| abstract |
Particulate polyoxymethylene fibres of length 50 microns or less and having a diameter ratio greater than 10 to 1 are formed from polyoxymethylenes prepared by irradiation. The polyoxymethylene may be prepared by irradiation of trioxane below 25 DEG C. in the solid state. The irradiation-produced polyoxymethylene may be suspended in particulate form in a gas stream and further gas injected at high velocity so as to cause turbulence and break down the particles, the process being operated at 5 DEG to 93 DEG C. The process may be carried out in a fluid energy mill or jet pulverizer apparatus using air as the suspending medium and a plurality of air jets to create turbulence. Specification 983,075 and U.S.A. Specification 3,150,834 are referred to. |