Sound-absorbing air duct for vehicle containing polyester fiber with low melting point

A sound-absorbing air duct for a vehicle containing a polyester fiber having a low melting point, the duct comprising:

• a lower non-woven fabric and an upper non-woven fabric sandwiching wires therebetween;
• and
• a film made of a first polyester resin having a low melting point and directly disposed on the upper non-woven fabric,
• wherein each of the lower and upper non-woven fabrics includes a mixture of:
• a first polyester fiber containing a second polyester resin having a melting point higher than 250° C.;
• and
• a second polyester fiber containing a third polyester resin having a low melting point and having a softening point of 100° C. to 150° C.,
• wherein the second polyester fiber is a sheath-core structured composite fiber having a core and a sheath surrounding the core,
• wherein the core is made of a polyethylene terephthalate (PET) composed of terephthalic acid and ethylene glycol, and the sheath is made of the third polyester resin,
• wherein the sheath includes the third polyester resin composed of:
• an acid component including terephthalic acid or an ester-forming derivative thereof;
• and
• a diol component including 2-methyl-1,3-propanediol, 2-methyl-1,3-pentanediol, and ethylene glycol,
• wherein the third polyester resin has a melt viscosity of 700 poise to 1,500 poise at 260° C.,
• wherein 2-methyl-1,3-pentanediol in the third polyester resin is contained at a content of 0.01 to 5 mol % based on a total content of the diol components, and
• wherein 2-methyl-1,3-propanediol in the third polyester resin is contained at a content of 42 to 50 mol % based on a total content of the diol components.