1. A process of producing a self-supporting cotton cloth comprising the steps of:
2. A process according to claim 1 wherein the fibers are formed into a
3. A process according to claim 1 wherein the step of passing said layer of fibers into the bath is carried out on a perforated apron, and said draining occurs through the perforations of the apron after the layer is
4. A process according to claim 1 wherein said wetting agent bath has a temperature in the range of between about 50°C to about
5. A process according to claim 3 wherein said wetting agent bath has a temperature in the range of between about 50°C to about
6. A process of producing a self-supporting cotton cloth comprising the steps of passing a pre-formed layer of raw cotton fibers into a heated bath of an anionic wetting agent, said bath having a concentration of between about two to about three grams per liter of said wetting agent, removing the layer from the bath, and draining the wetting agent solution from the layer.
The production of cotton felt from raw cotton fibers of any length, which fibers are arranged in the form of a cloth and then subjected to the subsequent operations of boiling, blanching, then washing and drying, is well known.
One difficulty of this process is that the raw cotton cloth must be deposited on a support so that it can be wound-up and subjected to various further treatments. This support must be flexible and must not be destroyed by the treatments affecting the cotton cloth.
When the cotton felt is obtained it must be separated from its support before conditioning and using it.
An object of the present invention is to eliminate the operations of placing the cloth on a support and of withdrawing the support.
A further object of the present invention is to make the cloth self-supporting by treating it by passage through a bath of a hot wetting agent.
This invention will be better understood with reference to the following specification and drawing in which FIG. 1 is a sectional view of the apparatus used in the process of the invention.
According to the present invention, after having been subjected to the classical operations of mechanical cleaning, the raw cotton fibers are opened and formed into a layer of suitable thickness. The thickness of the layer can be in the range from 5 to 600 g/m2. A slightly greater thickness also can be used. A thickness of 100 g/m2 has been found to be quite good.
The cloth is then brought by the carrier device into the wetting agent bath.
The carrier device providing passage through the bath is formed of two perforated metal aprons, or conveyor belts, 1 and 2. The portions of the aprons immersed in bath 10 are sloped to have a generally V-shape. This is accomplished by placing the aprons over bearing rollers with apron 1 riding on rollers 3, 4 and 5 and apron 2 on rollers 6, 7, 8 and 9. The two aprons 1 and 2 come together at a point below roller 6 in the bath 10 with the layer of cotton therebetween.
The speed of advance of these aprons is the same as that of the napping operation of the cotton.
The aprons are partially submerged in the wetting product bath 10 contained in the tub 11. Apron 1 is practically totally submerged, apron 2 is immersed only in its lower portion, the level of the bath being approximately at the height of the shaft of the central roller 6 which guides both aprons.
The layer of cotton fibers 12 arrives on apron 1 at the level of roller 3 and descends on this apron into the bath 10 until the central roller 6, at the level of which it is pinched between apron 1 and apron 2. While in the bath it is being wet by the wetting agent.
The cloth arises again between aprons 1 and 2 and comes out of the bath passing between rollers 5 and 7. The latter two rollers squeeze out the wetting agent impregnating the cloth. The liquid squeezed out of the cloth drains back into the bath through the perforated apron 1.
After passing over roller 5 the cloth leaves apron 1 and passes between guide rollers 13 and 14 which complete the removal of the wetting product.
After passing between these last two rollers the cloth has acquired such a consistency that it can be wound without any difficulty.
The wetting agents used for bath 10 are detergent, non-ionic products. One suitable wetting agent is that sold under the brand COTTO-CLARIN by HENCKLE. The concentrations in water of wetting agents used are of the order of 2 to 3 g/liter approximately. These products are not harmful, and promote subsequent operations. The bath temperature preferably should be of the order of 50 to 70° C. This can be accomplished by any suitable internal or external heaters.
The cloth obtained according to the invention can be wound at will and be subjected to all operations intended for the cotton fibers, particularly boiling, blanching, washing, without affecting its integrity.