Sintered Metal Filter - Technology & How it works

Installation of an SMF® sintered metal filter and the systems based on it is quick and simple. HJS diesel particulate filters are exceptionally reliable in operation and also benefit from a long service life. The pocket- type construction of the SMF® prevents clogging such as that familiar, for instance, from conventional ceramic filters with their honeycomb structure. The HJS filter system requires neither extra regeneration aids nor additives or any intervention in the engine management system. Electronic monitoring constantly guarantees the complete operability of the filter. Its modular design also minimises servicing and maintenance costs.

How the filter works

The hot exhaust gases from the engine – which contain soot particles – are fed into the filter housing and through the SMF® sintered metal filter developed by HJS. The gaseous components flow through the microscopic pores of the filter pockets; the soot particles, including the ultra-fine particles, are trapped on the surface and deposited on the individual filter pockets.

Filter cleaning

HJS's proven SMF® technology with passive regeneration is used to break down the soot that collects in the SMF®. The HJS system combines a highly efficient, upstream diesel oxidation catalyst (DOC) with an SMF®. Optimised tuning of the system results in the filter being continuously and effectively freed from the deposited soot.

Exhaust gas treatment with passiv filter regeneration
The passive regeneration technology continuously frees the filter from the deposited soot.


The SMF® modules are integrated in a stainless-steel housing with the same dimensions as the original silencer. This means that it can easily be fitted into the existing exhaust system of almost any Type-IDe of truck without the need to modify connections.

See for yourself: this short film shows you how simple it really is to install an HJS SMF® system.


With the service display contained in the items delivered the filter system is continuously supervised – at the same time the cleaning need is automatically indicated to the driver of the vehicle

Electronic Control Unit and Service Display
Electronic monitoring constantly guarantees the complete operability of the filter system   |   |   |   |   |