Subic Materials in Sports Equipment

1. Auflage 2007
ISBN: 978-1-84569-366-4
Verlag: Elsevier Science & Techn.
Format: EPUB
Kopierschutz: 6 - ePub Watermark

E-Book, Englisch, 376 Seiten

Reihe: Woodhead Publishing Series in Composites Science and Engineering

The first volume of Materials in sports equipment has become an essential reference describing improvements in materials technology and their impact on equipment in a range of sports. This second volume combines coverage of recent developments in advanced materials and their application in a number of sports not covered in Volume one.Part one discusses general issues such as modelling of materials behaviour in sports equipment, non-destructive testing methods, materials and design for sports apparel and mouth and skull protection. Part two analyses the materials and design of equipment used for specific sports: baseball, snowboarding, ice hockey, fly fishing, archery and rowing. The book also reviews design and materials in athletics and fitness equipment.This book is a unique and essential reference to all materials scientists and sports equipment designers and manufacturers developing products in this rapidly evolving field. - Reviews recent developments in advanced materials and their applications in a number of sports - Discusses issues such as modelling of materials behaviour in sports equipment and non-destructive testing methods - Analyses materials and design of sports apparel and athletic equipment

Autoren/Hrsg.

Subic, A

Subic, Aleksandar

Leseproben

Introduction
A. Subic, RMIT University, Australia Design and materials for sports equipment
The sports equipment industry is constantly driven by innovation. Much of this innovation is attributed to the ongoing intense competition for new markets, records and sports supremacy. Because of this the sports equipment industry has been one of the most receptive to new materials and processes, and to the rapid diffusion of advanced technologies developed by other industry sectors. Design and innovation are inseparable. This is particularly evident in the case of sports products. The sporting goods industry has diversified over the years to accommodate the different interests and needs of athletes and consumers in general. It has also promoted and helped to develop new sports that have in turn served as a catalyst for new types of products. This type of innovation, although frequently enabled by new materials and process technologies, derives from a deeper understanding of the particular needs of athletes and associated product attributes (including performance, aesthetics, ‘feel’, ‘fit’, etc.). Because of the greater value-added generated through design and innovation, the value of the product as perceived by the customer is much higher than the costs involved in making it. This is why the cost of a golf club can be as much as 20 times that of the materials that make it up. Fig. 0.1 adopted from Ashby and Johnson (2003) illustrates the material-cost sensitivity across different product types and industry sectors and more specifically for sports equipment. 0.1 Material-cost sensitivity for different product types and industry sectors. In order to achieve the desired product attributes it is essential that the designers of sports equipment identify the key design intents and relate them to the associated technical attributes, such as material and geometric properties. For example, for sports equipment described in principle as a beam in bending (such as tennis racquets, golf clubs, snowboards and surfboards), a relevant design intent would be achieving a high stiffness to weight characteristic. Other potential design intents include, for example, effective energy transfer (e.g. archery bow, fishing rod, baseball bat), energy absorption and impact resistance (e.g. protective helmets, mouth guards, gloves), aerodynamics (e.g. golf ball, tennis ball, racing car), hydrodynamics (e.g. rowing and sailing boats, swim suit). Different sports products may have the same design intents depending on the common functions that they may share. Also, the design of each product could be driven by a range of different design intents whereby achieving an optimal design would rely on achieving a range of objectives based on an optimal combination of relevant design parameters. This concept is illustrated in Figure 0.2, which shows the links between the potential design intents, sports products and material properties (adopted from Johnson et al., 2000). 0.2 Links between sports products, design intents and material properties. Lifecycle design and materials selection
Materials and processes used for sports equipment carry with them potential environmental risks. For example ski boots use PVC (poly vinyl chloride) based materials, athletic footwear uses petroleum-based solvents and other potentially damaging compounds such as sulphur hexafluoride in air bladders for cushioning and impact shock protection. Also, composites, such as carbon fibre reinforced polymers that are increasingly used in tennis racquets and other sports equipment provide greater strength or stiffness to weight performance but cannot be readily recycled at an acceptable cost or value. Advances in sports equipment have unintentionally placed additional burdens on the environment. It is estimated that around 80% of the environmental burden of a product is determined during the design stage. Hence, in modern design, environmental issues are given high priority, which has resulted in the development and application of new design tools and practices encompassed by the lifecycle design approach (Subic, 2005). Lifecycle design is about developing more environmentally benign products and processes based on detailed understanding of the environmental hazards, risks and impacts of products and processes over their entire life cycle including production, usage and disposal stages. Governments, particularly in Europe, have been providing incentives to companies willing to adopt ‘greener’ product design and manufacturing approaches. For example, Germany’s product take-back laws have prompted European and US industries to reduce packaging and start designing products with disassembly and recycling in mind. France, the Netherlands and Australia have special government agencies to foster clean technologies. In the US the Federal Government has initiated a number of energy efficiency programs and has prescribed the use of recycled and/or recyclable materials in product design. Clearly there is a growing worldwide concern for the environment whereby it is not acceptable any longer for products to be incinerated or dumped in landfill after their useful life. Lifecycle design implies lower social cost of pollution control and environmental protection through more efficient use of resources, reduced emissions and waste. In order to assess the environmental impact of a product it has become necessary for informed, science-based weighting of the wide variety of environmental damages using standardised criteria and approaches. This allows the different products and phases of the lifecycle to be compared on the same scale. Lifecycle assessment (LCA) is the method typically used to calculate the environmental impact and/or damages of a product across the entire lifecycle. The quantification of environmental impacts can be performed using several different methods, including unique customized methods. All techniques share the same basis, namely the characterization of a process (e.g. material production) based on several environmental effects, each of which can be quantified in terms of reference substances e.g. global warming in terms of CO2 kg produced, or acidification in terms of SO2 kg. Case study – LCA of tennis racquets
Two types of fibre reinforced composite racquets, namely carbon fibre (CF) and glass fibre (GF) reinforced, will be compared using a brief, simplified LCA with EcoScan life 3.1 (TNO, the Netherlands). This provides scope for a general discussion about the importance and role of LCA in design of composite sports equipment (Subic and Paterson, 2006). Both racquets under consideration possess the same overall weight while fibre reinforcement is varied from 5 to 50%. The functional unit is assumed to be ten years which requires four replacement grips and sets of strings. Usually a process tree would be included in LCA, but for the sake of brevity it is omitted here. Estimations of the weight of materials used for construction and packaging (assumed to be the same for both racquet types) were made as listed in Table 0.1. The materials and component manufacturing processes were then entered into EcoScan. Table 0.1 Estimates of materials used in racquet construction and packaging Material Weight Carbon black or Glass fibre 5 % (16 g) to 50 % (160 g) PA 6.6 (Nylon) resin (160 g) 95 % (304 g) to 50 % PUR rigid foam 40 g Nylon strings (× 5) 100 g EPDM rubber grip (× 5) 100 g Aluminium for case zip 20 g LDPE case cover 120 g Packaging paper 20 g Packaging cardboard 160 g PET bottle grade packaging plastic 60 g Figure 0.3 shows the EI-99 data for production of the two racquet types and Figure 0.4 shows the EI-99 data for disposal of the two racquets (Subic and Paterson, 2006). 0.3 Comparison of environmental impact of the production phase for different racquet frames. 0.4 Comparison of environmental impact of the disposal phase for different racquet frames. In Figure 0.3 it is evident that the environmental effects of nylon resin production are higher than those of both fibre types. Furthermore, the glass fibres have a lower impact than the carbon fibres, principally because of the types of materials chosen to represent GF and CF in the analysis. To reduce the environmental impact of the production phase of these racquets a high proportion of resin should be included. It should be possible to decrease the amount of reinforcement by increasing the quality of the fibres. However, higher grade materials generally require more refinement resulting in greater energy requirements and a higher environmental impact. Figure 0.4 shows the environmental impact for the default waste disposal scenario, which predicts municipal waste disposal (24% disposal by incineration and 76% by landfill) for all materials except the CF. This does not consider the energy required to separate the composite...