Winding
A cone wound for delivery is too dense to dye, and the number says by how much.
— kg/m3
Wound mass over the frustum volume it occupies
Density here is the package average. Real packages have a density gradient through the build - the inner layers are compressed by everything wound over them - so the core can be substantially denser than this figure while the surface is looser, which is exactly the gradient that causes uneven package dyeing. Package weight must exclude the tube. The dyeing limit is entered as an input because it depends on the machine, the pump capacity, the yarn and the shade depth; 400 to 420 kg/m3 is a common working figure for cotton but is not a universal constant. The geometry assumes clean frustum surfaces and takes no account of the nose and base profiles a real cone carries.
Cone Package Density, Volume & Dye Penetration Margin — free, with the formula and a worked example, at Textile School.