| HS Code | 487273 |
| Appearance | white to cream granular solid |
| Degree Of Hydrolysis | 87.0 - 89.0 mol% |
| Viscosity 4 Aqueous Solution 20 C | 28.0 - 32.0 mPa·s |
| Ph 4 Aqueous Solution | 5.5 - 7.0 |
| Ash Content | ≤ 0.9 wt% |
| Volatile Content | ≤ 5.0 wt% |
| Specific Gravity | ~1.26 |
| Bulk Density | ~0.60 - 0.70 g/cm³ |
| Melting Point | ~190°C |
| Glass Transition Temperature | ~75°C |
| Water Solubility | Soluble in water with heating and agitation |
| Particle Size | typically 20 - 100 mesh granular |
As an accredited SELVOL Polyvinyl Alcohol 823 factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | SELVOL Polyvinyl Alcohol 823 is a white granular powder supplied in 25 kg net multiwall paper bags with polyethylene liners. |
| Container Loading (20′ FCL) | 20' FCL container loading of SELVOL Polyvinyl Alcohol 823, ensuring secure, dry, ventilated stowage to prevent moisture damage. |
| Shipping | SELVOL Polyvinyl Alcohol 823 ships as a non-hazardous, water-soluble resin powder. Pack in dry, sealed bags or containers to prevent moisture absorption and caking. Use covered trucks or containers, keep away from humidity and ignition sources, and handle with dust-control measures to ensure safe, clean transport. |
| Storage | Store SELVOL Polyvinyl Alcohol 823 in a cool, dry, well-ventilated area in its original, tightly sealed container. Protect from moisture, excessive heat, and direct sunlight. Keep away from strong oxidizers and ignition sources. Avoid creating dust clouds. Maintain proper labeling and integrity of packaging. Under these conditions, shelf life is typically two years. |
| Shelf Life | Shelf life is typically 2 years from date of manufacture when stored in original, unopened containers under dry, cool conditions. |
Slot-die conversion of SELVOL Polyvinyl Alcohol 823 into water-soluble detergent unit-dose film begins with a 13–16 wt% aqueous solution prepared in a jacketed mixing vessel equipped with a high-shear rotor-stator disperser. Cold-water dispersion at 25°C avoids lump formation; after 10 minutes of hydration under agitation, the batch is heated to 88–92°C and held for 25–35 minutes to complete solubilization. The solution is deaerated under −0.09 MPa vacuum for 45–60 minutes to eliminate pinholing in the cast film. Coating onto a chrome-plated chill roll at 21–24°C through a slot die with 30–45 μm lip gap produces a self-supporting film at 38–50 μm dry thickness. The 87–89 mol% hydrolysis window of Selvol 823 limits crystallite formation while retaining sufficient hydroxyl functionality for plasticizer compatibility; glycerin or sorbitol addition at 6–12 phr yields a tensile strength of 35–48 MPa and elongation at break of 160–220% when tested under ASTM D882-18 at 23°C and 50% RH. Dissolution of a 38 μm film in 20°C tap water occurs within 50–70 seconds under mild circulation, while at 10°C the same film requires 120–180 seconds, which is the primary operational boundary for cold-fill laundering. In unit-dose pod sealing, a wetted-edge heat-seal at 150–170°C with 0.4–0.8 MPa jaw pressure for 0.5–1.0 s achieves burst strengths above 120 kPa in a closed pod.
High-humidity storage above 70% RH increases blocking tendency unless the film contains 0.5–1.5 phr of a particulate anti-block such as hydrophobic fumed silica. Films exposed to pH > 11 liquid detergents must be formulated without borate-based crosslinkers if the pod is intended for one-time immediate dissolution; otherwise crosslinking slows cold-water solubility and leaves gel residue on laundry load surfaces. Pre-drying of the PVOH resin is required when ambient relative humidity exceeds 60% RH, because surface moisture uptake above 0.8 wt% causes screw feeding variability and localized gel specks during solution make-up. Continuous casting lines running above 45 m/min typically require a closed-loop drying hood with 65–75°C supply air and exhaust humidity maintained at 25–35 g water/kg dry air to prevent skin-over defect. Line stop events longer than 8 minutes leave a static meniscus at the die lip that can dehydrate and form insoluble edge beads; restart therefore requires die lip flushing with 70°C demineralized water before film re-threading.
Grafting efficiency in high-ethylene vinyl acetate/ethylene (VAE) pressure kettles shifts substantially when the protective colloid carries 11–13 mol% residual acetate groups. SELVOL Polyvinyl Alcohol 823, with a 4% solution viscosity of 20–25 mPa·s at 20°C by Brookfield LV spindle 1 at 60 rpm, provides hydrophobic anchoring on forming PVAc particle surfaces without the excessive water resistance imparted by fully hydrolyzed homologues. In a typical 30–60 bar ethylene, 50–80°C batch process, 2.0–4.0 wt% Selvol 823 based on total monomer is fed as a 10 wt% aqueous solution over 3–5 h, while the redox initiator is metered separately at 0.05–0.15 wt% based on vinyl acetate monomer. The level of PVOH-g-PVAc graft copolymer generated during the reaction governs latex shear stability and particle size distribution; insufficient grafting yields a broad particle size distribution with visible coagulum on the reactor wall after 6 h, whereas excessive grafting caused by high initiator feed or delayed PVOH addition reduces open time in wood adhesives and lowers wet bond strength. A typical high-ethylene VAE stabilized with Selvol 823 finishes at 45–55% solids, 2,500–6,000 mPa·s Brookfield RVT at 20 rpm, and a mean particle size of 0.6–1.4 μm measured by laser diffraction. Residual VAM monomer below 0.1 wt% requires post-polymerization stripping at 70–75°C under 0.06–0.08 MPa vacuum.
The resulting latex meets indirect food contact adhesive status when formulated under 21 CFR 175.105; however, the finished adhesive must be tested for migration because ethylene-rich copolymers can swell in fatty-food simulants. In exterior architectural coatings, 1–2 wt% Selvol 823 solution post-added to latex improves high-shear ICI viscosity from 0.8–1.4 P without reducing contrast ratio. Process limitations arise when the PVOH feed is interrupted for more than 90 seconds: monomer flooding in the absence of protective colloid creates instantaneous coagulum that cannot be re-dispersed by agitation alone. VAE producers using Selvol 823 should avoid combining it with amine-based initiator systems above 60°C, because aldehyde-like intermediates from vinyl acetate hydrolysis can react with free hydroxyl groups and produce yellow-brown kettle fouling. Published data for high-ethylene grades above 25 wt% ethylene are limited; in such configurations, pilot polymerization at 40 bar is recommended before scale-up to verify grafting rate and minimum filming temperature shift.
Tape-cast alumina substrates require a binder grade that leaves ash below 0.5 wt% after burnout. SELVOL Polyvinyl Alcohol 823 is milled into a slurry containing 100 parts of D50 0.6 μm alumina powder, 4–8 parts PVOH solids added as a 15 wt% aqueous solution, 2.5–4 parts of a 50/50 glycerin–PEG 400 plasticizer blend, and 0.3–0.8 parts of an ammonium polyacrylate dispersant. Ball milling with 10 mm zirconia media for 16–24 h produces a slurry viscosity of 1,800–3,200 mPa·s at 20 rpm Brookfield RVT and 25°C. After deaeration, the slurry is cast onto a silicone-coated polyester carrier at 0.3–1.2 m/min with a doctor blade gap of 100–250 μm. Drying at 35–45°C under 0.5–1.5 m/s air velocity retains residual moisture at 0.5–1.0% to prevent brittleness. Green tape density after lamination at 60°C and 10 MPa is typically 2.0–2.2 g/cm³.
Binder burnout is the critical processing constraint: thermogravimetric analysis in air at 10°C/min shows main-chain scission beginning near 220°C, with complete oxidative removal by 480–500°C and residual ash below 0.2 wt% when the green sheet is fired with a 1°C/min ramp from 350°C to 500°C and a 30–60 min hold. Fast heating above 5°C/min between 250°C and 400°C creates internal lamination cracks because evolved acetic acid and water vapor exceed gas permeability through the unsintered ceramic particle network. Sintered alumina substrates require no evidence of carbon residue; XPS survey scans after firing should show C 1s intensity below 2 atomic%. Tape-handling automation should be designed for green tensile strength of 0.8–1.5 MPa as measured by ASTM D882-18 on 25 mm strips; lower values with PVOH loadings below 4 parts lead to edge cracking during via punching or roll-to-roll spooling.
Air-jet weaving of 40 s Ne cotton warp with 75 denier polyester filling demands a size film that resists shed abrasion without accumulating moisture at weaving-humidity levels above 60% RH. SELVOL Polyvinyl Alcohol 823 at 7–10 kg per 100 L of sizing liquor is combined with 50–60 kg native corn starch, 2–4 kg acrylic binder, and 0.5–1.0 kg of a hydrogenated tallow wax. Cooked at 90–95°C for 30–45 minutes in a jet cooker, the size bath is maintained at 82–87°C in the size box. A double-squeeze size box set to 18–25 kN at the pressure rolls yields 10–14% dry add-on on cotton warps entering a 12-zone multi-cylinder dryer with first zone temperature 120–125°C and final zone 95–100°C. The partially hydrolyzed PVOH contributes a clear, flexible film that reduces warp breaks to 0.5–1.5 per 100,000 picks on air-jet looms at 600–750 picks/min.
Sized yarn tensile strength tested according to ASTM D2256-22 increases by 15–25% over unsized cotton; elongation at break of the sized yarn should remain above 4.5%. Desizing in a 60–75°C bath containing 0.2–0.5 g/L of an enzymatic amylase removes the starch fraction, while the Selvol 823 disperses into the wash water and is subsequently degraded in activated sludge to BOD₅ below 25 mg/L after 24 h residence. Dry weaving rooms should maintain 20–28°C and 50–60% RH; below 45% RH, the sized warp becomes brittle and produces fly dust, while above 70% RH the Selvol 823 film softens and can cause end-to-end sticking at the lease rods. Sizing formulations containing Selvol 823 are unsuitable for filament glass yarns because the residual acetate content does not provide sufficient silane coupling.
On a flooded-nip size press converting recycled linerboard at 620 m/min, SELVOL Polyvinyl Alcohol 823 is applied as a co-binder in a 6.5% total solids surface-size solution containing 85 parts oxidized corn starch, 10 parts Selvol 823, and 5 parts calcium stearate dispersion. The bath temperature is controlled at 58–62°C to avoid starch retrogradation while the PVOH remains fully dissolved. Dry pickup of 0.8–1.5 g/m² per side raises the Cobb 60 value from 42 g/m² to 18–25 g/m² when tested under TAPPI T 441 om-20, and the water drop absorption time increases from 8 seconds to 35–60 seconds by TAPPI T 835 om-18. Grease resistance measured by the Kit test follows TAPPI T 559 cm-12; a 1.2 g/m² dry coat typically achieves Kit 5–7 on bleached liner, although fatty-food converters must verify reproducibility because recycled base stock porosity varies by ±15%.
The 20–25 mPa·s viscosity of Selvol 823 as a 4% solution at 20°C limits excessive pickup rheology at high machine speed, but it also imposes a maximum size-bath solids limit of 8% before rod-metering size press runnability deteriorates due to shear-thinning hysteresis. Re-wetting of the dried surface size during flexographic printing is minimized by adding 1–2% of a zirconium-based insolubilizer based on total solids; the insolubilizer must be metered inline no more than 30 minutes before use because its reaction with Selvol 823 increases Brookfield viscosity by 20–50% within 4 h and eventually forms irreversible gel particles. Mill effluent load is lower than starch-only sizing because the PVOH co-binder allows a 10–15% reduction in total applied solids while maintaining the same Scott bond strength as measured by TAPPI T 833 pm-19. The grade is compliant as a component of paper and paperboard intended for aqueous and fatty food contact when used under 21 CFR 176.170, provided the converter confirms extraction limits for total PVOH migration.
A 12 wt% aqueous adhesive base is prepared by dispersing SELVOL Polyvinyl Alcohol 823 in cold water followed by heating to 85–90°C for 30 minutes. After cooling to 40°C, 1.5 wt% propylene glycol is added as a humectant, and the adhesive is applied to clay-coated paperboard at 2–4 g/m² dry coat using a roller coater. Heat sealing against a polyethylene terephthalate blister requires 160–175°C jaw temperature, 0.5–0.7 s dwell, and 250–350 kPa sealing pressure. T-peel adhesion measured under ASTM D1876-08(2015)e1 on 25 mm strips is typically 3.5–6.0 N/25 mm for fiber-tearing bonds on uncoated kraft; on recycled clay board the failure remains cohesive paper stock above 2.8 N/25 mm. Open time at 23°C and 55% RH is 45–70 seconds, but above 75% RH the tack window contracts to 25–40 seconds because moisture plasticization accelerates skin formation.
Addition of 0.05–0.15 wt% borax decahydrate based on wet adhesive modifies tack through PVOH diol-borate complexation; above 0.2 wt% borax at 10 wt% solids the adhesive crosses the gel point and becomes uncoatable within 3–6 h. The adhesive is suitable for spiral paper-tube winding where the PVOH base acts as both lubricant and bonding agent during high-frequency induction drying at 80–100°C surface temperature. Thermal degradation during hot-melt mixing with vinyl acetate homopolymers should remain below 180°C because onset of PVOH decomposition under air produces acetic acid vapor and causes brown discoloration. For indirect food packaging closures, the formulation must meet 21 CFR 175.105; if the adhesive is used to bond a functional barrier layer to dry food packaging, the converter must demonstrate no detectable transfer through the substrate before commercial shipment. Cleaning of adhesive lines requires 60–70°C water with 0.5–1.0% sodium percarbonate to degrade residual PVOH film without chlorinated-solvent exposure.
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SELVOL Polyvinyl Alcohol 823 is a partially hydrolysed polyvinyl alcohol resin with a supplier-published hydrolysis range of 87.0–89.0 mol% and a 4% aqueous solution viscosity of 20.5–24.5 mPa·s at 20 °C. The residual acetate content of approximately 11–13 mol% interrupts vinyl alcohol sequences, lowers crystallinity relative to fully hydrolysed polyvinyl alcohol, and permits hydration at lower temperatures. Typical certificate-of-analysis parameters include pH 4.5–6.5 in a 4% solution, volatile content not exceeding 5.0%, and ash as Na₂O not exceeding 0.5%. The resin is supplied as a free-flowing granular powder; bulk density and sieve profile vary by manufacturing location and should be verified against the supplier’s certificate of analysis before large-volume silo transfer or automatic feeding equipment is commissioned. Because the viscosity specification is concentration-dependent, fixed-solids preparation is required for meaningful incoming inspection.
| Property | Range | Measurement Basis |
|---|---|---|
| Hydrolysis | 87.0–89.0 mol% | Supplier hydrolysis method; ISO 15023-1 designatory class |
| Viscosity, 4% aqueous solution | 20.5–24.5 mPa·s at 20 °C | ISO 15023-2 / rotational viscometry |
| pH | 4.5–6.5 in 4% solution | Supplier certificate-of-analysis method |
| Volatile content | ≤5.0% | Gravimetric moisture/volatiles method |
| Ash as Na₂O | ≤0.5% | Ignition residue method |
Within the partially hydrolysed product range, the numeric grade designation of 823 indicates a medium-viscosity product. Lower-viscosity partially hydrolysed grades provide lower 4% solution viscosity and may allow higher solids in size-press and coating applications, while higher-viscosity grades contribute more solution viscosity per unit solids but reduce maximum make-down concentration. The selection of SELVOL 823 over low-viscosity grades is generally made when film toughness and adhesion strength outweigh the cost of additional dilution water and longer hydration time. The hydrolysis range remains the principal compatibility factor with plasticizers, starches, and water-soluble resins.
Comparison with fully hydrolysed polyvinyl alcohol of equivalent viscosity reveals trade-offs in solubility, film strength, and water resistance. Fully hydrolysed grades at 98.0–99.0 mol% hydrolysis develop higher crystallinity and more extensive hydrogen bonding, producing films with higher tensile strength and lower cold-water sensitivity. SELVOL 823 exchanges a portion of that tensile strength and water resistance for reduced dissolution temperature and greater surface activity at the air-water and monomer-water interfaces. In adhesive and sizing uses requiring controlled re-wetability and flexible film formation, the residual acetate content of SELVOL 823 reduces the tendency of dried films to become brittle and difficult to rehydrate. In barrier film and molded articles where water insolubility is required, fully hydrolysed grades remain preferable. Published data for specific film tensile comparison under identical drying conditions is limited; selection decisions should be based on laboratory drawdowns at the intended coating solids, drying temperature, and plasticizer level.
In water-remoistenable adhesive formulations, SELVOL 823 is evaluated at 2–10 wt% solids in combination with plasticizers, humectants, and tackifying dispersions. Production make-down typically uses a jacketed vessel with a high-shear sawtooth disperser and a low-speed anchor stirrer. The powder is pre-dispersed in cold water before heating to 70–80 °C under moderate shear until no gel particles remain. Partially hydrolysed grades hydrate more rapidly than fully hydrolysed material at a given temperature, but undissolved granules can form if powder is added too quickly into warm water without an adequate vortex. In remoistenable envelope and label adhesives, the dried film re-wet speed, block resistance, and adhesion to paper are adjusted by blending SELVOL 823 with lower-viscosity partially hydrolysed polyvinyl alcohol or with plasticizers such as glycerol and sorbitol. Adhesion to porous substrates should be tested at final packaging moisture levels, not solely on dry laboratory coupons.
Paper and paperboard surface-size applications use SELVOL 823 as a film-forming binder in combination with starch, styrene-acrylic dispersions, or polyurethane dispersions. At a size press or film press, 2–6% total solids may be applied at 40–60 °C with rod, blade, or film-metering equipment. The partially hydrolysed structure contributes adhesion to lignocellulosic fibres and reduces dusting during subsequent printing and converting. Differences from fully hydrolysed grades appear as lower solution viscosity at a given solids, improved cold-water clean-up, and lower equilibrium water resistance, which must be considered when the sized paper will be subjected to wet-end exposure. Size-press solutions should not be evaluated solely by visual clarity; undispersed microgels can pass transparent and later create streak defects on metering elements. Production lines should monitor wet pick and dry pick after conditioning to the target moisture content, because PVOH performance shifts with equilibrium moisture.
Formulators switching from fully hydrolysed grades to SELVOL 823 in coated paper applications should re-optimize starch cook temperature and size-press viscosity because partially hydrolysed PVOH changes the temperature-viscosity profile of the blend. The lower dissolution temperature reduces the risk of undispersed PVOH in size-press circulation at lower run temperatures, but the final coated sheet may show higher Cobb values unless starch or crosslinker adjustments are made. Cobb testing per ISO 535 provides a quantitative check of water absorption changes.
Thermoplastic processing of polyvinyl alcohol is complicated by the proximity of the glass transition and decomposition onset. Plasticised SELVOL 823 may be extruded in twin-screw compounding equipment with a moderate screw L/D ratio if sufficient plasticizer and thermal stabilizer are used, but production-scale experience indicates that control of barrel temperatures and screw shear is critical to prevent gel formation and discolouration. Published data for this specific configuration is limited; converters considering melt-phase processing should begin with solution-cast or coated trials before transferring the product to plasticised extrusion.
Textile warp sizing formulations use SELVOL 823 as a film-forming binder that increases abrasion resistance during weaving and can be removed in hot-water desizing. In blends with starch, polyester resin, or acrylic ester size, SELVOL 823 at 5–25% of dry size solids improves film elongation and reduces dusting on high-speed looms. Size-box solids are typically maintained between 8% and 12% depending on yarn count, size-box configuration, and loom speed. The viscosity of SELVOL 823 stock solutions must be accounted for at high solids because viscosity rises non-linearly above 10%, and single-point Brookfield values are insufficient for predicting transfer-pump and size-box shear behaviour. Desizing uses water at 60–90 °C; partial hydrolysis promotes aqueous swelling, but complete removal is faster with mechanical counterflow washing and may be assisted by oxidative desizing agents or amylase enzymes when starch is present in the size formulation. Production trials should include yarn tensile testing per ASTM D2256 and abrasion resistance measurements under the intended loom-shed conditions, because the contribution of PVOH to weaving efficiency is load-dependent and cannot be inferred from film tensile data alone.
In emulsion polymerisation of vinyl acetate and vinyl acetate-ethylene copolymers, partially hydrolysed polyvinyl alcohol such as SELVOL 823 functions as a protective colloid. The grade is introduced into the aqueous phase before monomer feeding, usually at 3–8 parts per hundred monomer in stirred stainless-steel reactors with product discharge through fine filters. During polymerisation, grafting of vinyl acetate radicals onto the PVOH backbone increases the effective molecular weight and changes particle size distribution, final latex viscosity, and dry-film water sensitivity. The hydrolysis range of SELVOL 823 is high enough to maintain colloid stabilisation in the aqueous phase but low enough to avoid the excessive water sensitivity associated with higher residual acetate products. Reactor operators should monitor finished latex Brookfield viscosity per ISO 2555 and residual monomer rather than relying only on the original PVOH solution viscosity, because the latex viscosity is strongly influenced by graft polymer content and particle size distribution. Scale-up from small reactors should include shear-stability testing through the product filter and storage tank, since protective-colloid distribution affects filtration pressure drop and clean-in-place cycle frequency.
Processes that cannot maintain 80 °C jacket temperatures often select partially hydrolysed grades such as SELVOL 823 over fully hydrolysed equivalents. The lower crystallinity allows completion of hydration at 60–70 °C in typical 4% solutions, although time-to-clarity depends on particle size, agitation intensity, and pH. At ambient temperatures below 20 °C, dissolution slows markedly; pre-slurrying in cold water followed by controlled heating prevents gel-particle formation. Because polyvinyl alcohol solutions are susceptible to microbial attack, storage of prepared solutions beyond 24–48 h without biocide may result in viscosity loss and odour. The product should not be exposed to strong oxidising acids or high concentrations of hydrogen peroxide at elevated temperatures, which can cause chain scission and reduce film strength. Powder handling should use local exhaust ventilation; fine organic powders may form combustible dust clouds and fall under NFPA 654 or equivalent regional requirements. For food-contact uses, end-users must confirm the specific regulatory status of SELVOL 823 under 21 CFR 177.1670 for polyvinyl alcohol films or 21 CFR 175.300 for coatings, because compliance is formulation-dependent and not automatically conferred by resin selection.
Raw material release testing for SELVOL 823 should include viscosity, hydrolysis, pH, volatile content, and ash. Viscosity is sensitive to solution concentration; a 0.1% error in solids can shift the 4% solution viscosity by more than 1 mPa·s, so fixed-solids preparation and temperature control are required for valid comparisons. Ash and volatile measurements reflect isolation and packaging performance; excursions above supplier limits may indicate contamination or moisture pickup in storage. In water-soluble film casting and solution coating, SELVOL 823 can be processed as a 10–20 wt% aqueous dope at 60–80 °C onto a heated belt or drum, with staged drying to prevent skin-over and bubble formation. Film tensile properties vary with plasticizer type and level; polyethylene glycol, glycerol, and sorbitol reduce tensile strength and increase elongation. The moderate viscosity of SELVOL 823 limits dope solids relative to low-viscosity partial grades, which may be preferable for cast films requiring high solids and lower wet-film thickness. Higher-viscosity partial grades provide more solution viscosity per unit solids, but may reduce maximum solids in size-press and coating applications. The selection of SELVOL 823 over other products therefore depends on the balance between film strength, viscosity, solubility, and regulatory requirements for the specific converting line.
