Fiber

1 . A method of preparing a fiber, comprising:

spinning a melt comprising an aliphatic polyester, an aliphatic-aromatic polyester, and a polyhydroxyalkanoate through a hollow fiber spinning nozzle to obtain a precursor fiber; and

cooling the precursor fiber under a temperature gradient, thereby obtaining the fiber, wherein the temperature gradient is generated by cooling the precursor fiber from one side.

2 . The method of claim 1 , wherein the temperature gradient is generated by one or more temperature control elements.

3 . The method of claim 2 , wherein the one or more temperature control elements are arranged so that the precursor fiber is cooled from one side.

4 . The method of claim 1 , wherein the aliphatic polyester comprises an aliphatic C 2 -C 20 dicarboxylic acid and an aliphatic C 2 -C 12 diol,

wherein the aliphatic-aromatic polyester comprises a C 2 -C 12 aliphatic dicarboxylic acid, an aromatic dicarboxylic acid, and an aliphatic C 2 -C 12 diol, and

wherein the polyhydroxyalkanoate comprises a C 3 -C 18 hydroxyalkylcarboxylic acid.

5 . The method of claim 1 , wherein the fiber comprises the aliphatic polyester in an amount of from 30 to 70% by weight,

the aliphatic-aromatic polyester in an amount of from 10 to 60% by weight, and

the polyhydroxyalkanoate in an amount of from 1 to 25% by weight,

based on 100% by weight of the combined amount of the aliphatic polyester, the aliphatic-aromatic polyester, and the polyhydroxyalkanoate.

6 . The method of claim 1 , wherein the fiber comprises the aliphatic polyester in an amount of from 42 to 62% by weight,

the aliphatic-aromatic polyester in an amount of from 26 to 46% by weight, and

the polyhydroxyalkanoate in an amount of from 2 to 22% by weight,

based on 100% by weight of the combined amount of the aliphatic polyester, the aliphatic-aromatic polyester, and the polyhydroxyalkanoate.

7 . The method of claim 1 , wherein the aliphatic polyester is a polybutylene succinate (PBS), the aliphatic-aromatic polyester is a polybutylene adipate terephthalate (PBAT), and the polyhydroxyalkanoate is a poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBH).

8 . A fiber being made from a mixture comprising an aliphatic polyester, an aliphatic-aromatic polyester, and a polyhydroxyalkanoate,

wherein the fiber comprises, in a longitudinal direction, two types of portions,

wherein the one type of portions are thicker portions and the other type of portions are thinner portions,

wherein said thicker portions and thinner portions extend in a vertical direction relative to the longitudinal direction of the fiber,

wherein an extension in the vertical direction of a thicker portion is greater than an extension in the vertical direction of a thinner portion; and

wherein at least a part of the thicker portions has a cavity, and at least a part of the thinner portions has a compact structure.

9 . The fiber of claim 8 , wherein the thicker portions and the thinner portions are arranged in an alternating pattern along the longitudinal direction of the fiber.

10 . The fiber of claim 8 , wherein the aliphatic polyester comprises an aliphatic C 2 -C 20 dicarboxylic acid and an aliphatic C 2 -C 12 diol,

wherein the aliphatic-aromatic polyester comprises a C 2 -C 12 aliphatic dicarboxylic acid, an aromatic dicarboxylic acid, and an aliphatic C 2 -C 12 diol, and

wherein the polyhydroxyalkanoate comprises a C 3 -C 18 hydroxyalkylcarboxylic acid.

11 . The fiber of claim 8 , wherein the fiber comprises the aliphatic polyester in an amount of from 30 to 70% by weight,

the aliphatic-aromatic polyester in an amount of from 10 to 60% by weight, and

the polyhydroxyalkanoate in an amount of from 1 to 25% by weight,

based on 100% by weight of the combined amount of the aliphatic polyester, the aliphatic-aromatic polyester, and the polyhydroxyalkanoate.

12 . The fiber of claim 8 , wherein the fiber comprises

the aliphatic polyester in an amount of from 42 to 62% by weight,

the aliphatic-aromatic polyester in an amount of from 26 to 46% by weight, and

the polyhydroxyalkanoate in an amount of from 2 to 22% by weight,

based on 100% by weight of the combined amount of the aliphatic polyester, the aliphatic-aromatic polyester, and the polyhydroxyalkanoate.

13 . The fiber of claim 8 , wherein the aliphatic polyester is a polybutylene succinate (PBS), the aliphatic-aromatic polyester is a polybutylene adipate terephthalate (PBAT), and the polyhydroxyalkanoate is a poly(3-hydroxybutyrate-co-3-hydroxhexanoate) (PHBH).

14 . The fiber of claim 8 , wherein the fiber is biodegradable.

15 . A mixture comprising an aliphatic polyester, an aliphatic-aromatic polyester, and a polyhydroxyalkanoate, wherein the mixture comprises

the aliphatic polyester in an amount of from 30 to 70% by weight,

the aliphatic-aromatic polyester in an amount of from 10 to 60% by weight, and

the polyhydroxyalkanoate in an amount of from 1 to 25% by weight

based on 100% by weight of the combined amount of the aliphatic polyester, the aliphatic-aromatic polyester, and the polyhydroxyalkanoate.

16 . The mixture of claim 15 , wherein the mixture comprises

the aliphatic polyester in an amount of from 42 to 62% by weight,

the aliphatic-aromatic polyester in an amount of from 26 to 46% by weight, and

the polyhydroxyalkanoate in an amount of from 2 to 22% by weight

based on 100% by weight of the combined amount of the aliphatic polyester, the aliphatic-aromatic polyester, and the polyhydroxyalkanoate.

17 . The mixture of claim 15 , wherein the aliphatic polyester is a polybutylene succinate (PBS), the aliphatic-aromatic polyester is a polybutylene adipate terephthalate (PBAT), and the polyhydroxyalkanoate is a poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBH).

18 . The mixture of claim 15 , wherein the mixture of the aliphatic polyester, the aliphatic-aromatic polyester, and the polyhydroxyalkanoate is in the form of granules.

19 . The mixture of claim 15 , wherein the mixture of the aliphatic polyester, the aliphatic-aromatic polyester, and the polyhydroxyalkanoate is in the form of a melt.