Edge Buildup
Localised accretion of excess chemical finish, yarn density or structural thickness along the longitudinal boundaries of a fabric web defines this physical condition. During continuous open-width wet processing, selvage accumulation occurs when surface tension, mechanical roller deflection and lateral migration draw liquids toward fabric perimeters. Edge trimming cords, tight weave selvage constructions and pin tenter transport mechanisms exacerbate this differential concentration of solids.
The metric tracks percentage increases in dried mass, resin pickup or coating thickness at web edges relative to the central body. Standard testing compares punch cut weights taken within five centimetres of the edge against identical cuts from the fabric center. The evaluation ceases to apply once edges are slit off prior to packaging or when fabrics enter garment spreading tables as trimmed yardage.
Accumulation Mechanics
Physical transport mechanisms during stenter drying accelerate chemical concentration near fabric perimeters. As moisture evaporates rapidly from the exposed edges of the moving textile, capillary action pulls unfixed liquor outward, driving selvage accumulation. Squeeze rollers equipped with worn crowns apply less mechanical nip pressure at the outer deckle boundaries, leaving excess chemical bath volume in the selvages.
Polyurethane coatings compound this effect when surface tension causes the wet film to bead and thicken along the border before entering drying ovens. In woven fabrics, high warp end densities deliberately engineered into the selvage to resist pin tear-out absorb disproportionate volumes of finish chemistry. The resulting edge buildup generates severe thickness steps that distort fabric geometry across the roll package.
Winding Discord
Friction develops between finishing plants and cut-and-sew garment factories over the presence of thickened selvages. Finishing mills treat edge buildup as normal process waste that protects central fabric integrity and prevents stenter unpinning. Apparel cutting rooms discover that rolls with heavy selvage accumulation develop severe edge tightness, bagginess and telescoping during high-speed automated winding.
When rolls are unrolled onto long cutting tables, thick edges cause fabric layers to flare upward, inducing severe alignment errors and cut pattern distortion. Garment manufacturers demand financial rebates or reject fabric shipments outright when edge buildup forces extensive manual trimming outside standard marker allowances. Resolving these commercial claims requires clear contractual definitions of usable fabric width excluding the accumulated selvage margins.
Slitting Protocol
Purchase agreements define commercial acceptance by enforcing maximum edge-to-center thickness ratios along finished goods. Inspection standards mandate micrometer thickness scans across the full fabric roll width, flagging lots where perimeter thickness exceeds central values by more than ten percent. Production lines install rotary slitters or ultrasonic cutters upstream of final inspection winders to excise accumulated borders before packing.
Excised selvages are diverted to chemical reclamation or mechanical recycling streams. Selvage accumulation remains a critical checkpoint for preventing processing failures during downstream fabric spreading and garment assembly.
