AFS ENTWICKLUNGS + VERTRIEBS GMBH

The effect achieved by the corona treatment is an increase in surface tension to values between 38 to 60 mN/m. Since the surface tension is caused by dispersive and polar interaction components the introduction of polar functional groups in particular increased the polar component of the surface tension.

The Plasmajet® (registered AFS trademark) produces a plasma without a vacuum. The plasma, generated by high voltage in combination with any process gas, is blown out of the unit, and is potential-free. It is used for surface modification. When the plasma comes into contact with a plastic surface, the wettability is increased. Metal surfaces can effectively be cleaned, and it is also possible to weld plastic sheets. The system comprises of a plasma reactor with nozzle, a high-voltage generator with transformer and high-voltage rectifier. The application field for Plasmajet® is mainly where geometric, three-dimensional bodies or profiles are to be coated, printed, glued or cleaned. Typical application examples: Treatment of EPDM profiles for the automotive industry before flocking Treatment of adhesive grooves before gluing the lens of car headlights Treatment of razors and mobile phones before tampon printing Degreasing aluminum profiles before bonding

The compact electrode housings of our treatment stations are used for the reliable extraction of the ozone created by the corona treatment. Exhaust monitoring is an integral part of all corona stations and ensures that a corona discharge can not be activated without suction. The ozone is extracted by a pipe work and discharged to a safe height into the external atmosphere. To reduce the ozone load of the ambient air and comply with local environmental and health and safety regulations the extracted air can be passed directly into an ozone catalyser. Our ozone catalyser is a high performance filter unit designed specifically for ozone destruction in Corona treatment. Since ozone is extremely corrosive, all materials and seals used are corrosion resistant. The housing and all internals are made from corrosion resistant stainless steel. For reliable treatment of the exhaust air, three filter stages are contained within the housing.

AFS corona generators are THE standard for foil extrusion and the packaging industry. It is not without reason that the largest machine manufacturers opt for AFS as their standard equipment. The initial investment cost of any system is only part of the total running costs over the life time of a machine. Reliability and high efficiency results in minimum downtime and loss of production. The failure of a corona treater system can result in a total plant shutdown costing far more than the difference in price between a low quality and higher quality treatment system.

In this process, conical needles pierce the web (e.g., paper, thin metal foils, PE films). The grooves of the counter roller match exactly with the needle pattern. The needles create funnel-shaped holes. This causes, for example, in paper increased water permeability and in PE films air permeability.

Measurement of the surface tension The adhesion of a surface is usually directly dependent on the surface energy. If the surface energy is substantially lower than that of the printing ink used, the wetting is disturbed, resulting in poor adhesion. For this reason, plastic surfaces have to be pre-treated. Depending on the type of ink used the surface tension required can vary: solvent based inks => 38 bis 42 mN/m (=Dyn/cm) water soluble inks => 40 bis 44 mN/m UV inks => 44 bis 46 mN/m With the test inks of AFS, which are available from 34 to 56 dyn/cm surface tensions of plastic films can be easily and reproducibly determined according to DIN ISO 8296. Depending on whether the ink sticks or bubbles on the surface it indicated whether the surface tension is above or below the dyne-value of the currently used test ink. We also offer the test inks in a case with 12 bottles from 34 to 56 dyn/cm.