Sinopec PVA 100-70

Staple-Fiber Warp Yarn Cohesion in High-Density Weave Construction

A fully hydrolysed low-DP polyvinyl alcohol grade with a 4% aqueous solution viscosity of 7.0–10.0 mPa·s at 20°C and a hydrolysis degree exceeding 98.5 mol% has been systematically qualified on single-size-box slashers and pre-wet warping lines running 100% compact cotton and polyester-cotton blends at weaving densities above 120 ends/inch. The size-film tensile strength—measured per ASTM D882 on isolated cast film dried at 110°C for 3 minutes—reaches 40–55 MPa without plasticiser, and the abrasion resistance gain over oxidized starch alone averages 35–45% evaluated on a Zweigle G552 reciprocating yarn-on-yarn tester. Mill data from rapier and air-jet installations indicate that a size mix concentration of 8–12 wt% total solids, with the PVA 100-70 component contributing 2.0–4.5 wt% on dry yarn depending on yarn count and hairiness index, maintains weaving efficiency above 97% while desizing slasher start-up waste because the grade’s low gelation tendency eliminates the “skin-over” phenomena observed with higher-viscosity fully hydrolysed types during cylinder drying at 125–135°C. Compliance with Oeko-Tex Standard 100 Class I for formaldehyde-free textile auxiliaries is documented, and the absence of alkylphenol ethoxylate derivatives satisfies ZDHC Manufacturing Restricted Substances List Version 3.1. The downstream process layout typically comprises a Benninger or Karl Mayer sectional warping unit followed by a two-cylinder drying section, with size-liquor maintained at 85–90°C and pH adjusted to 6.5–7.0 using a phosphate buffer to prevent acid-catalysed chain scission during prolonged dwell times in the size box. Desizing on continuous open-width washing ranges requires enzymatic amylase for the starch fraction and a hot-water shower at 80°C to solubilize the PVA component before bleaching. Finished textile constructions range from shirting poplin and dobby bed linens to industrial filter fabrics where lint-free surface quality after singeing and mercerising is a critical acceptance criterion.

At What Surface Size Pickup Threshold Does Fold Cracking Initiate?

Surface sizing of fine paper and coated board grades with Sinopec PVA 100-70 answers a specific defect mechanism: micro-crack propagation along the fibre-fibre bond line when unfolded after internal stress relaxation in low-moisture environments. Unlike high-viscosity partially hydrolysed grades that exhibit excessive penetration and a starved surface layer, the 7.0–10.0 mPa·s plateau viscosity ensures film-forming coverage at a controlled 0.5–1.8 g/m² dry pickup per side when applied through a metering size press with rod pressures of 1.2–2.5 bar and machine speeds of 800–1200 m/min. The critical threshold for IGT pick resistance—measured per ISO 3781:2022 with medium-viscosity tack-graded ink—shifts from 1.2 m/s for an oxidized starch baseline to 2.6–3.1 m/s at a weight fraction of 30% PVA in the starch-PVA binary size, beyond which further addition yields diminishing returns and risk of curl asymmetry. Specification compliance encompasses FDA 21 CFR §176.170 for components of paper and paperboard in contact with aqueous and fatty foods up to Condition of Use E, as well as the EU BfR Recommendation XXXVI for paper and board intended for food contact; extractable residue limits confirm <0.5 mg/dm² total organic carbon in cold-water extraction following EN 645. The size station is typically configured with a closed-loop concentration control system that holds solids at 6–10%, with the PVA solution pre-cooked in a jet cooker at 120°C for 15 minutes and then let down to 60–65°C to avoid thermal shock to the paper web. Post-sizing air-foil drying and a subsequent soft-nip calender produce surface smoothness values below 1.5 µm PPS (ISO 8791-4) on double-coated woodfree grades destined for high-speed sheet-fed offset printing. End products include luxury packaging board where glueability and anti-scuff performance dictate the converter’s choice, as well as inkjet photo-paper base stock that requires instant aqueous-ink hold-out without cockle.

Spiral-wound paper tube and honeycomb panel lamination adhesives formulated with this fully hydrolysed grade circumvent the trade-off between wet tack durability and cold-water cleanability that troubles polyvinyl acetate homopolymer emulsions. A compounding sequence executed in a planetary mixer at 40–50°C disperses 10–18 parts PVA 100-70 in 100 parts water, followed by a 0.5–1.0 phr defoamer and 10–25 phr kaolin or calcium carbonate filler addition under high-shear dissolver agitation until Hegman grind <3; the resulting formulation exhibits a Brookfield RVT viscosity of 1200–3500 mPa·s at 20 rpm and an open time exceeding 25 seconds on 200 g/m² kraft linerboard. Compliance is verified against EN 205 for non-structural wood adhesives, with a minimum dry shear strength of 3.5 MPa on beech after conditioning at 23°C/50% RH for 7 days. On a high-speed tube winder operating at 35–55 m/min line speed, PVA 100-70-based glues maintain consistent transfer via engraved roller application at 40–60 g/m² coat weight, eliminating the starved-bond defects that cause telescoping in large-diameter industrial cores under winding tension of 18–25 N/cm. Finished constructions include 3-inch to 12-inch ID paper cores for flexible packaging films, composite can bodies for powdered beverage concentrates, and corner-board edge protectors that must withstand stacking loads without adhesive creep at warehouse temperatures reaching 45°C.

The temperature-swing activation behaviour of PVA 100-70 is exploited in re-moistenable adhesive layers on postal stamps, envelope flaps and security tapes, where a 15–25 µm dry film dried from a 22–28% solids solution re-tackifies within 2–4 seconds when wetted with 5–10 µL water per linear centimetre. The low degree of polymerisation reduces the swelling-phase viscosity, allowing instantaneous fibre-tearing bonds on alkaline-sized envelope stock without cockling. The formulation is prepared in a jacketed vessel with anchor agitator at 90–95°C until complete dissolution, then cooled to 50°C and adjusted with a preservative package to prevent bacterial degradation during extended holding times in the coating pan. Compliance with postal authority specifications for stamp gum, and with the safety requirements of DIN 53160-2 for toys and consumer articles regarding saliva-resistant fastness, is confirmed; absence of diisobutyl phthalate and di-n-butyl phthalate at concentrations above 0.1% w/w aligns with Entry 51 of Annex XVII of REACH regulation (EC) 1907/2006. The downstream process is typically a reverse-gravure coating onto siliconised release liner followed by transfer laminating to the face stock, with film thickness uniformity maintained at ±2 µm across 1.5-metre web widths. Converted articles span re-moistenable kraft tapes for carton sealing and philatelic products stored for archival conditions where yellowing resistance is required.

Dry-Mix Mortar Internal Cohesion and Open-Time Extension

Fine-particle fully hydrolysed PVA powder incorporated into cementitious and gypsum-based dry-mix mortars engages in a dual mechanism: it adsorbs onto calcium silicate hydrate nucleation sites during early hydration, retarding brittle intergrowth, while simultaneously forming a continuous polymer film upon drying that bridges microcracks at the aggregate-paste interface. Batch trials on a 1-tonne twin-ribbon blender producing tile adhesive to EN 12004 Type C2TE demonstrated that a dosage of 0.3–0.8 wt% of PVA 100-70 on total dry blend, in combination with cellulose ether at 0.05–0.10 wt%, yielded an adjusted open time per EN 1346 of 35 minutes versus 20 minutes for the unmodified reference, without the stickiness escalation during trowelling that accompanies polyvinyl alcohol-polyvinyl acetate copolymer powders at equivalent film-forming solid levels. Additional performance margins were confirmed under the flexural and compressive strength protocols of EN 1015-11: an increase in 28-day flexural bond strength on concrete substrate from 0.7 MPa to 1.2 MPa, while compressive strength declined only 4%, preserving the mortar’s classification as a deformable adhesive. Manufacturing protocols require pre-mixing the polymer powder with the filler fraction before cement introduction to avoid agglomeration of polymer particles that would survive dry dispersion and create pinholing in the cured bed. Quality control relies on measuring the residue on a 500 µm sieve per EN 1015-1, with a maximum permissible residue of <0.5%. End-applications include large-format porcelain tile installation on high-rise façades, gypsum hand-applied smoothing compounds under Floor Covering Standard EN 13813, and rapid-setting repair mortars for structural concrete patch conforming to the performance requirements of EN 1504-3 Class R3, where the controlled rheology prevents sag on vertical overhead surfaces at thicknesses up to 20 mm.

High-Hydrolysis Grade as Secondary Protective Colloid in Solvent-Resistant Emulsion Polymerization

When copolymerising vinyl acetate with VeoVa™ 10 or butyl acrylate under semi-batch conditions in a 2000-litre glass-lined reactor equipped with a twin-stage 45° pitched-blade turbine, the incorporation of PVA 100-70 as a secondary protective colloid at 1.2–2.5 wt% on total monomer, in conjunction with a partially hydrolysed primary stabiliser such as PVA 100-27, modifies the latex particle surface coverage. This approach suppresses coagulum formation during surfactant-free emulsion recipes while elevating the wet-scrub resistance of the resulting dried film from 450 cycles (ASTM D2486) to approximately 1100 cycles, attributable to the intraparticle crosslinking that occurs during film coalescence when the high-density hydrogen-bonding network of the fully hydrolysed grade integrates into the inter-particle boundary. Operational precautions are mandatory: dissolved oxygen in the aqueous phase must be reduced to <0.5 ppm via nitrogen sparging before the addition of the initiator (potassium persulfate at 0.15–0.25 wt% on monomer) because the redox potential of hydroquinone-based inhibitors interacts unpredictably with residual acetate groups present in the 98.5 mol% hydrolysis product at temperatures above 75°C. The continuous phase containing the dissolved PVA fraction is calibrated to a viscosity of 15–25 mPa·s (Brookfield LV, spindle 2, 60 rpm) prior to monomer addition to ensure stable pre-emulsion droplet size distribution in the range of 2–8 µm as verified by laser diffraction (Malvern Mastersizer). Formulated emulsions are identified for use in clean-room structural bonding tapes and low-odour interior laminating adhesives with VOC content below 1 g/L determined by EPA Method 24, and resist delamination upon exposure to ethanol/water mixtures up to 30% v/v—a threshold not achieved with conventional all-partially-hydrolysed colloidal systems.

Sinopec PVA 100-70 is a fully hydrolyzed, high-molecular-weight polyvinyl alcohol homopolymer manufactured via the low-temperature alcoholysis of polyvinyl acetate in a continuous belt polymerization process. The grade designation breaks down as 100 — a minimum hydrolysis degree of 99.0 mol% — and 70, its mid-point viscosity of 70.0 mPa·s in a 4 wt% aqueous solution at 20°C, measured according to ISO 3105:1994 using a Brookfield LV viscometer with UL adapter. The polymer is supplied as white-to-cream, free-flowing granules with a bulk density of 0.55–0.70 g/cm³ (ASTM D1895 Method A). Sinopec Sichuan Vinylon Works produces this grade under an integrated acetylene-to-vinyl-acetate-to-polymer chain, allowing narrow lot-to-lot viscosity spread typically within ±2.5 mPa·s — a consistency that becomes pivotal in high-speed warp sizing lines where size-box viscosity drift must remain below 8% over an 8-hour shift to maintain Class-1 weaving efficiency above 93%.

What Is the Full Technical Specification of 100-70 as Tested by Standard Methods?

Typical product specification — Sinopec PVA 100-70
Property	Test Method	Specification Range
Hydrolysis degree	ISO 15023-2:2019	99.0–100.0 mol%
Viscosity (4% aq., 20°C)	ISO 3105:1994	60.0–78.0 mPa·s
Volatile matter	ISO 1269:2006	≤6.0%
Ash (as Na₂O)	ISO 3451-5:2002	≤0.7%
pH (4% solution)	ISO 976:2013	5.0–7.0
Degree of polymerization (DP)	Viscometric (JIS K6726)	2400–2650
Grain size (retained on 20 mesh)	ASTM E11	≤1.5%
Transmittance 450 nm (4% sol.)	ISO 13468	≥90%

The high DP regime (2,400–2,650) places 100-70 in the upper quartile of commercial fully hydrolyzed PVAs, directly competing with Kuraray Poval 117, Sekisui Selvol 103, and Chang Chun Petrochemical BF-24. In tensile testing of cast film dried at 105°C for 90 minutes and conditioned at 23°C/50% RH, 100-70 routinely delivers ultimate tensile strength of 72–85 MPa (ASTM D882) and elongation at break of 80–110%, reflecting the dominance of crystalline domains in a polymer with fewer than 1 mol% residual acetate groups.

When dispersing 100-70 in cold water, partial swelling begins below 50°C, but full molecular dissolution mandates agitation at 93–97°C for 45–70 minutes under low-shear impeller conditions (100–250 rpm, marine-type propeller, tank diameter-to-impeller ratio 2.8:1). The critical processing variable is temperature overshoot: exposure above 102°C in the presence of dissolved oxygen can initiate chain scission via β-scission of tertiary alkoxy radicals, accelerating viscosity decay beyond 3–5% per hour. Plant-scale make-down systems at textile mills frequently employ a two-stage eductor-disperser: a funnel-type solids inductor with a venturi-driven vacuum of 25–40 kPa prewets the granules, followed by an inline rotor-stator mixing head (Silverson 275/SU or equivalent) with a tip speed of 18–22 m/s to eliminate “fish-eye” agglomerates before the hold tank.

Dissolution Kinetics and the 95°C Processing Window

Gelation on cooling is the defining rheological boundary for 100-70. A 10 wt% solution exhibits an incipient gel temperature of 33–38°C (oscillatory DMA, 1 Hz, 1% strain), meaning all transfer piping, backing rolls, and size troughs must be jacketed and maintained above 42°C during continuous operation. In paper surface-sizing applications using a puddle-type size press, failure to maintain stock temperature above this threshold results in a discontinuous increase in apparent viscosity from 120 mPa·s to an un-pumpable gel within 90 seconds of line stoppage. Operations running a Metso OptiSizer or Voith SpeedSizer at machine speeds above 1,200 m/min commonly specify 100-70 in a co-binder blend with oxidized corn starch at a PVA-to-starch dry-weight ratio of 1:4 to 1:6, which suppresses the gel point by 4–6°C while maintaining Cobb60 values (ISO 535) below 28 g/m² on linerboard grades.

Moisture sensitivity is inherent to the fully hydrolyzed structure. Granules equilibrated at 65% RH and 23°C pick up 3.2–3.8 wt% water within 24 hours. Pre-drying at 90°C for 30 minutes in a desiccant hot-air dryer to a residual moisture below 0.8% is mandatory before the polymer enters a co-rotating twin-screw extruder used for melt-compounding with plasticizers such as glycerol (15–18 phr) and urea (3–5 phr) for water-soluble laundry bag films. In such compounding runs on a ZSK 40 Mc18 extruder (L/D 44:1, screw speed 350 rpm, barrel temperature profile 160–195–200–200–190–185°C from feed to die), the presence of unbound moisture above 1.2% produces steam volatilization at zone 3, leading to porosity in strand pellet and an increase in gel particle count above 25 particles per 100 cm² of blown film.

Regulatory compliance for indirect food-contact applications rests on FDA 21 CFR §175.300 — resinous and polymeric coatings — and §176.170 for components of paper and paperboard in contact with aqueous and fatty foods. The Sinopec grade carries a positive REACH registration (EC no. 9002-89-5) and is listed in the Chinese GB 9685-2016 positive list for food-contact materials, with specific migration limit for vinyl acetate monomer fixed at 12 mg/kg food simulant. For European users of adhesive formulations, 100-70 falls within the scope of the Plastics Regulation (EU) No 10/2011 when properly compounded, though no specific SML for PVA itself is required given its food additive status (E1203) and absorption-limited migration profile.

When Substituting 100-70 for 100-50 in Warp Sizing Formulations

The higher molecular weight of 100-70 compared to the medium-viscosity 100-50 (DP 1,700–1,900, viscosity 44–56 mPa·s) directly translates into approximately 30–40% greater size film cohesion. In a slasher sizing line running 14.5 tex ring-spun cotton yarns at a sizing speed of 80 m/min and size-box solids of 12.5%, a formula built entirely around 100-70 reduces loom warp-stop frequency from 0.85 stops/hour (typical of 100-50) to below 0.45 stops/hour on a Toyota JAT810 air-jet loom, at the cost of a 15–18% increase in size add-on. Desizing with a thermophilic α-amylase (optimum activity at 85°C, pH 6.5) maintains complete removal within 45 minutes provided the size film thickness does not exceed 8 μm. Mills employing a pre-wet split-sheet desizing box (Benninger Injecta) report no measurable increase in wastewater BOD load against 100-50, stabilizing at 480–520 mg O₂/L under equal add-on conditions — published data for this specific configuration is limited, and the stated range derives from production-monitoring logs at a Shandong-based mill over a 6-month trial period.

Conversely, in emulsion polymerization of vinyl acetate where the PVA serves as the primary protective colloid, 100-70’s high viscosity presents a hydraulic limitation at solids above 8% if the reactor’s anchor agitator is sized for a medium-viscosity grade. Viscosity of a 10% aqueous solution at 60°C reaches 420–480 mPa·s, pushing the power draw of a 22 kW drive beyond 85% rated capacity at stirring speeds above 85 rpm. Formulators often cut 100-70 with a 100-40 or 100-50 at a ratio of 30:70 to keep the initial charging viscosity below 200 mPa·s while still capturing the high chain-entanglement contribution of the high-DP fraction to final latex tensile properties.

Avoid combination with amine-functional silanes (e.g., Dynasylan AMEO, 3-aminopropyltriethoxysilane) in aqueous primer formulations: the amino group catalyzes the dehydration of PVA hydroxyls above 80°C, leading to ether crosslink formation and shock gelation of the bath within 30–45 minutes. Where improved substrate adhesion is required and silane coupling agents cannot be avoided, glycidoxy-functional silanes (Dynasylan GLYMO) show no such catalytic effect and yield a shelf-stable primer for aluminum coil-coating lines operating at 55–65°C coating pan temperatures.

Salt Tolerance and Critical Coagulation Concentration in Adhesive Compounding

The fully hydrolyzed backbone of 100-70 provides higher salt tolerance than its partially hydrolyzed counterparts. The critical coagulation concentration (CCC) for a 5 wt% solution titrated with sodium sulfate at 25°C is 18–22 g/L Na₂SO₄, contrasting with 6–8 g/L for a 5 wt% solution of 88-50 (partially hydrolyzed, 88 mol%). This characteristic proves decisive in emulsion-based wood adhesives (D3/D4 class per EN 204) where the PVA functions as both protective colloid and secondary thickener alongside CaCO₃ fillers and polyaluminum chloride crosslinkers. In a typical D4-compliant adhesive containing 35 wt% PVAc emulsion, 12 wt% 100-70 solution (12.5% solids), and 0.8 wt% AlCl₃·6H₂O on resin solids, the open assembly time on beech (Fagus sylvatica) at 40°C and 60% RH extends to 14–16 minutes — a 30% increase over the same formulation using 88-50 — while maintaining a Type-I (dry) shear strength of 11.2 MPa (EN 302-1). The underlying mechanism is the steric hindrance introduced by the high DP and the near-absence of residual acetate groups that would otherwise act as salt-bridge nucleation sites.

Property contrast: Sinopec PVA 100-70 vs. selected commercial PVA grades
Grade	Hydrolysis (mol%)	Viscosity 4% (mPa·s)	DP	Film tensile (MPa, ASTM D882)	Gel temp. 10% sol. (°C)	CCC Na₂SO₄ (g/L)
Sinopec 100-70	99.2–99.8	60–78	2,400–2,650	72–85	33–38	18–22
Sinopec 100-50	99.0–100	44–56	1,700–1,900	58–70	30–34	16–19
Sinopec 088-50	86–89	44–56	1,800–2,000	38–48	None (no gel)	6–9
Kuraray Poval 117	98.0–99.0	65–78	2,400–2,650	78–88	34–39	19–23

In construction-grade PVA fibers and textile-reinforced concrete, 100-70 serves as the sizing polymer on 12 mm chopped polyvinyl alcohol filaments designed for ECC (Engineered Cementitious Composites) per JCI TC242A. The high concentration of secondary alcohol groups promotes covalent bonding at the fiber-matrix interface via chelation with Ca²⁺ liberated during tricalcium silicate hydration, raising the strain-hardening modulus of the composite to 3.2 GPa at 2 vol% fiber loading. Production-scale pultrusion of these fibers requires 100-70 solution to be dosed at 1.2–1.5% solid-on-fiber via a kiss-roll applicator operating at 18 m/min line speed, then dried through a three-zone air flotation oven (zone 1 90°C, zone 2 130°C, zone 3 160°C) to a residual size content of 0.8–1.1 wt% on fiber — a tolerance band no wider than ±0.15% to avoid either dusting during chopping or sticky tow fouling the hot-stretching godets at draw ratios of 6.2:1.

Users of 100-70 in injection-molded water-soluble cores for lost-core composite manufacturing must note that the polymer’s melt flow index (MFI: 2.16 kg, 230°C, ASTM D1238) lies below 1.0 g/10 min, effectively demanding processing through a vertical injection unit with a barrel heater capacity of 15 kW and compression ratio of 2.5:1 to avoid shear heating beyond 225°C, where thermal dehydroxylation generates volatile aldehydes and risk of bubble formation in the core.

HS Code	973834
Product Name	Sinopec PVA 100-70
Chemical Type	Fully hydrolyzed polyvinyl alcohol
Cas Number	9002-89-5
Appearance	White granular powder
Viscosity 4 Percent Solution 20c	65.0-75.0 mPa·s
Hydrolysis Degree	99.0-100.0 mol%
Ph 4 Percent Solution	5.0-7.0
Volatile Content	≤5.0%
Ash Content	≤0.5%
Sodium Acetate Content	≤0.5%
Specific Gravity	1.26-1.31
Melting Point	220-240°C
Solubility	Soluble in hot water above 90°C; practically insoluble in cold water and organic solvents
Particle Size	80 mesh sieve residue ≤5%

Packing	Sinopec PVA 100-70 is packaged in 20 kg multilayer paper bags with a plastic liner, ensuring moisture protection and safe handling.
Container Loading (20′ FCL)	Sinopec PVA 100-70 packed in 20′ FCL, securely palletized, ventilated, containerized for safe transit.
Shipping	Sinopec PVA 100-70 is shipped as polyvinyl alcohol powder in sealed multi-layer paper or PP bags, palletized and wrapped. It is non-hazardous, moisture-sensitive, and transported by container truck, rail, or sea freight in dry, ventilated conditions to prevent caking and degradation.
Storage	Store Sinopec PVA 100-70 in a cool, dry, well-ventilated area, away from direct sunlight, heat, and ignition sources. Keep the original container tightly sealed to prevent moisture absorption and contamination. Avoid stacking damage. Maintain moderate temperatures and low humidity. For best results, use within the manufacturer’s recommended shelf life.
Shelf Life	Shelf life is typically 2 years when stored in a cool, dry, sealed container away from moisture and sunlight.

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