1984 Volume 41 Issue 7 Pages 407-411
Fibrilar network structures are formed by drawing samples of unsintered PTFE tape. Electron microscopic observations were made to examine the structural changes of heat treatment of the drawn PTFE tape under fixed conditions. Periodical dents in the fibrils took place perpendicular to the fibrilar direction by heat treatment.
The edges of the band in fibrils heated under high tension were similar to those of the fracture surfaces of sintered bulk PTFE. Consequently, it seemed that the chain folding was formed in the fibrils by heat treatment of expanded PTFE under fixed conditions.
