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plastic injection history and information


Introduction
 


In today's world, life without plastics would be incomprehensible. Every day, plastics contribute to our health, safety and peace of mind. But how did this all start? how were plastic materials invented and discovered?


Long, Long Time Ago..
 
Natural rubber, obtained from the latex, a tree natural secretion resin. It is taken from the 'Cautchouc', the indian name for the 'crying tree', was discovered by the ocidentals in 1535 on Central America, were kids used to play with small, very elastic, balls made of it. It is very elastic, but doesn't flow, so it is not really moldable. When warmed it turns soft, but when cold is quite brittle.

Back in 1839 Charles Goodyear mixes small pieces of it with 'aqua fortis' and, after heating it and mixing with sulfur, gets a more resistend and durable material. He had invented Vulcanisation. On increasing the sulfur quantity of the mix - 50 parts of sulfur for 100 of rubber - e obtains a stiff material, Ebonite, and the first ever thermoset plastic was discovered.


First Man-Made Thermo Plastic
 


The first man-made plastic was unveiled by Alexander Parkes at the 1862 Great International Exhibition in London. This material - which the public dubbed Parkesine - was an organic material derived from cellulose that once heated could be molded but that retained its shape when cooled. Parkes claimed that this new material could do anything rubber was capable of, but at a lower price. He had discovered something that could be transparent as well as carved into thousands of different shapes. But Parkesine soon lost its luster, when investors pulled the plug on the product due to the high cost of the raw materials needed in its production.


Celluloid Makes Its Debut
 

celuloid plastic
celuloid plasticDuring the latter part of the 19th century, a rush was on to find a replacement for ivory in billiards balls. Billiards became so popular that thousands of elephants were killed just so their valuable ivory could be obtained. John Wesley Hyatt, an American, finally came upon the solution in 1869 with celluloid. Hyatt, upon spilling a bottle of collodion in his workshop, discovered that the material congealed into a tough, flexible film. He then produced billiard balls using collodion as a substitute for ivory.

celuloid plasticBut those were very brittle and the billiard balls would shatter once they hit each other, sometimes exploding naturaly. With the addition of camphor, celluloid became the first thermoplastic - a substance molded under heat and pressure into a shape it retains even after the heat and pressure have been removed.

Celluloid went on to be used in the first flexible photographic film for still and motion pictures.


The Story of Bakelite
 


bakelite plasticThe first completely synthetic man-made substance was discovered in 1907, when Leo Baekeland developed a liquid resin that he named Bakelite, by means of an apparatus he invented that enabled him to vary heat and pressure precisely so as to control the reaction of volatile chemicals. This new liquid (bakelite resin) would hardened quickliy and take the shape of its container.

Once hardened, the resin would form an exact replica of any vessel that contained it, and it would not burn, boil, melt, or dissolve in any commonly available acid or solvent. This meant that once it was firmly set, it would never change. While celluloid-based substances could be melted down innumerable times and reformed, Bakelite was the first thermoset syntetic plastic which would retain its shape and form under any circumstances.

bakelite plasticbakelite plasticBakelite could be added to almost any material - such as softwood - and instantly make it more durable and effective, so numerous products began to be manufactured based on this new material. Bakelite was also used for domestic purposes such as electrical insulators. For this purpose it proved to be more effective than any other material available - so effective, in fact, that it is still used as such today. Bakelite is electrically resistant, chemically stable, heat-resistant, shatter-proof and neither cracks, fades, creases, nor discolors from exposure to sunlight, dampness or sea salt.


Rayon and Cellophane
 


Cellophane was discovered by Dr. Jacques Edwin Brandenberger, a Swiss textile engineer, who came upon the idea for a clear, protective, packaging layer in 1900. Brandenberger was seated at a restaurant when he noticed a customer spill a bottle of wine onto the tablecloth. The waiter removed the cloth replacing it with another and disposed of the soiled one. He swore that he would discover some way to apply a clear flexible film to cloth, which would keep it safe from such accidents and allow it to be easily cleaned with the swipe of a clean towel. He worked on resolving this problem by utilizing different materials until he found a solution in 1913 by adding Viscose (now known as Rayon).

Brandenberger added viscose to cloth but the end result was a brittle material that was too stiff to be of any use. Yet he saw another potential for the viscose material. He developed a new machine that could produce viscose sheets, which he marketed as Cellophane. With a few more improvements, Cellophane allowed for a clear layer of packaging for any product - the first fully flexible, water-proof wrap.


The Discovery of Nylon
 


nylon plasticThe 1920s witnessed a "plastics craze", as the use of cellophane spread throughout the world. DuPont, one of the industry leaders, became a hotbed for innovation concerning plastics. Wallace Hume Carothers, a young Harvard chemist, became the head of the DuPont lab. The company was responsible for the moisture-proofing of Cellophane and was well on its way to developing Nylon, which at the time they named Fiber 66.

This fiber replaced animal hair in toothbrushes and silk stockings, those last being unveiled in 1939, to great public acceptance. Hume Carothers demonstrated that, by substituting and inserting elements into the chemical chain, new materials and uses could be developed. During the 1940s, the world saw the use of such materials as nylon, acrylic, neoprene, SBR, polyethylene, and many more polymers take the place of natural material supplies that were becoming exhausted.


PVC and Teflon®
 


pvc plasticAnother important plastic innovation of the time was the development of polyvinyl chloride pvc plastic(PVC), or vinyl. Waldo Semon, a B.F. Goodrich organic chemist, was attempting to bind rubber to metal when he stumbled across PVC. Semon later discovered that this material was inexpensive, durable, fire-resistant, and easily molded. Vinyl found a special place in the hearts of Americans as an upholstery material that would last for years in the average family's living room.


teflon plasticA DuPont chemist named Roy Plunkett discovered Teflon®, in 1938. Teflon® today is widely used in kitchenware. Plunkett discovered the material accidentally by pumping freon gas into a cylinder left in cold storage overnight. The gas dissipated into a solid white powder. Teflon® is unique because it is impervious to acids in addition to both cold and heat. Teflon® is now best-known for its slipperiness - which makes it highly effective in pots and pans for easy cooking and cleaning.


Polyethylene
 


In 1933, two organic chemists were testing various chemicals under highly pressurized conditions. In their wildest imaginations, the two researchers E.W. Fawcett and R.O. Gibson, had no idea that the revolutionary substance they would come across - polyethylene - would have an enormous impact on the world.

The researchers set off a reaction between ethylene and benzaldehyde, utilizing two thousand atmospheres of internal pressure. The experiment went askew when their testing container sprang a leak and all of the pressure escaped. Upon opening the tube they were surprised to find a white, waxy substance that greatly resembled plastic. When the experiment was carefully repeated and analyzed the scientists discovered that the loss of pressure was only partly due to a leak; the greater reason was the polymerization process that had occurred leaving behind polyethylene. In 1936, Imperial Chemical Industries developed a large-volume compressor that made the production of vast quantities of polyethylene possible. This high-volume production of polyethylene actually led to some history-making events.

It was not until after the war, though, that the material became a tremendous hit with consumers and from that point on, its rise in popularity has been almost unprecedented. It is currently the largest volume plastic in the world. Today, polyethylene is used to make such common items as soda bottles, milk jugs and grocery and dry-cleaning bags in addition to plastic food storage containers.


Plastics in Modern Life
 


Since the 1950s, plastics have grown into a major industry that affects all of our lives - from providing improved packaging to giving us new textiles, to permitting the production of wondrous new products and cutting edge technologies in such things as televisions, cars and computers. In fact, since 1976, plastic has been the most used material in the world and was voted one of the top 100 news events of the century.

None of the applications and innovations we take for granted would have been possible if it weren't for the early scientists who developed and refined the material. Those pioneers made it possible for us to enjoy the quality of life we do today.

 

contact :  jmfalcao@moldplast.com

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