Processing of chemically modified cellulosic fibres
AssigneeConvatec Technologies Inc.
InventorsWayne Lee BONNEFIN, Lucy Louisa BALLAMY, Sarah WROE, David PARSONS, Garry STOREY, Joseph THOMPSON
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Abstract
A chemically modified cellulosic fibre or filament having a moisture content of at least 7% by weight obtained by a process comprising the steps of (i) obtaining cellulosic fibres or filament and chemically modifying the cellulose by substitution to increase its absorbency; (ii) washing the fibres after step (i) in a mixture comprising water and up to 99% by weight of water-miscible organic solvent; (iii) drying the fibres to a moisture content of at least 7% by weight, tart abstract here
Claims43
A chemically modified cellulosic web of needled fibres having a tensile strength of at least 3N per cm measured in the cross direction obtained by processing fibres having a moisture content of at least 7% by weight.
A chemically modified cellulosic fibre having a moisture content of at least 7% by weight.
A chemically modified web of fibres or fibre as claimed in any preceding claim wherein the fibres are obtained from a chemical modification process comprising a wash step that uses a wash composition comprising less than 99% by weight of a water-miscible organic solvent.
A process for producing a non-woven web of chemically modified cellulosic fibres comprising the steps of:
- (i) obtaining chemically modified cellulosic fibres with a moisture content of at least 7%;
- (ii) carding and needling the fibres to make a nonwoven web of fibres.
A process as claimed in claim 18 wherein the relative humidity is from 45% to 85%.
A process as claimed in claim 18 or 19 wherein the relative humidity is from 50% to 65%.
A process for producing a non-woven web of chemically modified cellulosic fibres comprising the steps of:
- (i) obtaining cellulosic fibres or filament and chemically modifying the cellulose by substitution to increase its absorbency, then;
- (ii) washing the fibres with a composition comprising water and up to 99% by weight of water-miscible organic solvent;
- and then
- (iii) drying the fibres in a controlled atmosphere to a moisture content of at least 7% by weight.
A chemically modified cellulosic fibre or filament having a moisture content of at least 7% by weight obtained by a process comprising the steps of
- (i) obtaining cellulosic fibres or filament and chemically modifying the cellulose by substitution to increase its absorbency;
- (ii) washing the fibres after step (i) in a mixture comprising water and up to 99% by weight of water-miscible organic solvent;
- (iii) drying the fibres to a moisture content of at least 7% by weight.
A process for producing a non-woven web of chemically modified cellulosic fibres comprising the steps of:
- (i) obtaining cellulosic fibres or filament and chemically modifying the cellulose by substitution to increase its absorbency, then;
- (ii) washing the fibres with a composition comprising up to 99% by weight of an organic solvent;
- and then
- (iii) conditioning the fibres in an atmosphere having a relative humidity of at least 40% to increase the moisture content of the fibres to least 7%.
Dependencies are inferred from the claim text.