Plastic metal compounds CNC part

What is plastic wrapped metal?

Plastic wrapped metal is a common packaging method, i.e. covering a layer of plastic material on the surface of the metal to form a kind of protective layer to protect the metal from the external environment. Commonly used plastic wrapped metal materials are PVC, PP, PE and so on.The role of plastic wrapping metal is not only to protect the surface of the metal, but also to reduce the oxidation and corrosion rate of the metal, extend the service life of the metal, and improve the safety performance of the product. This type of wrapping is widely used not only in the food industry, but also in other fields of application

The role of plastic wrapped metal

1. Anti-pollution

In the process of transportation, storage and use, metal is susceptible to a variety of pollutants, such as water, oil, dust, etc., and these pollutants will cause damage to the metal surface. By wrapping the plastic, a protective barrier can be formed to prevent pollutants from contacting the metal surface and protect the cleanliness of the metal.

2. Protection against oxidation and corrosion

Many metals are susceptible to oxidation and corrosion. Rust, for example, is a product of iron in the presence of oxygen. By wrapping the plastic layer, it can prevent the metal surface from direct contact with oxygen, moisture or other corrosive substances, reduce the rate of oxidation and corrosion of the metal, and extend the service life of the metal.

3. Improve safety performance

Plastic wrapped metal can not only play a role in protecting the metal, but also improve product safety performance, for example, the food industry, the metal containers holding food after plastic wrapping, you can prevent metal contamination of food and metal and food detection.

The way of plastic wrapping metal parts

1.Bonding

TPE through the injection molding, and plastic bonding together, this bonding is mainly TPE itself has a hot melt adhesion, and did not occur in the interface of the cover of the two materials melt each other, TPE and metal cladding, but also the role of adhesion. However, metal and TPE can not be directly adhered to the metal surface needs to be coated first, and then wrapped with a layer of TPE soft material. The coating layer on the metal surface plays the role of a medium, thus realizing the TPE and metal cladding.

2.Fusing

Fusion refers to the fusion bonding between TPE and the coated part at the interface of the coating under high temperature. Generally occurs in the polarity and compatibility close to the TPE and plastic parts between. In the injection molding coating, TPE and plastic in the coating interface, microscopic molecular chain level of the two materials occurring mutual entanglement, macroscopic level of high temperature materials in the interface through the fusion of penetration, so as to produce excellent bonding force in the coating interface.

3.Embedding

Sometimes TPE is not strong enough to be wrapped with plastic or other materials, you can make holes in the proper position of the wrapped parts, and make the surface rough, concave-convex surface, concave groove, etc. This can increase the bonding strength between the TPE material and the wrapped part. This can increase the firmness of the combination of TPE material and the wrapped parts.

4.Adsorption

It happens between TPE and some polarity strong polyester plastics with high melting point, although TPE has done polarity modification, but it is still difficult to melt and penetrate with polyester plastics, only there is intermolecular force, which makes TPE and polyester plastics produce certain adsorption effect at the interface.

5.Wrapping

TPE will be completely wrapped around the entire surface of the rubberized parts (parts). Because it is a whole package, there is no problem of not being able to wrap. However, for some parts with irregular surface and corners, it is recommended to use TPE material with higher hardness to make the combination of TPE and parts more stable. With the help of the above various wrapping mechanisms, TPE can be wrapped with most plastics such as PP, PC, ABS, PA, PS, PE, POM (paraformaldehyde), and wood, and metal can be wrapped with adhesive.