properties of PEs were much lower than those presently available. Specific PEs such as LDPE, HDPE, UHMWPE, etc. have been developed, with higher product performance requirements, out of the original general-purpose PE. 

However, plastics processors must continually update their procedures and/or acquire additional knowledge on how to process plastics. New developments in this field are unlimited. This book has emphasized that it is not difficult to process plastics, and has reviewed the many fabricating processes used to produce many different sizes and shapes of thermoplastic and thermoset commodity and engineering resins, which are used either unreinforced or reinforced (in composites). As explained, process selection depends basically on product performance requirements, shape, required dimensional tolerances, plastics processing characteristics, production volume, and cost (1-3, 317-326). 

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