Gas filter
AssigneeW. L. Gore & Associates (UK) Ltd.
InventorsAndrew M. Allan, Akis Katsakoglou
Life of this patent
Estimating the term…
Abstract
An ostomy filter for colostomy and ileostomy bags is gas-permeable to allow venting, and liquid-impermeable to prevent leakage. It includes a hydrogen sulphide adsorbent to remove smells. The filter comprises 9 to 50% by weight of particles of unsintered granular polytetrafluoroethylene (PTFE), 30 to 82% by weight of particles of comminuted sintered expanded porous PTFE, and 9 to 30% by weight of particulate water-insoluble H.sub.2 S adsorbent. The particles are fused together by baking at elevated temperature to form a gas-permeable liquid-impermeable network. The comminuted sintered expanded porous PTFE is preferably formed by comminuting uniaxially expanded PTFE fibre.
Claims16
A gas permeable and liquid impermeable hydrogen sulfide filter which comprises a mixture of:
- (I) particles of unsintered granular polytetrafluoroethylene (PTFE);
- (ii) particles of comminuted sintered expanded porous polytetrafluoroethylene (PTFE);
- and
- (iii) a particulate water-insoluble hydrogen sulphide adsorbent;
- the particles defined in (I) and (ii) above being fused together such as to form a gas permeable liquid-impermeable network of interconnected particles.
A gas permeable and liquid-impermeable filter which comprises a mixture of:
- (I) particles of unsintered granular polytetrafluoroethylene (PTFE);
- (ii) particles of comminuted sintered expanded porous polytetrafluoroethylene (PTFE);
- and
- (iii) a particulate water-insoluble adsorbent comprising activated carbon impregnated with copper oxide;
- the particles defined in (I) and (ii) above being fused together such as to form a gas permeable liquid-impermeable network of interconnected particles.
A gas-permeable liquid-impermeable material which comprises a mixture of the following components:
- (I) particles of unsintered granular polytetrafluoroethylene;
- and
- (ii) particles of comminuted sintered expanded porous polytetrafluoroethylene;
- the particles defined in (I) and (ii) above being fused together such as to form a gas permeable liquid-impermeable network of interconnected particles.
A process for the production of a gas permeable and liquid-impermeable hydrogen sulphide filter material which comprises:
- (A) forming a mixture in liquid suspension of:
- (i) particles of unsintered granular polytetrafluoroethylene (PTFE);
- (ii) particles of comminuted sintered expanded porous polytetrafluoroethylene (PTFE);
- and
- (iii) a particulate water-insoluble hydrogen sulphide adsorbent;
- (B) applying the liquid suspension to a substrate and allowing to dry;
- and
- (C) baking so as to fuse the particles defined in (i) and (ii) above together such as to form a gas permeable liquid-impermeable network of interconnected particles.
Dependencies are inferred from the claim text.