PVOH 9913

In cotton and polyester-cotton blend weaving operations, PVOH 9913 functions as a primary film-forming size applied at a typical concentration of 8.5–11.0 wt% in an aqueous size bath. The hydrolysis degree exceeding 99.0 mol% and a 4% solution viscosity of 27–33 mPa·s (DIN 53015) create a cohesive, abrasion-resistant film that withstands repeated reed beat-up forces on high-speed air-jet looms running at weft insertion rates above 1,200 m/min. Size liquor is prepared in a jet cooker at 125–135°C for full dissolution, then held at 90–95°C in the size box to prevent gelation. A typical formulation adds 0.5–1.2 wt% of a medium-chain fatty acid ester wax dispersion and 0.1–0.3 wt% of an ethoxylated tallow lubricant to reduce dry-shed dusting and improve yarn smoothness during shedding. Regulatory compliance for ready-made garments exported to the EU requires the size film to meet Oeko-Tex Standard 100 Annex 4 limits for extractable heavy metals and formaldehyde, verified by EN ISO 14184-1. Desizing effluents are treated to achieve a COD below 150 mg/L before municipal discharge, as commonly mandated in the South Asian textile belt. On a 48-position sectional warping beam, size add-on is controlled gravimetrically to 10–14% for Ne 40 ring-spun cotton; exceeding 15% frequently causes brittle fracture at the lease rods and raises sizing cost beyond the acceptable USD 0.18/kg yarn threshold. A post-weave enzymatic desize using a thermostable α-amylase at 75°C and pH 6.5 removes the film within 20 minutes in a continuous open-width washer, leaving a residual starch-PVOH blend fragment below 0.3% on fabric weight.Why Paper Mills Choose 99% Hydrolysis Grade for Surface Sizing?When PVOH 9913 is applied at the size press of a fine-paper machine producing 80–120 g/m² inkjet bond, the target pickup is 1.8–2.4 g/m² per side, delivered from a 7–9% solids solution maintained at 55–60°C. The high hydrolysis level minimizes film tack under the hot calender rolls and resists blocking in sheet-fed printing at relative humidity up to 65%. Mills running alkaline papermaking with 15–22% precipitated calcium carbonate filler rely on PVOH 9913 combined with an oxidized corn starch at a 30:70 dry-weight ratio to raise the IGT surface strength above 2.8 m/s (ISO 3783). For direct food-contact grades, compliance is verified against FDA 21 CFR 176.170 (components of paper in contact with aqueous and fatty foods) and BfR Recommendation XXXVI/1, with extractives in hot water limited to 0.5 mg/dm². Production staff periodically renew the size-press solution to avoid microbial degradation; a preservative based on 2-bromo-2-nitropropane-1,3-diol at 50–100 ppm active is dosed when the holding time exceeds 4 hours. To prevent excessive penetration into the sheet and sizing loss, the wet-end starch content is reduced by 1.5–2.0 kg/ton before switching to a PVOH-bearing surface size. Mills running a metering film size press with 40–60 kN/m nip load can maintain a dynamic viscosity at the application temperature below 120 mPa·s, measured continuously with an in-line tuning-fork viscometer. Final converted products include laser printer paper, envelope stock, and pharmaceutical insert leaflets where low linting and sharp toner adhesion are critical.

PVOH 9913 – Surface Sizing Formula vs. End-use Properties

Formulation (parts dry wt)	IGT Pick Resistance (m/s)	Cobb60 (g/m²)	Inkjet Bleed Edge
Starch 100	1.6	28	Moderate
Starch 70 + PVOH 9913 30	2.9	22	Negligible
PVOH 9913 50 + styrene-acrylate 50	3.5	18	None (Instant dry)

Primary Suspending Agent for Vinyl Chloride PolymerizationIn the production of suspension-grade polyvinyl chloride (S-PVC) with K-values between 57 and 68, PVOH 9913 serves as a primary protective colloid, typically dosed at 400–800 ppm relative to vinyl chloride monomer (VCM) weight. The polymerization is carried out in a 130 m³ Pfaudler-type reactor with a Rushton turbine agitator at 90–120 rpm, where the partially saponified PVOH grades control particle size distribution, but the high-hydrolysis 9913 is added in minor proportion—usually 15–25% of the total colloid charge—to tighten the skin of the PVC grain and reduce “fish-eye” defects in flexible calendered film. A dual-colloid system pairs PVOH 9913 with a low-viscosity, 72–80 mol% hydrolyzed PVOH at a total charge not exceeding 1,200 ppm; exceeding this level increases reactor fouling and requires mechanical cleaning after every 15–18 batches instead of the typical 40–50 batches. The water-to-monomer ratio is held at 1.2:1 to 1.4:1 by mass, and the reaction temperature is maintained at 57–63°C with a deviation band of ±0.3°C to control molecular weight. Vinyl chloride residuals in the dried PVC powder are stripped to below 1 ppm though steam desorption, to comply with the EU Regulation (EU) No 10/2011 overall migration limit of 10 mg/dm² for rigid PVC food packaging. After centrifugation and flash drying, the resulting S-PVC exhibits a bulk density of 0.48–0.54 g/cm³ and a porosity below 0.15 mL/g, suiting it for rigid pipe and window profile extrusion where lubricant uptake must be strictly limited. PVOH 9913 residuals in the final compound are undetectable by FTIR when the colloid content remains below 0.1% of resin mass.When Controlled-Release Agricultural Films Require Hot-Water Triggered DisintegrationPVOH 9913 is extruded into monolayer blown film of 35–50 μm thickness on a single-screw extruder with a L/D 30 barrel and a water-ring cooling mandrel. The granules are pre-dried in a desiccant hopper to a moisture content below 0.3%; otherwise steam bubbles nucleate at melt temperatures above 190°C and create pinhole defects. Processing additives include 12–18 phr of a polyol plasticizer blend (sorbitol/glycerol 2:1) and 0.5 phr of erucamide slip agent to reduce film-to-film blocking during reel storage. The die temperature is profiled at 195–210°C, and the blow-up ratio is set to 2.2:1 to balance transverse and machine-direction tensile strengths above 35 MPa (ASTM D882). Because the hydrolysis level exceeds 99%, the film remains insoluble in cold groundwater contact but disintegrates completely within 8–12 minutes when immersed in water at 65°C, a performance window tailored for pesticide sachets that are loaded into sprayer tanks with warm agitation. Compliance data submitted under the FAO Specification for pesticide application equipment require the empty sachet dissolution time to be validated at 60°C and a water hardness of 342 ppm CaCO₃; batch-to-batch variability in dissolution time must not exceed ±90 seconds. The converted finished product is a heat-sealed pillow pack with a leak-tight seal strength of ≥20 N/25 mm (EN 868-5) and a labelled instruction: “do not handle with wet hands when temperature exceeds 40°C.”Dry-mix cementitious tile adhesives and self-leveling underlayments incorporate PVOH 9913 as a water-retention and rheology modifier at loadings between 0.3 and 1.2 wt% of total powder. The polymer is dry-blended with Portland cement CEM I 42.5 R, silica sand (grading 0.1–0.6 mm), and a retarder (tartaric acid 0.05–0.1%) in a gravity ribbon mixer for 6–8 minutes to achieve a coefficient of variation in PVOH concentration below 5%, verified by iodine colorimetric spot testing on 20 g powder samples. Upon addition of the specified 21–24% mixing water, the PVOH 9913 hydrates and forms a viscoelastic aqueous film that increases the open time of the adhesive from 15 minutes to over 35 minutes at 23°C/50% RH, as measured by the wetting performance test in EN 1346. The vertical slip of a 150 g tile on a notched trowel bed is held below 0.5 mm (EN 1308) when the PVOH dose approaches 1.0%. For European market compliance, the formulation must achieve the C2 classification in EN 12004-1:2017, which demands a tensile adhesion strength after water immersion of at least 1.0 MPa; batches formulated with 0.8% PVOH 9913 and 3.5% ethylene-vinyl acetate redispersible powder consistently reach values of 1.4–1.7 MPa. Overdosing beyond 1.5 wt% triggers a sharp viscosity climb that makes trowel application unworkable and traps air cavities at the substrate interface, reducing actual adhesion rather than improving it.High-Solids Adhesive Compounding for Kraft-Paper Honeycomb CoresIn the manufacture of lightweight honeycomb panels for aircraft interior partitions, PVOH 9913 is cooked into an adhesive solution with a final solids content of 28–32% and applied via engraved-roller transfer to 80 g/m² unbleached kraft paper at a spread rate of 40–55 g/m² (wet). The compound is prepared in a steam-jacketed planetary mixer at 95°C and held under slow agitation for 90 minutes to release entrained air. The adhesive is fortified with 8–12% (on PVOH solids) of a multimethylol melamine crosslinker activated by an ammonium chloride catalyst at 0.3%, which raises the wet shear bond strength after the B-stage cure to above 2.8 N/mm as per internal qualification protocol FQA-TS-211, minimizing node failures during the expansion and dipping stages. Because the honeycomb core must pass the vertical burn test of FAR 25.853(a) Appendix F, Part I, addition of 15–20 phr aluminum trihydrate (median particle size 8 μm) is permitted only after a surfactant pre-dispersion of 0.5 wt% dioctyl sulfosuccinate to prevent filler agglomeration that would clog the 120 lines/cm application roller. Exposed edges of trimmed core are sealed with a 50:50 PVOH 9913/urea-formaldehyde syrup blend to eliminate fiber peel-back under cyclic humidity testing at 95% RH for 72 hours. Substitution with lower-hydrolysis grades (88 mol%) results in a measurable creep of the honeycomb nodes under a 0.07 MPa sustained compressive load at 50°C, disqualifying the core from structural panel qualification.

PVOH 9913 in Vinyl Acetate-Ethylene Emulsion Polymerization – Protective Colloid Specification vs. End-use Limit

Parameter and Unit	Value for 9913	End-product Consequence if Exceeded
Ash content (%)	≤0.5	Film clarity below 90% transmittance at 550 nm
Methanol extractables (%)	≤2.0	Excessive foam in pressure-sensitive adhesive coating
Aqueous surface tension (mN/m)	60–63	Weakening of emulsion stability when target is 52–55 mN/m
Degree of polymerization	1,300–1,500	Excessive thickening causing premature flocculation in high-shear pumping

In vinyl acetate-ethylene (VAE) copolymer emulsion production using a continuous-loop reactor at 95°C and 30 bar, PVOH 9913 is pre-dissolved as a 12% stock solution and metered into the reaction zone at a rate that maintains 4.5–5.5% protective colloid based on total monomer. The finished waterborne pressure-sensitive adhesive, designed for paper labelstocks, passes the FINAT FTM 1 loop-tack test with values exceeding 4.2 N/25 mm only when the PVOH 9913 chain length is preserved—shear degradation in the gear pump circulation loop must be monitored by gel permeation chromatography, and the number-average molecular weight loss across a 72-hour run is kept below 8%. Industrial hygiene and environmental compliance for the formulated adhesive are demonstrated by a total VOC content below 1,000 ppm by EPA Method 24, achievable because PVOH 9913 replaces low-molecular-weight nonionic surfactants entirely. The coated facestock, after release liner lamination, is stored in rolls at 40°C and 85% relative humidity for seven days; adhesion to a stainless steel panel (ASTM D3330 Method A) must remain above 12 N/25 mm without transfer of adhesive to the silicone-coated backing. A formulation deviation that replaces ≥15% of the 9913 quota with 88% hydrolyzed PVOH results in a decline of cohesive strength causing fibrillar separation during high-speed die-cutting on a rotary press at 120 m/min. Published data for this specific configuration under EU Ecolabel criteria (Commission Decision 2014/312/EU) is limited, thus full formulation documentation is advised when seeking certification.