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Our testing facility evaluates fiber strands under standard atmospheric conditions to verify linear density, tensile strength, twist level, and structural uniformity before raw materials enter commercial knitting or weaving machines.
Spinning mills, fabric manufacturers, and export garment houses use these objective lab figures to detect raw material flaws, eliminate yarn breaks during production, and deliver certified verification data to global retail buyers.
Working with an accredited yarn testing lab protects textile producers from fabric rejections, uneven dyeing faults, and commercial weight disputes. Major export businesses, such as Asian Textile and regional apparel manufacturers, rely on third-party laboratory verification to:
A technical yarn testing laboratory organizes its operations into four core analytical benches:
SAB Labs runs fully equipped facilities in Karachi and Lahore, giving Pakistani spinning mills, yarn traders, and garment exporters direct access to certified yarn testing services.
Downstream fabric production demands consistent raw material properties. Variations in linear density, unevenness, or friction quickly cause loom stops, needle breaks, and fabric rejections.
SAB Labs provides comprehensive physical yarn testing services across Pakistan to benchmark spun yarns and continuous filaments against international ASTM International, ISO, and AATCC standards.
Yarn count defines the mass per unit length or length per unit mass of a textile strand. SAB Labs determines yarn linear density using the skein method under ASTM D1907.
Technicians wind a specified length of yarn on an automated wrap reel, creating a skein under uniform tension. The lab then conditions the skein and weighs it on an analytical balance reading to 0.1 mg.
The laboratory converts raw mass values into standard commercial numbering systems:
Count determinations establish whether incoming yarn shipments meet the exact commercial tolerances specified on purchase contracts.
When samples are too short to form full skeins, the laboratory deploys the short length method under ASTM D1059. This technique applies to short package remnants, yarn cut from small fabric swatches, or yarn retrieved from sampling cones.
Analysts place the short yarn segment on a precision measuring board, apply a predetermined pretension weight to straighten crimp without stretching the strand, cut the sample to exact length, and weigh it on an analytical microbalance.
This method calculates linear density from samples measuring as short as 1 meter, giving sourcing managers clear yarn count data when full production packages are unavailable.
Fabric deconstruction requires calculating the original yarn count of warp and weft systems after manufacturing. SAB Labs measures the linear density of yarn extracted from woven and knitted structures in accordance with ISO 7211-5.
Weaving and knitting processes induce crimp, take-up, and chemical finishing contraction. Lab technicians extract yarn strands carefully from conditioned fabric panels, clamp them into a precision crimp tester, apply standardized straightening loads, and measure the extended length.
Comparing the straightened length to the original fabric dimension yields the take-up percentage, allowing our chemists to compute the true un-crimped spinning count of the raw yarn before fabric processing.
Single strand tensile testing identifies how yarn performs under operational tension on warping creels, knitting feeds, and weaving sheds. SAB Labs measures breaking force, elongation, and tenacity using the constant-rate-of-extension (CRE) method specified in ASTM D2256 and internal procedure LD-TPCL.
The laboratory tests yarn strands on automated tensile instruments such as the Uster Tensorapid. The tester pulls the clamped yarn specimen at a controlled displacement rate until rupture, recording:
Testing single yarn strength prevents costly fabric barreling and excessive machine downtime in downstream manufacturing plants.
Mass variations along the length of a yarn cause cloudy fabric appearance, uneven dye absorption, and surface defects. SAB Labs assesses yarn cross-sectional mass variation according to ASTM D1425 using capacitance-based evenness testers, including Uster Tester platforms (UT4, UT5, and UT6).
Our technicians pull yarn through the instrument measuring slot to record critical quality indicators:
The instrument compares measured values directly with global Uster Statistics, giving spinning managers a clear percentile ranking of their yarn quality against world benchmarks.
Friction between moving yarn and machine contact points determines whether yarn knits cleanly or creates excessive needle tension. SAB Labs evaluates yarn friction characteristics under ASTM D3108.
The instrument draws yarn across a polished chrome or ceramic friction pin at fixed speeds and entry tensions, while load cells record the output tension. The lab calculates the kinetic friction coefficient () from the ratio of input to output tension.
Correct lubrication and low friction values prevent yarn breaks during high-speed sewing, reduce fly generation on knitting creels, and eliminate needle wear in circular knitting plants.
Twist binds staple fibers together, providing tensile strength and controlling the firmness, elasticity, and hand feel of the final textile product.
SAB Labs runs automated and manual twist measurement instruments to determine exact twist levels and geometric direction.
The untwist-retwist method provides a fast, reliable measure of twist in single ring-spun cotton and blended staple yarns. SAB Labs applies this test under ASTM D1422 and ISO 17202 using motorized digital twist testers.
The instrument clamps a conditioned length of yarn, untwists the strand until all rotational helices open completely, and continues rotating in the same direction until the strand retwists back to its original gauge length.
The digital counter divides total spindle turns by two to calculate the exact turns per unit length. This method delivers repeatable twist data for routine spinning floor quality control.
For plied yarns, cabled threads, rotor open-end yarns, and continuous filament structures, the direct counting method under ASTM D1423 serves as the international reference standard.
The lab technician mounts a measured yarn specimen into the tester jaws under a specified tension load. The analyst rotates the specimen clamp to remove all twist, simultaneously observing the fiber bundle through a magnifying glass or dissecting needle to confirm that every internal fiber lies parallel.
Direct counting eliminates tension errors, providing the precise measurement baseline required for research programs, buyer dispute resolutions, and official export inspection certificates.
Twist level directly alters yarn hardness, luster, and dye uptake. SAB Labs calculates the Twist Multiplier (TM or ) using standard engineering formulas:
TM=TurnsPerInchNe
Our laboratory reports both Twist Per Inch (TPI) and Twist Per Meter (TPM). Technicians also confirm structural twist orientation:
Checking twist balance prevents spirality defects in single jersey knit fabrics and eliminates torque kinks in woven warp yarns.
Technical textiles, sewing threads, and synthetic sportswear rely on specialized filaments and protective surface lubricants.
SAB Labs runs detailed material characterization to measure structural yarn construction and chemical surface finishes.
Synthetic yarn performance depends on total filament count and individual filament geometry. SAB Labs verifies filament yarn construction under in-house validated method LD-TPCL-Y01.
Technicians separate the filament bundle under a high-resolution optical microscope, counting individual continuous strands to verify denier-per-filament (DPF) specifications (such as confirming 75D/36F versus 75D/72F microfibers).
Cross-sectional inspection identifies the extrusion profile, distinguishing round, trilobal, hollow, or serrated filament profiles that determine fabric luster, moisture management, and surface grip.
Commercial trade of industrial sewing threads and yarn packages requires certified length verification to prevent short-shipment disputes. SAB Labs measures the absolute linear length of yarn packages under internal protocol LD-TPC-0004.
The lab winds packages through high-precision motorized length counters equipped with electronic sensors that eliminate slippage under controlled tension.
Deliverables verify whether sewing thread spools, dye cones, or filament bobbins match the labeled meterage declared by suppliers.
Spin finish lubricants, knitting oils, and coning oils control static electricity, minimize fiber-to-metal friction, and protect filaments from thermal damage during texturing. SAB Labs quantifies surface lubricant content under method LD-0045 using solvent extraction apparatus.
Analysts wash a dried yarn sample with laboratory-grade petroleum ether or hexane, extract the non-volatile oils through a Soxhlet extraction system, evaporate the solvent, and weigh the oil residue on a microbalance.
We report the exact oil pickup percentage (OPU%):
$$OPU\% = \left(\frac{\text{Mass of Extracted Oil}}{\text{Oven Dry Mass of Clean Yarn}}\right) \times 100$$
Maintaining correct OPU levels stops oil misting during high-speed circular knitting and avoids dye resist spots during wet finishing.
SAB Labs identifies unknown yarn structures and knitted construction variables according to ASTM D3887-4. The testing panel isolates yarn type, determines loop density, counts wales and courses per inch, and uncovers underlying yarn engineering.
The analytical workflow identifies:
High-volume textile trade requires verified, audit-proof analytical data. SAB Labs runs testing procedures designed to meet the rigorous compliance frameworks demanded by export retailers, buying houses, and industrial testing standards organizations.
SAB Labs operates in strict compliance with globally accepted textile test methods. Our primary testing standards include:
SAB Labs maintains permanent testing facilities accredited under the ISO/IEC 17025 standard under accreditation reference LAB-185.
This formal accreditation assures clients that:
Yarn dimensions and physical properties change with ambient humidity and temperature. Cellulosic yarns absorb moisture, increasing tensile strength, while synthetic yarns generate static electricity in dry air.
SAB Labs conditions all test specimens according to ASTM D1776 and ISO 139 inside walk-in conditioning chambers under standard conditions:
Yarn packages condition on open racks for at least 24 hours prior to testing. Technicians confirm that packages reach moisture equilibrium before testing, ensuring accurate and reproducible test figures.
SAB Labs provides structured sample intake logistics across Pakistan to maintain fast testing cycles for high-speed mills and apparel factories.
SAB Labs operates permanent, full-scale laboratories in Karachi and Lahore. Factories located within surrounding industrial zones enjoy rapid, reliable sample drop-off and collection services.
Factory quality teams can deliver test cones directly to our laboratory sample desks or request local courier pickup through our regional customer logistics teams.
Spinning mills, knitting units, and export vendors outside Karachi and Lahore submit samples through priority courier networks. We maintain dedicated intake desks for shipments arriving from major textile hubs:
Our logistics team logs every parcel on arrival, reviews sample status, and generates a chain-of-custody confirmation email to the mill within two hours of delivery.
Protect sample validity during transit by preparing yarn cones according to these laboratory guidelines:
Quality assurance decisions require clear, defensible laboratory documentation. SAB Labs delivers comprehensive digital and hard-copy test reports designed for technical directors, sourcing managers, and brand compliance officers.
SAB Labs reports go far beyond basic pass-or-fail summaries. Our technical deliverables provide the comprehensive analytical depth that spinning engineers and fabric technologists need:
This comprehensive reporting format enables spinning managers to adjust drafting zones, rectify spindle problems, and verify blend quality before dispatching commercial consignments.
To protect manufacturers and buyers against counterfeit quality certificates, every test report issued by SAB Labs features a unique digital verification QR code and report tracking number.
Scanning the dynamic QR code redirects auditors to the secure SAB Labs digital report verification portal. Overseas buyers, port customs officers, and retail brand compliance departments can review the original electronic report in real time to confirm:
Protect your fabric quality and avoid production rejections with certified test reports from SAB Labs. Our ISO/IEC 17025 accredited laboratory (Accreditation Reference: LAB-185) delivers precise, standards-compliant test data with direct access to our senior textile testing team.
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