Tham khảo tài liệu 'composites manufacturing - materials, product, and process engineering part 4', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | comparison should be based on final product cost not on the cost of initial materials. For the filament winding process the raw material cost is 3 to 8 times cheaper than the graphite epoxy prepreg used in the roll wrapping process but for large production volume and higher performance the roll wrapping process is selected for making golf shafts. Material Property Information Materials data enters at various stages of the design process but the level of accuracy required on material property information differs at each stage. In the initial stage of the design process conceptual stage approximate data for wide range of materials is gathered and design options are kept open. Table and Tables and in Chapter 2 provide basic information about the various types of composite materials. This information can be helpful in the preliminary assessment of these materials. In the preliminary stage a designer identifies which matrix material and fibers are more suitable. For example for a certain application polyester resin might be a suitable choice and for another application epoxy may be a more suitable choice. Similarly for a manufacturing process one specific type of material system may be more appropriate than the other. For a manufacturing process if the engineer selects a particular raw material the engineer needs to clearly write down key characteristics of the selected raw material. For example if prepreg material is selected for an application then the designer has to identify the following parameters Type of prepreg unidirectional or woven fabric prepregs Fiber type carbon glass Kevlar etc. Woven pattern plain weave satin weave etc. Width of the tape Resin content Areal weight Ply physical and mechanical properties Similarly the manufacturing engineer has to specify tack drape cure cycle processing temperature gel time flow characteristics and more for the application. Materials property information can be obtained from published literature suppliers
