Advantages and disadvantages of UV curing coatings
1 advantage
1.1 speed, is conducive to the production line
Liquid paint the fastest can be cured in the 0.05~0.1S time. Compared with the traditional shall be hours or even days to curing the thermosetting process, and greatly improves the production efficiency, save the semi finished stacking space, to meet the requirements of production automation. In addition, because it is room temperature curing, can avoid the heat sensitive substrate due to the high temperature may be damaged.
1.2 low cost
UV curing of low energy consumption, and coatings, high solid content, makes the material consumption greatly reduced; in addition, UV curing equipment investment is relatively low, plant covers an area of less.
1.3 little pollution
UV coating is substantially free of Vol (volatile organic Compounds of the volatile organic compounds), friendly to the environment, the construction site is not easy to generate fire or explosion accident.
1.4 excellent coating performance
The coating is formed by chemical cross-linking reaction to form a three-dimensional network structure of the membrane, and thus the overall performance of different.
2 limitations
2.1 the curing surface is limited
Light travels in straight lines, so the need curing surface to plane and convex is appropriate, and may produce light shadows concave and multidimensional surfaces to a curing difficult.
2.2 coating process is difficult
UV coating surface energy is high, the wetting of the substrate is relatively poor, also due to the UV curing is produced at the moment, internal stress of coating high, the adhesion of the coating between difference and due to the fast rate, paint antifoaming and short leveling time, easy to produce surface defects.
2.3 color effects on curing
The paint on the absorption of UV, and the inhibition of the reflection scattering, UV curing, so the UV coating on varnish.
3. Application of UV coating
a)wood finishing
Filling putty, surface coating, coating decorative veneer paper;
b)Paper, printed matter processing
c)plastic coatings
PVC wear-resistant floor surface coating, organic glass, polycarbonate sheet surface hardening coating, vacuum plating / bottom surface.
d)Metal coating
Anti rust coating, dry plating coating, metal products decorative coating.
e)Enhanced coating of optical fiber
Common defects and treatment methods of UVPaint roller
Common defects | Performance phenomenon | Analysis of the causes | Proposed processing method |
The workpiece before and after the end of "accumulation" or "leakage paint head, less paint" | The work before and after the end of "accumulation" or "leakage paint head, less paint" phenomenon | 1. Bending deformation of the workpiece, the thickness of the front and back ends are not uniform, large or small. 2. Paint viscosity is too large. 3. Is, reverse roller speed difference, height difference and conveyor belt speed regulating improper. 4. The amount of coating is not properly controlled. | 1. Choose and check the work piece. 2. Select a small viscosity of the paint or slightly rise paint temperature. 3. Adjust the reverse roller speed difference, height difference (pressing force on the workpiece) and the belt line speed. 4. Proper control of coating weight. |
The color uneven surface of the coating | The color of the surface coating is not uniform (dye color) | 1. Workpiece bending deformation. 2. Working sand light is improper, produce wave shape. 3. The roller is damaged or damaged. Roller sanding machine | 1. Choose and check the work piece. 2. Sander sanding to re adjust the uniform. 3.Repair roller coating machine or sanding rollers to qualified. |
The coating surface of a horizontal | The surface of the workpiece coating appears horizontal and shallow printing | 1. The bending deformation of the workpiece itself, sanding improper wave shape. 2. Cots is damaged,the concentricity of the poor. 3. High rollers low-key properly. 4. Sander roller damage concentricity, improper regulation. | 1. Choose and check the work piece. 2. Repair or replace the paint rollers. 3. Adjust the rollers height to the appropriate location. 4. Repair or replacement of sanding roller, adjust the. |
The coating surface is produced with straight lines | Longitudinal marks appear on the coating surface of the workpiece | 1. Paint leveling property is not good. 2. Roller damage, rough, light bath is bad. | 1. Choose the appropriate leveling UV paint well. 2.Maintenance cots, improve concentricity, surface finish. |
The coating surface of fine linen | The surface coating can do fine pits | 1. The viscosity of coating is big, and the leveling property is not good. 2. The rubber hardness is too soft, smooth, concentricity is not good enough. 3. Not on the workpiece clamping force of rollers. | 1. With low viscosity, good levelling of the UV coatings. 2. The replacement of the rubber hardness large, until the 90-100 degree, improve the roller surface finish. 3. To improve the pressing force of rollers on the workpiece. |
The coating surface "orange peel wrinkle" | The film "wrinkle orange peel appearance" | 1. The viscosity of coating is big, and the leveling property is not good. 2. Sanding caused uneven,. 3.Primer is not sufficient. 4. The amount of coating is not properly controlled. | 1. With low viscosity, good levelling of the UV coatings. 2. Re adjust the sander, re sanding to uniform. 3. The number of 1-2 increased primer. 4. Control of coating weight appropriate. |
Uneven surface gloss coating | The whole or part of the same block or block floor of the semi - or full - mute paint is off or on the low side | 1. The coating mixture is not uniform. 2. Coating amount is not uniform. 3. In the paint, wear resistant powder stirring is not uniform. 4.Leveling time is not enough, the non uniform coating curing. | 1. Select the UV extinction powder mixing paint evenly. 2. As far as possible to control the coating amount is consistent and uniform. 3. As far as possible super wear-resistant powder stirring evenly. 4. Extend the leveling time, coating uniform curing. |
The coating surface of a small hole | Film surface with a pinhole or small bubbles | 1.UV primer filler sealing degree is not good. 2. Paint mixed with water or other solvents. | 1. Try to do UV primer, back filling fully. 2. Try to avoid mixing with water or other solvents. |
The coating surface of a circular hole | The surface of the sand film is a crater shaped crater, with different sizes and different distribution. | 1.UV paint compatibility is not good. 2. Mixed with oil and water and other incompatible 3. The surface of the work piece is polluted, and the surface is not clean. | 1. Choose good compatibility coatings UV. 2. Try to avoid mixing with oil and water and other incompatible. 3. Try to clean the paint line around the environment, do a good job of cleaning the workpiece surface, to avoid pollution. |
The coating surface is pitted | A large film surface pitting | 1.UV paint or improper storage temperature is too high, has begun to produce pre curing paint, gel caused by small particles. 2. Dust pollution, dust caused by improper. | 1. Selection of stable performance coatings UV. 2. Strengthen the workshop, production line, surface dust removing effect. |