Question

Question 3 You need to make a light, stiff and strong structural component. To achieve the required physical properties you chose to make the component out of a fibre reinforced polymer composite material with a high fibre loading. (a) Why are long reinforcing fibres better that short fibres for this application? [6 marks] (b) Why is a thermoset resin system better than a thermoplastic for this application? [6 marks] (c) Describe the components of a thermoset resin system, and explain what happens when a thermoset resin system changes from a liquid mixture to a solid product. How can this change be speeded up, and what precautions should be observed? [8 marks] (d) Describe a suitable manufacturing process for high performance composite articles such as your component. (5 marks]

Answer 1

Solutions. In order to make a dignt, stiff, Strong Stretmal component to achieve this We Bhould require to choose a fibre reinforced polymer composition of ligt fibre loading. The long reason why reinforcing fibre better than short fibre desenetan can be easily understanable from the below Qualitative Influence of fibre longitu Stiffness Performance level Strength Toughness 1.0 Joo ç short fibre I long fibre impact resistance long reinfering fibre have more Strength they combine nigh level of stiffness, strength, and toughness together in a single material characteristics of long fibre The high mechanical performance over low Composites are the reason they are often Selected under-performing plastics or short fibre, as a replacement of due to its best in Benefits of chooting long fibre corrosion Resistance Stiffners Design freedom. - Strength or Durability hnen lower system cost Toughness or e » Light weighting Resistance e neat Resistance » Thermal Isolation.

see here we choose Thermoset relin because it has Bome unique properties, as compared to thermoplastics Thermo Setting Plasting Thermoplastics once formed they do not undergo Shape Conversion upon heating and cooling They are cheap They are not recyclable The best example us the cchrich Bakelite once formed does not change its shape upon further neating They are expensive They changes their shape upon heating & Cooling. Recycleoble The best example in polyethere which charger its Shape upon heating or cooling. Thermobet plastic home as low reg in visagity b) Good fibre wetting es Excellent thermal stability once polymerised d) Chemically resistant 5 But Thermoplastic have Door Melt flow Not have high very expensive toughnes. the curing the resins 2 plastic thermoset Cross link duri process to form an irreversible bord o coa za id dearada

Thermoset resins are used to make most composites. they are from a liquid solid Called. Converted to a through a process when used to produced finished polymerization, or Cross-linking goods, thermorsetting resins are "aused by the use of a a combustion of Catalyst , heat or the two. Gator resins Cannot be converted once cured, Solid thermoset back to their original liquid form. are Common thermoset polyurethane vinyl ester o epoxy Polyester formlated both Epoxy polyester home can be also and with other epony with different material or blended features. resins to achieve spectific performance more