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Pressure Bag Moulding
Pressure bag moulding is a process for moulding reinforced plastics. This process is related to vacuum bag molding. Procedure A solid female mold is used along with a flexible male mold. The reinforcement is placed inside the female mold with just enough resin to permit the fabric to stick in place (wet lay-up). A measured amount of resin is then liberally brushed indiscriminately into the mold and the mold is then clamped to a machine that includes the male flexible mold. Then, the flexible male membrane is inflated with heated compressed air or possibly steam. The female mold can also be heated. Excess resin is forced out along with trapped air. Due to the lower cost of unskilled labor, this method is used extensively in the production of composite helmets A helmet is a form of protective gear worn to protect the head. More specifically, a helmet complements the skull in protecting the human brain. Ceremonial or symbolic helmets (e.g., a policeman's helmet in the United K ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helmets
A helmet is a form of protective gear worn to protect the head. More specifically, a helmet complements the skull in protecting the human brain. Ceremonial or symbolic helmets (e.g., a policeman's helmet in the United Kingdom) without protective function are sometimes worn. Soldiers wear combat helmets, often made from Kevlar or other lightweight synthetic fibers. The word ''helmet'' is derived from ''helm'', an Old English word for a protective head covering. Helmets are used for recreational activities and sports (e.g., jockeys in horse racing, American football, ice hockey, cricket, baseball, camogie, hurling and rock climbing); dangerous work activities such as construction, mining, riot police, military aviation, and in transportation (e.g. motorcycle helmets and bicycle helmets). Since the 1990s, most helmets are made from resin or plastic, which may be reinforced with fibers such as aramids. Designs Some British gamekeepers during the 18th and 19th centuries wore hel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Composite Materials
A composite material (also called a composition material or shortened to composite, which is the common name) is a material which is produced from two or more constituent materials. These constituent materials have notably dissimilar chemical or physical properties and are merged to create a material with properties unlike the individual elements. Within the finished structure, the individual elements remain separate and distinct, distinguishing composites from mixtures and solid solutions. Typical engineered composite materials include: * Reinforced concrete and masonry *Composite wood such as plywood *Reinforced plastics, such as fibre-reinforced polymer or fiberglass *Ceramic matrix composites ( composite ceramic and metal matrices) *Metal matrix composites *and other advanced composite materials There are various reasons where new material can be favoured. Typical examples include materials which are less expensive, lighter, stronger or more durable when compared with com ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
