Antimicrobials

Nonwoven and woven materials have one thing in common; they face a common enemy. Bacteria, Fungi, algae, and many other microorganisms can consume and degrade these substrates during shipment storage and use, causing loss of product as well as exposing the manufacturer to potential liability.

Imparting an antimicrobial feature onto a nonwoven substrate can solve most of these problems. However, selecting the right antimicrobial is essential to provide the appropriate protection to the nonwoven product as well as to protect our environment. The use of a Silane Quat based antimicrobial can provide protection against a wide variety of microorganisms without the worry of leaching heavy metals or phenolic compounds.

The application of a Si-Quat based antimicrobial is as easy as it is safe. Antimicrobials of this type have been used on a wide variety of nonwovens with outstanding results. Application can be achieved using almost any type of wet process, such as a pad or spray. Once the material is cured onto the substrate it then provides the antimicrobial protection necessary to safeguard the product.

This paper and presentation will cover not only the ease of use of the Si-Quat antimicrobials but the unique bonding mechanism that is attributed to this eco-friendly antimicrobial. Test methodology and easy quality control methods that are used to identify these types of bonded antimicrobials when applied to the final product. This Eco- Friendly product falls in line with the current emphasis on sustainability and environmental impact that is dominating the nonwovens market.

We have done a lot of work producing fast acting, broad spectrum antimicrobial agents based on halamine chemistry. These agents have been successfully attached to a variety of surfaces including cellulose, polyester, glass, sand, and a significant number of plastics. Halamines can frequently be produced from the constituent material of nitrogen containing polymers. sometimes these halamines are quite labile and unsatisfactory for production of stable antimicrobial surfaces. A naturally occuring nitrogen in a few commercial fibers/polymers is appropriate for production of a stable halamine for antimicrobial surfaces. One of these fibers has been made into a nonwoven fabric and then treated to produce a stable antimicrobial fabric with a high chlorine loading. The fiber is described along with the halamine production procedure and the antimicrobial efficacy.

Non-wovens form part of an extremely diverse and versatile industry, with almost infinite end-use possibilities.  The potential of non-wovens for housing microorganisms and the potential for colonization by these organisms is, therefore, equally infinite.  A non-woven which is used in construction, automotive or geotextile application may not need to be sterile, but sterility would be beneficial for medical or personal care uses.  There are many different production technologies employed in web-formation as well as post-treatments and applications, some of which are more conducive to introducing or promoting colonization of microorganisms than others; especially those which employ water or water-based technologies.  The nature of the fibers used and the way in which the fibers are treated or manipulated (chemically, thermally or mechanically)  to form the desired non-woven will also determine the potential for spoilage or biodeterioration.  Even if attention is given to reducing microbe numbers during non-woven manufacture, there remains potential for contamination and spoilage if the non-woven is not packed and stored in a manner which is inhibitory to microorganism growth.  An understanding of the types of microorganisms able to colonize non-woven fabrics is the first step in formulating a strategy.  The mere nature of non-woven stock selects for fungal rather than bacterial colonization, due to a limitation in available water.  Most complaints, are therefore fungal-related, but this does not mean that bacterial spores could not pose problems further down the line, if water forms part of the end-use application.  In this paper, hints on how bio-control can be achieved or assisted are provided.  Chemistries commonly used in exercising bio-control in water & water-based additives such as polymer emulsions and adhesives (in-can biocides), as well as possibilities for imparting biocontrol by incorporating biocides which can impart protection against fungal contamination of the ‘dry’ non-woven are discussed.

Nonwovens are used in a range of applications in healthcare facilities and in the community that require attention to hygiene.  Due to high surface area, textiles in general often easily retain microorganisms and organic matter on which they feed, resulting in problems such as cross-contamination of pathogens, reduced product performance, and odor generation.  In particular, here at the dawn of the 21st century, we have a new set of concerns regarding pathogens – globalization.  According to the World Tourism Organization nearly 900 million international arrivals occurred at airports worldwide in 2007. Such global travel opens the opportunity for bacteria and viruses to spread among and across continents at a rate far greater than any time in history. Furthermore, hospitals are battling new strains of organisms that show high virulence and spread rapidly throughout the healthcare system, and more recently, the community.  The spread of these pathogens can occur by direct human contact, airborn vectors, or through fomites (surfaces that harbor pathogens) which include nonwovens.  Therefore, nonwovens with antimicrobial function have an opportunity to help limit cross-contamination from such fomites.  However, nonwovens such as filters, garments and respirators can help address the other mechanisms by which pathogens spread as well.  The important question is:  Does the efficacy of an antimicrobial nonwoven extend to the bacteria and viruses that are of most concern?  The research reported herein explores this question and the factors that govern performance of an antimicrobial nonwoven in a healthcare context.

This application of nanophase Mn(VII) oxides (NM7O) incorporated garments for chemical and biological (Chem-Bio) warfare agents protection suits and undergarments for soldiers engaged in battles will be discussed. Presently, nonwovens and melt blown fabrics are one of the most significant developments of the textile industry. Collaborative studies are being conducted to take advantage of nanotechnology to produce functional nonwovens for military applications. We have demonstrated that by using conventional processes and equipments, one can manufacture several such products. The formation, stability and chemical characteristics of NM7O will be discussed. The violet colored-NM7O is shown to be a very stable and reactive chemical that has the ability to neutralize strong Lewis bases including surrogate chemical warfare agents and/or protection of bacteria and algae. Peroxide is used as decontamination for Chem-Bio agents, and hazardous materials; therefore the reaction of NM7O with peroxide will be discussed for the purpose of remediation. Also the violet colored NM7O changes to brown colored Mn(IV) oxide which is the basis of developing a sensor to detect the exhaustion of the starting material.

There is a challenge of treating reusable underpads (7-9 osy, 95% polyester 5% rayon needle punch pad as absorbent core) with antimicrobial that can maintain the efficacy level through repetitive industrial laundering cycles. Most antimicrobial technologies, including nano-silver, do not have good durability to harsh industrial laundering cycles or cannot work with Chlorine bleach. Medline has developed a product with an innovative silver based technology, that is compatible with chlorine bleach and kill 99% MRSA after 50 industrial launderings.