POY → DTY Draw Ratio Calculator — estimated DTY denier & yield

From a POY denier and draw ratio, find the estimated DTY denier after texturing and the theoretical mass yield.

Formula

DTY denier ≈ POY denier ÷ draw ratio (ESTIMATED — the real value depends on the machine and texturing parameters). Typical draw ratio 1.5–1.7. Theoretical yield (%) = (1 − waste ÷ 100) × 100. Drawing thins the filament by stretching it; since mass is conserved, denier drops in proportion to the draw ratio. Reference constant: 250D ÷ 1.6 ≈ 156D.

Worked example

250 denier POY at a draw ratio of 1.6 → estimated DTY denier = 250 ÷ 1.6 = 156.25 ≈ 156D. With 4% waste entered, theoretical yield = (1 − 4 ÷ 100) × 100 = 96%; so 1,000 kg of POY ≈ 960 kg of DTY (denier is unchanged, only mass yield falls). This is an estimate — for exact denier and yield, see the machine report.

Estimated — indicative value.

Frequently asked questions

What is the difference between POY and DTY?

POY (Partially Oriented Yarn) is the unstable intermediate spun at high speed from the melt but not fully drawn. DTY (Draw Textured Yarn) is made by simultaneously drawing the POY (it gets finer) and texturing it (it gains crimp/bulk) on a draw-texturing machine, yielding a yarn ready for weaving and knitting.

How does draw ratio change the denier?

Drawing stretches and lengthens the filament; because mass is conserved, fewer grams fall on the same length and the denier decreases. DTY denier ≈ POY denier ÷ draw ratio. E.g. drawing 250D POY at 1.6 gives ≈ 156D DTY; at 1.5 it gives ≈ 167D, at 1.7 ≈ 147D.

What is a typical draw ratio?

For standard polyester DTY the draw ratio is usually in the 1.5–1.7 range; it is set on the machine according to yarn type, POY orientation and the target DTY denier.

Is this calculation exact?

No, it is an estimate. Actual DTY denier and yield vary with machine, temperature, tension, waste and orientation differences. Use the result for pre-planning and rely on the production/machine report for exact figures.