Patent GB-810040-A (GB)
Title: Process for dressing artificial filaments and fibres to give a soft feel
IPC: D06M23/00
Filed: 1955-10-17
Abstract: Continuous artificial filaments or threads or artificial staple fibres in the form of a fleece are, in a first stage, treated with an aqueous oil-inwater type emulsion containing 0.1-0.2 gram per litre of a liquid dressing agent of oily consistency, and the proportion of dressing agent necessary to complete the desired dressing is then applied in the form of an oil-in-water emulsion containing 70-200 grams per litre of the dressing agent in a second stage after the moisture content of the materials has been reduced by squeezing or centrifuging.  The moisture content of the materials may be reduced still further before the second stage by drying after the squeezing or centrifuging.  The proportion of the emulsion and the concentration of the dressing agent in the emulsion (within the range of 70-200 grams per litre) may be such that the treated materials have not only the desired content of dressing agent but also the desired moisture content, adjustment of the moisture content of the materials by a subsequent drying or humidifying process being thus rendered unnecessary.  Any dressing agent of oily consistency which can be emulsified to form an oil-in-water emulsion may be used.  The dressing agent can be applied in the second stage either by sprinkling or spraying or by means of moist rollers, and the treatment may be carried out at room temperature or at 50-60 DEG  C. If bundles of filaments, filament tows or groups of filament tows are being treated, the first stage of the process can be carried out as with staple fibres by spraying or sprinkling or by passing through a dressing bath.  During the second stage thick tows must be laid flat and are preferably treated by using rollers on to which the emulsion is fed.  In an example, a fleece of regenerated cellulose staple fibres is sprayed at 50-60 DEG  C. with an aqueous emulsion containing 0.1-0.2 gram per litre of a dressing agent to give a take-up of dressing agent of about 0.02 per cent of the weight of the dry fibres.  The dressing agent is a blend of 40 per cent by weight of a relatively weakly sulphonated tallow and 60 per cent of a mixture of 60 per cent by weight of white oil, 20 of ethenoxylated oleylamine and 20 of ethenoxylated oleyl alcohol. The fleece is thereafter centrifuged to a moisture content of 120-130 per cent and dried, without interposition of a humidifying zone.  Finally the fleece is sprinkled at room temperature with an emulsion containing 70 grams of dressing agent per litre, 23.3 litres of emulsion being used per 500 kg. of fleece.  The moisture content of the fibres is thereby raised from 6 per cent to 11 per cent and 0.35 per cent of dressing agent is applied to them.  In another example, a 50/50 weight/weight mixture of the sulphonated tallow and an ethenoxylated stearic acid (containing about 9.5 mols. of ethylene oxide per mol. of stearic acid) is used in a similar manner as a dressing agent.ALSO:Continuous artificial filaments or threads or artificial staple fibres in the form of a fleece are, in a first stage, treated with an aqueous oil-in-water type emulsion containing 0.1-0.2 gram per litre of a liquid dressing agent of oily consistency, and the proportion of dressing agent necessary to complete the desired dressing is then applied in the form of an oil-in-water emulsion containing 70-200 grams per litre of the dressing agent in a second stage after the moisture content of the materials has been reduced by squeezing or centrifuging.  The moisture content of the materials may be reduced still further before the second stage by drying after the squeezing or centrifuging.  The proportion of the emulsion and the concentration of the dressing agent in the emulsion (within the range of 70-200 grams per litre) may be such that the treated materials have not only the desired content of dressing agent but also the desired moisture content, adjustment of the moisture content of the materials by a subsequent drying or humidifying process being thus rendered unnecessary.  Any dressing agent of oily consistency which can be emulsified to form an oil-in water emulsion may be used.  The dressing agent can be applied in the second stage either by sprinkling or spraying or by means of moist rollers, and the treatment may be carried out at room temperature or at 50-60 DEG  C. If bundles of filaments, filament tows or groups of filament tows are being treated, the first stage of the process can be carried out as with staple fibres by spraying or sprinkling or by passing through a dressing bath.  During the second stage thick tows must be laid flat and are preferably treated by using rollers on to which the emulsion is fed.  In an example, a fleece of regenerated cellulose staple fibres is sprayed at 50-60 DEG  C. with an aqueous emulsion containing 0.1-0.2 gram per litre of a dressing agent to give a take-up of dressing agent of about 0.02 per cent of the weight of the dry fibres.  The dressing agent is a blend of 40 per cent by weight of a relatively weakly sulphonated tallow and 60 per cent of a mixture of 60 per cent by weight of white oil, 20 of ethenoxylated oleyl amine and 20 of ethenoxylated oleyl alcohol. The fleece is thereafter centrifuged to a moisture content of 120-130 per cent and dried without interposition of a humidifying zone.  Finally the fleece is sprinkled at room temperature with an emulsion containing 70 grams of dressing agent per litre, 23.3 litres of emulsion being used per 500 kg of fleece.  The moisture content of the fibres is thereby raised from 6 per cent to 11 per cent and 0.35 per cent of dressing agent is applied to them.  In another example, a 50/50 weight/weight mixture of the sulphonated tallow and an ethenoxylated stearic acid (containing about 9.5 mols. of ethylene oxide per mol. of stearic acid) is used in a similar manner as a dressing agent.