Understanding Size Add-on Dependencies

The amount of sizing material applied to yarn, known as the size add-on, is influenced by several application parameters. We need to identify which of the given options does *not* directly affect this initial add-on amount.

Factors Influencing Size Add-on

The size add-on is primarily determined by the application process itself. Key factors include:

• Size Paste Concentration: A higher concentration of sizing agents in the paste generally leads to a greater amount of size being picked up by the yarn.
• Machine Speed: The speed at which the yarn travels through the sizing bath and drying sections affects the pickup efficiency and the time available for application. Faster speeds can sometimes alter the add-on percentage.
• Roller Hardness: The pressure exerted by squeezing rollers (like weaver's beam or backrest rollers) influences how much excess size is removed and affects the uniformity and amount of size remaining on the yarn.

Factor Not Directly Affecting Size Add-on

The drying cylinder temperature relates to the drying phase *after* the size has been applied to the yarn. While temperature is crucial for effective drying and can influence the final properties of the sized yarn (like stiffness or brittleness), it does not directly determine the initial quantity (add-on) of size picked up during the application stage.

Therefore, the size add-on does not depend on the Drying cylinder temperature.