Healthcare is Nonwoven

What is Nonwoven?

It can be defined according to The European Disposable and Nonwoven Association, "Nonwoven is a manufactured sheet of directionally or randomly oriented fibers bound by friction or cohesion or adhesion, excluding paper and products which are woven, knitted, tufted, stitch-bonded incorporating binding yarns or filaments or felted by wet milling whether additionally needled or not. The fibers may be stapled or continuous filaments or are formed "in situ ".

The Nonwoven is also relatively simple compared to the traditional textile technologies of knitting and woven. Nonwoven technology is allowed for continuous production with minimal intermediate stages whilst the traditional textiles may be required several distinct discontinuous batch processes like spinning, winding, sizing before knitting, or weaving.

In comparison with traditional textiles technologies the:-

• Simple 
• productive
• Versatile
• Economic
• Innovative

The key reasons for the increase in demand for nonwoven and composites containing nonwoven are versatility, innovation, and economics.

Application Nonwoven:

1.Filtration

• Liquid, blood, body fluids, water
• Air, HVAC for O.R and other, areas of clinical significance.
• Anesthetic gases
• Anti-allergy bedding

2.Apparel

• Disposable patient gowns, shrouds
• Reusable-components of uniforms etc.
• Components of shoes and footwear.

3.Building

• Insulation-sound,heat
• Flame retardant materials
• Components of furniture
• Carpets

Why Demand the Nonwoven in Healthcare?

Nonwoven materials have an ability to be engineered to provide very special and sometimes unique that may be made them so effective for healthcare applications.

The demand for the highest performance at minimal coat has to enable nonwoven to find increasing use and scop of applications in modern Healthcare. Hospitals and clinics have used for many years the Nonwoven. These traditional and recognized used for nonwoven fabric like:

• Operating room apparel.
• Sterilization wrap or packaging.
• Cleaning material.
• Disposable bedding.
• Incontinence product.
• Wound dressings.
• Bandages.

However, there are other and less obvious, use for nonwoven in healthcare.

Composites:

As healthcare requirements become increasingly demanding, it is apparent that one individual material may not be able to satisfy the end-user, and that a composite of different properties is required. Composite can combine the individual function of the various nonwoven material, not only with other nonwoven fabric but also with a large number of other materials. The properties of all these materials can be combined to complement each other and produce a composite product that could not be archived by a single material.

Nonwoven is that ideal material with the appropriate properties to be incorporated into multilayer composite. the Nonwoven can be provided:-

• Coverstock layer transmission, wicking, low adherence.
• Wound contact layer- That can interact with the wound to form a gel.
• Padding layers- Absorbency, super absorbency, and Thermal or mechanical insulation and protection.
• Barrier Layers- Prevention of liquid bacterial strike through.
• carrier  Layers for other materials- Super absorbent powders, Activated carbon, Antimicrobial, Adhesive, Microspheres.
• Extelasticity/ Elasticity.
• Mouldability.

Aa Ideal Wound Dressing have to have requirements ar:

• To maintain a high humidity wound/dressing interface.
• To remove excess exudates.
• To allow gaseous exchange.
• To provide thermal insulation and mechanical protection.
• To be impermeable to bacteria.
• To be free of particles and toxic wound contaminants.
• To allow removal without causing Trauma

Wound Dressing Laminate:

The requirements for the ideal dressing may be obtained by using nonwoven materials combined with other technologies.

Image source from science direct website

• High humidity at the wound surface can be maintained by the use of a moisture vapor permeable film backing and a gelling wound contact layer.
• Excess exudate may be removed by the absorptive fleece and maybe enhanced by the use of wicking or diffusion layers.
• Gaseous exchange can be achieved by the choice of backing layers.
• Thermal insulation and mechanical protection as provided by the choice of absorptive fleece and backing materials.
• Impermeability to bacteria is recognized as a property pf most dry dressing. Bacterial mainly need to strike through of either wound exudate or liquid from or to the back or edge of the dressing to the wound. The layers which are resisted this strike-through can assist in increasing the time to strike through, however, the most effective barrier is a pinhole-free film, preferably moisture vapor and gas permeable.
• To be free of particles and toxic contaminates. The materials used in wound dressing are required to be nontoxic to the wound and the use of a combination of the particles can be minimized.
• The removal of dressing without trauma been the desire of clinicians for a long time. low adherent materials and polymer of the development that gel in contact with wound exudate and the careful choice of dressing types by clinicians been reduced the trauma on removal significantly.

Fibers for Nonwovens

Fiber is the main raw material for nonwoven and it is being carried the total weight of the raw material which is 70 to 100%. For manufacturing, the nonwoven has been used several polymers that are collected from the two sources.

• Natural source: Cotton, hemp, jute, etc.
• Synthetic source: Polyester, Polypropylene, Polyamide, Acrylics, Aramide, Carbon, And PTFE.
• Regenerates: Viscose, Cellulose acetate, Lyocell.

All the polymer have to have more specialist such as:

• Alginate
• Super absorbent
• Bicomponent
• Water-soluble
• Electrostatic
• Metal
• Biodegradable

Fibers of individual polymer types also have different physical attributes that can be used to produce different nonwoven properties such as modifiable fiber attributes include:

• Lenght
• Diameter
• Cross-section
• Crimp
• Splittable
• Color

Incorporation of other material like 

• Antimicrobials
• Flame Retardant.

The fiber can have the finish applied that can be changed their very nature for example the viscose fiber can be made hydrophobic whilst a hydrophobic polypropylene fiber can be changed into the hydrophilic.

Among several occurrences, fiber can not be able to provide the desired performance for that several fibers need to be blended for achieving optimum results.

The Nonwoven Process:

Nonwoven Production consists of two basic stages

1. Formation of the fibrous web
2. Binding of fibers

Formation of the fibrous web

The web may be formed out staple fibers either by dry laying like carding or air laying, wet laying, or direct polymer extrusion of continuous filament, like spunlaid or melt-blown.

Nonwoven Bonding

After forming the web further additional methods of web consolidation are usually required

Mechanical

Fiber entanglement by barded needles or water jets by physical means only. Mechanical bonding has very little effect on the inherent fiber properties and can produce 100% fiber materials, It is also possible to incorporate other materials like scrims, wood pulp into the structure of the nonwoven.

Chemical

Impregnation printing, spraying, with a suitable chemical, is followed by drying and further heating to fix the chemical reagent especially at fiber cross over points and achieve bonding. chemicals depending, foam, paste, or organic solvents. The organic solvent may be also be used to partially soften certain polymer types and on the removal of the solvent form a bond.

The chemical bonding is extremely versatile can be used to impart a number of different properties like water repellency, flame retardancy, antistatic, color and can be also reduced propensity.