Plastic jars refer to small packaging containers made of plastic or plastic-based raw materials, generally with a sealable can lid.
Among plastic jars, there are few pure plastic jars. Most of them are made of plastic, paper, aluminum foil and other composite materials, while the bottom and lid are made of plastic or metal. This kind of plastic jar is also called composite tank.
The difference between plastic jars mainly lies in the jar body, which can be divided into two types according to its composition structure:
① Laminated composite material tank. It is made from several materials, such as plastic film, aluminum foil, cardboard, etc., into composite materials, and then extruded to form a jar body. The jar body is mostly square with rounded corners. The bottom cover is mostly plastic and is connected to the jar body by high-frequency fusion sealing.
② Multilayer material winding jar. It uses a variety of materials to be shaped into a cylinder, then cut into a jar body as required, and then connect the jar bottom and the jar lid respectively.
Plastic jars have not appeared for a long time, but they have developed very rapidly. They have replaced metal jars and glass bottles on many occasions, mainly because they have many advantages:
① Light weight. The density of materials used to make plastic jars is relatively small. Compared with the quality of containers with the same volume, plastic jars are smaller than metal jars and glass bottles.
② The cost is lower. The material cost of the plastic jar is lower, and the manufacturing is easier, so the overall price is lower.
③ The product jar be reliably protected. The tank body is made of a variety of materials, with good chemical stability and barrier properties; the combination of the bottom, cover and the tank body adopts a reliable sealing structure, so the contents jar be reliably protected.
④ Good mechanical strength. Although the mechanical properties of plastic jars are slightly lower than that of metal jars and glass bottles, they are sufficient for packaging general products, and strength damage rarely occurs.
⑤ Good shelf effect. The surface of the plastic jar is easy to print and easy to decorate, which is very good for attracting customers and promoting sales.
Plastic jars also have some shortcomings: for example, the sealing quality of the bottom cover and the jar body is not stable; in vacuum packaging and pressure packaging, the strength of the jar body is sometimes not high enough.
As a new type of packaging container, plastic jars are widely used in the packaging field. They can package fruit juice, milk powder, carbonated beverages, coffee, cosmetics, oils, etc.
