Hydrophobic Standard
Standard moisture uptake values assigned to synthetic polymers define commercial dry weight standards for trading synthetic staple and filament yarns. Official trade rules establish synthetic fiber regain values for polyester, nylon, acrylic and polypropylene materials. The percentage indicates moisture mass absorbed by bone-dry fibre under standard ambient temperature and humidity.
The standard applies exclusively to non-cellulosic synthetic fibres, yielding to natural or regenerated cellulosic regain scales in blend calculations.
Polymer Hydrophobicity
Hydrophobic polymer backbones absorb minimal water compared to natural textile materials. Low synthetic fiber regain values reflect the non-polar molecular structure of polyester and olefin filaments. Nylon exhibits slightly higher regain due to amide groups in its polymer chain.
Invoice Adjustment
Commercial billing calculations use official regain allowances to convert gross weight to commercial weight. Because synthetic fiber regain rates are low, ambient humidity variations cause smaller financial impacts on synthetic shipments than on wool or cotton. Laboratories verify dry mass through standard oven-drying tests.
Static Interaction
Low moisture absorption increases static electricity generation during mechanical carding and spinning. Processing synthetic fibres with low synthetic fiber regain ratings requires humidity control and antistatic finish application. Spinners maintain high relative humidity in spinning rooms to reduce static friction.
