Method for forming cushions
A method for forming cushions including the following four steps: (1) a compression step in which the structure ( 2 ) is compressed in a mold ( 3 ); (2) a thermal softening step in which the structure ( 2 ) is thermally softened by means of a heating medium; (3) a curing step in which the structure ( 2 ) directly undergoes forced cooling in a cooling medium, and is then cured; and (4) a mold release step in which the structure ( 2 ) is released from the mold ( 3 ).
1. A method of secondary forming a cushion having a spring-like structure made of continuous filaments tangled at random in loops and made to partly adhere to one another with heat after primary forming the cushion, the method comprising:
a thermal softening step of thermally softening a three-dimensional netted structure having a plurality of surfaces formed thereon by hot press, wherein the three-dimensional netted structure comprises a first part and a second part, the bulk density of the three-dimensional netted structure is 0.03 to 0.20 g/cm 3 , and the three-dimensional netted structure is placed between a heated upper mold and a heated lower mold;
a compression step of compressing the first part of the three-dimensional netted structure with the upper mold and the lower mold;
a curing step of forcibly or naturally cooling down the three-dimensional netted structure with a coolant to cure texture of the three-dimensional netted structure; and
a mold release step of releasing the three-dimensional netted structure from the mold;
wherein:
in the thermal softening step and in the compression step, the second part of the three-dimensional netted structure is spaced from the upper mold and is not in contact with the upper mold; and
in the compression step, when the three-dimensional netted structure is in a compression state, a space is formed between the upper surface of the second part of the three-dimensional netted structure and the upper mold while the first part of the three-dimensional netted structure is compressed by the upper mold and the lower mold.
2. The method of claim 1 , wherein the upper mold has a frame structure, and the upper mold is used with compression elements to form the space.
3. The method of claim 2 , wherein the three-dimensional netted structure comprises a middle compressed part and peripheral compressed parts.
4. The method of claim 2 , wherein the thermal softening step comprises a pre-heating step and a main hot press step.