Patent ID: 8278227

Claim:
A bag made of a downproof fabric, said fabric consisting essentially of: a polyester fabric having a total cover factor of not lower than 1600 and a mass per unit area of not higher than 45 g/m 2 , the fabric having been treated by calendering, wherein said polyester fabric is composed of polyester multifilament A yarns having a total fineness of not higher than 25 dtex and a single yarn fineness of not higher than 2.0 dtex and multifilament B yarns having a total fineness of not lower than 35 dtex, wherein the multifilament B yarn comprises polyester multifilaments and/or polyamide multifilaments, wherein the arrangements of the respective yarns in the warp and weft directions are such that the yarn constitution ratio “B yarn/A yarn” is ¼ to 1/20, and wherein there are 4 to 20 A yarns and then 1 B yarn, and the distance between the B yarns is not longer than 7 mm.