Barrier products
AssigneeDRG (UK) Limited
InventorsAlan Tallentire, Colin S. Sinclair
Life of this patent
Estimating the term…
Abstract
A porous material, e.g. a paper, has pores with a range of sizes. A pore modifying agent comprising particles of a narrow size range is selectively incorporated within the larger pores to provide zones of high surface area. These greatly reduce the penetrability of the material, e.g. by mirco-organisms, while having relatively little effect on its air-permeability. The modifying agent may be incorporated by creating a pressure difference across the material, and treating it with a dispersion, e.g. an aerosol, of the modifying agent, under conditions of low inertia, and incorporating only a small amount of the agent, e.g. not more than 1% w/w.
Claims15
An air-permeable barrier material comprising porous material having pores with a range of sizes wherein a pore modifying agent is selectively incorporated in a minor proportion of the total number of the pores, said minor proportion being at the upper end of said range of sizes;
- said modifying agent being such as to provide zones of high surface area within said pores at the upper end of said range in such a way as to restrict the passage of air-borne particles through said pores at the upper end of said range;
- and wherein the pore modifying agent comprises particles of substantially uniform size, at least 90% of said particles having diameters falling within a three-fold size range.
A package comprising a medical or surgical item enclosed in packaging comprising an air-permeable barrier material comprising porous material having pores with a range of sizes wherein a pore modifying agent is selectively incorporated in a minor proportion of the total number of the pores, said minor proportion being at the upper end of said range of sizes;
- said modifying agent being such as to provide zones of high surface area with said pores at the upper end of said range in such a way as to restrict the
A method of enhancing the barrier performance of an air-permeable material having pores with a range of sizes, the method comprising:
- establishing a pressure differential across the material;
- providing at the higher pressure side of the material a suspension, dispersion or aerosol of a pore modifying agent, wherein the pore modifying agent comprises particles of substantially uniform size, at least 90% of said particles having diameters falling within a three-fold size range;
- and
- maintaining said pressure differential under conditions such that the pore modifying agent is selectively incorporated in a minor proportion of the total number of the pores, said minor proportion of pores being pores at the upper end of said range, so as to provide zones of high surface area within said pores at the upper end of said range in such a way as to restrict the passage of airborne particles through said pores at the upper end of said range.
Dependencies are inferred from the claim text.