Light Microscopy of Polymer-Treated Wool

Abstract

l'hotomicrographs are shown which confirm previous deductions that the effective ness of polymer treatments in reducing felting shrinkage of wool is rdated to the spreading of polymer over the surface of fibers. Chemical pretreatments which increase the critical surface tension of wool allow better spreading so that polymers are then deposited as thin surface films instead of in relatively large lumps as on normal wool. Only small amounts (1-2%; on the weight of wool) of polymer are therefore required when conditions for good spreading of polymer on wool are realized. Shrinkage-time curves of polymer-treated wool have the same shape as those of untreated wool and of wool made shrink-resistant by oxidative treatments. Polymer is not removed during the shrinkage tests. so that the actual mechanism of felting is probably the same in all cases.