Conjugate spinning can be divided into three types:sea-island, orange split, and side by side.

In this study, the conjugate fibers were prepared from polyester and copolyester by using side by side conjugate spinning,sea-island type conjugate

For thesea-island type conjugate spinning, copolyester and polyester were used as sea and island ingredients, respectively.

For the microfiber, there are two types of cross-sections of orange andsea-island in bicomponent microfiber.

The universalsea-island bicomponent microfiber contains 37 islands and is available from Japanese, Korean, Taiwanese and mostly Chinese fiber makers.

The Chinese application technology of the biconstituentsea-island fiber originated in Japan.

The dynamic mechanical behavior of polyetherimide(PEI)/dicyanate semi-interpenetrating polymer networks (semi-IPNs) was analyzed by using the conventional Takayanagi model for thesea-island morphology (PEI content of 10% or below) and a polyhedron model, which we developed for the dicyanate nodular structure (PEI content of 20% or above).

At relatively low thermoplastic content, typically below 10%, asea-island type morphology where the thermoplastic-rich phase segregates into spherical domains within thermoset continuous phase is formed.

However, using the Takayanagi model, the dynamic mechanical modeling of the semi-IPNs has been successful only with semi-IPNs with low content of thermoplastic, since the Takayanagi model can be applied only in a well definedsea-island morphology [13].