What type of fiber dyeing involves adding pigment color chips to liquid polymer before extrusion?

Solution dyeing, also known as dope dyeing, is a method that incorporates pigment directly into the polymer solution before it is extruded into fiber. This process allows for a uniform coloration of the fibers throughout their entirety. By mixing pigment color chips into the liquid polymer, the color becomes integral to the fiber itself, making it highly resistant to fading and providing excellent colorfastness. This method is particularly advantageous for synthetic fibers and is often used in producing outdoor fabrics and products that need to withstand harsh environmental conditions.

In contrast, other dyeing methods such as batch dyeing and continuous dyeing involve applying color to already formed fibers or fabrics rather than incorporating it at the polymer stage. Batch dyeing typically involves immersing pre-made textiles in a dye solution, while continuous dyeing takes place via a continuous process where fabric is fed through dye baths or applied with dye via other means. Knit dyeing generally refers to the dyeing of knit fabric and can use either batch or continuous methods, but does not involve the embedding of color during the fiber formation stage like solution dyeing does.