SELVOL Álcool polivinil ULTALUX FF

What Happens When Surface Size Pickup Exceeds 3.5 g/m² on a Film Press?

On alkaline woodfree fine-paper lines operating above 800 m/min, the film press applies a starch-based size liquor modified with SELVOL Polyvinyl Alcohol ULTALUX FF to raise OBA carrier efficiency and dry pick resistance. The batch cooker is charged with cold water and the dry PVOH is dispersed under high-speed agitation before steam injection raises the slurry to 90–95°C. Cook time is 45–60 min after reaching temperature. The cooked PVOH stock is held at 70–80°C and then metered into an oxidised starch bath. Typical working ratio is 1.0–2.0 parts dry ULTALUX FF per 100 parts dry starch. Total size solids are maintained at 6.0–10.0 wt% depending on base sheet porosity and machine speed. Final Brookfield RVT viscosity at 60°C is usually 120–250 mPa·s at 100 rpm. The value is adjusted with calcium chloride or sodium nitrate in closed-loop systems. Pickup on a Voith SpeedSizer or Metso OptiSizer is set between 1.5 g/m² and 3.5 g/m² per side. When pickup exceeds 3.5 g/m², the dried film develops a measurable curl differential and the sheet loses bending stiffness uniformity. Surface-size penetration shifts from a continuous film to a brittle surface layer. The critical threshold for this grade in high-speed converting is therefore managed by infrared dryer profiling and air-cap temperature. The surface-sized paper is tested for water absorptiveness using ISO 535 with a Cobb60 target from 20 g/m² to 28 g/m² for sheet-fed offset grades. Dry pick resistance is evaluated on the IGT AIC2-5 printability tester according to TAPPI T 459 om-20. Finished goods include high-opacity inkjet papers, cut-sheet laser stock and folded carton board where release lap and scuff resistance must remain stable after varnishing.

Slashing of ring-spun cotton yarns at 60–80 m/min requires a size film that remains intact through the lease rods and healds, then releases cleanly during enzymatic desizing. SELVOL Polyvinyl Alcohol ULTALUX FF is applied as the cohesion binder in formulations built from native corn starch, acrylic ester co-binder and a high-density polyethylene wax dispersion. The size liquor is prepared at 8.0–10.0 wt% total solids. ULTALUX FF is dosed at 5.0–7.0 kg per 100 kg of starch plus 1.5–2.5 kg of acrylic co-binder. Wax is limited to 0.5–1.0 wt% of the size bath to avoid excessive slashing cylinder deposits. Add-on on the yarn is controlled by squeeze roll pressure and is normally 10.0–14.0% dry size solids on warp yarn weight. Size-box temperature is maintained at 80–85°C and viscosity is measured continuously with an online viscometer. The dried yarn is split over 5–8 lease rods. Improper film formation appears as hairiness above 40 hairs per 100 m on an Uster Tester 5 when the size film fails to enclose protruding fibres. Desizing effluent compatibility is checked against the ZDHC MRSL for nonylphenol ethoxylates and restricted volatile organic compounds. Finished woven articles include high-count cotton shirting, 400-thread-count sheeting and cotton/polyester twill workwear where weaving efficiency at air-jet looms above 700 rpm depends on reduced warp breaks.

Emulsion Polymerisation Protective Colloid and Grafting Kinetics

In semi-continuous vinyl acetate-ethylene copolymer reactors, ULTALUX FF functions as a high-hydroxyl secondary protective colloid that increases high-shear stability and regulates particle size distribution after the first 40% of monomer feed has been added. The aqueous phase is prepared with 1.0–2.5 wt% ULTALUX FF based on total monomer, alongside a partially hydrolysed PVOH primary colloid at 3.0–5.0 wt%. Sodium acetate buffer and ferrous ammonium sulfate are added for pH and trace metal control. Initiator feed is 0.03–0.08 wt% ammonium persulfate or hydrogen peroxide/tartaric acid. The persulfate system generates hydroxyl radicals that abstract tertiary hydrogen from the PVOH backbone, forming grafted polymer stabilizer at the latex particle surface. Reactor temperature is controlled at 75–85°C under ethylene pressure of 2.5–5.0 MPa in a jacketed stainless steel pressure reactor. The batch is terminated at 45–55 wt% solids and residual monomer is reduced with tert-butyl hydroperoxide and sodium formaldehyde sulfoxylate. The resulting dispersion exhibits a viscosity of 2,000–6,000 mPa·s at 25°C measured with a Brookfield RV spindle 6 at 20 rpm. Storage stability at 50°C over 28 days requires preservation with 0.08–0.12 wt% sodium benzoate and 0.10–0.20 wt% ammonia. The protected dispersion is used in wood assembly adhesives, paper laminating and finger-joint glues where ASTM D905-08 shear strength and ASTM D5751-99 water resistance are controlled. Reactor operators must avoid adding borate salts or aluminium sulphate before the letdown stage because borate crosslinking with the fully hydrolysed fraction can generate particle bridging and filter-blocking coagulum.

Re-wettable adhesive coaters running at 100–150 m/min on litho-laminated board demand a dry film that re-tacks within 2–4 s after water activation and does not block under 70% relative humidity. SELVOL Polyvinyl Alcohol ULTALUX FF is dissolved at 18–22 wt% solids in a jacketed dissolving vessel at 85–95°C for 60–90 min. The batch is then cooled to 60°C and blended with maltodextrin or thin-boiling dextrin at 10–20 parts per 100 parts PVOH solids. Glycerin or sorbitol is added at 2–5 parts as plasticiser. A nonionic acetylene glycol wetting agent is dosed at 0.1–0.3 parts. The adhesive is applied by a slot-die or gravure coater at 2.0–4.0 g/m² dry coat weight. Drying is performed in a 5-zone air flotation dryer with zone temperatures from 60°C to 100°C. Residual moisture after drying is held between 2.0% and 4.0% to preserve re-wetting speed. Blocking resistance is checked with a face-to-face stack test at 50°C and 80% relative humidity for 24 h. Adhesive transfer to paper is evaluated by a wet tack tester. A dry film of 25–40 g/m² on Kraft should develop enough tack after 25–35 µm of water is applied. United States food-contact use is covered by 21 CFR 175.105 for adhesives when the coating is separated from food by a functional barrier. Finished products include remoisturizing envelopes, repositionable stamps, bill-head file strips and paper splicing tapes.

When Aqueous Alumina Slurries Exceed 70 wt% Solids Loading in Tape Casting

Aqueous tape casting of alumina substrates with 70–75 wt% solids loading creates a rheological boundary where a small error in binder hydration can shift viscosity from a coatable 1,000–4,000 mPa·s to a non-leveling 8,000 mPa·s fluid within 30 min. ULTALUX FF is dry-blended with the ceramic powder before dispersing in deionised water that contains 0.5–1.5 wt% ammonium polyacrylate dispersant based on dry ceramic mass. The binder addition is 3.0–6.0 parts per 100 parts alumina powder, with PEG 400 plasticiser at 1.0–3.0 parts. Mixing is performed in a planetary centrifugal mill or high-torque dissolver under vacuum to remove entrapped air. Final slurry temperature must remain below 30°C to prevent premature PVOH gelation at the ceramic surface. The slurry is cast onto a silicone-coated polyester carrier at 100–300 mm/min through a doctor blade set to 50–150 µm wet thickness. Drying uses an enclosed multi-zone convection oven at 60–90°C with relative humidity maintained at 50–60% for the first two zones to allow uniform skin formation. Green tape density after drying is 2.2–2.4 g/cm³ for 96% alumina. Tensile strength is measured according to ASTM D882-18 with a crosshead speed of 5 mm/min. Lamination is conducted at 80–90°C and 20–30 MPa for 10–20 min. Binder burnout requires a kiln ramp of 0.5–1.0°C/min to 450°C with air flow above 20 L/min. Residual carbon after burnout must remain below 0.05 wt%. Finished goods include LED alumina substrates, thick-film sensor plates and high-frequency ceramic interposers.

Water-Soluble Film Sealing Thresholds Depend on Plasticiser Partitioning

Unit-dose detergent film is cast from an aqueous dope containing 18–22 wt% ULTALUX FF and 8–15 parts plasticiser per 100 parts dry PVOH. Glycerin, sorbitol or trimethylolpropane are selected based on sealing temperature and ambient humidity resistance. The dope is degassed under vacuum and cast onto a polished steel belt heated to 70–90°C. Drying air is supplied in four zones. The first zone is kept at 60–70°C and 50–60% relative humidity to avoid skin-over that would trap residual water. Final film thickness is normally 38–76 µm and residual moisture is controlled to 6.0–10.0 wt%. The dry film is conditioned at 23°C and 50% relative humidity for 24 h before heat-sealing. Seal initiation temperature is determined on a laboratory heat sealer at 0.25 MPa jaw pressure and 0.5 s dwell. Values typically fall between 120°C and 160°C depending on plasticiser partition and film moisture. Dissolution time in cold water is tested in a standard detergent dissolution cell using 500 mL water at 15°C and 25 mm film squares. Packaging-grade films dissolve to pass through a 4 mm screen in 45–120 s. Physical properties are measured with ASTM D882-18 tensile testing and ISO 527-3. Packaging-grade films are specified to exceed 150% elongation at break before ageing. Compatibility with liquid detergents is evaluated under 45°C accelerated storage for 8 weeks. Films containing anionic surfactants above 30 wt% may plasticise the seal layer and lower seal strength. Unwinding of film in an area above 60% relative humidity leads to blocking and loss of seal integrity. Environmental biodegradability of the PVOH film is assessed by OECD 301B or ISO 14852. Finished products include laundry monodose sachets, automatic dishwasher tablets and agrochemical water-soluble pouches where container dimensions and seal area are fixed by machine fill volume.

Pigmented top-coating of coated woodfree and folding boxboard grades uses ULTALUX FF as a co-binder and OBA carrier in low-latex formulations where gloss and ink set-off are controlled at high coater speeds. The coating colour is prepared from 100 parts of a 60:40 ground calcium carbonate/kaolin pigment blend, 8–12 parts styrene-butadiene latex, 0.3–1.0 part ULTALUX FF, 0.05–0.20 part dispersant and 0.1–0.5 part optical brightening agent. Solids content is 58–62 wt%. Brookfield viscosity at 25°C is 800–1,800 mPa·s at 100 rpm. Hercules high-shear viscosity at 4,400 s⁻¹ is kept below 70 mPa·s to avoid blade scratching. The colour is applied with a bent-blade coater operating at 1,000–1,800 m/min and a dry coat weight of 8–12 g/m² per side. Drying is performed with gas-fired infrared dryers followed by air flotation at 90–120°C. OBA fluorescence uniformity is assessed under D65 illumination after re-wetting. ULTALUX FF binds the OBA molecules and reduces migration into the base sheet. Wet pick and dry pick are measured with the IGT AIC2-5 device in accordance with TAPPI T 459 om-20. Print gloss is measured with a 75° glossmeter according to ISO 8254-1. The coated board is converted into high-gloss food cartons, cosmetic packaging and magazine covers where optical brightness must remain stable across the run.