The history of plastic bags

Public date： 2021-4-16 14:30:04

A photographer's experiment in a darkroom led to the creation of the original plastic. Alexander parks has many hobbies, and photography is one of them. In the 19th century, people could not buy ready-made photographic films and chemicals as they do today. They had to often make what they needed. So every photographer must also be a chemist.

One of the materials used in photography is "collodion", which is a solution of "nitrocellulose", that is, nitrate cellulose solution in alcohol and ether. It was then used to glue photosensitive chemicals to glass to make the equivalent of today's photographic film.

In the 1850s, parks looked at different ways of handling collodion. One day, he tried to mix collodion with camphor. To his surprise, the mixture produced a flexible hard material. Parks called the substance "paksin," which was the first plastic.

Parks used paksin to make all kinds of things: combs, pens, buttons and jewelry. However, parks has little business sense and has lost money on his own business venture. In the 20th century, people began to explore new uses of plastics. Almost everything in a home can be made of some kind of plastic.

It's up to other inventors to continue to develop parks' achievements and profit from them. John Wesley hayatt, a printer from New York, saw the opportunity in 1868, when a billiard company complained about a shortage of ivory. Hyatt improved the manufacturing process and gave paksin a new name, celluloid. He got a ready market from billiard manufacturers and soon made a variety of products out of plastic.

Early plastics were easy to catch fire, which limited the range of products made from them. The first plastic that successfully withstood high temperatures was "bakelite.". Leo Baekeland obtained the patent in 1909.

In 1909, bakeland of the United States first synthesized phenolic plastics. In the 1930s, nylon came out again, known as "a fiber made of coal, air and water, thinner than spider silk, harder than steel, and better than silk". Their appearance laid the foundation for the invention and production of various plastics. Due to the development of petrochemical industry in the Second World War, petroleum replaced coal as the raw material of plastics, and plastics manufacturing industry also developed rapidly.

Plastic is a kind of very light material, which can be softened by heating at a very low temperature, and can be made into various shapes at will. Plastic products are colorful, light weight, not afraid of falling, economic and durable. Its appearance not only brings a lot of convenience to people's life, but also greatly promotes the development of industry.

However, the invention of plastics is less than 100 years old. If people were overjoyed at their birth at that time, now they have to take great pains to deal with these things which are full of life and bring great threat to human living environment.

Plastics are chemical petroleum products extracted from petroleum or coal, which are difficult to degrade naturally once produced. Plastics will not decompose in the ground for 200 years. A large number of plastic wastes buried in the ground will destroy the permeability of the soil, harden the soil and affect the growth of plants. If livestock eat mixed feed or residual plastic in the field, it will also cause death due to digestive tract obstruction.

At present, the annual output of plastics in China is 30 million tons, and the consumption is more than 6 million tons. The annual output of plastics in the world is 100 million tons. If calculated by 15% of the annual plastic waste, the annual plastic waste in the world is 15 million tons. The annual plastic waste in China is more than 1 million tons, and the proportion of waste plastics in the garbage accounts for 40%. Such a large amount of waste plastics are buried underground as garbage, which undoubtedly brings greater pressure on the arable land that is lacking.

Plastic not only brings convenience to people's life, but also brings the future trouble to the environment. People call the disaster of plastic to the environment "white pollution".

At present, many countries adopt incineration (thermal energy regeneration) or reprocessing (product regeneration) to treat waste plastics. These two methods make waste plastics recycled and achieve the purpose of saving resources. However, waste plastics will produce harmful gases to human body and pollute the environment when they are burned or reprocessed, so it can be said that the treatment of waste plastics is still a headache in environmental protection.