TABLE OF CONTENTS Designers have a valuable role to play in ecodesign because of their involvement at the early stages of the product development process, where the design brief is most flexible and the most critical decisions are made with respect to cost, appearance, materials selection, innovation, performance, environmental impact, and perceptions of quality (longevity, durability, repairability) [1]. The design of a polymeric product for a specific application is a complex task. This is particularly true in the case of polyethylene (PE), which exists in a great variety of material forms and many processing methods are available for it.
When a product is needed for a specific application, it has to meet several requirements, sometimes termed constraints , which can be divided into three categories: geometric constraints, property constraints, and economic constraints [2]. Geometric constraints involve the shape and dimensions of products and may be dictated by aesthetic, functional, and other factors. Property constraints are associated with material characteristics and environments (loads, chemicals, and others). Economic constraints correspond to the cost limits and they are closely related to the volume of production.
The design of a PE-based product normally results in the specification of a geometry for the product (shape and dimensions), a material choice (commercially available grades with specifications; see Table 3.8 for the properties of various PE types), and a process equipment choice (commercially available equipment fitted with product-specific tool). The three constraints are interdependent in a product design so that the design procedure must be an iterative process. A...
