# Rieter

### Winding helix and delivery speed

#### Index

A traversing yarn guide rod equipped with slotted yarn guides determines the angle of intersection (winding helix) of the yarn. The traversing motion is created by a traverse gear in the headstock. Each machine side has its own traverse gear, operating in opposite directions on the two sides. The maximum permitted delivery speed depends on the winding helix but also on the tube shape and the number of rotors per machine.
The yarn winding angle mainly affects the package density and the unwinding performance of the package. It therefore has to be matched to requirements with the utmost precision by adjusting the traverse per unit time of the thread guide. The angle can usually be varied between 30° and 40°. The larger the angle, the lower the density and hence the greater the softness of the package. (Where the latest generation of high-pressure dyeing equipment is available, dyeing can also be carried out with harder packages).

As already mentioned, the density (γ) of the package depends not only upon the winding angle but also on:

• the (adjustable) winding tension,
• the (adjustable) contact pressure of the package on the winding roll, and
• the yarn count.

A finer yarn always gives a higher package density, which can be calculated according to the well-known physics equations:
$density(\gamma)= \frac{mass}{volume}$,
$\gamma=\frac{yarn\ net\ mass\ (g)}{yarn\ volume\ (cm^3)}$

Standard values for package density for yarns made from cotton and cotton-like fibers:

• packages for package dyeing: γ = 0.33 - 0.38 g/cm3;
• hard packages: γ =  0.38 - 0.42 g/cm3.