Antimicrobial nonwoven fabric

Abstract

The present invention relates to woven or nonwoven fabric material having antimicrobial activity, and to its uses ranging from wound dressing, facial masks, surgical drapes and surgical clothing, to filter materials and similar applications where the antimicrobial effects are employed, as well as to a process for the preparation of the woven or nonwoven fabric material.

Description

[0001]The present invention relates to a nonwoven fabric which possesses antimicrobial properties and is useful in applications where the growth of microorganisms should be inhibited, such as surgical drapes, medical devices and clothing, filters for air handling and specific antimicrobial packaging materials.BACKGROUND OF THE INVENTION[0002]In recent years, the increased occurrence of hospital-acquired infections has had serious implications for both patients and healthcare workers. Hospital-acquired infections typically originate in a hospital or long-term care setting. Consequently, hospitals and other healthcare facilities extensively use materials impregnated or otherwise foreseen with antimicrobial agents for a variety of topical applications, such as wound dressings and drapes, and / or sterile drapes and articles that need to be discarded after a short usage due to infection risks.[0003]Surgical drapes are presently made from nonwoven fabrics, and are typically used during sur...

AI Technical Summary

Benefits of technology

[0075]The present invention further also relates to a metallised woven or non-woven fabric material such as sheet cloth and its applications as part of a filter cartridge. Filters in HVAC systems providing physical separation ability can be enhanced with antibacterial features according to the process of the present invention. The effect is desirable in high quality air environments such as hospitals and health care facilities, but also public spaces, such as preferably public transport, e.g. underground trains, large office buildings, schools, housing and the like. The present invention further relates to a filter comprising the metallised non-woven material with bacterial growth suppressing activity. The filter, and cartridges comprising the nonwoven fabric material according to the invention may be employed for air and / or liquid filtration, such as for instance for drinking water. In the latter it may advantageously remove smells, discolouration and chemical contaminants such as chlorine besides its antimicrobial function. The antibacterial filter comprising material according to the invention can further positively reduce the microbial load, and hence impact air quality in stand-alone ventilation circuits in the automotive and aerospace industries.

[0076]The woven non-woven fabric may be used alone, or in combination with other materials for a further spectrum of products with diverse properties, such as components of apparel, home furnishings, health care, engineering, industrial and consumer goods. In addition, the (non)woven fabric material substrate may also serve other purposes, such as providing water absorption, barrier properties, etc. Any of a variety of (non)woven fabric material substrates may be applied with the antimicrobial composition in accordance with the present invention. Accordingly, the present invention also relates to the use of the materials according to the invention, or those materials obtainable according to above described process, for the control or restriction of antimicrobial growth.

[0077]Although several specific embodiments of the present invention have been described in the detailed description above, this description is not intended to limit the invention to the particular form or embodiments disclosed herein since they are to be recognised as illustrative rather than restrictive, and it will be obvious to those skilled in the art that the invention is not limited to the examples.

Problems solved by technology

Unfortunately, however, the required high levels of antimicrobial agents employed are undesired in many cases.

For instance, the use of high levels of certain types of antimicrobial agents may be undesired due to an increased likelihood of contacting sensitive areas, such as wounds.

This resistance spread is exacerbated by the low number of antibiotics in the development pipeline which could result in a major world-wide public health problem.

However, the use and application of silver salts, or colloidal silver particles usually requires the use of complex application technologies, e.g. sonochemical application or impregnation with dispersions, which—if applicable at all due to the sensitivity of in particular non-woven materials to water or solvents—requires handling of solvents and their removal, as well as drying of the obtained products.

This renders the application process complex and cumbersome.

Furthermore, the silver particles will be distributed over the whole material and not available at the contact area with moisture, such as in skin contact.

Therefore, in order to be effective, such materials require a relatively high silver loading, which makes a widespread use prohibitively difficult.

Yet further, due to the complexity and nature of this process, it is difficult to control the amount of silver deposited on the fibre and furthermore, the amount of silver deposited is limited by the surface area of the fibre.

Other attempts have been made to apply silver salts on the surfaces of fabrics and yarns with little success in terms of controlled release of the silver ions to the wound, while maintaining adequate absorption capabilities.

Thus, a topical treatment with metal-based antimicrobial agents has not been successfully developed and applied to a substrate having the combination of characteristics described herein, as desired for an effective wound care device.

Likewise, hospitals, and generally facilities sensitive to microbiological pathogens have been increasingly facing issues with microbiological contamination of the air, spread through building air handling systems, specifically in Heating Ventilating and Air Conditioning (HVAC) systems.

The microbiological contamination cause odour in their mildest form, but generally may cause much graver issues.

The microbial contamination frequently found includes fungi such as Aspergillus spp., Fusarium spp., Penicillium chrysogenum and / or Candida albicans, but also Legionella, a pathogenic Gram negative bacterium, including species that cause legionellosis or “Legionnaires' disease”, most notably, Legionella pneumophila, has caused many issues with infections transmitted through HVAC systems.

However, films obtained by sputtering methods have generally polycrystalline structures with columnar grains, thereby reducing the available surface area of the metal atoms.