Materials

Technologies

Neenah Filtration's range of technologies

Using different technologies, we produce special papers and nonwovens. On our paper machines, we produce wet-laid nonwovens while, on our meltblown machines, we make dry-laid, fully synthetic micro-fibred nonwovens. Impregnation and coating lines allow us to add special properties using water- or solvent-based systems. Our lamination line uses different bonding technologies and supports the further specialisation of our media.

In our own research and development centres, and using our own expertise, experience, know-how and new ideas, we develop solutions for our technical media based on cellulose, synthetics and nonwovens, all of which are used in many diverse applications.

Wet-laid process

The principle of wet-laid process is similar to traditional paper manufacturing. The difference lies in the amount of synthetic fibers present. A dilute slurry of water and fibers is deposited on a moving wire screen and drained to form a web, then thermally bonded. Our company uses both incline and flat wire paper machines, combining a wide variety of fibers, and saturants to create unique and specialized products for our customers.

Meltblown

Meltblown technology is one of the most effective ways to make very fine, highly efficient filter media. A meltblown fibre has a diameter of less than 10µm, many times finer than a human hair, which has a diameter of 120µm, or a cellulose fibre of about 50µm.

The raw material is a thermo-plastic synthetic material which is melted and forced through an extruder consisting of a very large number of tiny nozzles. Immediately after exiting the nozzles, the individual filaments are blown by hot air in the same direction while still in their semi-melted state, extending them and creating very fine, endless fibres, within a few milliseconds.

Using this dry-laid process, Neenah Gessner can produce media with weights from 10 – 300g/m².
Alternatively, the meltblown can be directly applied to a carrier media [cellulose or spunbond], producing combination media in one step.

Additional there are many options to choose: fiber diameter, thickness, grammage, FDA-conformity, haptic surface design, resistance to chemicals, heat resistance, compostability, dust loading, low shedding surface polarity, UV-Protection, antibacterial, colors, elctrocharging and antistatics

Saturation

Neenah impregnates its special technical papers using the Kiss Coat process based on methanol or, in a size press, based on water. Impregnating with phenolic, epoxy, acrylic resins or latex gives high strength, dimensional stability and improves resistance to solvents, chemicals and high temperatures.

Special additives, depending on need, can be added to give further functionality. For example, hydrophobic, hydrophilic or oleophobic properties, flame retardancy, various colors, UV stability, bactericides, fungicides, etc, can all be built-in.

Using two further coating devices [air knives], we can add still further functionality.

Lamination

Neenah Filtration’s lamination line is capable of combining substrates such as paper, wet- or dry-laid nonwovens and films, as well as any combination of these, into a final multi-layered material.

Two bonding technologies and a finely adjustable web tension system allow us to process many light weight materials, as well as substrates with high stretch.

An ultrasonic bonding system with its dot-array pattern is used to bond up to four layers in one process step. Alternatively, the adhesive unit can spray either hotmelt adhesive or reactive hotmelts for a full-surface lamination of two layers in one process step.