| HS Code | 789628 |
| Product | SELVOL Polyvinyl Alcohol 09-523 Solution |
| Chemical Type | Partially hydrolyzed polyvinyl alcohol |
| Appearance | Clear to slightly hazy viscous liquid |
| Color | Colorless to pale yellow |
| Odor | Mild, characteristic, non-irritating |
| Solids Content | Approximately 25% by weight nominal |
| Viscosity | 23-32 mPa·s for a 4% aqueous solution at 20°C |
| Ph | 5.5-7.5 |
| Degree Of Hydrolysis | 87-89 mole percent |
| Specific Gravity | Approximately 1.05 at 25°C |
| Water Solubility | Fully miscible with water |
| Stability | Stable under normal storage conditions; protect from freezing |
As an accredited SELVOL Polyvinyl Alcohol 09-523 Solution factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | SELVOL Polyvinyl Alcohol 09-523 Solution is packaged in 200 kg drums or 1,000 kg IBC totes for safe handling and storage. |
| Container Loading (20′ FCL) | 20′ FCL: SELVOL PVA 09-523 solution loaded in sealed drums/IBCs, secured, with proper labeling and ventilation. |
| Shipping | SELVOL Polyvinyl Alcohol 09-523 Solution ships in sealed, corrosion-resistant containers to prevent leakage and contamination. Store away from incompatible materials, protect from freezing, and keep upright during transit. Standard ground transport is typically acceptable; confirm local regulations for chemical solutions, and use proper labeling and documentation for safe handling. |
| Storage | Store SELVOL Polyvinyl Alcohol 09-523 Solution in tightly closed original containers in a cool, dry, well-ventilated area away from heat, sparks, and direct sunlight. Protect from freezing and extreme temperatures to prevent separation or viscosity changes. Keep containers upright to avoid leakage, and use within the manufacturer’s stated shelf life to maintain product performance. |
| Shelf Life | Shelf life is typically 6 months from manufacture when stored sealed, cool, and protected from freezing. |
On a 12-shaft air-jet weaving line running 100% ring-spun cotton at 900 rpm, the size film must withstand cyclic weft insertion abrasion without generating loom dust that blocks reed dents. SELVOL Polyvinyl Alcohol 09-523 Solution is introduced after starch gelatinisation because the base PVOH has nominal hydrolysis of 87–89 mol% and a 4% aqueous Brookfield viscosity of 5.2–6.2 mPa·s at 20 °C under JIS K6726. The as-supplied solution at nominal 9% solids is cut with deionised water to 6.5–7.5% dry solids before blending with oxidised corn starch at a PVOH-to-starch dry ratio of 25:75 to 35:65. The starch fraction is jet-cooked at 120–125 °C and flashed to 85–90 °C before the diluted 09-523 stream is metered into the post-flash tank. Addition before the jet cooker causes unnecessary chain scission and lowers sized-yarn abrasion resistance. Published data for this specific grade in steam-injection shear fields is limited, but the reduction in film tensile strength follows the molecular-weight loss mechanism documented for low-viscosity partially hydrolysed PVOH. Final size-box solids are held at 9.5–11.0% depending on yarn count. Air-jet looms require a size add-on of 10–14% dry weight on yarn for Ne 30–40 ring-spun cotton and 12–16% for 65/35 polyester/cotton blends. The sized warp is dried over seven to nine drying cylinders at 105–115 °C surface temperature. Slasher speed is kept below 65 m/min when the add-on exceeds 12% because higher speed traps moisture at the yarn core and produces tacky warp ends. Creel tension is held at 0.2–0.3 cN/dtex before the size box because higher tension on the dried PVOH-starch film can delaminate size from the yarn surface. Desizing effluent is tested under OECD 301B. The PVOH fraction in the desize effluent generally records ready biodegradability greater than 60% within 28 days in acclimatised mill effluent. The terminal output is a loom beam carrying 550–650 ends for high-density shirting and downproof woven goods. ZDHC MRSL screening of the size formulation must confirm no alkylphenol ethoxylates and no intentionally added heavy metals. The PVOH solution meets that condition when handled as supplied.
Vinyl acetate-ethylene emulsions for low-VOC interior adhesives are synthesised semicontinuously in 10 m³ jacketed reactors fitted with a 0.5 m diameter pitched-blade turbine at 85–95 rpm and an anchor impeller at 20–30 rpm. The 09-523 solution is charged at 2.5–6.0 wt% polyvinyl alcohol on total monomer. The solution is diluted to 5–6% solids with demineralised water before the monomer feed begins. The protective colloid must remain below its cloud point under ethylene pressure. For the 87–89 mol% hydrolysis grade, the lower critical solution temperature in acidic reaction media is sufficiently above the 75–85 °C operating window that thermally induced precipitation is not observed. The more important instability arises from grafting of vinyl acetate onto PVOH. Grafting produces a branched PVOH-g-PVac layer that stabilises latex particles but increases serum viscosity. At PVOH addition levels above 6.5 wt% on total monomer, the reactor discharge filter can retain more than 0.1% coagulum on a 100 µm mesh after 6 h of feed. This is not a linear thickening effect but a cliff-edge caused by bridging of grafted PVOH chains across adjacent particles. Kinetic studies for low-molecular-weight partially hydrolysed PVOH show the grafting frequency rises sharply when the free monomer concentration exceeds 10–12% in the trickle feed. Operators therefore control the vinyl acetate feed to maintain a starved-feed condition and use redox initiation with tert-butyl hydroperoxide and sodium formaldehyde sulfoxylate at 0.05–0.12 wt% on total monomer. Ethylene pressure is maintained at 30–50 bar gauge to depress the glass transition temperature of the final VAE copolymer to −5 °C to 10 °C. Laser diffraction under ISO 13320 shows a mean particle size of 1.0–2.5 µm for the PVOH-stabilised VAE. This is larger than typical surfactant-stabilised acrylic latex and contributes to strong adhesion on polar substrates. The finished latex has total solids of 55–58%, pH 4.5–5.5, and Brookfield viscosity of 800–3,000 mPa·s at 23 °C. Residual vinyl acetate monomer is stripped to below 500 ppm by steam distillation at 70–80 °C and −0.6 to −0.8 bar gauge. VOC content is determined under ISO 11890-2. End products are low-VOC carpet laying adhesives and fibrefill binders. For food-packaging adhesive uses, the dried film must comply with FDA 21 CFR 175.105 and the relevant migration limits of EU 1935/2004. Brookfield viscosity of the latex is measured under ISO 2555.
A metered film size press on bleached kraft linerboard runs at 450–650 m/min with nip pressure 70–100 kN/m. The size base is oxidised tapioca starch at 7–9% solids. Replacement of 20–40% of the starch dry solids with 09-523 solution is performed by pumping the PVOH stream into the starch feed line downstream of the hold tank. The blend is kept at 55–65 °C to prevent retrogradation of the starch and to keep viscosity in the return pan stable. Target viscosity at the nip is 30–60 mPa·s at 60 °C, measured with a Brookfield LV spindle 2 at 12 rpm. Above 70 mPa·s, rod marks and skip coating appear on closed-loop blade-metered film presses. The dry pick-up is controlled to 1.8–3.2 g/m² on linerboard destined for post-print corrugated boxes. Because the 09-523 solution contains a low-molecular-weight PVOH fraction, the film forms a continuous barrier at lower coat weight than oxidised starch alone. The Cobb60 water absorption value on the sized surface is reduced to 25–35 g/m² from an unsized baseline above 100 g/m². This measurement is performed under ISO 535:2014 with 60 s contact time. If water resistance is required for wet-end packaging, 0.5–2.0 wt% ammonium zirconium carbonate on total solids is added to the size press circulation loop, and the web is dried to 90–95 °C surface temperature to trigger insolubilisation. Without such a crosslinker, the 09-523 film remains water-sensitive and will not survive pasteurised liquid immersion. For dry food cartons, FDA 21 CFR 176.170 permits polyvinyl alcohol as a component of paper and paperboard intended for aqueous and fatty food contact. The finished article must also meet overall migration limits under EU 1935/2004. The end product is clay-coated or uncoated folding carton stock with improved ink holdout for flexographic and inkjet printing.
For aqueous tape casting of BaTiO₃-based multilayer capacitor films, the 09-523 solution serves as the main binder. A typical slip contains 100 parts by weight of BaTiO₃ or alumina powder, 1.5–4.0 dry parts PVOH from 09-523 solution, 10–30 parts of a polyol plasticiser on PVOH dry weight, and 0.3–0.8 parts of ammonium polyacrylate dispersant on dry ceramic. The slip is milled in a zirconia-lined ball mill at 45–55% solids for 12–18 h. After de-airing under vacuum at 50–80 mbar, the slip is tape-cast onto silicone-coated polyester carrier film with a doctor blade gap of 150–400 µm. For a 45% solids slip, dry thickness is approximately 0.6–0.8 of the doctor blade gap because solvent evaporation removes the continuous phase. The target dry tape thickness is 40–120 µm. Drying is performed in a three-zone tunnel at 50–70 °C with controlled relative humidity. The process window is asymmetric. Below 45% relative humidity, the exposed surface skins over before internal water can diffuse through the newly formed PVOH film. This causes capillary stress cracks along the casting direction. Above 70% relative humidity, the PVOH film plasticises with residual water, and cast tape blocks on the roll. This is a cliff-edge condition because the 09-523 solution has a lower molecular weight than film-forming PVOH grades, so its wet-film strength is lower and the crack-free drying envelope narrows by approximately 10–15% relative to a 20 mPa·s grade. Published data specific to 09-523 in this drying configuration is limited. The stated envelope shift is inferred from the viscosity-to-film-strength relationship in JIS K6726 and published tape-casting studies. Binder burnout is performed at 350–500 °C in air, with a hold of 1–2 h at the peak to char and oxidise the PVOH. Residual carbon is controlled below 0.1 wt% because carbon residues reduce dielectric insulation resistance. End products are green ceramic sheets for multilayer ceramic capacitors, LTCC substrates, and piezoelectric actuators. Cleanroom conditions commonly specified for casting are ISO 14644-1 Class 8. RoHS Directive 2011/65/EU compliance of the final fired part is unaffected by the PVOH binder because the organic phase is removed during sintering.
In water-transfer printing and embroidery release applications, cast water-soluble transfer film is produced from 09-523 solution at 9% solids, mixed with 8–12 phr sorbitol on dry PVOH and 0.05–0.2 wt% silicone-free defoamer. The solution is cast with a knife-over-roll coater onto 50 µm PET carrier at 30–50 m/min. Wet gap is set at 250–500 µm to achieve the target dry film thickness of 25–50 µm. The three-zone drying tunnel uses 60 °C, 70 °C, and 80 °C, with the final zone humidity below 30% relative humidity to prevent residual water from blocking the film. Film dissolution in water at 20 °C completes within 120–180 s for 25 µm film when measured by the time for the carrier to release during water-transfer printing. Above 50 µm, dissolution time exceeds 240 s, and the transfer decal can shift during slide-off. Because the PVOH grade in 09-523 is low molecular weight, the film lacks the toughness of fully hydrolysed high-viscosity grades. For embroidery stabilisers punched by needle at 800–1,000 stitches/min, the film is laminated with a nonwoven to avoid tearing. The sacrificial film must be stored in low-tack packaging below 25 °C and 50% relative humidity. At higher humidity, the PVOH film absorbs water, becomes tacky, and blocks on the roll. The terminal products are water-transfer printing films, laundry bag release seams, and water-soluble embroidery stabilisers. Compostability testing of the formulated film is performed under EN 13432. The 90% disintegration threshold in 12 weeks applies to the finished film, not to the raw solution. For decorative transfer products with food-contact packaging, plasticiser and defoamer components must meet overall migration limits under EU 1935/2004.
The remoistenable adhesive system uses the 09-523 solution at 7.5–9.0% solids, blended with 10–20 dry wt% dextrin and 5–10 phr glycerin on dry PVOH. The coated film is applied by a slot-die pattern coater at 60–80 m/min to envelope flap gum lines. The adhesive must pass a blocking test at 40 °C and 60% relative humidity for 24 h under 40 g/cm² stack pressure. Glycerin migrates to the gum surface under these conditions and can create a pressure-sensitive line if the coat weight exceeds 10 g/m². At 8 g/m² and 7.5 phr glycerin, the film remains non-blocking on standard copy paper. Open time after remoistening is 5–15 s, sufficient for high-speed inserting lines running 20,000–30,000 envelopes per hour. Drying uses steam-heated drums at 70–80 °C surface temperature, followed by 10 s in a conditioned cooling section. If the final moisture content of the gum line is above 7 wt%, the envelope flap will curl during storage. The adhesive bond is tested by a 90° peel at 300 mm/min after 30 s dwell. The paper must tear before the adhesive separates from the substrate. FDA 21 CFR 175.105 applies for adhesive components used in packaging with incidental food contact. The final gum line must not exceed overall migration limits under EU 1935/2004 when used on food-packaging mailers. End products are printed envelopes, direct-mailers, paper sleeves, and spiral-wound tube seams.
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SELVOL Polyvinyl Alcohol 09-523 Solution is an aqueous, ready-to-dilute preparation of SELVOL 523, a medium-viscosity partially hydrolysed polyvinyl alcohol homopolymer. The prefix 09 designates nominal solids at 9% w/w; the suffix 523 identifies the base resin. Published base-resin release specifications include viscosity of 5.0–6.0 mPa·s measured as a 4% aqueous solution at 20°C, degree of hydrolysis of 87.0–89.0 mol%, pH of 4.5–6.5, and ash content not greater than 0.5% by mass. The supplied solution is pseudoplastic and its as-received viscosity is substantially higher than the 4% resin test condition, requiring temperature-controlled storage and shear-compatible pumping. Compared with dry resin of the same 523 grade, the solution eliminates high-temperature dissolution, reduces airborne dust, and provides fully hydrated polymer, but it adds preservative demand, freeze-sensitivity, and higher transport cost per dry kilogram.
The differentiation from other SELVOL products is primarily based on hydrolysis level and molecular weight. Fully hydrolysed grades give higher water resistance after drying but require elevated dissolution temperatures and show reduced cold-water redispersibility. In contrast, the partially hydrolysed 523 backbone remains soluble in cold water and is suited to remoistenable, paper-laminating, tube-winding, and water-activated adhesive formulations where dried film re-wetting is intentional. Against starch or polyvinyl acetate dispersions, the PVOH solution provides higher film strength and oil resistance but lower wet tack and higher cost per dry kilogram. At equal solids, the viscosity contribution of the 523 base resin is higher than that of low-molecular-weight partially hydrolysed grades, and lower than that of high-molecular-weight fully hydrolysed grades.
Because the product is supplied as a solution, the main specification shifts from powder hydration behaviour to solution stability, microbial resistance, and coating rheology. Dried film properties still reflect the base resin: partially hydrolysed films are less water-resistant than fully hydrolysed films but redissolve more readily after heat and pressure exposure. This makes 09-523 appropriate where dry film re-wetting is part of the functional mechanism, such as remoistenable envelope adhesives and water-activated label gums.
Dry SELVOL 523 powder processing requires jacketed mixing vessels capable of maintaining 80–95°C for 30–60 min under high-torque agitation; incomplete cook produces microgel fisheyes that translate into coating ridges when applied to board. SELVOL Polyvinyl Alcohol 09-523 Solution is diluted by adding ambient process water under low-shear agitation in stainless or polypropylene tanks of 1–5 m³. Centrifugal pumps are unsuitable for undiluted transfer where Brookfield viscosity exceeds 1,000 mPa·s at 25°C; air-operated diaphragm or rotary lobe pumps with 25–50 mm suction lines maintain forward flow without excessive shear. Filtration through 150 µm bag or cartridge housings removes dried edge-skin particles and agglomerates before coating stations. Production records from paperboard laminating operations indicate that unfiltered solution held in unsealed premix tanks for more than 48 h produces doctor-blade streaks and edge-ribbon defects.
Temperature control during transfer and application is more critical than for many starch-based adhesives. A temperature drop of 5°C can increase apparent viscosity by 25–40% in the processing range, with the temperature coefficient generally falling between 5–8% per °C. Jacketed feed tanks with ±1°C regulation are therefore specified on high-speed coating lines. Cleaning-in-place uses warm water at 40–50°C; dried film removal requires soaking rather than aggressive alkaline cleaning, because strong caustic can darken PVOH residues and increase tank wall adhesion. Avoid combination with amine-based additives that can raise pH above 8.5 and accelerate viscosity drift or colour formation.
| Attribute | SELVOL 09-523 Solution | Dry SELVOL 523 | Fully hydrolysed PVOH solution |
|---|---|---|---|
| Nominal solids content | 9% w/w | ≥97% w/w | grade-dependent |
| Base resin viscosity, 4% solution at 20°C | 5.0–6.0 mPa·s | 5.0–6.0 mPa·s | grade-dependent |
| Degree of hydrolysis | 87.0–89.0 mol% | 87.0–89.0 mol% | typically 98.0–99.3 mol% |
| Cold-water redispersibility of dried film | high | high | low to moderate |
| Required processing | ambient dilution and filtration | 80–95°C cook | hot dissolution or ready-made supply |
| Primary operational vulnerability | microbial growth and freeze damage | incomplete hydration and dust | insoluble gel formation if improperly cooled |
Ribbing and die-lip build-up are the most frequently documented defects when SELVOL PVOH 09-523 Solution is applied by slot-die to clay-coated board at line speeds above 150 m/min with a coating gap below 100 µm. The failure signature is capillary break-up at the die exit, not resin incompatibility. Reducing solids to 6% by mass, raising die-lip temperature to 30–35°C, or reducing line speed to 90 m/min suppresses ribbing in most trials. Dilute solutions for gravure or reverse-roll application are commonly adjusted to 150–400 mPa·s Brookfield LV viscosity at 25°C using ISO 2555 or ASTM D2196; reported viscosity is meaningful only when spindle and rotation speed are fixed because the material is non-Newtonian. Air-entrained foam from open return pans creates crater defects on air-knife coaters; silicone-free defoamer addition at 0.05–0.2% of solution is typical, but compatibility trials are required because high-shear mixing can increase foam instead of reducing it.
Surface tension reduction is rarely required for uncoated paperboard, but on silicone-treated release liners or high-gloss polycoated board, wetting agents are used at 0.1–0.5 g/L of diluted coating. Density of typical as-received solution is 1.02–1.04 g/cm³ at 20°C, and solids control by inline refractometer or viscosity-triggered water addition is preferred over manual top-up. Operators sampling tank bottoms on recycled board lines report that cellulosic dust and starch fines increase filter pressure and create die-pressure spikes; a 100 µm in-line screen ahead of the die reduces this variability. At shear rates of 10,000 s⁻¹ in slot-die lips, apparent viscosity can fall by 50–70% relative to low-shear Brookfield values because of pseudoplasticity.
Drying speed on paperboard is controlled more by substrate absorbency than by solution solids. Where board porosity is low, dry coat weight of 2–5 g/m² is typical for adhesive tie coats; higher coat weights of 5–12 g/m² are used in barrier coatings and laminating bonds. At these coat weights, residual moisture after oven exit should be below 0.5 g/m² to prevent blocking. Wet coat weight is calculated from solution solids and target dry weight; with 9% solids, a wet coat weight of 27–33 g/m² yields approximately 2.5–3.0 g/m² dry polymer.
In remoistenable and packaging adhesives, the 09-523 solution is blended with dextrins, plasticisers, humectants, and preservatives. Glycerol at 5–15% of dry PVOH reduces film brittleness, while urea at 2–8% of dry PVOH extends open time in high-humidity conditions. The solution is generally compatible with many starches and polyvinyl acetate emulsions but can precipitate with high concentrations of borate or certain polyvalent metal salts unless stabilised. Borate-containing preservative packages should be avoided because they can induce reversible gelation of polyvinyl alcohol. Formulating under 21 CFR 175.105 applies to indirect food adhesive applications; paper and paperboard components for aqueous and fatty food contact fall under 21 CFR 176.170, and dry food contact uses 21 CFR 176.180. European compliance is assessed under EU Regulation (EC) No 1935/2004 through migration testing to EN 1186 series methods. Resin lot certificates should be reviewed for methanol content; typical values remain below 0.5% by mass, but final article compliance is use-dependent.
Adhesive performance is evaluated by set speed, open time, and dry film properties rather than by solution viscosity alone. In paperboard laminating, T-peel adhesion is commonly tested per ASTM D1876 after 24 h conditioning at 23°C and 50% relative humidity. In remoistenable envelope adhesive trials, dry film redissolution time is measured by applying a controlled water film and recording tack recovery; values below 5 s are frequently achievable with plasticised formulations, but this is dependent on coat weight and board porosity. Blocking resistance is evaluated in stacked sheets under 40 kPa pressure at 35°C for 24 h; plasticiser level is the dominant control factor.
| Regulation or method | Scope |
|---|---|
| 21 CFR 175.105 | Indirect food contact adhesives and adhesive components |
| 21 CFR 176.170 | Paper and paperboard components in contact with aqueous and fatty foods |
| 21 CFR 176.180 | Paper and paperboard components in contact with dry food |
| ISO 2555 | Brookfield viscosity measurement for non-Newtonian fluids |
| ASTM D2196 | Rotational viscosity of non-Newtonian materials |
| ASTM D1876 | T-peel resistance of adhesive bonds |
| ASTM D3985 | Oxygen transmission rate of barrier films |
| EN 1186 series | Overall migration testing for food-contact plastics and coated articles |
Open coating pans continuously lose water by evaporation; viscosity and solids increase within 4–8 h of run time unless make-up water is controlled to ±0.5% of target solids. Diluted solutions held above 25°C can support microbial growth, producing black specks and hydrogen sulphide odour within 72 h in unpreserved systems. Isothiazolinone-based preservatives at 10–50 ppm active content are common, but their food-contact status must be verified for the specific formulation. Sealed stainless storage at 5–30°C reduces viscosity drift and fungal contamination. Freeze-thaw cycling is not recommended; partially hydrolysed PVOH solutions can form irreversible gel aggregates after freezing, and thawed material may require 150 µm filtration and re-qualification before use.
Tube-winding and envelope-gumming lines reveal a different bottleneck: open-pan recirculation returns air-entrained solution to the holding tank, and level-control systems that use float switches may misread foam as liquid. Diaphragm pumps with suction from the tank bottom, combined with side-entry low-shear agitation, reduce foam carry-over. On single-station tube winders running at 80–120 tubes/min, excessive viscosity from evaporation produces stringing at the unwind and false set after compression. Correction by water addition must be based on solids measurement rather than visual viscosity because temperature differences of 5–10°C in the coating pan can mask solids drift.
In surface-sizing and barrier-coating applications, the 09-523 solution is used where oil resistance and oxygen barrier must be balanced against cold-water clean-up. Published PVOH film data commonly report oxygen transmission rates below 1 cm³/(m²·day·atm) at 23°C and 50% relative humidity for 10–15 µm dry films tested per ASTM D3985; however, published data for this specific 09-523 solution configuration is limited, and laboratory confirmation is required before specifying a barrier stack. When wet-rub resistance is critical, formulators may mix 09-523 with 10–25% of a fully hydrolysed SELVOL grade by dry PVOH weight. This blend raises dried-film water resistance without returning to high-temperature fully hydrolysed dissolution practice, but it can increase solution cloudiness after prolonged storage.
Compared with lower-molecular-weight partially hydrolysed solutions, 09-523 provides higher viscosity per unit solids and greater film toughness, but it may require more dilution for the same wet coat weight. Lower-molecular-weight PVOH solutions may be preferred for high-solids, low-viscosity surface sizing where penetration into paperboard is required; higher-molecular-weight fully hydrolysed grades are selected for maximum grease resistance and water resistance, but they lose remoistenability and require heated handling. The 09-523 solution therefore occupies a mid-viscosity, partially hydrolysed position used for adhesion and redispersibility in packaging and converting lines. Published data for certain highly specific configurations is limited; final coating, adhesive, or barrier specifications should be confirmed by lot certificate, plant trial, and end-use migration testing.
