US2738271A - Process for degumming ramie fiber - Google Patents

Description

United States Patent PROCESS FOR DEGUMMING RAMIE FIBER Frank Fabian, Dunedin, Fla., assignor to Fiber Processors, Inc., Clearwater, Fla., a corporation of Florida No Drawing. Application April 2, 1954, Serial No. 420,739

1 Claim. (Cl. 92-16) This invention relates to a process for treating the fiber from ramie plants and the like.

In the treatment of ramie plant to produce fibers, the ramie plant is first decorticated (bark and wood removed) and it is then submitted to a bath wherein the fibers are, as in the case of linen retted (degummed).

The fibers of ramie are held together by certain gums, pectins and other extraneous matter, and the treatment given these fibers is principally for the purpose of freeing them from such gums, pectins and so forth.

One object of the present invention is to provide an improved process of treating the ramie wherein the chemicals used will be of extreme cheapness.

A second important object of the invention is to provide a novel process whereby all of the fibers in the ramie will be freed from extraneous matter.

A third important object of the invention is to provide an improved chemical process wherein an alkaline solvent will be used by having its effect so modified that the freed fibers obtained are softened but not weakened and are kept with their original properties.

A fourth importantobject of the invention is to provide an improved process wherein uniform treatment of all fibers, both in the batch and in successive batches, may be assured, thereby producing a uniform grade of product, which grade may be regulated in accordance with commercial requirements.

With the above and other objects in view, as will be hereinafter apparent, the invention consists in a novel process for treating ramie for the production of fibers wherein an improved order of steps and a new combination of chemicals will be used to results.

A batch of decorticated ramie, say 400 kilograms, is submerged in a bath prepared in a suitable autoclave. This bath consists of 4 cubic meters of water, 50 kilograms of sodium hydroxide, 100 kilograms of sodium carbonate and 20 kilograms of a suitable penetrant or wetting agent such as a sulphated alkaline higher alkyl or other similar commercial product. The batch is kept in the above mentioned bath at 120 centigrade more or less and under a pressure of 3 atmospheres for 6 hours.

The next step in the process is to draw on the prepared bath from the autoclave and supply the autoclave with fresh Water. The ramie is then boiled in this fresh water for 1 /2 hours and at the pressure of 2 atmospheres.

The fiber is then removed from the autoclave and subjected to a jet of fresh water at a pressure of 4 or 5 atmos pheres.

Following this degumming portion of the process, the fiber is treated by bleaching. In the bleaching treatment the fiber is dipped in an aqueous solution of sodium hypochlorite weighing 2% of the weight of the fiber, the solution being between 8 and 10 Beaum. The density and duration of this dip will be varied according to degree of whiteness desired.

produce the desired "ice After this bleaching some of the used alkali may still remain in the fiber and eventually render it Weak and nonflexible. To neutralize all traces of the used alkali the fiber is thoroughly washed in plain water. dipped in an aqueous solution of .02% sulphuric acid of 66 Beaum, for 20 minutes.

After removal from the sulphuric acid bath the fiber is again thoroughly rinsed and placed in a solution of a commercial softener in the strength of .l% for 30 minutes.

From there the ramie is removed and dried in open air by centrifugal motion and/or other suitable methods.

The use of the enetrant or Wetting agent soaks all of channeling of the mass and the solution boils through all of the fibers instead of in channels. The use of the pressure with these chemicals will prevent undue tangling of the fibers and produce a mass of degummed fiber which is more or less free of snarling, and thus permit the production of long staple fiber when the degummed material is combed in the mill.

The chemicals used are all plentiful so that the operation has a low cost in chemicals.

A tabulated statement below shows the relative quantities of ramie fiber and these chemicals:

Ramie kg 400 Sodium hydroxide NaOH kg 50 Sodium carbonate NazCO3 kg Penetrant (or wetting agent) kg 20 Sodium hypochlorite NaClO per cent weight of fiber 2 Sulphuric acid HzSO4 per cent weight of water .02 Softener do .1

Having thus described the invention, what is claimed as new is:

That process of degumming decorticated ramie fiber which consists in subjecting the fiber to a bath containing water, sodium hydroxide, sodium carbonate and a suit able penetrant of the class consisting of sulphated higher alkyls, in the proportions of 400 kilograms of the decorticated fiber, 4 cubic meters of water, 50 kilograms of sodium hydroxide, 100 kilograms of sodium carbonate and 20 kilograms of the said penetrant, while maintaining the bath under a pressure of 3 atmospheres for six hours at a. temperature of centigrade, replacing the bath with fresh water and boiling the same at a pressure of 2 atmospheres for IV: hours, removing the fiber from the fresh water bath and subjecting the same to a jet of fresh water at a pressure of 4 or 5 atmospheres, bleaching the fiber,

and neutralizing the alkali retained content by a suitable acid solution, the bleaching agent consisting of an aqueous solution of sodium hypochlorite, weighing 2% of the weight of the fiber, the solution being between 8 and 10 Baum and thereinafter the neutralizing solution being an aqueous solution of .02% sulphuric acid of 66 Baum for 20 minutes. I

It is then