Glass mesh printing failures are caused by a variety of factors, including screen printing screens, screen printing squeegees, screen printing inks, screen printing equipment, silk screen materials and operating technology. There are single reasons for the occurrence of silk screen failures, but more are the result of cross-effects of various causes. This is the operator's special attention when determining the cause of the failure and taking appropriate countermeasures.
1. Oil Absorption Felt Description
Oil Absorption Felt is made of oil-friendly super-fine fiber nonwoven Fabric or 100geniue wool materials, Oil Absorption Wool Felt can quickly absorb the oil dozens of times its weight.
Color: white/wool natural yellow color.
And it doesn`t absorb water. With a light weight, floating in the water
2. Industrial Oil Absorption Felt Specification
Material
100% Wool or Polyester
Thickness
1mm-50mm
Density
0.10g/cm3-1.0g/cm3
Width
1-2m
Length
1-200m
3. Industrial Oil Absorption Felt Feature
Small specific gravity, light weight, doesn`t absorb water, not deformation;
become loose after oil absorption, not affected by temperature, excellent acid and alkali resistance, anti-corrosion, easy to store
4. Industrial Oil Absorption Felt Application
Mainly used for the cleaning of manufacturing, aviation, petrochemical and other industries;
Oil removal for slick oil, Battery , steamship, various oil spill recovery processing, etc.
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First, paste version
Paste plate, also known as blockage, refers to the phenomenon that the screen printing graphic through-hole portion cannot transfer ink to the substrate during printing. The appearance of this phenomenon will affect the quality of printing, and even in normal cases, normal printing will not be possible.
The cause of the paste phenomenon generated during the screen printing process is complicated. The reason for the paste can be analyzed from the following aspects.
1. The reason for the substrate. The surface of the glass is not cleaned, and there are also watermarks, paper marks, mime prints, hand prints, dust particles and the like. This caused a paste.
2. Reasons for workshop temperature, humidity and ink properties. The screen printing workshop requires a certain temperature of about 20 degrees and a relative humidity of about 50%. If the temperature is high and the relative humidity is low, the volatile solvent in the ink will quickly evaporate, and the viscosity of the ink on the net becomes high, thereby blocking Mesh. Another point to note is that if the downtime is too long, it will also produce a paste phenomenon. The longer the time, the more serious the paste. Secondly, if the ambient temperature is low, the ink flowability is poor and the paste is easily generated.
3. The reason for the screen printing plate. The prepared screen printing plate can be used after being rinsed with water and dried before use. If it is placed in the plate for a long time and is not printed in time, it will adhere to dust more or less during the preservation process. If it is not cleaned during printing, it will cause paste.
4. Reasons for printing pressure. Excessive embossing force during printing will cause the squeegee to bend. The squeegee is not in line contact with the screen printing plate and the substrate, but is in surface contact, so that the ink cannot be scraped clean every time the squeegee is left, leaving a residue. Ink, after a certain period of time, the conjunctiva will cause a paste.
5. Reasons for improper gap between screen printing and substrate. The gap between the screen printing plate and the substrate should not be too small, and the gap is too small. After the printing, the screen plate cannot be separated from the substrate in time. When the screen plate is lifted, a certain ink is stuck on the bottom of the plate, which is also easy. Cause a paste.
6. The reason for the ink. When the particles of the pigment and other solids in the screen printing ink are large, the phenomenon of blocking the mesh is apt to occur.
In addition, the mesh size and the through-hole area of ​​the selected mesh are smaller than the particle size of the ink, and it is also one of the reasons why the ink of the coarser particles is not easily passed through the mesh. The paste caused by the large particles of the ink can be solved from the time of manufacturing the ink, and the main method is to strictly control the fineness of the ink.
In the printing process, the viscosity of the ink is increased to cause the paste, the main reason is that the ink solvent on the screen printing plate evaporates, resulting in an increase in the viscosity of the ink, and a phenomenon of sealing the net occurs. If the printed graphic area is relatively large, the ink on the screen printing plate consumes a lot, and the paste phenomenon is less. If the image area is small and the ink consumption on the screen printing plate is small, it is easy to cause a paste. The countermeasure is to use a small number of ink replenishment principles. The poor fluidity of the ink causes the ink to form a paste when it is not passed through the screen. This can be solved by reducing the viscosity of the ink and improving the fluidity of the ink without affecting the print quality.
After a paste failure occurs, it can be scrubbed with a suitable solvent for the nature of the ink on the plate. The main point of scrubbing is to start from the printing surface and gently wipe from the middle to the outside. Check the plate after wiping. If there is any defect, it should be repaired in time. After the repair, the printing can be restarted. It should be noted that the plate is thinned every time it is scrubbed. If the film causes a major defect in the film, it has to be updated.
Second, the ink is not fixed firmly on the substrate
1. When printing on glass, it is important to perform strict degreasing and pre-treatment inspection of the glass before printing. When a substance such as grease, a binder, or a dust adheres to the surface of the glass, the ink and the glass are poorly bonded.
2. Insufficient adhesion of the ink itself causes the ink film to be fixed firmly, and it is better to replace other types of ink for printing. If the dilution solvent is improperly selected, the ink film may not adhere well. When selecting a dilution solvent, the properties of the ink should be considered to avoid the phenomenon that the ink and the substrate are not firmly bonded.