Waterborne non-woven inkjet fault recovery
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First, the common fault - gag
Main reasons: 1. The ink is not fully shaken before spraying, causing the pigment deposited on the bottom of the tank to clog the nozzle when spraying; 2. The force of shaking the ink before spraying is too large, causing the stirrer (glass beads) to break and block the nozzle ; 3. After spraying, there is no inverted cleaning nozzle after use, causing the nozzle residual ink to dry and block the nozzle; 4. Inverted or side down during storage, the pigment precipitate in the ink blocks the discharge hole of the valve; 5. The product exceeds the shelf life The resin or pigment filler in the system is used to coarsely block the valve discharge hole; 6. The solvent evaporates too quickly in the aqueous inkjet system; 7. The inkjet is too thick; 8. The ink does not resist freezing.
Precautions: 1. Shake the ink well before spraying; 2. Master the correct method of shaking, avoid excessive force when shaking the ink; 3. After using it once, do not use it, and spray the ink tank for 1-5 seconds. After removing the residual ink of the nozzle, store it again to ensure the normal use next time; 4. Be careful not to invert or side the can body during storage; 5. Use it within the shelf life before use; 6. Adjust the amount of solvent; 7. Inkjet grinding Some; 8. Add antifreeze.
Remedy: 1. Shake the ink and then invert the ink tank for 1-5 seconds; 2. Use gas to open the blocked nozzle; 3. Add 3H4 heat stabilizer; 4. Replace the nozzle; 5. Re-filter the inkjet; 6. Place on a hot water bath to dissolve it.
Second, the common fault - the end of the spray (spray pressure drop)
Main reasons: 1. There is a reverse spray phenomenon during spraying; 2. The ink tank is excessively tilted during spraying, and the inclination angle exceeds 45°; 3. The automatic inkjet storage time is too long, exceeding the shelf life; 4. The bending direction of the liquid guiding tube of the valve is The nozzle holes are in the opposite direction.
Precautions: 1. Master the correct spraying technology to avoid backspray; 2. Avoid the ink tank angle more than 45° when spraying; 3. Avoid expiration or misuse of other inkjet products; 4. When spraying to the remaining 20% Left and right, when the spray feels that the concentration (or viscosity) of the discharge is not enough (the spray is mainly propellant), the nozzle is rotated at an angle of 180° to continue use.
Remedy: 1. When it is found that the spray pressure drops, try to spray the inkjet once. 2. When the spray pressure is insufficient and the temperature is low, the ink can be heated by 50 °C water and then operated.
Third, common faults - inkjet viscosity is too low (ink is thin, cover is insufficient)
Main reasons: 1. The ink is not fully shaken before spraying; 2. The tilt angle of the ink tank is too large when spraying, so that the gas content in the ink system is high, the ink is diluted; 3. The ambient temperature of the spraying site is too low; 4. The spraying environment lacks heating and drying equipment, and the air circulation is not smooth; 5. The one-time spraying is too thick (such as flashing color).
Precautionary measures: 1. Correctly master the spraying technology to avoid back spray and oblique spray; 2. Avoid inkjet in rainy, wet or cold weather.
Remedy: 1. Operate the spray at room temperature or put the sprayed print into a heating device at 50-60 °C.
Fourth, common faults - sag
Main reasons: 1. The nozzle is too close to the surface to be coated; 2. The nozzle moves too slowly 3. The spraying environment is poorly ventilated; 4. The flashing time between the layers is insufficient during spraying; 5. The surface is contaminated.
Precautionary measures: 1. Use the correct spraying distance (15-25cm); 2. Keep the nozzle moving speed (30-60cm/s); 3. Keep the environment well ventilated; 4. Set the corresponding color layer flashing time according to the temperature ( 3-10min); 5. Make sure the painted surface is completely clean before spraying.
Remedy: 1. Slightly hang the ink film thoroughly dry (fixed temperature 16h ripening period), sanding with P1500 or more sanding, waxing or coating varnish; 2. Severe sag to be fully dry After grinding with P800 or more sandpaper, it will be re-sprayed, usually the length of the spray will be lengthened.
Five, common faults - pinholes, ink drops
Main reasons: 1. The ink is not evenly mixed; 2. The viscosity of the ink system is too high; there are bubbles; 3. The finger presses the nozzle unevenly, the nozzle ink is not smooth, resulting in ink accumulation; 4. The ink film is too thick or too thin ; 5. The surface of the coated substrate is contaminated.
Precautions: 1. Shake the ink vigorously before spraying until it is evenly mixed; 2. Spray at a constant speed; 3. Thoroughly clean the coated surface before spraying.
Remedy: 1. Slight bubbles, ink droplets can be flashed and cleaned with a clean cotton cloth and continue to spray; 2. Severe bubbles, ink droplets, after the ink film is completely dried, polished with P800 sandpaper, even with heavy alcohol. The mixed solvent is washed with cotton wool and then sprayed.
Six, common faults - orange peel
Main reasons: 1. The spraying distance is too far or too close; 2. The ink is not evenly atomized; 3. The spraying is too thick or too thin.
Precautionary measures: 1. Master the correct spraying technology; 2. Fully shake the ink or properly warm it; 3. Use even force when the index finger presses the nozzle to ensure uniform and constant ink output.
Seven, common faults - whitening (matte)
Main reasons: 1. The spraying environment temperature is high and the humidity is large; 2. The spraying workshop site is poorly ventilated or cold; 3. The solvent ratio in the ink system is poor.
Preventive measures: 1. Avoid rainy weather, high temperature and high humidity weather operation; 2. Design inkjet production with mixed solvent.
Remedy: 1. Rapidly spray 80TNY white water or O solvent or alcohol ether solvent in the whitening place; 2. Immediately add infrared light or electromagnetic wave baking (less than 60 ° C) when whitening occurs; 3. Toner film After drying, waxing and polishing to remove or re-spray with alcohol and water mixed solvent, can also be saved in its ink plus X8 or trace 3114.
Eight, common faults - wrinkling, curling
Main reasons: 1. Ink film layer is too thick; 2. Poor self-drying conditions (such as low temperature, high temperature weather or excessive ventilation); 3. Spraying ambient air is polluted or poor ventilation; 4. Crosslinking agent in the ink system Excessive or colored material is too small.
Precautions: 1. Avoid spraying too thick ink film layer; 2. Ensure the air in the inkjet environment is fresh and have normal temperature and humidity; 3. Control the specific surface area of the coloring material and moderately reduce the crosslinking agent.
Remedy: 1. Slight wrinkles or slight curling angle must be smoothed after the ink film is dry or cleaned with alcohol water and re-sprayed; 2. Heavy wrinkling or heavy warping needs to be thoroughly used After the water mixed solvent is cleaned, it can be re-sprayed, or it can be saved by adding color paste or 308 leveling agent to the ink system.
Nine, common faults - bite the bottom (color)
The main reasons are as follows: 1. The background color and the complex color are not matched. The solvent in the upper layer ink system has a certain solubility to the previous one (such as the background color); 2. The front color is not dry, that is, the surface ink is sprayed; 3. The latter color (Face ink) Sprayed too thick at one time.
Precautions: 1. Avoid direct spraying on the same ink film; 2. Add gray or thinner between the unmatched background color (previous color) and the complex color; 3. Apply thin spray several times to the printing operation. Leave the flashing time between the passes; 4. Pull the distance between the inkjet and the substrate.
Remedy: 1. Avoid using true (strong) solvents for inkjet systems; 2. Add appropriate amount of curing agent or drier.
Ten, common faults - cracking
The main reasons are as follows: 1. The front color (such as the base color) and the back color (such as the complex color) are not matched. The flexibility of the front color and the latter color is especially too large. 2. The front color ink layer is not dry. That is, one color after spraying; 3. the latter color is too thick; 4. The old bottom ink layer is caused by excessive, aging, chalking, brittle cracking, etc.
Precautionary measures: 1. Confirm that the previous ink film (ground color) and the latter ink film can be matched, and if necessary, spray the ink layer; 2. Master the correct spraying technology; 3. The aged or excessive coloring agent ink layer should be After the cleaning, the ink is applied.
Remedy: 1. Shovel to the substrate or wash it with alcohol water and re-ink.
Eleven, common faults - rough ink layer
Main reasons: 1. The nozzle is too far from the surface of the substrate to be sprayed; 2. The spray can moves too fast; 3. The ink fineness is too thick.
Precautions: 1. Master good inkjet technology; 2. Ensure a good spray environment; 3. Fully filter the ink.
Remedy: 1. After a light dry spray, the ink film is dried and then wetted with P1200C sandpaper to restore the gloss. 2. Severe dust, granules are polished or leveled or re-sprayed.
Precautions: 1. Avoid long-term exposure of the ink film to sunlight; 2. Keep the ink film clean as much as possible; 3. Increase the medium content by appropriate amount; 4. Control the pH value between the colorant and the medium to be alkaline; A certain degree of rewet in the process of ink film formation.
Remedy: 1. Remove the powdered old ink layer with BOTNT deinking agent, or work with the blade to the substrate; 2. Increase the medium connecting the coloring material (such as softer binder); Apply an appropriate amount of UV-resistant absorbent.
Twelve, common faults - peeling off
The main reasons are: 1. The substrate has oil, dust and stains; 2. The surface of the non-woven fabric is too smooth; 3. The old bottom layer is caused by aging, chalking and brittle cracking.
Precautions: 1. Ensure that the inkjet surface is completely cleaned; 2. Remove the oil stains, powder layers, etc. from the surface before inkjetting; 3. Remove the aged ink layer and spray the surface ink.
Remedy: 1. Scrape the peeling part and the surrounding parts of the adhesion and re-injection.
Thirteen, common faults - not washable and smashed
The main reasons are as follows: 1. The PH value of the binder in the water-based non-woven inkjet system is too high or too low, especially the rewetting and resolubility; 2. The ink is too hard (the coloring material is too much or the softening point of the binder is too High) or excessive use of crosslinkers.
Precautions: 1. Control the pH value of water-based inkjet 6.5-7.5; 2. Select a coloring material with small surface tension and softening point between 100-130 °C; 3. When the ink formula is designed, add appropriate amount Alcohol ester or silicone oil; 4. Introduction of oil mustard amide dispersant.
Remedy: 1. Add pH adjuster; 2. Control the technical parameters of the binder or introduce appropriate amount of film-forming aid; 3. Add appropriate amount of plasticizer and slip agent.
Fourteen, common faults - dust, particles
Main reasons: 1. The surface of the substrate to be sprayed is not cleaned; 2. The inkjet environment is polluted, such as dust falling in the workshop, dust in the air, etc. 3. Other sources of pollution such as dust on the operator and coverings.
Precautions: 1. Thoroughly remove the surface to be sprayed; 2. Ensure the cleanliness of the inkjet environment and clean the air; 3. Remove any incompetent sources of pollution; 4. Seal the surface that will cause dust; 5. Control the temperature and humidity of the workshop .
Remedy: 1. Slightly granules are wet-polished with sandpaper above P1200, polished or sprayed with a varnish; 2. Severe dust, granules are polished and then re-sprayed.