Compressive Creep Properties of Synthetic Fiber and Regenerated Fiber Assemblies under High Humidity Environment

Abstract

In this study, a compression creep behavior of three-dimensional fiber assembly for futon wadding use is investigated under high humidity condition, which simulates sleeping microclimate condition. Compression creep tester is used for the measurement, and humid air is supplied to the tester with high humidity air generator. Samples used are twelve kinds of staple fiber made of polyester (PET) fiber with round, w-shaped and hollow section, polytrimethyleneterephtalate (PTT) fiber, cupra-ammonium (cupra) fiber and Lyocell fiber. Results are obtained as follows.
(1) Compression creep deformation ratio of regenerated fiber assembly is significantly large compared to that of synthetic fiber assembly for high and low stress.
(2) The order of creep deformation ratio for the same fineness and fiber diameter is as follows. Cupra is the largest, PET with round section follows and PET with w-shaped section is the smallest for fineness of 1.4 dtex and fiber length of 38 mm. PET with hollow section is larger than PET with round section for 6.6 dtex and 51 mm
(3) There is no significant difference in compression creep deformation ratio for staple fiber assembly made of same fiber material of which fineness ranges 1.3 ∼ 6. dtex and fiber length ranges 38 ∼ 51 mm.
(4) Compression creep deformation ratio in high stress condition (2156 Pa) is larger than that of low stress condition (1176 Pa).
(5) Compression creep behavior of staple fiber in high humidity condition is expressed as following equation.
ε_t＝Y₀ ln (vt+1)
where, Y₀ and v are constants derived from measurement curve.
(6) Y₀ is the magnitude of compression creep at a certain time, and V_ini(=Y₀·v) is the initial tangential rate of creep. Parameters Y₀ and V_ini is useful for describing compression creep behavior of synthetic and regenerated fiber assembly.