Procurement assessments for polyvinyl alcohol (PVOH/PVA) entering Turkish mill supply chains begin with Harmonized System code 3905.30, where the product is classified regardless of residual acetate content. This PVA Supply to Turkey: Textile & Paper Market Guide addresses hydrolysis-grade selection, viscosity boundaries, machine integration parameters, and import documentation. The Turkish textile and paper sectors absorb the majority of PVA imports for warp sizing and surface treatment, with demand concentrated in integrated cotton and polyester-cotton weaving plants and in packaging-grade paper machines. Specification limits for industrial PVA delivered to Anatolian mills generally require volatile matter below 5%, ash below 0.5% as Na₂O, and a 4% aqueous solution pH in the 5.0–7.0 range; these values should be verified against ISO 15023-1:2017 rather than accepted from a certificate of analysis without method codes.

Why Does Hydrolysis Degree Dictate Weaving-Shop Performance?

In cotton warp sizing, fully hydrolysed PVOH with a degree of hydrolysis above 98 mol% forms a high-tensile film that can reduce warp breakage on high-speed air-jet looms, but its removal in desizing demands wash water at or above 80–90°C. Partially hydrolysed grades in the 87–89 mol% range produce more elastic films and dissolve at lower temperatures, which suits difficult-to-desize constructions and sized yarn with high twist. Data from film tests run under ASTM D882 typically show tensile strength of fully hydrolysed grades at 40–75 MPa and elongation at break near 20–45%, while partially hydrolysed materials may fall below 40 MPa and exceed 100% elongation. The selection conflict on a production sizing range is therefore between weaving efficiency and wash-off energy. On a double size box with a 12-cylinder drying zone operating at cylinder surface temperatures of 120–135°C, a medium-viscosity fully hydrolysed grade can maintain size-bath viscosity within 18–25 mPa·s at 85°C when solids content is adjusted to 7–9%.

Batch-to-batch viscosity drift above ±2 mPa·s in the same nominal grade may shift size add-on by more than 1.0 percentage point on a fixed squeeze nip, so incoming quality control should require the supplier to report Brookfield viscosity at 4% solids and 20°C under ISO 15023-2:2019. PVA is rarely used as the sole size in Turkish weaving plants; starch/PVA blends dominate because of cost and drying energy. Oxidized corn starch at 8–11% solids blended with PVA at 15–30% of total dry binder increases film toughness without a proportional rise in size-bath viscosity. High-hardness ground water above 180 mg/L CaCO₃ can destabilize starch size and precipitate scale in the size box, causing rod-clogging and uneven pickup on section beams. Production records from high-density weaving mills indicate that water softening to below 50 mg/L hardness and continuous size-bath agitation are required when PVA exceeds 25% of the dry size mix. Desizing audits commonly use spot tests for residual size; residual PVA after two open-width washes at 90°C should be below the detectable limit to prevent dyeing interference in subsequent reactive dyeing.

In Turkish paper mills, PVA functions as a surface-sizing co-binder and as a pigment-binding component in coated board formulations. A typical metering size press running packaging board at 900–1,200 m/min benefits from low-viscosity PVOH because high molecular weight grades can generate blade pressure fluctuations and misting at the application unit. Surface sizing formulations based on oxidized starch at 8–12% solids are modified with 0.5–2.0 dry parts of PVOH per 100 dry parts of starch. The resulting starch-PVOH film increases IGT pick strength measured under ISO 3783 and reduces Cobb water absorption measured under ISO 535; reductions in Cobb₆₀ on recycled linerboard are commonly reported in the range of 10–18% when PVA is added at 1 part per 100 parts starch, provided the size press pickup is held constant. Direct addition to a starch cook at 95°C can create lumps if the PVA is not pre-slurried in cold water at 20–30°C.

When PVA is used as a co-binder in coated board, it is added to coating color at 0.2–1.0 dry parts per 100 dry parts of pigment. The main process conflict is with calcium carbonate, which buffers coating pH above 8.5; high-pH coating can increase PVA solubility and interfere with immobilization during metered coating. Coat weight control on a blade coater is therefore more variable if the PVA selection has a low degree of hydrolysis and the coating color temperature exceeds 35°C. Medium-viscosity grades in the 12–18 mPa·s range improve water retention and optical density on recycled liner, but they also raise high-shear viscosity under ASTM D4287 cone-and-plate conditions. Trials on production blade coaters show that substituting one-third of the styrene-butadiene latex binder with PVA can lower dry pick resistance unless the PVA dispersion is fully cooked and screened through a 100 µm filter before addition.

Import Certification, KKDIK, and Supplier Quality Agreements

Suppliers shipping PVA to Turkey should provide a certificate of analysis that references ISO 15023-1:2017 designation data and the actual batch viscosity, hydrolysis degree, ash, and volatile matter. Turkish importers must verify that the non-Turkish manufacturer or the appointed only representative has addressed obligations under KKDIK, published in Official Gazette No. 30105 of 23 June 2017, where the substance falls within the registration scope. Because PVA is a polymer, the registration discussion normally concerns the main monomers and any residual vinyl acetate monomer above applicable thresholds; the supplier should confirm that residual vinyl acetate is controlled to the limit specified in the safety data sheet, commonly below 0.3%. For paper and board intended for food contact, compliance with 21 CFR 176.170 or Commission Regulation (EU) No 10/2011 should be documented by migration testing on the finished paper article, not inferred from resin composition alone. Published data for specific PVA migration limits under Turkish food-contact legislation is limited; therefore, a written supplier declaration with the test report and extraction conditions is the operational control point at the mill gate.

Integration of PVA in Turkish weaving plants exposes a recurring bottleneck when a mill switches from starch-only sizing to starch-PVA blends on existing high-pressure squeeze sizing machines. The addition of PVA raises size-film elongation and reduces dusting, but it also increases dryer demand because PVA films retain water more strongly than starch films. On a 12-cylinder sizing machine with cylinder surface temperatures at 120–135°C, maintaining 70–85 m/min production speed may require lowering wet pickup by 2–3 percentage points, which can conflict with the size add-on target of 10–14% for cotton warps. Process audits at Denizli and Bursa weaving mills show that mid-viscosity PVOH grades in the 12–18 mPa·s range provide the most stable size-bath performance, whereas high-viscosity grades above 40 mPa·s can create grooved roller picking and size-shedding defects on high-density polyester-cotton warps. Pre-blending of PVA with starch before the cooker is not recommended when PVA exceeds 20% of the dry mix; separate dispersion in cold water followed by controlled addition to the starch cook at 85–90°C reduces gel particle formation. The operational boundary is narrow: size-bath temperature below 80°C slows fully hydrolysed PVA dissolution, while sustained temperatures above 95°C can degrade starch and lower paste viscosity.

PVA recovery through ultrafiltration is installed in some large Turkish weaving operations to reduce effluent chemical oxygen demand and reuse size liquor. A membrane unit with a molecular weight cut-off of 10–30 kDa retains PVA while allowing water and low-molecular-weight impurities to pass. Recovery becomes technically feasible when PVA constitutes more than 25% of the size recipe, but the economic break-even point is site-specific and published data for specific Turkish mill configurations is limited. Accumulation of waxes and spin finishes in recovered liquor can lower film clarity, so recovered solids are typically blended with fresh PVA at a ratio not exceeding 80:20. The operation should be audited against filter flux rate and cleaning chemical consumption rather than treated as a guaranteed cost reduction.

If Low-Viscosity PVOH Replaces Oxidized Starch on High-Speed Paper Machines

Replacement of oxidized starch in paper surface sizing is not a direct drop-in; the rheology of PVA solutions at the application unit differs. Low-viscosity PVOH with a 4% solution viscosity of 3–5 mPa·s at 20°C can maintain blade-metering stability on a film press at machine speeds above 1,000 m/min, whereas starch pastes at equivalent solids can exhibit shear-thinning and transfer roll build-up. The limiting factor is usually not PVA viscosity but the adhesive character of the film at the drying section. After the size press, wetter paper enters the after-dryers; PVA films are thermoplastic and can pick on dryer fabrics if the first dryer surface exceeds 80–90°C before the sheet moisture falls below 20%. Mills control this by reducing initial after-dryer steam pressure and increasing the exhaust humidity set point. At addition levels above 2.0 dry parts per 100 dry parts of starch, Cobb₆₀ values may continue to fall, but the sheet can develop curl and changes in coefficient of friction measured under ISO 15359. Published data for this specific configuration is limited at very high machine speeds above 1,500 m/min, so pilot coater trials with the actual base paper are required before a full campaign.

Incoming PVA storage at Turkish mills requires sealed packaging and warehouse relative humidity below 60%; at higher humidity, the powder can form agglomerates and dissolve unevenly. Sacks should be conditioned to production hall temperature for 24–48 h before opening to reduce condensation on cold resin. For large textile plants, bulk handling systems with pneumatic transfer can introduce fines that affect dust explosion risk; the minimum explosible concentration for PVA dust should be taken from the supplier safety data sheet, and equipment grounding should follow IEC 60079-10-2 for hazardous area classification. Because PVA powder is not classified as dangerous for transport under the UN Model Regulations, supply contracts can simplify freight documentation, but the moisture content on arrival should still be checked by oven drying at 105°C for 3 h and compared with the certificate of analysis. Shipment lead times from Asian production sites to Turkish ports typically require buffer stock of 30–45 days because of port congestion and customs inspection cycles; this inventory target is a procurement parameter rather than a product specification.