Full Dull Filament Yarn Nylon 6 is widely used in textile weaving, outdoor fabrics, sportswear, home textiles and industrial textiles. Compared with bright and semi-dull PA6 yarn, full dull PA6 filament is added with titanium dioxide (TiO₂) matting agent during chip polymerization, which brings matte appearance and unique physical properties. To guarantee fabric quality and meet overseas buyer inspection standards, manufacturers and traders must carry out complete yarn performance testing. This article lists the core testing indicators of full dull Nylon 6 filament and explains their practical significance for textile production and export orders.
Main Testing Indicators for Full Dull Nylon 6 Filament
1. Linear Density (Denier / Tex)
Linear density represents yarn thickness, expressed in denier (D) or tex. It is the basic specification agreed between supplier and buyer.
Test requirement: The actual denier should be within agreed tolerance range.
Influence: Uneven denier will cause barry marks, uneven fabric texture during weaving. Full dull PA6 has higher TiO₂ content; improper spinning may increase denier deviation.
2. Tensile Strength & Elongation at Break
Tensile strength reflects the breaking resistance of filament; elongation at break shows yarn ductility.
Feature of full dull PA6: Under the same specification, its breaking strength is slightly lower than semi-dull Nylon 6 filament because TiO₂ particles exist in polymer matrix.
Application significance: Critical for fabrics under tension, such as outdoor fabrics, backpack cloth and protective textiles. Low strength will lead to fabric tearing risk in end usage.
3. Boiling Water Shrinkage
Boiling water shrinkage is one of the most important indicators for nylon filament. It refers to the length change rate after yarn is treated in boiling water without external force.
Impact on downstream: Unstable shrinkage will result in fabric width variation, crease, weft bar after dyeing and finishing. Full dull PA6 needs strict shrinkage control for high-grade fabric orders.
4. Matting Uniformity / Luster Uniformity
This is the special core indicator for full dull Nylon 6, which semi-dull yarn does not emphasize so much.
Failure performance: Uneven matte effect, partial bright spots or white spots on finished fabric.
Root cause: TiO₂ agglomeration, uneven masterbatch feeding or unstable spinning condition. Overseas buyers usually check luster consistency by visual inspection and comparison sample.
5. Yarn Defect Inspection
Includes broken filament, loose filament, slub, white powder, black dot impurity.
White powder is a typical defect of full dull PA6: TiO₂ powder precipitates from filament surface. Excessive white powder will pollute loom, cause fabric stains and affect dyeing quality.
Black dots usually come from polymer carbonization or impurity mixing.
6. Network Point Quantity & Network Fastness (for interlaced yarn)
For full dull PA6 interlaced filament:
Network number: How many network knots per meter.
Network fastness: Whether network knots are easy to untie under tension.
Function: Stable network can reduce filament splitting during warping and weaving, decrease broken ends. Important for warp knitting and high-speed weaving.
7. Heat Resistance & Yellowing Resistance
TiO₂ matting agent will affect anti-yellowing performance.
Test focus: Yellowing tendency under thermal setting and long-time storage.
Export requirement: Especially critical for light color fabric orders. Yellowing problem may appear after shipment during sea transportation.
8. Dyeing Performance Test
Check dye uptake, color difference and color fastness after fabric dyeing.
Full dull nylon has different dye absorption characteristics compared with semi-dull PA6. TiO₂ particles cover fiber surface and affect color presentation.
Main color fastness items for export: washing fastness, rubbing fastness, light fastness. These are standard inspection items for EU and US textile orders.
9. Other Conventional Safety & Environmental Indicators
These are mandatory for export textile orders:
AZO free test
Formaldehyde content
PH value
Heavy metal test
Why These Indicators Matter for Foreign Trade
Overseas textile purchasers will review test reports before bulk shipment. Full dull Nylon 6 fabric defects mostly trace back to filament performance. Unqualified indexes will lead to claim, cargo rejection and delayed delivery. Professional quality control of raw filament helps factories reduce after-sales risk and build stable cooperation with global buyers.
Conclusion
When purchasing or producing full dull Nylon 6 filament, buyers should focus on linear density, tensile property, boiling water shrinkage, matting uniformity, white powder, network fastness, anti-yellowing and color fastness. Reasonable index control and third-party testing can stabilize weaving and finishing quality, satisfy international textile standards, and support long-term export business.
