Green, pink, blue, yellow ... Thick and thin, durable and easily torn, huge and miniature ... All these epithets characterize the same thing - a plastic bag. Made of a special material, the bags at the slightest touch to them make a rustling sound. Many wondered - why is the package rustling? Let's try to solve this problem.
The history of plastic bags
The first plastic bag appeared due to laboratory experiments of the German scientist Hans von Pehmann in 1899. It was Pehman who invented a peculiar mixture called polymethylene. Improvement of the material was continued by E. Fawcett and R. Gibson in 1934.
The first bags were made from celluloid. They were intended for storing film. However, such bags had one unpleasant feature - explosiveness. Only in 1911, scientists were able to invent material characterized by transparency and elasticity. They called the novelty cellophane. But innovation was not in high demand due to overpriced.
Polyethylene, which appeared in 1933, completely replaced the expensive cellophane. Already in the mid-50s in the UK began to use packaging bags in supermarkets. Soon, plastic bags began to be produced in large quantities (about 11 million annually).
In the USA since 1957, cellophane packaging of products was used in large quantities. And in the USSR, the first packages were one of the revenue items of farmers. Kulki with import inscriptions meant the status of the owner. They were cared for and used only in exceptional cases. The situation changed with the beginning of the production of plastic bags in the Soviet Union.
The difference between cellophane and polyethylene
As already mentioned, cellophane was invented at the beginning of the 20th century. And then, and today the material is made from viscose. In view of this, cellophane bags are more expensive than plastic ones. Currently, packaging made of cellophane can be found on packs of cigarettes, candy wrappers or a wrapper for flowers.
Unlike polyethylene, cellophane contains glycerin, which gives the material a sweet taste. Color on such packaging lasts a very long time. In addition, cellophane is tougher than polyethylene. This may explain why a bag of cellophane is rustling.
What are plastic bags made of?
In 1950, low-cost polyethylene completely replaced cellophane. Soft, pliable plastic bags immediately fell in love with consumers. In addition to aesthetic properties, plastic bags are extremely reliable and roomy.
Plastic packaging bags are made from the finest plastic polymer, which is extracted from gaseous hydrocarbon - ethylene. There are two types of plastic bags - LDPE and HDPE. The first type is made using high pressure, and the second low.
Types of plastic bags
The answer to the question of why a plastic bag is rustling may depend on the shape of the bag. There are several main varieties of packaging bags made of polyethylene:
- T-shirt packages. Such bags are made of material made using LDPE or HDPE technology. In the production of such packages, large economic costs are not required. This does not prevent the shirts from being roomy and durable. Bags boast a carrying capacity of 5 to 35 kg. True, the larger the load, the more the shape of the product is deformed.
- Pouches with a banana-cut handle. Such bags have a flat rectangular shape. The handle in these bags is a hole in the hole at the top of the product. Bags made of LDPE or HDPE materials. The softness and elasticity of the bags answers the question of why the bags rustle. Such bags are a good solution for wrapping gifts, advertisements, books, etc.
- Plastic bags with a loop-shaped handle. A distinctive feature of such bags is the presence of a handle that can join the package in three ways:
- a dense polyethylene strip is attached to the bag from the wrong side;
- the plastic handle is attached with a special fastening method in order to increase the carrying capacity;
- rope handles are fastened by threading the ends of the rope into the holes in the upper area of the bag and tying knots for strength.
- Pouches with loop handles, like previous versions of pouches, are made using HDPE and LDPE technologies. They are quite dense and therefore strong. Often on such bags logos and prints are applied. These bags are reusable, they can be used literally in all situations - in the process of shopping, carrying school shift, textbooks or products. The density of the product explains why a bag-bag with an attached handle rustles.
- Filling container. Such bags are not very durable. The main objective of the packages is to protect the packaged goods from dirt and moisture. This is the only packaging that is made from HDPE materials. Such bags are thin and inexpensive. They are disposable. The load capacity of the packages is small - only 2-7 kg. But they were created, mainly, not for carrying, but for packaging. The subtlety of the product explains why the package rustles.
Why are they rustling?
Comparing the plastic bag and the plastic bag, you can see that when compressed, the cellophane sounds sharper and louder. But polyethylene also makes a sound that is somewhat quieter and softer. How to explain why the package rustles The thing is that polyethylene is the same plastic, only several times thinner. Everyone knows that plastic is a dense and hard material. When breaking a plastic object, a characteristic crack is issued. The same thing happens with the plastic bag. When squeezing and wringing, the sound is rustling. At the same time, the bag does not break like plastic, but remains intact.
However, not all bags are rustling with the same sound. It depends on the material from which the product is made. The most sonorous rustling can boast packages of material using HDPE technology.
Plastic bags: interesting facts
Why is the package rustling? It depends on the density of the material and the method of production of the item. Throughout the history of the emergence of plastic bags, many interesting episodes have accumulated. For instance:
- Russia is one of the leaders in the production of high-quality plastic bags.
- In addition to the production of containers, polyethylene is successfully used in the manufacture of branded clothing.
- In a number of European countries, the cost of the bags includes a special monetary fee, which goes to the disposal of polyethylene.
- Today, there is a special technology that allows the production of bags of self-splitting polyethylene. However, such bags are extremely expensive due to high material costs.
Pros and Cons of Plastic Bags
Among the advantages of plastic bags are the following:
- The plastic packaging is waterproof and therefore protects the product well from moisture and dust.
- The bags are practically weightless and extremely compact.
- Plastic bags are durable. Many of them are reusable.
- Plastic bags are relatively cheap.
- The most popular plastic bag-shirt is made in a few seconds. This means that the production of bags does not require large energy costs.
However, polyethylene has one drawback, which began to reflect on recently. Plastic products are practically not split. They cause significant harm to the ecology of the Earth. Their disposal requires a lot of material and energy costs. As a result, developed countries began to switch to an ecological alternative to plastic bags - paper bags.