How To Improve The Adhesion Of UV Ink And Its Effective Method

                              How to improve the Adhesion of UV Ink and its effective method


         When printing some materials with UV flat printer, the problem of low adhesion of UV ink to substrate is sometimes caused by the instantaneous drying of UV ink. This article is to study how to improve the adhesion of UV ink to substrate.


        Corona treatment

        Corona treatment is an effective way to improve the adhesion of UV ink! The positive and negative electrodes of the corona device are connected to the ground and the inductive air nozzles respectively. Using high voltage and high Zhou Bo, the electric shock molecules are ejected from the inductive air nozzles, and the electric shock molecules are speeded up to the positive poles with high energy free electrons. In this way, the polarity of non-absorbable materials can be changed, the surface thickness is increased, the ability of combining with ink is enhanced, the adhesion of UV ink can be achieved and the adhesion fastness of ink layer can be improved.


        The surface tension stability of the corona treated material is poor, and over time the corona effect will gradually weaken. Especially when stored in a higher humidity environment, the corona effect will weaken faster. If the corona substrate is used, Must work with suppliers to ensure the substrate is fresh. Common corona treatment materials include PEPPE, Nylon / PVC PET, etc.


        UV ink adhesion accelerator (AdhesionPromoters)

        In many cases, cleaning the substrate with alcohol increases the adhesion of the UV ink to the substrate. If the substrate has very poor adhesion to the UV ink, or if the product has a higher demand for UV ink adhesion, That can consider the use of UV ink adhesion to promote the bottom coating / UV ink adhesion accelerator.


       The adhesion of UV ink on non-absorbable substrate can be improved and the adhesion of UV ink can be improved. Different from corona treatment, non-polar oil molecules are not found in the material of chemical bottom coating. It can effectively eliminate the problem of unstable corona effect caused by the migration of this kind of molecule. However, the application range of bottom coating is selective and better for substrates such as glass, ceramic, metal and acrylic PET.


       UV ink curing degree

      Generally speaking, in the case of UV ink not fully cured, we can observe the UV ink on non-absorbable substrate adhesion difference. To improve the curing degree of UV ink can be started from the following aspects:

     1) increase the power of UV light curing lamp.

     2) reduce printing speed.

     3) prolonging the curing time.

     4) check that UV lamp and its accessories work properly.

     5) reduce the thickness of the ink layer.


     Other methods

     Heating: in the screen printing industry, it is recommended that the substrate be heated before UV curing before printing the hard substrate. The adhesion of UV ink to the substrate can be strengthened after 15 to 90 seconds of heating with near infrared or far infrared light.


     Varnish: if UV ink is still attached to the substrate after the above recommendation, a protective finish can be applied on the surface of the printed matter.


     Shear: if there is a problem of adhesion during shearing, it is recommended that the substrate be cut to the required size before printing. The cutting tool must be sharp.