beam material holder has been taken which is intended to receive fabric in the form of rolls however the transformation of the material holder in order to receive reels of yarn is within the scope of a man skilled in the art and has already formed the subject of numerous constructions for this type of horizontal autoclave tank the autoclave treatment tank 1 such as that illustrated in fig1 comprises a removable cover 2 which seals the tank 1 hermetically the material 3 to be treated which in this case is in the form of a roll of fabric is located on a material holder comprising in particular a beam 4 supported by a cradle not shown in this respect it should be noted that it is imperative to fix the various parts present in the tank firmly in order that no part moves during the circulation of the treatment fluid the beam 4 comprises a periphery provided with a multitude of perforations or a grille its end being blocked in order that when injecting treatment fluid inside the beam this fluid escapes through the peripheral orifices and penetrates the roll 3 of fabric this circulation of treatment fluid is carried out by a circulation pump 5 stream lined by a connecting sleeve 6 in.