AIJU improves the painting of flexible polyolefins by Low Pressure Plasma

Online, May 31, 2010 (Newswire.com) - Nowadays, plastic materials are the most used raw material in the toy sector, because of its good adaptation to any designs, physic-chemical characteristics, easy processing and low cost. Elastomeric polyolefins, and especially elastomeric polyethylene (PE), give excellent mechanical stiffness properties and very low hardness. Due to these particular properties, these materials are appropriate for the toy and childcare articles manufacturing.

One of the most relevant difficulties for its application in some sectors is the decorating and painting issues of pieces made up of PE. In the polyolefins painting, for example, its surface energy is noticeably lower to wet the surface and remain unchangeable on it during the product's useful life. The surface treatment tries to adequate the substrates in a way that allow them to be used for painting, metallization, printing or the substrate adhesion. In the specific case of painting, this process is done by increasing the energy of the material for it to be higher than the energy of the painting (or the blending with solvents, whose surface energy must be similar).

Suny Martínez, the project coordinator states: "the modification of the polymers surface by means of low pressure plasma treatment presents several advantages against others mechanical or chemical surface treatments, as it does not give heat, it is quick and environmental non-aggressive and it allows the modification of the complex geometry of the piceces, as they are introduced in the reaction chamber where the treatment is made in an homogeneous and controlled way. That is why the plasma treatment acceptation has increased in industrial applications".

The low pressure treatment efficiency depends on the different experimental parameters, like the time of treatment, the plasma generation power and the partial pressure of the plasma generator gas, among others. The study carried out by AIJU has proved how the elastomeric PE painting properties have deeply improved by means of low pressure plasma surface treatment, in few seconds of treatment.

Some of the results obtained were presented in the 16th International Symposium on Plasma Chemistry in Taormina (Italy).