Industrial Vacuum Filter Options & Filter Cleaning Systems: you are just one blog away from efficiency!

July 12, 2022

Entering the world of industrial vacuuming entails discovering a full range of options and applications. All customers are dealing with different needs and requirements. Some will need to get rid of dust from hard surfaces; some others from the air or from hard-to-reach locations in any area within a facility. Some will need to vacuum dust – which sometimes is even combustible; others will need to collect liquids, bulk material or even oil and chips.

Yet, all  industrial vacuum customers will have the same needs:

  • guaranteeing efficiency and productivity
  • preventing downtimes
  • safeguarding for the worker’s health
  • preventing cross-contamination
  • keeping working environments clean
  • preventing risks of explosions in hazardous areas or when handling combustible dust

So, how can we do that?

There are some main tips and guidelines that Delfin Industrial can provide like checking the efficiency, integrity and condition of gaskets, brushes in single-phase motors or the hoses used to pick-up the material.

But there is one main feature that, above all else, can guarantee the respect of the above listed needs: the integrity of filters. Keep reading this blog and you will become a real expert of filters and their maintenance.


First of all, it is important to say that there are many different types of high-quality filters that Delfin Industrial can provide and that they are usually combined to guarantee the highest levels of efficiency and safety.

There is always a primary filter installed that, being in the “front line”, becomes the trap of the largest amount of dust entering the system. Then, the second level of filtration, the absolute (or HEPA) filter, prevents any dust that may have succeeded in escaping the first trap and the smallest particles to reach the motorhead.

So, even if dealing with the smallest and most hazardous particles of dust, the two filters combined guarantee the protection of the motor from wear caused by even the smallest particles of dust, and the reinsert of pure air into the environment.


According to the type of material to collect, its granulometry and size, the choice of filter can vary. To guarantee the correct efficiency, Delfin Industrial can provide:

  • CLASS L (low) FILTERS: This filter can retain more than 99% of dust particles smaller than 3 Microns. It is usually used for applications where dust can pose a moderate risk to the workers’ health like general cleaning.
  • CLASS M (medium) FILTERS: This filter can retain more than 99,9% of dust particles smaller than 1 Micron. It is usually used for applications where dust can pose a medium risk to the workers’ health like in food or plastic industries.
  • CLASS H (high) FILTERS: This filter is combined with a star class M filter and its efficiency 99,995% down to 0,18 Micron. The H filter is the perfect choice when dealing with hazardous dust that may pose a serious threat to the workers’ health in applications such as pharmaceutical industries or surface preparation.


Delfin Industrial will always be there to provide you with consulting support and to guide you through the choice of the best filter for your needs. However, let’s have a primary, general look at the different kind of filters that you can choose among. While you are doing so, please keep in mind that the air load on filter (the amount of air passing through the filter when the motor is running at its highest possible performance) will be essential in the choice and that, even if you don’t see what you are looking for in the below list, it doesn’t mean that we don’t have it. Just ask and we will be glad to help you!



These filters are a good solution for standard cleaning operations with mobile vacuum cleaners. They are flexible, easy to replace and clean. They are also called “star filters” due to their shape. In fact, they are made of 14, 16 or 20 pockets that can provide a different, higher filtering surface, according to the application and need.

Delfin Industrial polyester star filter_large filter surface

Cartridge filters have high permeability and area and so are very suitable for large amounts of fine dust – up to 1 micron. The large filtration area and the small overall dimensions make this filter a great option for generic applications. According to the application, they can be made of pleated paper, synthetic products or with PTFE coating to facilitate the detachment of clogged dust.

Delfin Industrial polyester cartridge filter

Both polyester star and cartridge filters can be antistatic. What differentiates this option from the previous ones, is an internal wire mesh that, with the vacuum’s grounding, creates a circuit that allows discharging electrostatic energy to the ground. This way, vacuuming operations are always safe for the operators, even when dealing with static material. This filter is compulsory for combustible dust applications.

Delfin Industrial polyester star antistatic class M filter

When it comes to vacuuming very fine and hazardous dust, the absolute HEPA filter is a must-have. In fact, thanks to its levels of efficiency (99.995% at 0.18 micron), this filter can capture even the smallest dust particles and environmental contaminants. It is a guarantee for performing motor and pure air reinserted into the environment. This filter never goes alone; in fact, it is always installed with a primary filter.

ABSOLUTE FILTER (HEPA) for the finest and most hazardous dust

This is just like a polyester star filter, but with a PTFE (Polytetrafluoroethylene) coating which makes it very suitable for all those applications where clogging material is involved. The PTFE coating makes it easier for the dust to detach from the filter and fall into the collection unit.

Delfin Industrial polyester star filter_large filter surface

These bags are usually used for common dust and installed in smaller vacuums. They are provided with the same metal mesh as the other antistatic filters. The filter bags are closed products, so that the operators never get in direct contact with the vacuumed material.

Filter bags with metal mesh for common dust



The NOMEX filter can bear high temperatures – up to 482°F, and so can be used in applications such as oven cleaning in bakeries, where it is fundamental to protect the motor from hot residues. Important notice: the NOMEX filter can work with very high temperatures but gets damaged if put in direct contact with a flammable source.


The PPL bag filters are made of a polypropylene mesh that allows the practical filtration of liquids from solid material (100-300 microns). They are very useful for CNC applications when it is necessary to separate oils from chips.

PPL bag filters 3 micron to separate oil and chips

This filter is very popular among industries that need to capture (bad) smells before they are spread into the environment.

Activated carbon filter for bad smells

Very suitable for engineering industries, this filter protects the motor from possible oily fogs.

OWR filter - hydro repellent protects the motor from possible oily fogs


So far, you have learned that there are many different options available for your filtering needs. Now, we are going to get a closer look at how to keep these filters clean thereby improving the total efficiency of your vacuum cleaner.

Keeping your filter clean means guaranteeing:

  • Constant vacuum performance (a clean filter does not limit the airflow)
  • Increase the life of the filter (less maintenance required and cost-saving on spare parts)​
  • Motor protection (a clean filter will allow more airflow into the motor and reduce the risk of overheating)​
  • Easy, safe, and clean (the filter cleaning will contain all the dust inside the vacuum, and avoid dispersion of the dust, making the process cleaner, safer and more user-friendly).

There are three main categories of filter cleaning systems: manual, semiautomatic and automatic. Star filters can be cleaned by means of all these three systems (AUT for the automatic option, see below), whereas the star filter can only be cleaned by using either the semiautomatic or the automatic PN system. Let’s have a closer look to all of them.


Or filter shaking system. An external lever is directly connected to the filter cage placed inside the filter chamber, where the star filter is located. By shaking up and down this lever, the dust detaches from the filter and directly falls into the collection unit. Examples of applications: cement dust; chemicals; wood dust; textile fibers; packaging.

Manual filter shaking_filter cleaning system


This filter cleaning system can be either with the Dustop or with the Self Clean systems.

The first one, the Dustop cleaning system, is named after the black lever placed right below the motorhead. All the operator needs to do is to switch on the vacuum while keeping the suction inlet closed with the red cap provided with the vacuum and open and close the Dustop black lever 4 or 5 times. This operation will generate a pressure differential inside the filter chamber which will detach dust from the filter, making it fall into the collection unit.  Examples of applications: surface treatment; food industry; construction powders.

Dustop_semi-automatic filter cleaning system

On the other hand, the Self Clean system makes use of a manual pneumatic valve that causes the shaking and therefore the cleaning of the filter. There is no need of external supply for this system. Thanks to the pneumatic cylinder, the star filter is shaken by means of a manual pneumatic valve. Every time the industrial vacuum is not in use, the operator can move the lever to power it on. Examples of applications: carbon dust, metal dust, and cement powder.


The automatic filter cleaning system can be either AUT (automatic) or PN (pneumatic).

The AUT – automatic cleaning system doesn’t require any action from the operator.

There is an adjustable timer installed in the electrical panel that allows to keep using the vacuum for cleaning operations without turning it off while cleaning the star filter on regular timings. Examples of applications: carbon dust, metal dust, and cement powder.

Automatic filter cleaning system - AUT

On the other hand, the PN – pneumatic cleaning system is used with cartridges. This system cleans one filter at a time so the vacuum can keep working and so the other cartridges may be used even during vacuuming operations. A timer is installed in the electrical panel, so that a reverse pulse jet is released at 6 bar on each cartridge. The air released on the inside of each cartridge makes pressure on each filter thus detaching dust particles. It is possible to either use an external compressor or having an on-board compressor. Examples of applications: carbon dust, metal dust, and cement powder.

Automatic pneumatic filter cleaning system - PN


As you can see, there is a very wide range of filtering options to meet your needs, no matter if you have an industrial vacuum cleaner or a portable dust collector.

Still haven’t found what you are looking for? No worries, we’ve got you covered.


Give us a call or contact us online, our experts will guide you through the decisional project!

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