{"id":10980,"date":"2026-08-01T00:00:43","date_gmt":"2026-08-01T00:00:43","guid":{"rendered":"https:\/\/longchangchemical.com\/?p=10980"},"modified":"2026-08-09T14:54:11","modified_gmt":"2026-08-09T14:54:11","slug":"waterborne-screen-varnish-additives","status":"publish","type":"post","link":"https:\/\/longchangchemical.com\/de\/waterborne-screen-varnish-additives\/","title":{"rendered":"Waterborne Screen Varnish Additives: Fit & Defects"},"content":{"rendered":"

Waterborne screen varnish additives<\/strong> must be selected around mesh transfer, stencil release, drying and the finished print. First stabilize viscosity, screen, squeegee, deposit and dryer. Then separate flow from slip or anti-blocking. One product cited in many generic shortlists\u2014D912R\u2014is explicitly solvent-based and should not enter a waterborne trial.<\/p>\n

\n
\n
Transfer<\/strong>
Mesh, squeegee, rheology and deposit.<\/div>\n
Film<\/strong>
Flow, air, pinholes and drying.<\/div>\n
Finish<\/strong>
Adhesion, gloss, slip, block and wear.<\/div>\n<\/div>
Original waterborne screen varnish map: process fit comes before surface additives.<\/figcaption><\/figure>\n

Lock the printing process first<\/h2>\n

Record substrate and treatment, mesh count and thread diameter, stencil thickness, squeegee hardness\/angle\/pressure\/speed, snap-off, flood cycle, varnish temperature, viscosity at a defined shear, solids, pH, wet deposit, flash, dryer temperature and line speed. Compare candidates with the same screen history and controlled water loss.<\/p>\n

Identify where the defect appears: in the screen, immediately after print, during drying, after stacking or during use. Screen drying and mesh marks are not the same as poor leveling; bubbles introduced by mixing are not the same as craters from contamination.<\/p>\n

Correct the shortlist<\/h2>\n\n\n\n\n\n\n\n
Produkt<\/th>\nPublished system fit<\/th>\nDocumented range\/process<\/th>\nDecision<\/th>\n<\/tr>\n<\/thead>\n
3345<\/a><\/td>\nWater, solvent and UV<\/td>\n100% active; 0.1\u20131.0%<\/td>\nEligible flow\/leveling screen<\/td>\n<\/tr>\n
3482\/3482X<\/a><\/td>\nWater only<\/td>\n80\u00b12% solids; 0.05\u20131%; staged water dilution<\/td>\nEligible slip\/wear screen with warnings<\/td>\n<\/tr>\n
D912R<\/a><\/td>\nSolvent-based systems only<\/td>\n2% active; 0.1\u20130.25%; grind-stage addition<\/td>\nExclude from waterborne formulation<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Use 3345 for a verified flow defect<\/h2>\n

3345 is a polyether-modified polysiloxane published at 100% active and 0.1\u20131.0% of total formulation. It can be added in grinding, stirring or after production. Screen low, middle and high points against a process-controlled blank. Measure mesh release, print-edge definition, surface waviness, crater count, gloss and recoat or overprint acceptance.<\/p>\n

Do not use it to compensate for the wrong viscosity, an overloaded screen, poor substrate treatment or insufficient flash. If a co-solvent such as dipropylene glycol methyl ether is introduced, include it in drying, odor, VOC and block evaluation.<\/p>\n

Use 3482\/3482X for slip or wear<\/h2>\n

3482\/3482X is an ultra-high-molecular-weight polysiloxane pre-emulsion for water-based coatings and inks. The page reports 80\u00b12% solids and recommends 0.05\u20131.0%. It must first be diluted with a small amount of water in multiple stages while stirring, then added to the system. The diluted material should not be stored for long periods.<\/p>\n

Protect it from freezing and do not mix it with alcohol solvents. The page warns of pinhole risk. Treat 3482X\u2019s thickener and better dilution stability as a rheology change to be measured, not a free benefit. Release only if slip or abrasion improves without pinholes, haze, gloss shift, poor adhesion or screen instability.<\/p>\n

Exclude D912R from waterborne trials<\/h2>\n

D912R is a 2% active fluorocarbon-modified polysiloxane solution in isobutyl adipate. Its product page specifies solvent-based application areas and a 0.1\u20130.25% range, with grind-stage addition. That evidence does not support use in a waterborne screen varnish. Do not test it merely because the page also mentions coatings and inks generally.<\/p>\n

If foam is the actual waterborne problem, locate its entry point and request a current waterborne-compatible defoamer shortlist with active content, carrier, dosage and addition instructions. Qualify compatibility and print behavior before production.<\/p>\n

Build two separate experiments<\/h2>\n\n\n\n\n\n\n\n
Experiment<\/th>\nVariants<\/th>\nPrimary response<\/th>\nAuslassventil<\/th>\n<\/tr>\n<\/thead>\n
Flow<\/td>\nControl plus 3345 low\/mid\/high<\/td>\nTransfer, leveling, craters<\/td>\nDry, adhesion, gloss, block<\/td>\n<\/tr>\n
Slip\/wear<\/td>\nControl plus 3482\/3482X low\/mid\/high<\/td>\nCOF or agreed slip panel, abrasion<\/td>\nPinholes, haze, adhesion, printability<\/td>\n<\/tr>\n
Foam<\/td>\nProcess study before product<\/td>\nWet density, foam decay, microbubbles<\/td>\nOnly waterborne-compatible candidates<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Measure adhesion after full drying<\/h2>\n

ASTM D3359<\/a> was developed for relatively ductile coatings on metal. If the screen varnish is on another substrate, agree whether the method is suitable and report the limitation. Keep film thickness, conditioning, cut spacing, tape and removal technique fixed, and note the actual failure plane.<\/p>\n

Measure gloss and abrasion comparatively<\/h2>\n

ASTM D523<\/a> measures specular gloss. Use the same geometry and substrate background. ASTM D4060<\/a> provides a Taber abrasion comparison for organic coatings. State wheel, load, cycles, conditioning and endpoint; do not convert one laboratory wear result into a universal service-life claim.<\/p>\n

Test blocking and finishing<\/h2>\n

Stack printed specimens under defined pressure, temperature, time and face-to-face or face-to-back orientation. Record offset, sticking, gloss transfer and surface marking after a fixed recovery time. Then test die cutting, folding, overprinting, laminating or bonding if those operations follow. Surface slip can reduce friction yet harm an adhesive or overprint.<\/p>\n

Repeat the best candidate after one controlled press restart and after a defined varnish hold time. This exposes viscosity drift, screen drying and dilution instability that a single fresh laboratory print can miss.<\/p>\n

Entscheidungsregeln<\/h2>\n