Mercerized Wool Smooth Mixed Oil HOD-31

In worsted top-making, Mercerized Wool Smooth Mixed Oil HOD-31 is applied after scouring and drying but before carding to establish a uniform fibre-to-metal slip layer across batch weights exceeding 800 kg. The emulsion is prepared at 1:8 to 1:10 dilution with demineralized water at 40–45 °C, and target add-on is 0.8–1.2% w/w on dry fibre for mercerized merino top. Application is performed in a final mixing bin using a twin-nozzle atomizing sprayer delivering 50–80 mL/kg per pass, followed by 24 h conditioning at 22 ± 2 °C and 65 ± 5% relative humidity. Downstream, the stock passes through worsted carding with main cylinder surface speeds up to 1,600 m/min, vertical intersecting gill boxes, and rectilinear combing at 185–220 nips/min. Terminal products from this route are 2/28–2/60 Nm worsted tops converted into suiting and fine-gauge knitwear. Compliance for this sector is governed by REACH Regulation (EC) No 1907/2006 Annex XVII Entry 46 for NPEO/OPEO residues, ZDHC MRSL v3.1 Section 1.4.1, and OEKO-TEX Standard 100 Class II for finished textiles. Process limits are narrow: add-on below 0.5% w/w increases static fly and comber web breaks under 40% RH; add-on above 1.5% w/w causes lapping on front drafting rollers and false drafts in third gilling passages. Residual wool grease after scouring, typically 0.3–0.6% w/w by extractable-matter method, interacts with the applied film, and HOD-31 add-on should be adjusted downward when residual grease exceeds 0.5% w/w to keep combined extractable matter below 1.5% w/w. Published grade-specific frictional data for HOD-31 under this exact combing configuration is limited; the thresholds above are class-level values for initial 500 kg mill trials. Yarn-to-yarn coefficient of friction should be tracked by ASTM D3108/D3108M-20 to maintain an incoming lot range of 0.18–0.25; deviation from this window correlates with drafting force shifts outside 45–60 cN/ktex on 23 µm merino top.

What Produces Static-Loading Failures on High-Speed Semi-Worsted Cards?

Semi-worsted carpet yarn lines running cards above 250 kg/h expose HOD-31 to a shear regime in which fibre-to-metal slip must be maintained without sacrificing card web cohesion. The recommended add-on for this route is 1.0–1.8% w/w on dry fibre, applied as a 1:6–1:8 emulsion in softened water at 45–50 °C immediately before the opening line. Downstream processing includes blending, high-speed carding, pin drafting, roving, ring spinning, and steam heat-setting at 110–120 °C for 60 min to stabilize twist in 3.5/2–5.0/2 Nm carpet yarns. Terminal articles are cut-pile and loop-pile tufted broadloom carpets and area rugs. Regulatory requirements include REACH Regulation (EC) No 1907/2006 Annex XVII Entry 46 and ZDHC MRSL v3.1 Section 1.4.1 for APEO control; finished floor covering classification under EN 1307:2014 may also apply depending on export destination. Static-loading failures occur when add-on is below 0.6% w/w, resulting in card web breaks and excessive fly deposition on pin-drafter faller bars. Above 2.0% w/w, dust and short-fibre adherence to card clothing increases, and ring drafting shows uneven twist due to fibre slippage. The dilution water pH should be held at 5.5–6.5; outside this range emulsion droplet coalescence can produce lubricant streaking on the card lap. Batch-to-batch variation in card output CV% is a useful on-line control: when card web CV% exceeds 3.5%, lubricant add-on and emulsion temperature should be re-verified before adjusting machine settings.

Woollen ring-spun knitwear grades containing 35–55 mm merino lambswool place the controlling variable on fibre-to-fibre cohesion rather than fibre-to-metal release. HOD-31 is added during blending at 2.0–3.5% w/w on dry fibre, diluted 1:4–1:6 with demineralized water at 50 °C, because the shorter fibre length distribution requires a thicker lubricant film to suppress drafting waves on the condenser unit. Downstream sequence: blending, carding, condenser, mule or ring spinning, and winding onto cross-wound packages. Terminal products are lambswool sweaters, scarves, and blankets in counts from 1/5–2/14 Nm. For skin-contact articles, OEKO-TEX Standard 100 Class I limits apply to finished yarn, while REACH Regulation (EC) No 1907/2006 Annex XVII Entry 46 governs APEO content in the chemical formulation. The upper processing boundary is 4.0% w/w: beyond that, card cylinder loading and fly deposits on condenser tapes measurably increase, and yarn extensibility becomes excessively variable due to fibre slippage during mule drafting. Below 1.8% w/w, end-breakage at mule drawing rises because the fibre assembly cannot transmit drafting force without fibre breakage. Combination with cationic quaternary antistats beyond 0.3% w/w is not recommended unless streaming potential measurements verify emulsion charge stability, because charge inversion can deposit hydrophobic film on card clothing. If the mill operates at relative humidity below 45%, the add-on should be moved to the upper end of the specified range and surface resistivity checked by DIN EN 1149-1:2008.

When Warp Sizing Follows a Residual Oil Window Below 0.10%

Before warp yarn enters a size box, residual HOD-31 controls the adhesion of PVA or acrylic film formers and the tendency of sized ends to stick during shed opening. The recommended processing route is to apply 0.4–0.6% w/w during spinning and to avoid re-lubrication after spinning; the sized warp is produced by sectional warping at 350–600 m/min, single-end sizing, and weaving on air-jet or rapier looms. Terminal articles include worsted woven suiting in the 180–260 g/m² range and dress goods in the 90–120 g/m² range. Compliance in this segment requires ASTM D2257-20 for extractable matter verification, ISO 3071:2020 for aqueous extract pH, and EU Ecolabel 2014/350/EU where applicable to finished woven textiles. The critical residual window before the size box is below 0.10% w/w extractable matter; levels between 0.10% and 0.20% w/w are associated with intermittent size film delamination and end sticking, while levels above 0.30% w/w can produce reed marks and uneven warp let-off. pH of the residual film should remain in the 5.5–7.0 range to avoid interfering with carboxymethylated starch or PVA chain entanglement during film drying. Production-scale defects documented in warp preparation include size shed on the weaving machine reed, end sticking in dense worsted constructions, and uneven warp let-off; these are field indicators of residual oil above the threshold. Where export markets require restricted substance documentation, the same residual levels should be cross-checked against ZDHC MRSL v3.1 Section 1.4.1 for APEO and the buyer’s finished goods restricted substance list. Published data for HOD-31 in combination with starch-based size pastes is limited; therefore the 0.10% threshold should be confirmed by a 100 kg sizing trial using ASTM D2257-20 and a standard size film rub test on dried warp sheet.

High-speed automatic winding of mercerized wool knitting yarns at spindle speeds above 1000 m/min shifts the failure mode from drafting slip to fibre shedding and needle-fly deposition. The residual HOD-31 level after spinning should be 0.5–0.8% w/w on conditioned yarn; where a conditioning top-up is required, it is applied as a 1:10 emulsion at 25–30 °C to an add-on of 0.2–0.4% w/w. Downstream sequence: automatic winding with optical clearing and splicing, then high-speed circular knitting in 18–26 gauge single jersey or fully fashioned flat knitting. Terminal products are lightweight mercerized wool knitwear panels and next-to-skin garments. Compliance is checked by ISO 2062:2009 for conditioned yarn tensile strength and DIN EN 1149-1:2008 for surface resistance; static half-life should remain below 2 s at 40% RH to prevent balloon collapse and splicing failures. The practical upper limit for topping is 0.5% w/w; above this level, needle soiling and stitch cam wear are documented on circular knitting machines operating at 24 h continuous production. Below 0.4% residual, fibre shedding increases and knit holes may appear in fine-gauge fabric due to yarn breakage at the yarn feeder.

Low-Tension Skein Winding and Surface Conductivity Boundaries

Final skein finishing leaves only the boundary lubricant layer that remains after scouring, dyeing, and hydroextraction; this residual layer governs winding tension and package hardness in balling machines. For HOD-31, the target final residual is 0.1–0.3% w/w on finished yarn, with an optional topping from a 1:20 emulsion in the last conditioning bath. Downstream process flow: hank reeling, scouring, dyeing, hydroextraction, hot-air drying at 70–85 °C, conditioning for 12–24 h, and low-tension balling at 400–700 m/min. Terminal articles are hand-knitting skeins and balls in counts from 2/8–4/16 Nm. For skin-contact hand-knitting yarn, OEKO-TEX Standard 100 Class I applies to finished yarn, REACH Regulation (EC) No 1907/2006 Annex XVII Entry 46 governs APEO, and OECD 301B is often referenced where buyers require ready biodegradability above 60% in 28 d. The upper residual limit of 0.8% w/w is critical: above this level, dye uptake variation can appear in pale shades, and flammability classification under EN 71-2 for yarn used in toy applications may be affected. Below 0.05% w/w, static charging during balling is sufficient to cause package sloughing and yarn entanglement in low-tension winders. Published data for HOD-31 in EN 71-2 toy yarn flammability classification is limited, so final-article validation is required before making any compliance claim. The residual surface conductivity should be monitored by DIN EN 1149-1:2008, with a surface resistance below 1 × 10¹⁰ Ω maintained on the balled yarn.