METHOD AT MANUFACTURE OF CARBON-COATED FIBRE MATERIAL

Abstract: A method of manufacturing fibre material containing atomized active carbon. According to the invention, the method is carried out in aqueous suspension with the addition of a tenside.

Description: Method at manufacture of carbon-coated fibre material This invention relates to a method of manufacturing a fibre material coated with atomized particles of active carbon. Such material is used as absorption material , for exanple, in gas masks, protective clothing, at waste disposal and, above all, in bandages. As a component in bandag¬ es, the material absorbs bacteria and odours from infected wounds and assists in a rapid healing of the wound. Active carbon is well-known as absorption material and is since long used in many different connections. In certain connections, however, it is an advantage if the active~carbon could be available in sheet fom-Progosals.. have been mgde earlier to produce such sheet form. One proposal implies that a normal rayon fabric is exposed to an atmosphere of carbon dioxide at an- increased temperature of about 300 C, where¬ after a partial carbonizationn of the fabric is brought about by heating to about 900 C. This method, however, is time-consuming and expensive, and the resulting properties of the material did not satisfy the expectations. • It further has been proposed to manufacture a fibre material coated with active carbon by a method in aqueous solution. As fibre material have been used cotton and asbestos, which were disintegrated in water and to which atomized carbon was added at heavy stirring. The problem, however, has been to make the carbon particles adhere to the fibres. It was tried to solve this problem by adding certain binders to the aqueous solution. The effect of the binder, however, is low, and at the same time the properties of the material are affected in negative direction. This problem is solved by the present invention in a simple and effect¬ ive way. According to the invention, the atomized active carbon is applied on a fibre material in aqueous suspension by adding a tenside to the suspension. According to an especially -Important eirfoodiment of the method according to the invention, active carbon in sheet form is produced in that the atomized carbon is applied on cellulose fibres in suspension, and that thereafter sheets are formed of the suspension. The amount of carbon contained in the carbon - cellulose pulp mixture is 1-65*. The amount of added tenside should be so that the tenside concentration in the fibre suspension is 10 -7 - 10-1 %. Suitable tensides have proved to b^quar e nary ammonium compounds based on dinonylphBnQl,for example Berocell 564. ϊor measuring the absorption of the material produced an absorption test with ethylene blue was used. A certain amount of the material was shaken in a solution of methylene blue, the material was filtered off, and the colour depth of the solut¬ ion was measured in a spectrophotometer. At experiments for the manufacture of cellulose fibres coated with active carbon different pulp types were used, viz. unbleached pine sulphate pulp, bleached pine sulphate pulp, bleached birch sulphate pulp and chemi-mechanical pulp, so-called CTMP. From the different pulp types a suspension with a concentration of 3 g/1 was made. The desired carbon amount was added to 1 litre of the suspension in question. To the pulp suspension a cationic tenside was added in an amount of 0,02 ml/g pulp. After careful stirring resulting in the safe wetting of all carbon, the mixture was moulded to sheet form. After the moulding, the sheet was pressed and dried on a rotary drier at 60 C for 2 hours. The results obtained are shown in the Table below. Charged Real Retent Absorption carbon carbon ion amount amount < Iheor. Theor. Pulp porport. % % % mg MB/g mg MB/g mg MB/ g carbon % X) Carbon - 111 Unbleached 0 0 25 pine 10 V 57 sulphate 20 16,5 83 pulp 30 15,3 51 30 38 58 79 Bleached 0 0 0 pine 10 i 59 sulphate 20 14,8 74 pulp 30 23,8 79 20 27 84 74 Bleached 0 0 17 birch 10 7,3 73 . sulphate 20 18,4 92 pulp 30 24 80 24 40 46 60 CTMP 0 0 22 10- 8 80 20 13,2 ββ 30 25,6 85 28 46 46 61 X) MB = methylene blue As is apparent from the test results, it is possible to make sheets of carbon andce?TuT< .pulp with good retention of the carbon and without deteriorating the abso∑ption capacity of the carbon. ϊhe invention is not restricted to the eiiibodiments described, but can be varied within the scope of the invention idea.

Claims: Claims 1. A method at the manufacture of fibre material containing atomized active carbon in aqueous suspension, c h a r a c t e r ¬ i z e d i n that prior to the addition of the active carbon a tenside is added to the aqueous suspension of the fibre mater¬ ial. 2. A method as defined in claim 1, c h ar a c t er i z e d _7 i n that the tenside is used in a concentration of 10 - 10 "1 %. 3. A method as defined in claim l o 2, c h a r a c t e r ¬ i z e d i n that the tenside consists of a quarternary amm¬ onium compound of dionylphenol. 4. A method as defined in the claims 1-3, c h ar a c t e r ¬ i z e d i n that the fibre material consists of cellulose pulp.-

Inventors: LUNDSTROEM HANS EINAR, LUNDSTROEM, HANS, EINAR
Applicants: SCA DEVELOPMENT AB, SCA DEVELOPMENT AKTIEBOLAG
Application year: 1985
Main classification: D21D3
IPC codes: D21H17