To judge the effectiveness of a UV printing device, in addition to accuracy and color effects, attention should also be paid to the friction resistance, bending resistance, high temperature resistance, and water bath resistance of the printed product. These all reflect the adhesion of the printing and directly affect the practical application of the printed product.
How can we improve the problem of weak adhesion in UV printing?
Pay attention to environmental impact
Excessive humidity: When the working environment humidity of UV flatbed printers is too high, there may be residual moisture on the substrate or surface, which makes it difficult for UV ink printing to dry completely and affects the quality of printing.
Low temperature: When the working environment temperature of the UV flatbed printer is too low, it will affect the smoothness of the UV ink. Viscous ink can easily cause problems such as floating ink, unclear printing, incorrect color, and may also cause dryness, peeling, and other issues.
Therefore, it is necessary to avoid storing consumables and operating equipment in excessively harsh environments. Dehumidification or drying can be carried out appropriately according to the climate to maintain indoor air humidity between 30% -70%; The indoor temperature should be kept between 20 ℃ and 30 ℃ as much as possible to reduce the impact of environmental factors on the printing effect.
Pay attention to thorough curing of UV lamps
Different inks may have different curing characteristics. If the UV wavelength of the UV lamp does not match the performance requirements for ink curing, or if the LED lamp power is too low during the printing process, there may be incomplete curing of the UV ink on the material surface, resulting in a decrease in the adhesion of the pattern.
You can try increasing the power of the UV lamp or replacing it with a higher power UV lamp to solve the adhesion problem.
Clean the surface of the substrate before use
When substances such as oils, adhesives, and dust adhere to the surface of the substrate, it can cause poor adhesion between UV ink and the substrate. Insufficient surface treatment of plastic products before printing can also cause ink adhesion failure. Before UV printing, the substrate can be inspected, degreased, and treated to increase adhesion.
Using printed coatings
Printed substrates with smooth surfaces and insufficient adhesion can also cause ink instability during UV printing. Coating can be added to the surface of the material, and different materials can be coated with corresponding coatings to effectively improve adhesion and increase the weather resistance of the ink on the material surface.
Use compatible UV ink
UV printers are generally equipped with specialized ink, which can be divided into soft ink, hard ink, and neutral ink. The ink used for different materials is also different. The quality of ink on the market now varies greatly. The cheaper the ink, the worse its quality, compatibility, and adhesion, which increases the likelihood of clogging and damage to the nozzle. Try to use the ink configured by the device as much as possible, which can greatly ensure the quality of the ink and also make it easier to ensure the printing effect.
Perform flame, corona or other special treatments
In order to improve the adhesion performance with ink during printing, some printing materials must undergo surface flame treatment. For metal materials, degreasing and dust removal treatment must be carried out before printing. After printing, drying treatment should be carried out according to the required temperature of the ink. Improper drying treatment can also cause ink film peeling failure. In addition, in textile printing, in order to make the textile waterproof, waterproofing agents are generally added and coating, coating, impregnation and other methods are adopted, so that poor ink adhesion is less likely to occur during printing.
