STUDIES ON FATTY SOIL ON POLYESTER FIBER USING A RADIOACTIVE TRACER

Abstract

The diffusibility of soils into multi-layer polyester and cellulose films was studied by means of a radioactive-tracer technique and the following results were obtained:(i) Into polyester film, considerable diffusion of soils was observed when the soiled films were heated to 105°C and more diffusion at 120°C, even though almost no diffusion of soils occurred after they have been allowed to stand for six months without heating. On the other hand, no diffusion into cellulose films was observed under the similar conditions.(ii) The diffusibility considerably differed with the types of soils. Namely the degree of diffusion increases in the order:tripalmitin tristearin carbon black palmitic acid stearyl alcohol stearic acid oleic acid cetyl alcohol cholesterol(iii) It seems that fatty soils having a small molecular volume diffuse more easily into fibers than soils having a larger one except cholesterol.(iv) It was confirmed that even a solid soil like carbon black was able to diffuse into polyester film.(v) It was also confirmed by autoradiographs that the diffusion behavior of carbon black differs from that of fatty soil.(vi) By comparing the removability of soils in the previous paper1) with the diffusibility now studied, it is made clear that in general the soils which could easily diffuse into fibers are easily removed by washing.In conclusion, fatty soils and/or carbon black accumulated on or inside fiber will cause gradual loss of whiteness of polyester fabric.