What is the effect of plasma cleaning treatment before PP plastic printing adhesive?

Why is plasma cleaning machine the primary choice for printing surface treatment technology? Plasma technology can solve problems such as poor printing and coating adhesion on plastic film surfaces, such as PP polypropylene, polyethylene (PE), polyvinyl chloride (PVC) polyester (PET) and other plastic materials. Due to the different polar groups, crystallinity and chemical stability of the molecular structure substrate, their surface characteristics also vary greatly, which have a significant impact on the adhesion strength of the printing ink layer.

If surface pretreatment is not carried out before printing, the fastness to ink printing will be very low.

Therefore, before printing adhesive, plasma cleaning technology must be used to clean the plastic surface, activate and generate new chemical bonds, roughen the surface, and improve the adhesion between ink and film surface; After plasma surface treatment, the surface molecular structure, surface roughness, surface wettability, and adhesion of plastic products undergo significant changes The process of activation modification technology for normal plasma cleaning technology is as follows:

1. The changes in surface molecular structure generate a large number of plasma particles during plasma treatment, which directly or indirectly interact with plastic surface molecules, resulting in the formation of extreme functional groups on surface molecular chains, such as substrates and gas containing groups. Meanwhile, they can also induce cross-linking and permanent polarization charges on the surface molecular chains.

2. Changes in surface roughness: After plasma treatment, the surface roughness of plastics changes and increases with the increase of temperature and treatment time. This can be explained by the combined effect of polymer surface oxidation degradation and surface dielectric. The physical accumulation of molecular hydrogenation degradation products at the surface charge center forms surface protrusions. Extending the treatment time, increasing the treatment temperature, reducing the surface dielectric charge center, but increasing the strength, thus forming large and small protrusions on the surface, the surface roughness changes greatly,

3. Changes in surface tension: The increase in surface tension is mainly due to the contribution of polar components, which is caused by the oxidation reaction on the plastic surface leading to an increase in surface polar molecules. Introducing polar groups, increasing surface tension, or improving surface roughness onto plastic surfaces through plasma treatment. This process provides a new method for printing difficult to print plastics.

The plasma cleaning machine can be used to add active groups before printing to improve its surface hydrophilicity. Before printing, the plasma surface processor of Shaker Corporation can be used to add active groups to improve its surface hydrophilicity and adhesion. The rotating nozzle of Shaker's plasma cleaning machine can process panels with a total width exceeding 3 meters at a speed of 25 meters/min.

For example, in the pre-treatment process of automotive headlights, the sealing area of the low-temperature plasma surface treatment machine is one of the first applications in the plasma clean production process. However, the automotive industry requires more detailed control functions to effectively monitor each production stage.

In order to effectively improve its surface tension, an ideal solution has been developed to firmly print on plastic hoses before the optimal date and on food labels: the relevant area is pre treated with a low-temperature plasma surface processor before printing, which allows the UV ink to quickly dry and produce a reliable adhesive.