"Alpanol" is a trade name for a range of textile auxiliary chemicals, often surfactants like wetting agents, detergents, or emulsifiers. In the context of sizing, these types of chemicals are used as components of the size liquor (sizing paste). Let's evaluate the options:
- (a) Sizing unit: Refers to the sizing machine or the department. Alpanol is a chemical product.
- (b) Sizing ingredient: The size liquor is a mixture of ingredients, including a primary film-former (adhesive like starch or PVA) and various auxiliaries (lubricants, softeners, wetting agents, antistatic agents, etc.). A chemical like Alpanol, if used as a wetting agent or emulsifier in the size mix, would be a sizing ingredient (auxiliary).
- (c) Sizing treatment: Refers to the overall process of applying size to warp yarns.
- (d) Post sizing operation: Operations after sizing, like drying or beaming. (The text "Post sizing operation" appears below the options in the image, possibly as a section header for next questions, not an option itself).
Since Alpanol products are chemical auxiliaries, they function as
sizing ingredients when added to a size formulation. For instance, they can help in wetting out the yarn for better size penetration or emulsify lubricants. \[ \boxed{\text{Sizing ingredient}} \]