Felted cotton fiber textile materials, and methods and apparatus for producing the same

摘要

An unwoven felt-like material is produced by subjecting a body consisting wholly or mainly of cotton textile fibres to the action of a strongly alkaline liquid swelling agent for cellulose, while supporting it substantially free from tensional stress, thus causing intercurling and kinking of the cotton fibres, and contraction of the body in area, and removing the swelling agent without substantially stretching the body. The swelling agent may be an aqueous solution of a caustic alkali, of sodium zincate or of a quaternary ammonium base such as benzyl trimethyl ammonium hydroxide, but is preferably a 10 to 18 per cent solution of sodium hydroxide at a temperature of from -10 DEG to +25 DEG C. A cotton fibre sheet F, made by superimposing carded webs, may be fed from a roll 10, between feed-rollers 12, floated on the surface of the liquid swelling agent C in a tank 14 and removed therefrom on a conveyer screen 16 which passes round the rollers 18, 34, 36, 38, 40 and 42. The rollers 12 feed the sheet at a faster rate than the conveyer 16 removes it. Refrigerated caustic soda solution is supplied to the tank 14 from a container 20 through a pipe 22; it enters the tank over a weir 30, is removed at the far end through a pipe 24, and returned to the container 20 by a pump 26. The width of the tank decreases, and its depth increases as the liquid progresses, so that the rate of flow of the latter decreases. After removal, the sheet passes over a suctionbox 50, where it is washed by water flowing over the weirs 46, 48, and over the box 60, where it is sprayed with dilute acetic acid from a spray head 56, and washed with water flowing over a weir 58. It then passes between squeeze rollers 66 and is dried by cans 68 or otherwise. A denser felt may be produced by compressing the sheet before treatment, as by passing it between rollers. Other fibres, such as kapok, wool, silk, "Vinyon" (Registered Trade Mark) nylon, or regenerated cellulose, may be mixed with the cotton. Specification 654,869, [Group VIII], is referred to.