How are PET plastic bottles made?

As a manufacturer of cosmetic packaging materials as a small editor, every day in order to share some valuable knowledge, it is really "exhausted". Because in this industry, professionalism is very strong, I casually share some knowledge that is not nutritious, it is very easy to be demolished, so editing articles really headache ~!

Talking to a coworker aboutpet plastic bottlesWhen the time came, it happened that the knowledge of its manufacturing process was a bit lacking, so I went to Baidu:PET plastic bottleHow is it made? The answer to a variety of answers, although taken from different aspects of the interpretation of this issue, but I always feel that in the entry point of the problem, there is a lack of, and so organized this PET plastic bottle manufacturing detailed process out, so that you can more simply understand the process:

In this article, we'll teach you the process of manufacturing PET plastic bottles and the exact reasons why PET plastic is perfect for bottles.

What are PET plastic bottles?

PET stands for polyethylene terephthalate, which is used to make 70 percent of the soft drink bottles produced worldwide. This makes it the most popular choice globally, putting it well ahead of competitors aluminum and glass.

Polyethylene terephthalate is a naturally transparent thermoplastic with a wide range of applicability in the bottling and packaging industry, and can also be used as an engineering plastic when combined with other materials. Due to its applicability in the textile industry, polyester has led to a better understanding of its name.

Where does polyethylene terephthalate come from?

PET was developed by DuPont chemists over seventy years ago. They set out to find polymer materials that could be used in textiles and produced PET in the synthesis of ethylene glycol and terephthalic acid . They noticed that it was a very strong material with no additives, especially when they considered how lightweight it was.

This strength means that less material is needed in certain applications, which explains why plastic bottles are made from what appears to be a relatively thin material. Research has also shown that PET is extremely sustainable, due to the fact that it can be recycled and reused over and over again.

Why is polyethylene terephthalate so useful?

PET is a useful material due to a combination of factors. For the bottling industry, PET is useful because it provides manufacturers with some chemical resistance. It does not react with food or water, making it ideal for consumer packaging.

It is also almost completely shatterproof, making it safer to use than glass alternatives.PET is also much lighter than glass, making it easier to transport the finished product.

You must also consider the fact that polyethylene terephthalate is a widely available substance at a relatively affordable price. After consumers use it, they can recycle it. This can be accomplished in one of two ways, and the plastic will be used in one of two ways:

a) after a series of washing processes or
b) Break it down into a set of raw materials.

How are PET plastic bottles made?

A variety of methods are used to manufacture PET plastic bottles, but the most common methods can be broken down into the following steps:

Step 1:PET is first heated to melt into a molten state and then placed into a tubular mold. This process is called injection molding. Once the PET becomes the same shape as the mold, it is called a parison. After the system has cooled down, the parison is cut to the correct length.

Step 2:The parison is then reheated and placed into a mold shaped like the bottle being made. A steel rod is then placed inside the parison itself and high pressure air is blown in to stretch the parison into the shape of the mold that surrounds it. the molecules inside the PET are then polarized and the stretching process leaves you with a plastic bottle.

Step 3:The bottles must then be quickly cooled and removed from the mold. Manufacturers often use several different methods to cool bottles quickly. Some of these methods are direct and others are indirect. For example, water can be pumped through a pipe that surrounds the mold, thus cooling the plastic bottle indirectly. Or, the plastic can be cooled by applying carbon dioxide directly.

Step 4:Most bottles produced by the manufacturer are then reduced to a certain size. If the bottles are made in a continuous molding process, one bottle will need to be trimmed from the one next to it. If the bottles are made in a discontinuous molding process, some excess plastic may seep in. This will need to be trimmed.

Step 5:The bottle can now be transported to its destination.

What is the role of the compressor when making PET plastic bottles?

Regardless of which method a manufacturer uses to produce PET plastic bottles, compressors, there is a common problem. Many different types of compressors are used throughout the industry, and the compressor is the piece of hardware that requires the most attention.

The compressor is responsible for injecting high-pressure air into the parison, stretching the parison until it fits perfectly into the bottle-shaped mold that surrounds it. This means that the compressor must be good enough to accurately control the overall air flow into the parison, otherwise the shape will not be formed.

Traditionally, reciprocating compressors are used in the manufacturing process of PET plastic bottles. These compressors use pistons to generate a lot of pressure, but they are not very good as far as cost efficiency is concerned. As a result, most new companies prefer to use centrifugal compressors. These compressors are very cost effective and use less pressure.

Are quality tests performed?

Quality tests must be carried out regularly during the manufacturing process of PET plastic bottles. These tests are steps to ensure that the bottles are safe to use, and also check things like impact resistance and permeability to carbon dioxide.

Keep in mind that PET has a high recycling rate and sustainability is demonstrated in the manufacturing process. Many PET plastic bottles are now manufactured using bottles that were previously recycled.