About Wet Laid Nonwoven

• The manufacturing process of nonwovens by the wet lay technique is consequential from papermaking technique.
• The following stages in the process are typical:
• Dispersion of fibres in water
• Continuous web forming on a wire cloth through filtration
  
  
• Consolidation, drying and batching up the web
• In the roll good industry 5-10% of nonwovens fabric is being manufacturing by using the wet laid technology.
  
  Equation to increase the entanglement of the fibre in the wet-laid :

Generally, synthetic fibers are longer, stronger, homogeneous, and less compatible with water than the natural fibers. Their plasticity and length can mean that they entangle well known as "flocculate”, when they are isolated in water, which either put a stop to or limits their use in nonwovens. Flocculation increases with increase in length to diameter ratio, which is given as:

L = Length of fibers in mm
D = Diameter of fibers in mm
Tt = Fiber fineness in dtex

Special features of the wet-laid process and its products

• Compared to the dry web-making practice such as card lying, aerodynamic lying and the wet method are high efficient and wet-laid process are having variety of end use.
• Given that short fibers are necessary, the web structure is closer, rigid and less strong than in comparable web made from longer, warped fibers in dry processes. Special cure is necessary to achieve analogous textile properties.
• In this technique it is possible to align the fibers randomly or longitudinally in the web.
• The basis weight commonly termed, as GSM (grams/square meter) is variable within broad limits.

Process flowchart of wet-laid nonwoven:

Raw materials

Application of wet laid nonwoven fabrics:

• Air filter paper
• Battery separators
• Bed linen
• Cigarette paper
• Liquid filter paper
• Medical underwear
• Nonwovens for coating
• Nonwovens for mat
• Sausage wrapping paper
• Synthetic fibre paper
• Table cloths
• Teabag paper
• Vacuum cleaner bag paper
• Water proofing sheets
• wet toilet paper