Plasma cleaner effect verification evaluation test
It is well known that the surface of the material treated by the plasma cleaning machine will have some subtle changes, which we can not distinguish with the naked eye. So how do we tell if the plasma-treated sample has changed? In general, there are several commonly used methods for validating effectiveness evaluation tests. The first and most direct method is to use the plasma-treated sample directly for the next process. If it meets your requirements, the plasma cleaning machine is effective. Of course, if you can not meet the requirements of the next process, we can not conclude that the plasma cleaning machine processing material is invalid. However, the treatment effect is different. Plasma surface treatment is applicable to all materials in a sense, and the treatment effect is also affected by many factors. Here are three commonly used methods to judge the effect of plasma treatment: Contact Angle/edge Angle verification: Contact Angle refers to the contact Angle between the droplet profile and the solid surface when observing the projection of a static droplet on a solid. By physical definition, surfaces with a contact Angle less than 90° are hydrophilic (wettable) and hydrophobic (non-wettable) when the contact Angle is greater than 90°. With plasma surface treatment, the contact Angle changes (becomes larger or smaller). Through the appropriate plasma process or in the plasma process process, the appropriate coating treatment. Hydrophilic surfaces convert to hydrophobic surfaces (hydrophilic coatings have the opposite effect). Test ink verification: Measuring method for estimating surface energy: If the test ink is concentrated in one place after being painted on the surface, the solid surface energy is lower than the ink, and if kept wet, the solid surface energy is equal to or greater than the liquid surface energy. By using a series of test inks with a gradient surface energy, the total surface tension of the solid can be determined. However, this method cannot determine the polar and non-polar parts of the surface energy. Grid cutting test verification: In order to check the adhesion of the coating, a mesh cutting test is performed. After painting, the paint layer of the plastic parts is cut into a mesh, then the standard tape is attached to the cutting mesh, the tape is secured, and then suddenly torn off. If there is paint on the tape, there is not enough adhesion. Cut the mesh to show the bonding strength of the paint coating on the plastic parts.
Application of improving biocompatibility of plasma-injected plasma
Improving the biocompatibility of materials is another successful application of plasma ion implantation, which can be applied independently or in combination with PVD or CVD processes. For example, standard low temperature isotropic pyrolytic carbon shows strong image shape thrombotic aggregation in vivo, but titanium-based biomaterials treated with PIII oxygen do not appear obvious thrombotic after being put into vivo. Through oxygen ion bombardment, oxide growth is controlled and rutile phase is formed. In addition, the biocompatibility of PIII treated LTI carbon materials was also greatly improved, and the platelet density was significantly reduced after implantation in vivo. It may be caused by the formation of the CN surface layer after nitrogen injection. Until now, these materials, which are very useful, have not been used in conventional surgery, because there are many obstacles. For example, the law stipulates that "a long process of testing and clinical trials is required before a new synthetic material can be implanted into the human body." This requires a legal procedure. PII has been successfully applied to ion implantation of nonmetallic materials. When conventional ion implantation is used, non-metallic materials are easy to be charged. Since the ions on the material surface will be repelled by static electricity, when PII treatment is carried out in the plasma environment, the electrons in the plasma will automatically complete charge neutralization.
Plasma cleaning machine Classification
According to the different ways of plasma production, the plasma cleaning machine can be classified into which kinds, the following introduction: corona plasma cleaning, glow plasma cleaning, rf plasma cleaning, dielectric barrier plasma cleaning, microwave plasma cleaning and atmospheric pressure plasma arc cleaning these types. Among them, low-pressure plasma cleaning is generally corona plasma cleaning, glow plasma cleaning and rf plasma cleaning, atmospheric plasma cleaning is generally plasma cleaning, microwave plasma cleaning and atmospheric plasma arc cleaning. Corona plasma cleaning machine: Use an electrode with a small radius of curvature and apply a high voltage to it. Due to the small curvature radius of the electrode, the electric field near the electrode area is particularly strong, which is easy to form electron emission and gas ionization, thus forming corona. This method is difficult to obtain stable corona discharge, easy to produce partial arc discharge and discharge energy is not uniform, used in flue gas desulfurization denitrification, automobile exhaust purification and other fields. Glow plasma cleaning machine: At low voltage, a certain voltage can be applied to the two flat electrodes to form a glow discharge, which is a stable self-sustaining discharge with the discharge current at milliamps. It is sustained by secondary electron emission from the cathode bombarded by positive ions. The power supply can be DC or AC. Although a typical large volume and strongly excited low-temperature plasma can be produced, its working pressure is too low to be continuously produced in industrial applications and its application cost is high. At present, it is mainly used for cleaning in semiconductor industry. Rf plasma cleaning machine: Rf discharges are usually operated at low pressure, but can also be operated at normal pressure or even under pressure, characterized by discharge gas not in contact with the electrode. Rf discharge is the use of high frequency electric field to discharge the gas in the reactor, through inductance or capacitance mutation to produce plasma. Due to the high energy and wide range of rf single electrode discharges, it has been used in surface treatment of materials and removal and cracking of toxic wastes. DBD plasma cleaning machine: Between two different discharge electrodes into work gas, with a dielectric cover one or two electrodes, or the medium can be suspended in the discharge space directly, or fill the granular medium, when applying high enough voltage between two electrodes, the gas will be breakdown and between the electrode discharge, dielectric barrier discharge is happened. Dielectric barrier discharges can operate at high pressure and over a wide frequency range. In practical applications, the flat electrode structure is widely used in the modification, grafting, surface tension improvement and hydrophilic modification of polymer and metal films and plates in industry. Microwave plasma cleaning machine: Microwave discharge is a non-electrode discharge, which avoids the influence of discharge materials on the reaction. It can operate over a wide range of frequencies and gas pressures and can produce large volumes of uniformly non-equilibrium plasma. Microwave plasmas are mainly used in material surface machining, modification and hardening treatment of tools, dies and engineering metals. APPA cleaning: Atmospheric atmospheric plasma arc cleaning is the use of high energy density plasma beam directly on the surface of the workpiece. Under the activation of high-energy particles, the layer to be cleaned will produce a series of physical and chemical reactions, such as thermal shock, activation decomposition, thermal expansion, etc., to achieve the purpose of separating pollutants from the workpiece. Different kinds of working gases can be used to deal with different surface pollutants. For example, a mixture of plasma gases can clean both organic dirt on the substrate and oxides on the surface.
Plasma surface processor printing, bonding, welding pre - treatment process
Plasma surface treatment can improve the surface adhesion of various materials, so that all kinds of materials in printing, spraying, bonding, welding and other processes, glue, ink, solder joints, coating, etc., effectively adhere to the surface of the material, to ensure the firmness. About printing, pad printing, screen printing, printing, thermal transfer, lettering, printing process, such as in the process, plasma surface treatment has obvious effect, before printing, first for plasma surface treatment, in order to improve the material surface adhesion and hydrophilic, make the printing after printing satisfy clients' demand for all kinds of inspection, the inspection requirements, either with a specific type of 3 m tape, have a plenty of judged by printing fastness printing whether accord with the requirement of the customer, have a plenty of friction with his nails to test; Some use a hundred squares to detect; Some use special cotton fabrics for friction testing; No matter which test method is used, the purpose is to test the firmness of printing and whether it meets the customer's requirements. Spraying aspects, involving stainless steel spraying, plastic spraying, etc., these processes are generally used in stainless steel thermos cup, auto parts, the need for pre-treatment of products, the particularity of product use reflected in the product use environment and frequency. If some parts on the car, PP + GF is generally selected materials, the characteristics of the material surface adhesion stress is low, heat resistant, wear resistant, good toughness, but the material itself but the corrosion resistance is not high, so in the subsequent process need to spray coating corrosion resistant layer on the surface of a material, because of material itself bond low, surface treatment by plasma surface treatment machine, spray on subsequent strong degree, can effectively guarantee; Such as stainless steel insulation cup, before spraying, the need for multiple pickling process, to ensure that the surface of stainless steel pollutants are effectively cleaned, the use of plasma surface treatment equipment, can replace the pickling process before spraying. In terms of bonding, it is mainly reflected in the box paste machine, PP+ wood pulp and cotton bonding, LED lamp waterproof glue bonding before, car horn and buzzer bonding before, etc. Materials in these bonding processes all have a characteristic: the surface bonding strength is low, glue is difficult to bond effectively. Such as film coated cartons, UV coated cartons, the surface adhesion is low, before the general adhesion, with a grinding machine before the grinding, such as LED lamp waterproof glue before coating, are generally used to wash water and other chemicals to clean the surface before adhesive, and then coated with adhesive. Such as car parts, generally before the glue, the surface with polypropylene water, and then the glue. And with plasma cleaning equipment, can completely replace grinding machine, instead of washing water, replace PP water, in line with the national environmental protection requirements, pollution-free belongs to dry cleaning. Welding, are generally new energy battery - lithium battery, battery, pole ear soft packages, nickel surface plasma cleaned before welding, PCB micro welding surface, the bonding chips, substrate or substrates using a suitable cleaning process is very important, in the traditional solvent after cleaning, add a dry ion cleaning process, can be more effectively remove residue and oxides. The plasma cleaning technology can be used for the cleaning of all kinds of PCB through holes, pads, substrates and optical glass touch screens, including printing, bonding, spraying, inkjet, surface activation before electroplating, cleaning, coating, coating, modification, grafting, roughening, etc.
Plasma surface activator
The surface of the material must have good wettability, so that it can be well bonded with the adhesive material in painting, bonding, printing or pressure welding. Not only does dirt containing oil and grease prevent wetting, but the surfaces of many materials cannot be completely wetted by various fluids, adhesives, and coatings. After the liquid drops, even after curing and drying, it cannot be well attached to the surface. The surface can be activated and treated with the plasma surface activator. This is because the substrate has a low surface energy. Normally, materials with a low surface energy are those with a high surface energy that can be wetted, but conversely, materials with a high surface energy are those that cannot be wetted. The surface energy of the liquid added, also known as surface tension, must in any case be lower than the surface energy of the substrate. Most plastics have a very low surface energy, and because the surface is nonpolar, liquid molecules cannot find connections where they can aggregate and therefore cannot be wetted by adhesives and coatings. The surface energy of the material surface is increased so that the surface is activated and the activated surface establishes a gathering point for the added liquid. Chemical primers and liquid adhesion promoters can generally be used to activate the material surface. But the treatment is often corrosive and harmful to the environment. On the one hand, adequate ventilation must be carried out before follow-up processing; on the other hand, activation state cannot be maintained for a long time. Nonpolar materials such as polyolefin cannot be fully activated by chemical primers. In addition, it can be activated in the arc corona. This is a form of atmospheric pressure plasma surface activated machine treatment, but only for flat or convex surfaces, where an arc is introduced. For atmospheric plasma activation cleaning machine, arc plasma will be ejected through the nozzle, so the surface of complex parts can also be activated. When activated in an air or oxygen plasma, the nonpolar hydrogen bonds of plastic polymers can be replaced by oxygen bonds. It can provide free valence electrons to bond with liquid molecules, thus improving the surface polarity. "Non-viscous" plastics, such as polyformaldehyde, polyethylene and polypropylene, can also have good adhesion and sprayability when activated by plasma at low or atmospheric pressure. The required surface energy can be adjusted very precisely, which also prevents over-activation, which can lead to etching. In a low pressure plasma, gases other than air and oxygen can be used, and these gases must be able to adsorb nitrogen (N2), amine (NHx), or carbonyl (-COOh) at the position of oxygen as the reaction group. The surface of the plastic remains active for 24 hours. However, follow-up treatment should be carried out as soon as possible, because with aging, new dirt will be absorbed. Adhesion of PTFE can also be achieved by plasma treatment, however it is not activated but etched. Metals, ceramics and glass usually have higher surface energy than plastics. If they need to be bonded or printed, it is advantageous to use plasma-surface activators for activation. The surface tension of the solder alloy is very high, however, some of it will still come off the metal surface. Therefore, plasma activation can improve the wettability during the welding process. The activation of the metal is mostly short and the welding must be carried out immediately.
Improvement of plasma treatment technology and bonding coating performance
The barrier coating can be used on the inside and outside of the package, but many factors need to be considered in the specific choice of which method, plasma treatment technology is an effective method in this application. The permeability of the gas in different parts of the PET container is also different due to the biaxial orientation of the molecules inside the plastic. The outer coating is easy to cause mechanical damage. But in order to improve the scratch resistance, secondary coating process can be used for treatment. The advantage of inner coating is that it can prevent the change of packaging bottle material from having an impact on the food performance, but the inner layer is in direct contact with the food, so the interaction between the two must be considered. The coating on the inside of the filling bottle is subject to intense cleaning and may fall off during cleaning. In order to prevent fracturing of the bottle body, the outer space of the bottle body needs to be vacuumed when the vacuum coating system works. In addition to improving the mechanical and optical properties of the polymer, it is necessary to ensure that the polymer has good bonding properties, so plasma surface treatment is needed. The substrate surface condition before coating treatment is an important factor to determine the performance of vacuum deposition barrier coating. Many common polymers have low surface energy, so it is difficult to get a good barrier layer by coating treatment. The surface of the material can be treated by plasma treatment with high-energy ions, free radicals, electrons and neutral particles, which can make the surface modified molecules reach a certain depth. In the process of plasma surface treatment modification, not only dirt (such as organic matter) can be removed, but also some functional polar groups can be generated, which promote the bonding and generate the compensation effect through crosslinking. Corona discharge is often used in the process of winding coating, which is efficient and economical for many polymers. According to the practical application, the newly developed surface treatment technology can be used to ionize the mixed gas in the rf plant, combine with the DC magnetron sputtering technology, and use the plasma treatment technology to oxidize, nitride, ammoniate or hydrolyze the surface, so as to enhance the surface energy of the material and improve its binding performance. In addition, the surface morphology of selected materials also has a great influence on the performance of the barrier layer. For example, a smooth, flat base is easier to coat with high-quality septal faults.
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