Particle filters can be classified by their basic structure as follows:

• Panel and compact filters
• Bag filters
• Compact filters

Panel and compact filters

Panel filters, or filter mats, are coarse mesh filters installed in a frame or equipped with a frame of their own. A loosely pleated filter material is used in coarse panel filters. The filter materials include glass fibre and plastic fibre. The advantage is the low purchase cost. The disadvantage is the low separation level, dirty replacement work, and short service life.

Bag filters

Bag filters are recommended as economical general-purpose filters for a variety of site types. Bag filters are manufactured of both glass fibre and plastic fibre. The sustainability of the pocket shape with increasing pressure loss is important for the functioning of the filter. It is essential that the pockets not touch each other during use. This way, the surface area of the filter is fully utilised, which means a longer service life, and the pressure loss remains optimal throughout the filter’s useful life.

Compact filters

Compact filters are cellular filters whose filtering surface is many times the size of their front surface. This filter type is usually paper-like and can be made of glass fibre or plastic fibre, or a combination of the two. The benefits of compact filters are low pressure loss, sturdy structure, good mechanical durability, suitability for difficult air flow conditions, and a low space requirement.