Some additional tests were performed using air or argon/O2 blends as plasma gas.

The results indicated that often air or a blend of gasses with a lowered amount of O2 offer a better wettability to the treated PP material. This effect can also be linked to the previous observations. Plasma treatment with pure O2 seems to be so aggressive that very easily an "over-treatment" is obtained reducing again the wanted hydrophilicity effects. Treatment with air as plasma gas might reduce the aggressiveness of the treatment and as a consequence the plasma parameters become less critical. Future trials have to confirm these findings for a larger range of individual plasma parameters.

As a conclusion we can state that for PP oxidative plasma treatments can be very beneficial in order to improve wettability and increase the surface tension. However the treatment conditions should be selected with utmost care especially since selecting conditions that are too aggressive will result in a lowering of the positive effects.

Often, when the feasibility of an industrial oxidative plasma treatment has to be proven, the first trials are performed with an intensive plasma. If the results are insufficient people tend to increase further the plasma intensity. As was discussed above it can be worth while to try the opposite and to lower treatment time or plasma power or to increase the vacuum pressure. This might not only simplify and reduce plasma treatment costs but can also improve the wanted properties.

Applications

The number of applications where plasma is or can be used successfully is very large. Also the type of application can be very different. A short list of application were plasma machines are used is given below:

Medical industry

• wettability of filter material (paper and synthetic)
• medical textiles and blood filters

Fibers

• cord for industrial and automotive belts

Technical textile:

• automobile textiles

Safety textiles:

• work wear

Structural textiles

• fibres for structural composites (building, sports wear)

Foils

• Packing material and foils

Europlasma capabilities

Following services can be delivered:

1. custom designed machines
2. test facilities
3. service contracting

Europlasma is a growing company with sales allover the world. Agents in Germany, Swiss, France, Asia, U.K and a division in the USA. Standard and custom designed machines are produced in Belgium and placed all over the world.