Three dimensional netted structure
A three-dimensional netted structure having an upper surface, a lower surface, two side surfaces a left end surface, and a right end surface, including at least a plurality of filaments helically and randomly entangled and thermally bonded together, wherein the filaments are formed out of a thermoplastic resin by extrusion molding followed by cooling with a liquid; and the netted structure is four-surface molded, the upper surface, the lower surface and the two side surfaces being molded. An apparatus and a method for manufacturing the three-dimensional netted structure.
1. A three-dimensional netted structure having an upper surface, a lower surface, two side surfaces, a left end surface, and a right end surface, the structure comprising a plurality of filaments helically and randomly entangled and thermally bonded together, wherein:
said filaments are formed out of a thermoplastic resin by extrusion molding followed by cooling in a liquid;
said upper surface and said lower surface are molded;
the structure has a pattern of sparse and dense portions, wherein said upper surface and said lower surface have a higher density than a density of inner portions that are adjacent to said upper surface and said lower surface;
said pattern of sparse and dense portions is formed by cooling in a liquid; and
a side view of a single loop of a filament in said upper surface and said lower surface is bent along a horizontal direction from an entangled portion of said filament to have a bending degree between 5 and 20 degrees.
2. The structure of claim 1 , wherein the apparent density of the structure is between 0.02 and 0.9 g/cm 3 .
3. A three-dimensional netted structure having an upper surface, a lower surface, two side surfaces, a left end surface, and a right end surface, the structure comprising a plurality of filaments helically and randomly entangled and thermally bonded together, wherein:
said plurality of filaments are formed out of a thermoplastic resin by extrusion molding followed by cooling in a liquid; and
said upper surface and said lower surface are molded; said upper surface and said lower surface are flat; regions of the three-dimensional netted structure, which extend a predetermined distance from said upper surface and said lower surface into an inner portion of the three-dimensional netted structure are compressed; a density of said regions is higher than a density of said inner portion of the three-dimensional netted structure; and a side view of a single loop of a filament in said upper surface and said lower surface is bent along a horizontal direction from an entangled portion of the filament to have a bending degree between 5 and 20 degrees.
4. The structure of claim 3 , wherein an apparent density of the structure is between 0.02 and 0.9 g/cm 3 .
5. The structure of claim 1 , wherein the structure is four-surface molded; and
said upper surface, said lower surface, and said two side surfaces are molded.
6. The structure of claim 3 , wherein the structure is four-surface molded; said
upper surface, said lower surface, and said two side surfaces are molded; and said
upper surface, said lower surface and said two side surfaces are flat.
7. The structure of claim 1 , wherein said filament in said upper surface and said lower surface has a width of between 5 and 23 mm.
8. The structure of claim 1 , wherein said filament in said upper surface and said lower surface has a length of between 8 and 35 mm.
9. The structure of claim 3 , wherein said filament in said upper surface and said lower surface has a width of between 5 and 23 mm.
10. The structure of claim 3 , wherein said filament in said upper surface and said lower surface has a length of between 8 and 35 mm.
11. A three-dimensional netted structure comprising a first part, a second part, and a third part, wherein:
said first part comprises an first surface and a first plurality of filaments;
said second part comprises a second surface and a second plurality of filaments;
said third part is disposed between said first part and said second part and comprises a third plurality of filaments;
said first plurality of filaments is helically and randomly entangled and thermally bonded to one another;
said second plurality of filaments is helically and randomly entangled and thermally bonded to one another;
said third plurality of filaments is helically and randomly entangled and thermally bonded to one another;
said first surface and said second surface are molded;
a density of said first part and a density of said second part are higher than a density of said third part;
each of said first plurality of filaments is bent from the said first surface toward said inner part;
each of said second plurality of filaments is bent from said second surface toward said inner part;
each of said first plurality of filaments comprises a first end and a second end;
a first bending degree between said first surface and a line connecting said first end and said second end is between 5 and 20 degrees;
each of said second plurality of filaments comprises a third end and a fourth end; and
a second bending degree between said second surface and a line connecting said third end and said fourth end is between 5 and 20 degrees.
12. The structure of claim 11 , wherein each of said first plurality of filaments has a width of between 5 and 23 mm; and each of said second plurality of filaments has a width of between 5 and 23 mm.
13. The structure of claim 11 , wherein each of said first plurality of filaments has a length of between 8 and 35 mm; and each of said second plurality of filaments has a length of between 8 and 35 mm.
14. The structure of claim 11 , wherein an apparent density of the structure is between 0.02 and 0.2 g/cm 3 .
15. The structure of claim 11 , wherein the structure further comprises two side surfaces, and said two side surfaces are molded.