Process for sizing spun yarns

In the sizing of a spun yarn by performing the steps of:

• (1) applying to a yarn substrate an aqueous solution comprising a solution polymerized polyacrylamide polymer which has a viscosity of about 400 to 900 cps at 20% solids and (2) drying the treated substrate,
• the improvement comprising adding urea to the polymer solution to form a mixed solution and applying the mixed solution, wherein the urea is added in an amount of about 10 to 50% by weight of the weight of the polyacrylamide polymer and wherein the polymer and urea are applied in an amount sufficient to impart a high order of abrasion resistance to the yarn while being capable of being removed from the yarn by aqueous washing.