28. January 2022

Product Applications for Filter Cartridges

Precision extruded EXPO-NET plastic sleeves, nets, meshes, inner cores and outer cages provide vital mechanical support and reinforcement to filter cartridge media

Filter cartridges are an important product group, widely used in industrial processing, commercial and domestic applications for gaseous (air and gas) and liquid filtration. Many designs in use include depth, pleated and membrane cartridge filters with fine PTFE, nylon or PES porous membranes, or pleated paper, polymeric and cotton woven fabric filter media.

Composite Resin Infusion       Composite Resin Infusion

Filtration has been an important EXPO-NET market for many years. The company has an established customer base of filter cartridge producers with whom they work closely, customising orders to meet market needs. To provide the physical support and reinforcement needed by all filter media, EXPO-NET has developed an extensive range of inert, precision extruded polypropylene (PP), low density polyethylene (LDPE) and high density polyethylene (HDPE), rigid and flexible, net and mesh products, all specifically developed and produced for filter cartridges.

EXPO-NET’s extruded plastic net, pleat support mesh, sleeve, cage and core product ranges for filtration are manufactured from FDA approved PP, LDPE and HDPE polymer grades. Rigid filtration core and cage products are extruded on dedicated production lines, maintained silicone free to the highest cleanliness level. All EXPO-NET products have full traceability, according to ISO 9001:2015 and ISO 1400: 2015 accredited processes and systems. EXPO-NET manufactures to order three extruded product categories used in the production of filter cartridges:


  • Rigid inner cores and outer cages – from 25.5mm (1.08”) to 244mm (9.61”) inner diameters, providing structural support, strength and media protection to filter cartridges in environments from -40°C to 120°C (-40°F to 248°F). To avoid contamination issues, cores and cages are only supplied in the unpigmented, natural HDPE or PP resin.
  • Flexible cartridge net sleeving – Specified for filters without a rigid outer cage, but which still need to provide some outer protection to filter media on the inner core for easy, damage free handling and installation; the low density polyethylene (LDPE) sleeves are flexible and stretchable for ease of application during filter production. Standard cartridge sleeving is natural resin coloured, but can be pigmented to use the sleeve to colour code cartridges.
  • Filtration nets and meshes – flat nets and pleat support meshes, extruded from LDPE, HDPE and PP in diamond, square and trellis netting designs. These EPO-NET products are widely used in filter cartridges to provide interlayer separation, spacing and support to finer media, especially pleated paper and fabric filters materials. Both standard and bespoke plastic filtration net and mesh products are produced in a wide range of length, width and gauges, with a monofilament thickness down to 0.5mm (0.02”) and mesh aperture size options down to 1mm (0.04”).

A key advantage of extrusion is its production flexibility, enabling the manufacture of exact cartridge lengths as needed, with no additional tooling cost. The flexibility to order any combination of standard or custom made extruded cages, cores and meshes, subject to minimum orders requirements, has proved particularly beneficial for customers looking to rapidly extend their product offering with new filter cartridge sizes or designs.

To provide a 100% recyclable plastic option to metal cartridges produced from rolled flat steel that is shaped and welded, EXPO-NET developed Spiral Net, which is also flat, supplied on a roll and then formed to make outer cartridges or media support cores. Spiral Net is specified by a number of industrial air filter manufacturers looking to offer a more sustainable product to metal and plastic cartridges, which can also reduce their transport carbon footprint by up to ten times less.

To read the full article, go to Downloads, tick Filtration & HVAC and find the article "EXPO-NET Filter Cartridge Market Product Applications article".