Wet spun fibers, wet formed film, and production method therefor

A method for producing wet spun fibers using a double-walled pipe type micronozzle apparatus, wherein

• in a step of extruding an internal phase comprising a fiber material and a good solvent for the fiber material in a linear form from a circular end of an internal pipe of the apparatus into an external phase comprising a poor solvent for the fiber material, the external phase flowing in an external pipe of the apparatus,
• an external phase line speed at an orifice portion at which the internal phase and the external phase merge is 0.1 ms−1 or more, and a ratio of a flow rate of the external phase to a flow rate of the internal phase is 1 or more,
• wherein the fiber material is:
• a polyamide resin selected from the group consisting of an aramid and a polyamide acid (polyamic acid);
• a polyester resin selected from the group consisting of polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polytrimethylene terephthalate (PTT), polybutylene terephthalate (PBT), polybutylene naphthalate (PBN), polyglycolic acid, polycaproic acid, polyhydroxybutyric acid, polybutylene succinate, and polyhydroxyalkanoates;
• a cellulose derivative selected from the group consisting of cellulose acetate, cellulose propionate, cellulose nitrate, ethyl cellulose, and carboxy methyl cellulose;
• a vinyl resin;
• or
• a carbon material selected from the group consisting of carbon fibers, graphene, fullerenes and derivatives thereof.