32, 21 belong to the fixed weight system: (British)
How many 840 yards of 1 pound (454 grams) of raw material can be spun is defined as how many yarns. 32 840 yards, i.e. 32 pieces.
150D, belonging to fixed length system:
Denier (d): the weight gram of 9000 meter long silk at a given moisture regain is called denier. It is 9000 meters long and weighs 150 grams, i.e. 150D.
Pure polyester yarn is to cut the polyester yarn into 32mm or 38mm long and then spin it. (the length of cotton fiber is about 38mm long).
36F, 72F, 96F: refers to the number of holes in the spinneret when making polyester yarn. In other words: 150d36f polyester yarn is composed of 36 pieces. 150d96f polyester yarn is composed of 96 pieces. 150d144f is already microfiber.
They are all conceptual knowledge. Please understand them slowly. I hope they will help you.
Another: conversion
1tex = 0.111d = 590.6 / British branch = 1000 / male branch
Another: silk = infinite length (continuously produced)
Yarn = cut the silk into the same length (38mm) and then spin it. Weigh the yarn (e.g. polyester sewing thread)
