About Airlaid Nonwoven Fabrics:

• Air-laid technique is invented by Karl kroyer. This technique produces paper by means of air instead of water. And the products that are made from this technique provide special characteristics such as absorbing quality & environmental benevolent. 
• In air laid process the fibers are brought into an air flow and from there to a moving belt or perforated drum, where they shape a randomly leaning web.
• Air-laid webs had a lower density & a higher softness contrast to the carded webs. Air-laid webs also put forward an immense adaptability in terms of the fibers and fiber blends that can be bring into play.

The Airlaid nonwoven fabric manufacturing process

• The air-laid nonwovens fabric manufacturing took place in three primary steps:
• Fiber opening
• Web formation and
• Web bonding

• Fiber opening

As the main characteristics of the air-laid nonwoven fabrics is to produce a fabric which is absorbent in nature & to gain this property we need that fibre should be opened up properly. For fluff pulp special type of small hammers are required, which, rotate at high speed separating the pulp into individual loose fibers. For manmade fibers bale, bale opener is used, which loosen and separate the bales into individual fibers.

• Web Formation

The web can form with two main process; one with the help of air vacuum & other with the help of drums formers.  Mentioned both way the web sheet is kept in place by a vacuum system located below the forming wire, and additives, such as superabsorbent polymers or odor control powders, can be incorporated into the web at this stage. Generally to increase the production rate normally more than one web formers are used. Before bonding, the web is compressed by large rollers to give some integrity and cohesiveness. In some time the web can also be printed with a design or symbol as requisite by the client.

• Web Bonding

The air-laid nonwoven fabrics can be bonded in three main ways

• Latex bonding
• Thermal bonding and
• Hydrogen bonding.

However, sometimes,  more then one of the above technologies are used in combination to bond the web (generally latex and thermal bonding), & this bonding type is known as the multi-bonding technology.

• Latex bonding.

The latex can be applied to the web in two ways:

One-method:  In this technique, the top of the compressed web is sprayed with latex, dried out in an oven and flipped so that it can be sprayed on the other surface. It then goes through a next oven that dries and cures the binder before the web is cooled. The web is then slit and wound into rolls.

Other-method:  In this process, latex foams are used as a replacement for of using sprays. The advantage of using latex foam is that, it is a cleaner, lower maintenance application technology. However it is comparatively latest and limited in make use of. Usually it is only taken into consideration for those materials, which exceed 100 gsm.

• Thermal Bonding.   

Generally, in thermal bonding the web must contain thermoplastic synthetic bonding fibers, usually polyethylene, polypropylene etc. After compaction, the web is conveying into an oven, which softens and melts the cover of the fibers to the position where they mingle together, implies bonding the variety of components of the web. The web is then passed through hot calender rolls to get the correct thickness. After calendering the web is cooled and transported to the slitting cum winding machine.

• Hydrogen-bonding.

Hydrogen bonding makes use of the capability of cellulose fibers to bond collectively as soon as naturally happening moisture contained in the fibers is detached. Normally, the bonding is carried out under high temperature and pressure. This process has an advantage that it eliminates the requirement of synthetic binders which are added to the airlaid web.

• Multi-bonding.

Multi-bonding is nothing but the mixture of latex bonding and thermal bonding. In this process, the latex is slightly sprayed on both the sides of the thermally bonded web. The purpose of this method is to lessen the lint which normally generates  at the time of  high-speed converting operations.

Airlaid nonwoven fabric manufacturing line: 

Airlaid nonwoven fabrics characteristics

• It should be soft in feel.
• It should have greater tear resistance and tensile strength, particularly when wet.
• Superior in absorbency

Raw materials:

• The most important fiber used to produce airlaid nonwovens is fluff pulp; however, other natural and synthetic thermoplastic fibers can also be used.
• For binder in air- laid nonwoven technology generally latex emulsions is popular.

Application:

The applications of air laid nonwoven fabric are

• Baby wipes
• Wet hand wipes
• Household cleaning wipes and mops
• Industrial wipes (dry and wet)
• Napkins
• Dinning table covers
• Catering paper
• Food Pads
• Female napkins
• Adult Incontinence diaper
• Baby diapers
• Wound Pads
• Moisturized Toilet Paper
• Sweat Pads