Nano-processing technology for non-absorbent material printing
We are a big printing company in Shenzhen China . We offer all book publications, hardcover book printing, papercover book printing, hardcover notebook, sprial book printing, saddle stiching book printing, booklet printing,packaging box, calendars, all kinds of PVC, product brochures, notes, Children's book, stickers, all kinds of special paper color printing products, game cardand so on.
For more information please visit
http://www.joyful-printing.com. ENG only
http://www.joyful-printing.net
http://www.joyful-printing.org
email: info@joyful-printing.net
In the field of special printing, plastics can not be directly printed by printing materials, and the surface of the printed materials should be subjected to surface treatment and surface roughening, so that the ink can be smoothly attached to the surface, although the surface modification technology is It has been a year, but its breadth and scale of application have grown significantly in the last 10 years. Much of this growth was attributed to the development and spread of rapid and reliable surface characterization techniques. These methods include chemical, photochemical, and high energy physics to improve the polymer surface. Chemical methods include reactions such as halogenation, addition, etching, and oxidation. Photochemical methods include surface reactions such as oxidative and non-oxidative depolymerization, halogenation and photografting. Physical methods include corona discharge, plasma, electron and ion beam processing. This article will introduce corona treatment, UV treatment and ion plasma treatment.
▼Corona treatment
The principle of corona treatment is to use an electrostatic discharge method to improve the coating adhesion of a plastic film, and to solve the problem of adhesion caused by printing of a polypropylene or polyethylene film. In addition, the moisture generated on the surface of the film and the high solids radiation cumable ink cause an increase in surface energy. For example, both polyvinyl chloride and polyester are such films. The pretreatments generally employed for the film include: combustion treatment, corona treatment, or coating work to improve adhesion.
The corona treatment system includes: a generator, a high voltage transformer, and a treating machine. The processing machine is basically a capacitor, and the processed material is placed between the electrodes, so that The voltage is gradually increased until the purpose of corona treatment is achieved. Therefore, corona treatment can increase surface oxidation, promote chemical bond cleavage and cause more hydroxyl groups, carbonyl bonds and hydrogen peroxide. When the key is pressed, the surface of the film changes to rougheng, which reduces surface contamination.
The plastic film is typically placed between the rollers and treated with a bipolar material and separated from the electrode surface by the electrodes by a few centimeters. Corona treatment decreases with time, and its influencing factors include: elevated temperature and humidity. In addition, there are additives to reduce surface energy and improve slipperiness after coating. Therefore, corona The treatment needs to avoid the occurrence of rabbits and the increase of surface energy, which affects the loosening and winding.
Corona treatment is used for various changes in the film and related reports. The applicable range is polypropylene and low surface energy plastic. When the air gap is raised to 5omm, the voltage is 5600 OKHz, so that the corona discharge can be controlled.
▼UV treatment
UV treatment is generally suitable for the combustion treatment of polypropylene buffers produced by the automotive industry. The treatment method is divided into two stages: first, the buffer is sprayed with a primer to form a layer of 3~5um. Film. The primer is mainly benzophenone or chlorinated polymer. The purpose of the primer is to add to the surface to improve the properties of the polypropylene. Therefore, the primer can be uniformly coated on the plastic to prevent ultraviolet rays from being irradiated. Therefore, Suitable for top coating operations on bumpers.
▼Ion slurry treatment
Recently, the ion slurry treatment method has been highly valued, and the method can improve the adhesion of the surface of the plastic film and improve its physical properties, such as wear resistance and gas permeability. The ionic slurry method is a low pressure vacuum in a cold or non-equilibrium Under the use of voltage to produce ion paste, cold ion paste is usually used in the electronics industry, such as: circuit melting and shielding of photonics, as well as the role of clean contact surface, so as to apply insulating coatings ). Such equipment is quite expensive compared to pre-treatment equipment, so the scope of application of this method is limited, and it has the advantage that the engineering is clean and only a small amount of volatile organic compounds (VOCs) are produced. However, this method can promote the surface energy and reactivity of the plastic film surface. In addition, it also has the function of regeneration. This method can also provide good bonding and synthesis in electronic applications. Potting compound.
Ion slurry treatment is widely used in plastic surface treatment. Ion paste is produced by using components and electrons from each other, or placing electrons on the circumference and components at the center. AC ions usually use microwave or electric frequency. The airflow entering the vacuum chamber must be maintained at 50~100 cm3 per minute. The surface depth treated by this method is about 0. 02 μm. Before this method is performed, the surface dirt must be removed. Usually, the plastic surface is exposed to electrons. The impact of positive ions and photon (photon), as well as the type, pressure and strength of the ion paste, the influencing factors are as follows:
The organic contaminants present on the surface of the joint, when the ion slurry method is utilized, the dirt is destroyed to cause a vapor phenomenon.
Since the ion paste destroys the chemical bond, an ablation phenomenon occurs to cause small molecules on the surface of the plastic. This phenomenon is due to the fact that the crystalline state of the amorphous plastic is relatively easy to remove due to the semi-crystalline state, thereby changing the surface state.
The use of ion paste treatment can break the surface of the plastic and ablate the surface molecules, resulting in new chemical groups. For example, polar functional groups (such as hydrogen groups) containing oxygen molecules can increase surface energy.