Flat screen printing common defect analysis and solution
2016-07-09 16:07:25
1. Pressed paste
The phenomenon showed the outline of the pattern is unclear, fuzzy complex color contact surface or edge airway pressure paste. Pressure will be based on the principle of paste, wet on wet printing, the latter version will be pressed to the previous edition, the number of the next version mouth pressed more serious pressure paste.
Solution: First, you must choose the appropriate blade (hardness), pulp Guayin close to the net; when opened between conditional version and version distance, if necessary, intermediate heating hair; printings arranged in the correct version of the position, the first Indian fine stems India block face; when dealing spend as little as possible out of the draft open, avoid contact with bit too much squeeze; to spend money to make appropriate side filler treatment, to reduce the contact area of the imprint.
2.Paste side
Fabric edge airway pressure paste. Since the fabric margins missing, the first narrow width or patch not in the same straight line, flat screen plasma screen printed onto both ends of the conduction band, stick to the back of the next screen, then print to the next run selvage, resulting paste edge; suction side failure, not a straight line into the side boob; width flat screen close up edge after more than cloth width.
Solution: For a width varying fabric must rearrange, machine printed into the fabric width need the same width. Two letters from the screen cloth printing width and position of the edge, does not allow any excess paste pattern printed onto the conduction band; suction side intact, when the patch side equidistant from the conduction band, does not drift; squeegee blade width greater than Buffon on each side of at least 5cm above.
3.Melting
printing-shaped profile blurred color pattern to penetrate the fiber direction.
Reason: After cleaning wiper conduction band quit, gray paste with water after the conduction band watermark, resulting in penetration paste printed after; low viscosity paste, dye concentration is extremely thick, printed absorbing excessive amount of pulp or the amount of moisture absorbent and the original paste hold more water-poor, will result in after-opening printing; printings dry on the printed version is not washed, resulting in the previous version of the open, which are required attention.
Solution: Check the conduction band hanging washing water tank means is good; a good choice to hold the aqueous paste; reasonable inspection process prescribed amount (saturated amount of dye, the amount of additives different fabric), pulp aside time not too long; printings Version washed dry before use.
4. Scraped incorrectly
Different color paste is scraped into form does not shade or light-colored printings mixed with a dark color.
Causes: Dark printing block is large with multiple slurry; column side printing box well, printings pulp imported version from the conduction band; a mistake when adding liquid chromatography.
Solution: The fabric width Elam spend a good bit version. When the printing paste to net income, add less pulp, pulp spare. When changing chromatic scraper to clean, to avoid residual magma into a new color pattern, the pulp can not be a mistake. Without prejudice to complex color conditions, the exchange took Edition location.
5. Frames print
The printings near the edge of the next version showing printing version frame shape abnormalities streak. This is due to improper network version, frame mounting bad, uneven gaps or network version and the conduction band is too small.
Solution: You can slightly raise the screen frame or flat screen frame, can also be processed correctly open printings and printing maintain proper distance from the edge of the screen frame.
A version in color (or uneven squeegee transverse fabric showing tint spaced)
Cause: Screen deficiencies, Sensitive adhesive uneven thickness, uneven exposure printing-shaped, and the impact of differences in the amount of slurry cast. Second, the frame is not on the same plane, or poor installation. Third, the blade is loose, or beating causing uneven squeegee blade opening time.
Solution: For the defect caused by the halftone screen needs to re-create, if it is a photosensitive film, you must also check the quality of the film. The frame flatten, but when printing to observe whether the printing shape. Network Installation two consistent height. Scraper blade consistent thickness and consistent level of place.
6. Connected version stains
The next version of the printing color shades embossed or overlap or disengaged. Printing belt running back position settings are not allowed; not regulate the pressure around the blade; network box is too high from the conduction band, he found the edge of the squeegee from the screen off; printings open line size is too large, resulting in the next version mouth pressure area Big.
Solution: According to the printing-shaped back position of the conduction band running back position, or check the conduction band is functioning properly; squeegee pressure is adjusted to just under slurry suitable; regulate the screen height; halftone next version on the back can be large pores fine mesh partial foil ; amending irrational open.
7.Bite printing Edition
Uneven color shades have daisy-like fluff. When the paste is pulled filed printing version, printing version stained paste negative impact of the next version of printing; paste viscosity is too thick or less puffed; some amount of dye is too high.
Solution: Adjust printing paste viscosity paste or adjust puffing time: old slurry was filtered and then replaced with a new or slurry; timely adjustment prescription wash printing version.
8. printings bit exposed at the fabric color or color penetration, as spotted shark skin traits.
Reason: After making printing version curing agent does not rinse or printing version used for too long, which makes the slurry mesh smaller cause blockages; scraper or improper selection pressure is too small, not enough to lower the slurry; the viscosity of the paste is too thick hard squeegee; there is grease, wax and other stains on the fabric; Qiantao printings dry, after being set printing version pick up the opposite.
Solution: Check the production version after version printing hole is good; after each printing stencil to clean; selected scraper force appropriate; prepare for printing fabric must be checked capillary effect, if necessary, re-re-training cloth; every printing paste viscosity paste is tested; and select the number of mesh pattern relative.
9. Crude and thin stems
Cause: screen making thickness defects; magnetic table about magnetic size and cause printing pressure caused by different; screen uneven place, squeegee pressure is inconsistent, edge is not neat, blade thickness inconsistent; squeegee paste without a net.
Solution: carefully check the version of each to back a slender stems are the same flower; check the magnetic magnetic force; printing screen mounting to flat; choosing the blade and the blade pressure adjustment; replace the blade when the blade to be consistent; the good net tube height is adjusted according to the thickness of the fabric.
10.Printing shape skew
The warp and weft yarns of the fabric are inclined or bent.
Cause: printed fabric (thick) is weft sewing or sticking cloth askew bad.
Solution: printed fabric (especially printed geometric flower shaped) need weft and check, after passing before entering the production, joint according to the weft direction parallel sewing; and the upper patch to keep straight.
11. Trachoma
Exposed printed fabric like sand color dot size trachoma.
Reason: screen time than life, a partial loss sensitive adhesive, permeable; poor quality of the plate, is not strong film after film squeegee blade off.
Workaround: always observe the screen, we found that trachoma instantly mended; for halftone strict inspection before the car.
12.Plasma leakage
In the non-printing color appears.
Reason: printing printing version or release version welt bad.
Solution: Check the machine before the Web version, appears midway timely repair.
Plug network
Incomplete or partial printing ribbon color point, white point or part of the missing printings or
13. Mesh plug
Reason: slurry impurities, clogged mesh, especially pigment printing; after long printing mesh edge node slurry; cloth invaded impurities such as lint, etc; when the network system photosensitive film not rinse; fabric strip fluff or wire.
Workaround: When printing ground observation network discovery plug immediately wipe garbage; found a large area of the plug immediately car wash net screen, filter paste; small surface obviously outside the flat screen or the back of the screen there are impurities, tools scrape.
Pine printed version
Ripples appear on the printed pattern.
Reason: The mesh screen and printed fabric yarns organizations overlap, interference; network box boron yarn too loose mesh inappropriate.
Workaround: mesh with oblique boron, mesh fabric angle and the angle of 10-15 degrees to maintain, exchange suitable mesh; stretching tension consistent throughout.
14.fluff
printing-shaped fuzzy feeling displaced ghosting.
Cause: The version from improper operation; screen stretched too loose; conduction band operation and the halftone operation is not synchronized; even Edition operating, the border is pressed hair.
Solution: slow or obliquely from the version played; according to the standard stretch box; check printing machine screen and the conduction band running synchronization problems.
15. Pull printing paste
Similar tadpole-like print.
Reason: the paste is too thin, add too much pulp; pulp yield too soon.
Solution: Pick a good fit puree; you need to adjust the viscosity.
16. Splashing syrup
Color or slurry paste drag caused by flying open.
Cause: The printing operation excessive, improper action from the version; paste viscosity inappropriate; plus pulp slurry tank plus too.
Solution: adjust the viscosity of the paste; appropriate operating force; add less spare.
17.Flying Color spots
Irregular dye color dots sprinkled cloth, forming small dots of color dirty version. Or the same color of the printings contain a color spell color monochrome color point.
Reason: printing paste is too sticky; pulp yield after printing without a net, from the version too fast, too hard; undissolved dye in the paste or attached impurities; forming spots to cloth after printing.
Solution: Place the puree enough time, into a paste good; improved printing operation from the version, screen-sided slant from the light received pulp, squeegee speed adjustment; the dye is dissolved countless available high mesh gauze filter paste, if there is need to adjust paste, pay attention to the operation of the material.
18.Wrinkle printing
Face wrinkled white cloth strips.
Cause: Oil is not affixed flat, wrinkled Indian presence, failed when the printing paste through to the crease inside; fabric is not firmly affixed, to be brought up from the version when, after a longer version of the printing press down when changing location; Baipi track width and side edges, crease when the patch; seam produced uneven wrinkled or printed silk into uneven tension; on the flat end of the conduction band of the resin, so that India scrape uneven.
Solution: Into the fabric to be smooth, adjust well into the fabric tension; check the viscosity of the resin surface conduction band or patch pulp viscosity, check the hot rollers questions or patch roll pressure lay patch pulp or re resin; seam to smooth the patch will not affect the results.
19.After part of the warp and weft of the fabric flip or move to the positive and negative.
Causes: poor permeability paste, the dye can not penetrate into the interior of the fiber; squeegee too little, not enough to lower the slurry, resulting in insufficient fact-colored dye, fabric water repellent, does not absorb paste; when post-processing after printing washing Phi silk, fabric structure relatively loose, small amount of fiber flip, exposing the white on the bottom.
Workaround: Ensure puree swelling time to prepare a paste mixing evenly, so when the printing paste penetrate into the thickness of the cloth two-thirds; for the water-repellent fabric line to be re-processed fabric; printing process after attention when uniform tension, In particular twill, satin weave fabric type.
20. Printing depth
Color same color or shades printing at the back, mud in size.
Reason: the conduction band of rugged resin; paste viscosity is too high, poor moisture absorption fabric; scraper uneven force; halftone inconsistent thickness, screen not in the same horizontal plane.
Solution: Check the patch resin smooth surface like a mirror; viscosity paste inspection, adjustment, detection fabric capillary effect, all failed to be refurbished after conducting printing; shades in the same place to reproduce the printing is mesh Version or scraper problems. Scraper blade uniform and consistent about scraper pressure tube network penetration rate took place at pulp consistency.
21.Left, right shades
Cloth on both sides of the intermediate hue and different depths.
Reason: Fabrics bleaching bad; screen frame mounting bad; the blade is formed is not enough; printing conduction band edge thick resin.
Workaround: When the fabric bleaching cloth PL-1 to homogeneity; consistent level of the frame from the conduction band; squeegee blade distance beyond the edge of the fabric more than 5cm prevent deceleration effect when flipping the blade; different printing width of fabric, to be converted patch location.
22. Water stain
It occurred in anti-India (anti-paint) and Diaoyin the printing around the colored irregular displacement.
Reason: reducing the amount of excess, not all in the steaming process of decomposition, in hot and humid state continues to destroy colored; when halftone printing back staining, printing sets are not allowed; mesh stretching tension is too loose.
Solution: According to the amount of dye and printing colored shades, proper control of reducing the amount of testing prior to use; middle note printing operation, do not frequent debugging; screen tension unified appropriate.
23. Discharge color dirty or poorly resist effect
Cause: insufficient or reducing the amount of additive in question; squeegee is under little pulp; printing drying after air exposure time is too long, early oxidation; steam improper conditions; colored dye can pull poor.
Workaround: Before printing on each vehicle must be colored white cloth pull test, to prevent not pull into the cloth printing; printed on the front paste in reducing the actual active ingredient is measured; moderate pulp squeegee down, maintain adequate slurry cloth; printing after drying fabric with cloth to prevent air and oxygen encountered early oxidation and timely steaming, keeping the steam pressure steaming.
24. Stain friction drag open
Fluff with a printing pattern in the direction of the edge.
Cause: When printing drying, drying room temperature is low, not timely drying, rubbing cloth-shifting when the car dragged off; contact with foreign objects when printing the pattern has not been sufficiently dried, and contamination to other parts of the formation of defects; in the printed fabric is not sufficiently dried state of the fabric drag pressure.
Workaround: Indian Oven backward to be smooth, drying room temperature to ensure drying conditions. Decided drying temperature according to the fabric thickness and speed; not loading too full after the cloth and squeeze down or drag.
When printed fabrics up local printing site expansion out of the conduction band of fabric, seersucker similar shape, such as a thin strip of cloth round printing, printing thick nylon umbrella
Reason: stretch fabric when wet.
Workaround: In the extended state of qualitative fabric before printing, so that in the event of wet elongation lose space (Taiwan plate printing is a wet patch to solve this problem).
25. Printed printing arch
Cloth uneven, performance stretch fabrics or knitted fabrics pigment printing portion on the highlight.
Causes: Stretch fabrics or knitted fabrics have a certain flexibility with elongation phenomenon patch, after printing, textile coatings portion of the printed fabric is fixed in a stretched state, the printing part is the return to its original state, since printing and the non-printing parts of the contraction varies, causing fabric arch.
Workaround: Before printing on fabric overfeed process, even beyond the end product shrinkage, relaxation of tension-free patch.
26. After finishing color fastness of decline, after washing color fastness meet the standards, but by some soft or finishing, finished color fastness (especially rubbing fastness) dropped even half a grade level.
Reason: add some softener, fabric surface to form a film, and fiber in combination, but also part of dye binding and, therefore friction when the dye out. Especially when combined with disperse dyes and fibers, dye molecules altar electron donating groups and electron withdrawing groups so that the dye molecule dipole, and = C = 0 group dipole moment is formed on the fibers to form a hydrogen bond. At a high temperature, a small amount of unbound or bound unsound disperse easily precipitated.
Workaround: reactive printing, select the appropriate softener. For disperse dyes printing, the most convenient solution is baking at high temperature into a simple new water immediately.
