Silicone corona roller corona treatment of difficult problems analysis, silicone corona roller corona treatment of difficult problems analysis, corona roller corona treatment is a kind of electrocution to solve, corona roller make the surface of the printing process with better adhesion. Corona roller basic principle is the use of high-frequency high voltage in the solution of the plastic surface corona charging and discharging (high-frequency AC current up to 5,000-15,000V/m2), resulting in ultra-low-temperature plasma, so that the surface of the plastic caused by the free ionic base reflecting the polymer to produce chemical crosslinking. Surface becomes not smooth and enhance its wetting of polar solvents, this positive ions by electrocution and infiltration into the surface of the printed body to destroy its molecular formula, so that the surface molecular structure of the solution to air oxidation and electrode, positive ions electrocution corrosion of the surface, and even enhance the surface of the printing process of the adherence of the working capacity. Corona rollerCorona roller machine

Corona treatment is jeopardized by film surface temperature and gas air humidity.

In the corona treatment process, film surface temperature and gas air humidity are the obvious independent variables that jeopardize it. As the air humidity and surface temperature increase, the longer the corona treatment time is required, i.e., the less susceptible the film is to corona treatment. This is because when the air humidity in the air increases, the moisture content in the air expands, and the active oxygen formed in the whole process of corona can dissolve water, at room temperature and pressure, the solubility of active oxygen in water is about 13 times higher than oxygen, 25 times higher than gas.

Because of the reduction of carbon dioxide concentration, so that the oxygen-containing functional group isomerization in the membrane surface into and the opportunity to stationary pole is greatly reduced, and thus reduce the actual effect of corona treatment. Along with the increase of the temperature of the film surface, the reliability of the electret molecular structure decreases, and the proportion of the transfer of the surface molecular structure expands, which is unfavorable to the generation of high surface energy areas on the film surface, and partially counteracts the effect of corona to enhance the surface tension of the film. But on the other hand, according to the specific manufacturing experience, the temperature of the film surface is not as low as possible. During the manufacturing process, a lot of heat is generated during the corona treatment. In order to avoid the film surface temperature is too high, generally we choose the cooling circulating water roller to carry out closed loop system, and enhance a set of heating devices to make the cooling circulating water to maintain a certain temperature.

Corona roller corona machine

Too low a temperature will make the molecular structure of the film surface in the electrode and produce chemical reaction basically kinetic energy is not enough, will also lead to the surface of the film surface support force is not enough problems, therefore, the corona treatment rollers at the film surface temperature manipulation in a reasonable temperature range is the corona treatment of a critical issue, which is also our long-term production in the manufacture of the exploration of the discovery.

Manipulation of corona compressive strength and solution time in corona treatment

In the production process, in order to better enable the film surface support to achieve a certain level of resolution, the general choice of methods is to enhance the corona treatment of the compressive strength, within a certain range, this type of approach is immediate, when beyond this boundary, even if the corona is raised again, will not make the film surface energy level to get a boost, this is due to the film in the instantaneous development of the corona treatment of the whole process, the level of electricity and corona roll in the This is because when the film in the whole process of instantaneous corona treatment, the electric level and the corona roller in the amount of gas in a kind of relative balance, and the relative stability of the amount of gas in the oxygen molecule composition is certain, even if you raise the electric level of the working voltage and current, but also can be stimulated to talk about a large number of oxygen atoms, so that a large number of oxygen-containing functional groups isomerization electropolar to the surface of the film to achieve the purpose of enhancing the surface energy of the film.

Corona roller

Generally speaking, the longer the time period of corona treatment, the higher the surface energy. However, on the one hand, under the premise of the original machinery and equipment, increasing the corona treatment time will definitely reduce the production efficiency; on the other hand, too long a corona treatment time will make the surface of the film to support a great deal of deterioration or even dissolution, which is not conducive to the film's primary unwinding and secondary rewinding, and we have carried out a successful experiment on the facilities of a certain enterprise since then.

Corona treatment of rollers and parallel surfaces of electric levels

Roller surface and electric level surface of the non-parallel surface will cause corona treatment is not uniform, the reason is that the corona compressive strength of the difference in the size of the gap, immediately causing the total area of the enterprise charging and discharging power output is not uniform, because of the difference in the corona of the various places, and finally jeopardize the consistency of the infiltration of the support force.

Corona roller

Stability of membrane operation

If the membrane in operation, the rollers increase in the surface tension on the membrane of the inconsistency, such differences will produce part of the wrinkles, so that the location of the corona treatment capacity changes, and finally also cause the infiltration of the support force of the disproportionate.

In addition to the difference between the above rollers and 歩, there are also corona treatment rollers on the pinch roller and corona treatment rollers to the expansion of the film after the expansion of the rollers, and its rollers and rollers in the middle of the flatness, the flatness of the rollers, and so on, may result in the lack of stability of the film operating position.

The problem of film embrittlement

Corona treatment, there should be a degree of difficulty, if the introduction of the output power is too high, the temperature will be too high, endangering the film molecular structure of the subvalent bonding between the film brittle, that is, jeopardizing the application of the film, but also to make the production of power capacitors can not be rolled edge to edge, can only reduce the rate of production of the daily task, which in turn, to the processing of power capacitors to the processing of the process leads to a bad.

Corona Roller

Wastewater pollution problems

In the whole process of corona treatment, the molecular structure in the air between the valence electrons and the corona roller is impacted and agitated because of the increase in the high pressure between the two sides, resulting in reactive oxygen and nitric oxide and other chemicals, which, at a certain temperature and because of their water absorption, combine with the moisture in the air, resulting in wastewater with the components of sodium nitrite and phosphate, which is elevated with the increase in the relative humidity of the air. If the wastewater is not removed immediately and effectively, and if it is left in the discharge pipeline or in the cover of the electric grade machine, it is likely to drip onto the roll surface and cause environmental pollution of the film surface along with the rotation of the roll, resulting in the reduction of the film part of the infiltration support force, unstable adhesion, etc., and generating problems in the quality of the product.

Corona roller

Corona treatment can not only change the film's surface dyne value, but also continue to produce harm to the film's other process performance, the key involves the following levels:

Coefficient of Friction

Because the mechanism of corona treatment is that the film has two high piezoelectric levels that cause electron flow, causing positive and negative poles on the surface of the film, and the film surface and the non-film surface, the additives (including antistatic agents and sliding agents) that are located in the film fiber tubes are more prone to exuding from the surface of the film surface. In the case of the ABA type of film, which has the same secret structure on both sides, the coefficient of friction on both sides of the film without corona treatment is the same, but after corona treatment, the coefficient of friction on the solution side of the film is lower than the coefficient of friction on the non-solution side of the film.

From manufacturing to 14 days later, the additives of the film fiber tubes are in a rapid transfer period, and the static and dynamic friction coefficients of the solution surface and the non-solution surface show a decreasing trend, and the standard value remains stable after 14 days. In general, the coefficient of friction of the solution side is lower than that of the non-solution side.

Shrinkage

The shrinkage rate of the film decreases to a certain extent due to the heat generation in the corona treatment process.

Heat seal compressive strength

Silicone corona rollers are used in the production of BOPP heat sealable films with butadiene-pe polymer surfaces. As mentioned earlier, in reality, the polymer must only be used at a lower solution voltage if the same solution compressive strength is required. However, special attention should be paid to the fact that too high a corona treatment value can cause cross-linking effects between the polymers, resulting in a loss of sealing efficiency of the heat-sealable film. Therefore, in the real production of heat-sealable films, especially when adjusting for higher corona treatment values, the heat-seal compressive strength is an essential test countermeasure.