Porous webs
AssigneeBowater Packaging Limited
InventorsAlan Tallentire, Colin Samuel Sinclair
Life of this patent
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Abstract
A method of coating porous webs wherein porous materials having a range of pore sizes are given desired characteristics by selective depostion in the large pores of particulate treatment agents. Thus some characteristics are achievable by control variation of pore size distribution (e.g. sample, uniformity, liquid filtration properties) while others depend on specific attributes of the treatment agents (e.g. response to calendaring, catalysis, security marking adhesion properties).
Claims13
A method of modifying a web of porous material comprising providing a substrate web of porous material having pores with a range of sizes;
- and treating at least a part of the material with a particulate material agent under conditions such that the agent is selectively incorporated in a minor portion of the total number of the pores, said minor portion being at the upper half of the size range;
- and wherein the material agent is selected from particulate materials which, when selectively incorporated, affect at least one property of the web selected from:
- (i) ion exchange properties, the agent being an ion exchange resin;
- (ii) catalytic properties, the agent being a catalyst;
- (iii) detectable marking or colouring, the agent being a pigment, dye, or other marking agent;
- (iv) deoderising ability, the agent being an odour removing agent;
- (v) absorption properties, the agent being an absorbent agent;
- (vi) conductivity.
A method of modifying a web of porous material comprising providing a substrate web of porous material having pores with a range of sizes;
- and treating at least a part of the material with a particulate agent under conditions such that the agent is selectively incorporated in a minor portion of the total number of the pores, said minor portion being at the upper half of the size range;
- and subsequently calendaring the web;
- and wherein the particulate material modifies the smoothness or porosity as a response to calendaring;
- such that calendaring of the web causes a reduction in pore size which is greater than for a corresponding calendared web which has not been treated with said particulate material agent.
Dependencies are inferred from the claim text.