塑料的歷史history_of_plastics-資料下載頁

【導讀】andtoughness.His―sulfurized‖rubber,laterknownas―vulcanized‖

　　

【正文】 s offered unprecedented precision and energy efficiency pared to their conventional hydraulic counterparts. Today, more than 35% of the molding machines Milacron Ferromatic sells are ―ALL ELECTRIC‖. The emerging field of ―Micro Injection Molding‖ is in its infancy today. In recent years, injection molding machinery suppliers have started to manufacture very small scale molding machines, having clamp tonnages as low as three tons and shot capacities less than a gram. Now that this equipment is available, microscopic plastic parts can be manufactured with unprecedented precision. The micro molded plastic medical parts shown on the left below are molded by Miniature Tool and Die in Charlton, MA and weigh just grams each. The Micro Injection Molding Lab at UMass Lowell’s Plastics Engineering Department is sponsored by Sumitomo Plastics Machinery. In the mid 1980’s, General Motors Chairman Roger Smith set out to “rethink” the way automobiles were designed and manufactured. Working with a clean slate, GM rethought everything from marketing to materials of construction to manufacturing. Plastics played a large roll in this effort. The new automobile, the Saturn, was the very first passenger vehicle to make extensive use of injection molded “thermoplastics” for exterior body panels. Most of the Saturn’s body panels are molded from a blend of polycarbonate and acrylonitrile butadiene styrene (PC/ABS). The use of the PC/ABS gave designers much greater design freedom when pared to traditional sheet metal body panels. The PC/ABS body is also, lightweight, corrosion resistant and durable. The very first Saturn was driven out of the Spring Hill Tennessee assembly plant by Roger Smith himself on July 30, 1990. More than million Saturns have been produced since that time. Plastics have been used for telephone housings since the turn of the last century. The early black plastic phones were pression molded from thermosetting phenolic and had wall thicknesses up to 13 mm. Injection molded ABS phones were introduced in the 1950’s. ABS has a very high gloss, good impact resistance, and unlike phenolic, could be molded in a variety of different colors. The ABS phones had wall thicknesses of about 3 mm. Today’s cell phones are injection molded using a polycarbonate amp。 ABS blend (PC/ABS). The pact and lightweight phones of today have wall thicknesses in the range of 1 mm. Telephones are a good example of how plastic products evolve over time. Creative product designers make use of new plastic materials and new plastic processing technologies as they bee available in order to improve product performance. Nypro The NYPRO Corporation, with headquarters in Clinton, MA, is a leading global supplier of precision injection molded assemblies and tools. The pany was founded in 1955 as the Nylon Products Corporation with annual sales of less than $1 million. Using borrowed funds, the pany was purchased by Gordon Lankton in the 1960’s. Today, the pany has more than 30 manufacturing facilities around the world, including facilities in the UK, Germany, Russia, India, Mexico, Hungary, and China. NYPRO, sponsor of UML’s ―Precision Injection Molding Laboratory‖, has annual sales that now top $800 million. This year, NYPRO will mold and assemble more than 6 billion plastic parts. That is one part for every man, woman, and child in the world. Mico Kaufman, a Tewksbury sculptor, is most famous for his traditional metal artwork. As a sculptor, his bronze artworks include the ―Homage to Women‖ and ―Indian Maiden‖ which are both located in Lowell. He is also well known for his Presidential Inaugural Metals, including those of Presidents Ford, Regan and Bush. Always on the lookout for new ideas, Mico found his next artistic medium — molten plastic. I finally felt that I had a medium, had the material, where only the imagination was the limit, he says. I was letting my hair down and doing something that I always wanted. Each type of plastic has a temper and personality of its own, so everything you do inspires you to do something more.― Over the past ten years, Mico has been creating plastic artwork in the laboratories of the Plastics Engineering Department at UML. The artwork is created by forming strips of molten plastic as it exits an ―extruder‖. Mico has produced more than 30 plastic sculptures including the one to the right. Mico Kaufman “Very Large” Part Injection Molding This HUSKY 8800 ton clamp injection molding machine is being used to mold ―thermoplastic‖ Jeep Wrangler174。 hardtops. This is one of the largest injection molded parts ever made. Some of the most advanced plastic products being manufactured today are used in the medical industry. The angioplasty catheter is a good example of a life saving medical device that would not be possible without plastics. Balloon angioplasty is a minimally invasive nonsurgical alternative to coronary artery bypass grafting surgery. The angioplasty balloon is used to press obstructing plaque in a clogged artery against the arterial wall so that blood can flow freely again. The doctor positions the balloon of the angioplasty catheter at the site of the blockage and gently expands it to press the plaque and create a wider opening in the artery. This procedure has a very high success rate and greatly reduces the chances of surgical plications. Angioplasty balloons are made from a variety of plastics including PET, nylon 11 or nylon 12. The exciting new materials science field known as ―nanoscience‖ has a number connections with plastics. For example, nanoposites are plastics that are reinforced with very finely divided and dispersed nanoclays or nanofibers. These nanoposites can offer unprecedent