Unidirectionally stretchable substrate, stretchable composite sheet, and method of manufacturing the same

1. A method of manufacturing a unidirectionally stretchable substrate, comprising:

manufacturing a non-woven fabric formed of a plurality of continuous filaments made of a thermoplastic resin, wherein the manufacturing step comprises:

extruding the thermoplastic resin in molten state from a melt blown die toward a conveyor to form the plurality of continuous filaments,

rotating a gas flow oscillating mechanism in a form of an elliptic column provided between a melt blown die and the conveyer, which is configured to periodically move a falling position of the plurality of continuous filaments on the conveyor backwards and forwards with respect to a transport direction of the conveyor while accumulating the plurality of continuous filaments on the conveyor and to partially fold the continuous filaments on the conveyor in transport direction thereof and a direction opposite to said transportation direction so that the a plurality of continuous filaments are linearly arranged only in those directions, and

bonding a meshed material to the non-woven fabric, wherein the meshed material comprises a plurality of elastomeric linear members arranged orthogonal to each other, the linear members having stretchability and thermoplasticity, wherein the meshed material is bonded to the non-woven fabric such that a direction in which the continuous filaments of the non-woven fabric are arranged is parallel with one of directions in which the linear members of the meshed material extend.

2. The method of manufacturing a unidirectionally stretchable substrate according to claim 1 , wherein the step of bonding comprises;

bonding the non-woven fabric to the meshed material by thermal compression bonding; and

crushing the linear members and intersections of the linear members during the thermal compression bonding.

3. A method of manufacturing a stretchable composite sheet, comprising:

providing the unidirectionally stretchable substrate according to claim 1 , and

laminating a fabric on the unidirectionally stretchable substrate wherein the fabric and the substrate are fed from individual feed rolls such that a direction in which the fabric and the substrate are fed corresponds to a direction in which the continuous filaments of the unidirectionally stretchable substrate are arranged.

4. A method of manufacturing a unidirectionally stretchable substrate according to claim 1 , wherein the linear members of the meshed material are made of styrene-based elastomer or urethane-based elastomer.

5. A method of manufacturing a unidirectionally stretchable substrate according to claim 1 , wherein the continuous filaments are made of polyethylene terephthalate.

6. A method of manufacturing a unidirectionally stretchable substrate according to claim 1 , wherein the non-woven fabric has a weight per area of less than or equal to 10 g/m2, and the meshed material has a weight per area 20 of less than or equal to 50 g/m2.

7. A method of manufacturing a unidirectionally stretchable substrate according to claim 1 , wherein the continuous filaments are brought into close contact with two drafting cylinders that are arranged close to each other and the continuous filaments are subject to short distance drafting.