| HS Code | 393273 |
| Product Name | Shuangxin 20-99 PVA (PVA 100-35) |
| Alternative Designation | PVA 100-35 |
| Chemical Name | Polyvinyl alcohol |
| Cas Number | 9002-89-5 |
| Chemical Formula | (C2H4O)n |
| Appearance | White granular powder |
| Degree Of Hydrolysis | 99.0-100.0 mol% |
| Viscosity 4 Percent Solution 20c | 35.0 mPa·s |
| Average Degree Of Polymerization | 2000 |
| Ph Value | 5.0-7.0 |
| Volatile Content | ≤5.0% |
| Ash Content | ≤0.5% |
| Whiteness | ≥90% |
| Solubility | Soluble in hot water |
As an accredited Shuangxin 20-99 PVA (PVA 100-35) factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | Shuangxin 20-99 PVA (PVA 100-35) is supplied in 25 kg multi-layer paper bags with inner plastic liner, ensuring safe storage and handling. |
| Container Loading (20′ FCL) | Shuangxin 20-99 PVA packed in palletized bags, loaded tightly into a 20′ FCL for safe, dry transport. |
| Shipping | Shuangxin 20-99 PVA (PVA 100-35) ships as a dry, free-flowing powder in sealed multi-layer paper or woven bags, typically 20–25 kg net each. Keep pallets dry, ventilated, and away from heat or ignition sources. Avoid dust generation and use appropriate respiratory protection during handling. |
| Storage | Store Shuangxin 20-99 PVA (PVA 100-35) in a cool, dry, well-ventilated area, away from heat, sparks, and direct sunlight. Keep the original container tightly sealed to prevent moisture absorption and contamination. Avoid high humidity and temperature fluctuations. Use proper handling to prevent dust accumulation. Under these conditions, shelf life is typically maintained as specified by the manufacturer. |
| Shelf Life | Store in a cool, dry, sealed container. Shelf life is typically 24 months from manufacture date under proper storage conditions. |
On high-speed air-jet looms running 800–1,200 picks/min, Shuangxin 20-99 PVA (PVA 100-35) is incorporated into cotton and polyester/cotton warp size formulations to transfer tensile strength and abrasion resistance to the warp yarn bundle before shedding. The compliance anchor for this application is Oeko-Tex Standard 100, Annex 4, for skin-contact finished textiles, combined with GB 4287-2012 limits on desizing effluent COD; because fully hydrolyzed PVA in the 98.0–99.0 mol% alcoholysis range (GB/T 12010.5) forms a crystalline film with low cold-water solubility, oxidative desizing using 3.0–5.0 g/L hydrogen peroxide or sodium persulfate at 80–90°C is required before finishing. The addition ratio is 4.0–8.0 wt% of total size solids, typically combined with 40–60 wt% oxidized starch and 5–15 wt% acrylic size on dry solids. Downstream production on a multi-cylinder slasher uses a two-box, double-squeeze size box, with the size cooked at 95–98°C for 30 min and held at 75–80°C during application; size pick-up is controlled at 10–14% dry on warp mass, and drying runs over Teflon-coated cylinders at 110–135°C to a residual moisture of 6.0–8.0%. Terminal products include high-density cotton sateen, polyester/cotton workwear, and compact-spun cotton shirting where low fiber lay and tensile strength after desizing are specified. The operational boundary is sharp: if the size-box temperature falls below 65°C, film split at the nip causes warp end breakage and visible size deposits on the reed.
The processing window for 20-99 in surface sizing is bracketed by two failure modes observed on short-dwell metering size presses: film split at low temperature and blade streak formation at high solids. The additive is prepared as a 9.0–12.0 wt% batch cooked at 95°C for 30 min, then diluted to 1.0–4.0 wt% dry solids for application; dry pick-up on the paper web is controlled between 0.3 and 0.8 g/m² per side. On a metering size press running 800–1,200 m/min, the 20–35 mPa·s viscosity of a 4% aqueous solution (GB/T 12010.3) imposes a practical upper limit of 4.0 wt% stock concentration without post-metering dilution; above this level, blade streaking and film breakage at the transfer nip are consistently reported from production campaigns. In alkaline papermaking, borax should not be added to 20-99 size solutions because the fully hydrolyzed product forms elevated-viscosity complexes under high pH conditions and may gel in the return loop. Compliance for food-contact surface sizing is assessed under FDA 21 CFR 176.170 and EU 1935/2004/EC, with migration testing performed on the finished paper; Cobb uptake is measured per ISO 535:2023, and surface strength is measured by IGT pick velocity per ISO 3783:2014. Downstream production uses a film press or short-dwell size press with pre-moisturizing water to control surface transfer, followed by after-dryer sections at 100–130°C to a final moisture of 4.0–6.0%. Terminal products include food-grade folding carton board, cupstock, release liner base, and coated white-top liner where gluing strength and print pick resistance dominate end-use performance.
In a 20 m³ baffled stainless-steel reactor equipped with a three-blade turbine agitator running at 80–120 rpm, 20-99 is used as the high-molecular-weight protective colloid in vinyl acetate homopolymerization only when blended with a partially hydrolyzed 88 mol% PVA; using the fully hydrolyzed grade alone produces a large mean particle size and poor shelf stability. Compliance for the resulting PVAc dispersion includes FDA 21 CFR 175.105 for adhesives, REACH Regulation (EC) No 1907/2006, and GB 18583-2008 for volatile organic compounds in indoor adhesives. The addition ratio is 1.5–4.0 wt% of 20-99 on vinyl acetate monomer mass, in a dual-colloid system with 2.0–6.0 wt% of an 88 mol% grade; the 20-99 fraction is dissolved in demineralized water at 90–95°C for 45–60 min, cooled to 55–65°C, and metered into the pre-emulsion. Downstream production involves semi-batch addition of vinyl acetate and a persulfate redox initiator over 3–4 h, with jacket cooling to maintain 65–75°C; because the high degree of hydrolysis reduces grafting efficiency, the 20-99 component accumulates in the aqueous phase and raises final Brookfield viscosity (ISO 2555) beyond the neat 88 mol% baseline. The operational limit is a maximum 20-99 level of 4.0 wt% in the total colloid package for stable latex with low coagulum retention on plant sieves; above this threshold, gel levels increase and heat transfer at the jacket wall deteriorates due to high viscosity. Terminal products are PVAc homopolymer dispersions for D2/D3 wood assembly adhesives under EN 204, paper converting adhesives, and general-purpose wood gluing where the dried film must meet the relevant EN 204 classification without cold-crack failure. Published plant-trial data for this specific 20-99 dual-colloid ratio in emulsion polymerization is limited, so particle size distribution targets should be established on the specific reactor geometry rather than transferred from one plant to another.
Tape casting of high-purity alumina and barium titanate granulate uses PVA 20-99 as the temporary binder in water-based slurries where clean burnout and green strength are the controlling variables. The compliance anchor for this ceramic process is RoHS Directive 2011/65/EU for electronic substrates, with residual ash from the binder held below 0.5 wt% of dry solids to avoid conductive residue after firing. The addition ratio is 3.0–8.0 wt% dry basis on ceramic powder; below 3.0 wt%, green flexural strength measured by three-point bending per ASTM C1161-18 falls below the level required for automated sheet handling, and above 8.0 wt%, drying shrinkage gradients cause edge cracking and lamination defects. Downstream production involves aqueous slurry milling with ZrO₂ media for 12–24 h, vacuum de-airing at 20 kPa, and tape casting with a doctor blade gap of 200–500 µm onto a PET carrier. Drying proceeds at 60–80°C with infrared assist to a residual moisture below 1.5%; binder burnout requires a controlled ramp of 0.5°C/min from 200–450°C, followed by sintering at 1,500–1,650°C depending on the ceramic system. Terminal products include alumina substrates for thick-film circuits, ferrite components, and low-temperature co-fired ceramic tape where binder migration is not observed during vacuum lamination. Because published data for this specific binder in all ceramic systems is limited, thermogravimetric analysis per ISO 11358-1 should verify complete decomposition before the first sintering hold.
Substitution of starch ether by Shuangxin 20-99 in a self-smoothing cementitious compound shifts the formulation behavior from water retention toward cohesion and surface wear resistance, but the replacement is not one-to-one. Compliance for the finished underlayment is specified under EN 13813, with strength properties expressed as C25-F6 class, while the PVA powder falls under REACH Regulation (EC) No 1907/2006 and the installed system is evaluated for indoor VOC release under ISO 16000-9. The addition ratio is 0.6–1.2 wt% of total dry mortar, lower than typical starch ether dosage because the high-molecular-weight fully hydrolyzed PVA develops rapid solution viscosity in alkaline cement pore water. Above 1.5 wt%, the mix becomes air-sensitive: rotor-stator pumping at 8–12 L/min entrains air beyond the EN 1015-7 air content limit, and open time shortens. Downstream production uses a planetary mixer at 150 rpm for 120 s dry blending, followed by on-site addition of 0.30–0.35 L water per kg of dry compound and drill mixing for 90–120 s. The wet compound is pumped through a rotor-stator mortar pump and applied as a 1.0–5.0 mm layer; flow ring spread is checked against EN 12706 at 140–160 mm before final setting. Terminal products are calcium aluminate cement-based self-smoothing underlayments for vinyl flooring, luxury vinyl tile, and ceramic tile where residual moisture tolerance of the adhesive layer must be maintained. A known operational boundary is calcium ion sensitivity: fully hydrolyzed PVA has lower calcium ion tolerance than partially hydrolyzed grades, and high-alkali cement with potassium aluminate accelerators can cause localized precipitation if the 20-99 solution is injected as a pre-dissolved stream rather than dry-blended into the powder.
Water-gummed paper substrates are coated with an aqueous remoistenable adhesive prepared from PVA 20-99 at 5.0–10.0 wt% dry solids; the formulation is plasticized with 1.0–2.0 wt% glycerol or polyethylene glycol on PVA dry mass to prevent brittle film loss during die-cutting. Compliance for adhesive-coated paper intended for indirect food contact is evaluated under FDA 21 CFR 175.105 and EU 1935/2004/EC. Downstream production uses reverse-roll or gravure coating at 80–120°C drying air temperature to a residual moisture of 4.0–6.0%; at line speeds of 120–200 m/min, the film cools before rewinding to prevent blocking at 40°C and 60% RH. The moistening open time after remoistening is 3–8 s depending on coat weight; fully hydrolyzed 20-99 provides slower cold-water tack development than 88 mol% grades, so the grade is selected when block resistance and dry optical clarity are more important than instant tack. Terminal products include gummed labels, stamps, and remoistenable paper tape.
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Shuangxin 20-99 PVA, also listed in export documentation as PVA 100-35, is a fully hydrolyzed polyvinyl alcohol powder produced from vinyl acetate monomer by suspension polymerization followed by alkaline alcoholysis. The 20-99 designation identifies a 4 wt% aqueous solution viscosity of 20.0–26.0 mPa·s at 20 °C and an alcoholysis degree of 98.0–99.0 mol%. The parenthetical PVA 100-35 code appears in distributor and procurement records as an alternative identifier for the same mid-viscosity, fully hydrolyzed resin; however, certificate-of-analysis verification is required because the 100-35 synonym does not follow the viscosity-hydrolysis naming convention. The product is supplied as a white to off-white granular solid with low cold-water dispersibility. It is selected where film toughness, hot-water solubility, water resistance after drying, and moderate solution viscosity must be balanced.
At an alcoholysis degree above 98.0 mol%, polyvinyl alcohol chains contain sufficiently regular hydroxyl sequences to crystallize. The granules swell in water before dissolving, and cold-water addition can produce a gelled surface layer that encapsulates dry powder and forms lumps. In production mixing, the powder is dispersed in water at 20–35 °C under high shear, then heated to 85–95 °C and held for 20–40 min with low-shear agitation at 100–200 rpm. Direct steam injection is used only when local heat flux is controlled to prevent gel skins from forming on heat-transfer surfaces. At 8 wt% solids, solution viscosity at 20 °C is approximately 3–4 times the 4 wt% value, and air entrainment becomes significant above 10 wt%. The solution is usually screened through a 100–150 μm filter before coating or film casting to remove microgels. Cast films conditioned at 23 °C and 50 % relative humidity typically show tensile strengths in the 40–60 MPa range, as measured by ASTM D882-18. Fully hydrolyzed films have lower equilibrium moisture uptake and higher hot-water resistance than partially hydrolyzed 20-88 films, but they remain hot-water soluble unless crosslinked or thermally annealed.
Commercial certificates of analysis for Shuangxin 20-99 PVA typically list the following specification window; batch-specific values may be tighter. Viscosity is determined as a 4 wt% aqueous solution at 20 °C using a Brookfield LV rotational viscometer with spindle 2 at 20 rpm, following the general procedure described in GB/T 12010.2-2010. Alcoholysis degree is measured by residual acetate saponification and back-titration. Volatile matter is determined after oven drying at 105 °C, and ash is determined after ignition at 750 °C.
| Property | Typical range or limit | Test basis |
|---|---|---|
| 4 wt% solution viscosity at 20 °C | 20.0–26.0 mPa·s | GB/T 12010.2-2010, Brookfield LV, spindle 2, 20 rpm |
| Alcoholysis degree | 98.0–99.0 mol% | Saponification/back-titration; GB/T 12010.2-2010 |
| Volatile matter | ≤5.0 wt% | Oven drying at 105 °C |
| Ash | ≤0.5 wt% | Ignition at 750 °C |
| pH of 4 wt% solution | 5.0–7.0 | Electrometric pH measurement |
| Whiteness | ≥90 | Reflectance method |
| Bulk density | 0.40–0.60 g/cm³ | Settled bulk density |
In textile warp sizing, the replacement decision is controlled by size-box viscosity tolerance and weaving abrasion. Compared with 17-99, 20-99 has a higher average molecular weight and forms a tougher size film, which reduces size shedding on high-speed shuttleless looms. The viscosity increase, however, limits the maximum size solids that can be pumped without exceeding a target size-box viscosity of 12–18 s measured by Zahn cup. A 17-99 formulation running at 12–14 wt% solids may require a reduction of 0.5–1.5 percentage points when shifted to 20-99. Compared with 24-99, 20-99 lowers size-box viscosity and improves penetration into dense polyester/cotton warps, but isolated cast film tensile strength is lower. The exact strength loss is normally determined by ASTM D882-18 film testing rather than predicted from grade name alone. In paper sizing and adhesive mixing, the medium viscosity of 20-99 provides sufficient film strength without the high shear viscosity of 24-99 or 26-99.
For aqueous adhesives, 20-99 is used in paper tube winding, carton side-seam gluing, and lamination where water resistance is required. The high hydroxyl density creates strong hydrogen bonding to cellulose and polar films. Glycerin or sorbitol at 10–25 wt% of PVA solids reduces film brittleness. Borax or boric acid must be limited because the fully hydrolyzed resin gels at low additive levels.
In polyvinyl butyral production, 20-99 is used as the hydroxyl-bearing feedstock in acid-catalysed acetalization with butyraldehyde. The residual acetate level of 1–2 mol% reduces the number of acetyl groups retained in the PVB chain, and the molecular weight controls the melt flow of the resulting interlayer. The particle size of the PVA feed influences dissolution kinetics; fines below 100 μm may form local gel chunks if added too rapidly to the acidified reaction medium.
| Grade | 4 wt% viscosity at 20 °C | Alcoholysis degree | Main processing difference |
|---|---|---|---|
| 17-99 | 17.0–21.0 mPa·s | 98.0–99.0 mol% | Lower molecular weight; faster dissolution; lower film strength |
| 20-99 | 20.0–26.0 mPa·s | 98.0–99.0 mol% | Target grade; balanced film strength and solution viscosity |
| 24-99 | 24.0–30.0 mPa·s | 98.0–99.0 mol% | Higher viscosity; stronger film; slower penetration |
| 26-99 | 26.0–32.0 mPa·s | 98.0–99.0 mol% | Highest molecular weight in this series; requires lower solids |
| 20-88 | 20.0–26.0 mPa·s | 86.0–89.0 mol% | Partial hydrolysis; cold-water soluble; lower water resistance |
At 20 °C, a 4 wt% 20-99 solution shows slight shear thinning under rotational viscometry. Boric acid or borax added at 0.1–0.3 wt% of solution weight increases low-shear viscosity by an order of magnitude through borate-diol complexation. Above 0.5 wt%, the solution can set to a rubbery hydrogel with visible syneresis after 24 h. The threshold is narrower than for partially hydrolyzed grades because the high hydroxyl content increases crosslinking site availability. In paper surface sizing, the size press solution is typically prepared at 4–8 wt% solids and maintained at 50–60 °C; borate-containing broke or alum must be controlled below the gel threshold to avoid roll deposits. Transfer lines should be flushed before cooling below 40 °C to prevent gel formation in low-flow zones.
Paper surface sizing with 20-99 at 4–6 wt% solids and 55–65 °C increases resistance to liquid penetration as measured by TAPPI T 530 om-14 and improves IGT pick strength under ISO 3783. The dry pickup is controlled by nip pressure and base-sheet porosity, with typical target add-ons of 1.5–3.0 g/m². The exact improvement over starch-only control depends on base paper porosity and size press configuration; published data for this specific grade and paper combination is limited. In cementitious dry mixes, 20-99 is added at 0.5–1.0 wt% of cement weight to increase tensile adhesion after wet-dry cycling, but it can retard setting when combined with high-calcium aluminate phases. The degree of retardation depends on calcium ion availability and the presence of polycarboxylate superplasticizers.
Thermal processing of 20-99 requires external plasticizers because the fully hydrolyzed resin has a melting range close to its decomposition onset. Formulations containing glycerin or sorbitol at 20–35 wt% of PVA shift the gel point below 180 °C. On a 45 mm single-screw extruder with an L/D ratio of 30:1, the feed throat is kept below 50 °C to prevent pellet bridging, and barrel zones are ramped from 120 °C to 185 °C. Pre-drying at 60–80 °C for 1–2 h is required if the powder has been stored above 60 % relative humidity. Avoid combination with strong oxidizers such as hypochlorite bleach, which can reduce viscosity and shift solution color. Where final articles may contact food, the specific grade must be confirmed against 21 CFR 175.105 or 21 CFR 175.300; supplier documentation is required for the specific batch because additive composition can vary.
