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6 Types of processes used to produce Nonwoven Filter Media

Nonwovens Lamination | Andrea Ruggiero, 17 March 2020

Filtration is a critical part of our daily life. From coffee filters to air purifiers to water and automobile filters, many industries and consumers rely on having high-quality filter media that will purify the air they breathe, the water they consume and that will keep their machinery and vehicles working properly.

In some instances, filter media can protect the health and safety of individuals and even save lives.

Despite the fact that we are shifting from the industrial age into the age of technology, the filtration market continues to flourish and is expected to grow by more than $13 billion by the year 2025. Within that market, air filtration is expected to grow by 6.6% (to $15.4 billion) by 2025. When it comes to liquid filtration, the market is expected to grow to nearly $3 billion by 2026.

These projections are promising for the filtration market in general and for the production of nonwovens filter media in particular, which provides high-quality products at a lower cost than woven materials.

What is nonwoven filter media?

The filtration of air and water is paramount to our health and safety. Filters come in all shapes and sizes and can be made using woven or nonwoven textiles.

Woven textiles are made by weaving individual strands of materials like monofilaments or fibrillated yarns on a loom, while nonwoven textiles are made using a process that first bonds fibers together in either ordered or random patterns and then bond layers of nonwoven textiles with a polymer to create a porous material suitable for filtration.

Six different ways to produce nonwoven filter media

The method you use to make nonwoven filter media will primarily depend on the type of filtration desired. There are six primary methods, which are as follows:

1. Carding

Carded filter media have traditionally been used in face masks and to filter cooking oils, coolant oils, and milk.

Typically bonded with the use of resin or heat, this method is being replaced in some cases with the other methods described here.

2. Wetlaid

Wetlaid filters media are used for swimming pool filters, coffee filters and HEPA filters.

They are made with a process that is similar to the paper-making one, where a mixture of short manmade, natural or fiberglass fibers is formed into a paper-like media on standard papermaking equipment.

3. Meltblown

Meltblown filter media is ideal for the fine filtration of particles such as dust, asbestos, and smoke.

This is the type of filter commonly found in respirators and it can easily be made in large quantities. It is formed without the use of fibers: instead, the melted polymer is blown into a microporous web.

4. Spunbonded

Spunbonded filter media are lightweight and used for both air and liquid filtration.

Like meltblown media they are made without the use of fibers, but they are instead made by the spinning together of nylon, polyester, or polypropylene. In addition, they are lightweight and heat-resistant.

5. Needlepunch

The manufacture of needlepunch filter media is a mechanical process that involves the use of barbed felting needles to orient and interlock the fibers in either the spunbonded or carded web.

The three-dimensional structure of the needle punch filter media is ideal for trapping particles on the surface and in the interior of the filter. This is a common filter type to clean, for example, intake water and sewage. 

6. Lamination

Nonwovens lamination is the process that involves the use of different techniques to bond multiple layers of nonwoven material and polymers into a composite that combines the properties of each layer.

Filtration media made using the process of lamination are ideal for heating, cooling, and ventilation in homes, buildings, and automobiles.

The advantages of lamination for nonwoven filter media

The process of lamination to create filter media offers a number of distinct advantages over other methods. With lamination, the material:

  • can withstand sterilization and cleaning with harsh chemicals;
  • offers stability at high temperatures;
  • is wear-resistant and has a long lifespan;
  • can easily be made with a wide range of porosity, weights and thicknesses;
  • is water-resistant, breathable, and soft;
  • is versatile and can be used for any filtration needs;
  • is cost-effective to manufacture.

No matter what type of filter media you need, it is important to take into account the cost of production, ease of manufacture and specific characteristics required of the final product.

Nonwovens have proven to be versatile materials for creating filter media that can be used in any situation and in any area of the filtration industry, whether filtering water, air, blood, oil or another substance.

If you want to produce filter media using nonwovens lamination, you won’t probably miss our free eBook: 4 Essential Hacks for Your Lamination Process. Download it now!

4 Essential Hacks for Your Lamination Process