| Customization: | Available |
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| After-sales Service: | Online Support, Video Technical Support |
| Warranty: | One Year |
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Corona refers to the phenomenon of partial discharge on the surface of the charged body in a gas or liquid medium, often occurring around the high-voltage wire and near the tip of the charged body, which can produce ozone, nitrogen oxide and other substances.
Most plastic films are non-polar polymers, the surface tension generally 29-30mN/m, in theory, if the surface tension of an object is less than 33mN/m, the currently known ink and adhesive can not be firmly attached to the above, so the surface of the corona method treatment.
The processing principle is to apply high frequency and high voltage electricity to the processing equipment to generate high frequency and high voltage discharge, resulting in small and dense purple-blue sparks. Various ions produced after air ionization accelerate and impact the plastic film in the treatment device under the action of a strong electric field.
The chemical bonds of plastic molecules are broken and degraded, increasing the surface roughness and surface area. The discharge also produces a large amount of ozone, which is a strong oxidizing agent that can oxidize plastic molecules and produce strong polar groups such as carbonyl and peroxide, thereby improving its surface energy.
When the plastic film surface is not treated, its surface tension is low, in order to further improve the binding force between the printing ink or vacuum aluminum plating layer and the surface of the plastic film, and increase the adhesion fastness, it is often necessary to surface treat the plastic film. Plastic film surface treatment methods are: corona treatment method, chemical treatment method, mechanical hair method, coating method, flame method, etc., the most commonly used is corona treatment method.
The basic principle of corona treatment method is: by applying a high-frequency and high-voltage power supply between the metal electrode and the corona roller (high temperature, ozone resistance, high insulation silicone rubber roller), the discharge is generated, so that the air is ionized and a large amount of ozone is formed. At the same time, high-energy electrical sparks impact the surface of the film. Under their combined action, the surface of the plastic film is activated and the surface energy is increased. The tension of polyolefin film can be increased to 38 dyne/cm by corona treatment. The surface tension of the polyester film can reach 52-56 dyne/cm or more.
Because the corona roller is used in high voltage electric field for a long time, the coating is required to have excellent electrical insulation, arc resistance, corona resistance and flame retardant. But the existing corona roller can not reach the ideal effect, easy to produce reverse corona. The reverse corona may produce the anti-sticking phenomenon of ink printing, the transfer of aluminum plating layer will occur in aluminum plating, and the transfer of adhesive layer will occur in glue coating, and the ideal corona effect can not be achieved. Therefore, it is very important to choose a high quality corona roller.
Huatao corona roller adopts imported special silica rubber, and the corona roller is guaranteed by the high voltage test of 200,000 volts, which effectively increases the surface roughness of the plastic film and makes the surface of the plastic film have higher adhesion. Widely used in famous brand BOPP & BOPET film production line. Effectively increase the surface roughness and improve the surface energy of the film.
Shell construction: 2OS Double-shell from Q345B
Shrinked and welded shafts from Q345B
surface:Silicone rubber coated, hardness apprx 70HRC
Disks and shafts 2-layer painting RAL
Out of roundness <=0.1mm
Cylindricity <=0.1mm
Dynamic balancing G2.5
Flow-system: Channels between inner and outer tube separated with welded leading spirals
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