Zähe Flüssigkeit in einem Laborglas vor Hochregallager mit Fässern

Chemical and Pharma Industry

Filtration of polymeric MDI before filling

Use of polymeric MDI

Polymeric MDI (*methylene diphenyl isocyanate) is virtually indispensable in everyday use.

Due to its versatility, it is used in numerous areas, such as insulation materials in construction (boards, foams for joints and roofs) and as foam for mattresses, upholstery, and car seats. It is also used in the manufacture of paints, adhesives, sealants, shoes (soles), sporting goods (skis, running tracks), and textiles (spandex, functional clothing).

To remove solid particles, by-products, and impurities that arise during production or storage, filtration must be carried out before filling. This ensures high product quality and guarantees process reliability in subsequent applications.

Blocked filter bags and high product loss.

Previously, bag filters with a nominal separation of 50 µm were installed for polishing filtration, but due to the manual effort required to replace and wash the bags, as well as the risk of chemical exposure to personnel, a different solution had to be found.

Minimal losses with maximum yield.

The use of an automatic backwash filter system ensures that the required customer quality of <50 µm can be easily maintained.

In addition, the stainless steel mesh of a LENZING OptiFil system offers a much more reliable particle barrier than a needle felt filter bag.

This enables efficient filtration with minimal backwash volumes and negligible operating costs.

The solution: LENZING OptiFil

Filtration of polymeric MDI prior to filling to maintain premium quality.

33 µmprecision fabric
200 m³/hFlow rate per filter
continuous operationSeveral months
operating expensesinsignificant

Process diagram for the filtration of polymeric MDI — Process representation of a LENZING OptiFil installation prior to filling

Advantages LENZING OptiFil

Advantages of using LENZING OptiFil.

Healthy employees

Employees are no longer exposed to chemicals.

High filter fineness

The use of precision fabrics ensures high product quality.

Efficient backwash

Patented backwash mechanism enables continuous operation for several months.

System performance

The closed system, combined with long filter service life, enables a high degree of automation and reduces manual intervention to a minimum.

LENZING OptiFil

The LENZING OptiFil system is a reliable backwash filter for the finest filtration of industrial fluids and in water treatment. Its patented backwash system enables maximum process continuity with minimum backwash quantities.

High backwash efficiency (patented)

Filter fineness down to 1 μm

Very high throughput rates

Completely closed system

Learn more