Sustainable filtration

What does sustainability generally mean?

According to the definition in the German Duden dictionary, sustainability is the "principle of not consuming more that can be renewed, regenerated or provided again in the future. New technologies are for ensuring the sustainability of the power supply."

What does sustainability mean in the context of filtration or oil maintenance?

Every user using products from RT Filtertechnik GmbH makes a small contribution to saving resources. Filter elements are primarily offered on the market with a direction of flow from the outside to the inside. The main filtration direction of our filter elements is from the inside to the outside, which has been the case ever since the company was founded.

Normally, filter elements with a direction of flow from the outside to the inside can be built up to 20% smaller, at the same separation capacity and similar retention characteristics, which is normally a sales argument, if space is required in the hydraulic system for the pipe filter. However, normally, return line filters are integrated in the tank, where the space conditions are usually relatively moderate.

The sustainability idea can be well illustrated, when it comes to changing the element. In the case of elements through which the oil flows from the inside to the outside, the oil may flow out of the filter element during its removal, without the system being contaminated with dirt. If the direction of flow is from the outside to the inside, the oil is disposed of that remains in the housing on the dirt side, or may get mixed with the already filtered oil after the removal of the filter.
The product portfolio of RT Filtertechnik GmbH includes additional applications for the filter system with pre-filtration, thus sparing the filter medium and increasing the service life of the element. If the filtration direction is from the inside to the outside, it is possible to use one or more magnetic cores at the inflow end, which ensure the pre-separation of (ferro)magnetic dirt. In normal hydraulic systems, this may well be a practical alternative, in particular if a driving gear or a coupling is supplied with the system or installed in the system. Analyses have shown that filter elements in hydraulic systems with driving gear have magnetic dirt of between 25 and 35 percent by weight, as opposed to systems without direct driving gear supply with only 10 to 25 percent by weight. In addition, these days, the metallic particles are <10µm and place a load on the fine filter medium directly in the filter element.

E-line and RT-Pleat filter elements

In the recent past, we at RT Filtertechnik GmbH have continued to pursue the idea of sustainability and currently have a product line of filter elements not supported independently by a protective pipe. These filter elements that can be fully reduced to ashes of our E-line (efficient line) or our RT-Pleat elements are offered in various diameters and in the common fineness grades of 3µm, 5µm,  7-10µm, 12-15µm and 20µm.

The basic idea is relatively simple. According to the energy analysis of the filtration concept and the creation of a CO2 balance, the production and processing of steel cylinders is hardly acceptable from an ecological perspective. As the filter elements as exchangeable parts have a specific service life, the filter housings are designed for this service life.

A standard filter element normally consists of two end caps made of elastomer or of sheet metal. There is also the filter element mat, in which the filtration media are installed and supported by a wire mesh and finally a supporting cylinder, which absorbs the axial and vertical forces generated by the oil flow. Using new folding techniques and special filter materials, RT-Filtertechnik GmbH has managed to assemble filter elements that do not require a separate supporting cylinder any more. It is only installed once in the housing for the entire service life of the filtration system.

For the E-line elements, in particular, special attention was paid to the cap material. The production and further processing of the end caps enable degrees of freedom, allowing the elements to be installed in existing customer applications without seams or adaptation. We look forward to your challenges.

Pure glass fibre media, micro glass fibre media or melt-blown materials are generally not used in these filters, as is normally the case, but instead, special wet-laid composite materials for the product, with encapsulated glass fibre core.

E-line elements and RT-Pleat

G-line filter elements

A fully bio-degradable filter element from the product families of the E-line elements has just been developed. The elements of the Green Line (G-line) product family are also not supported independently by a supporting cylinder in the element.

The end caps of the filter elements are made of bio-degradable elastomers, the support for the filtration media is made of renewable raw materials and the filtration medium is made of non-woven fabric or of cellulose-based filter materials with bio-degradable filler materials as an alternative to glass fibre.  Using new production technologies, RT Filtertechnik GmbH is able to assemble the filter element without any adhesive at all.

We look forward to any questions you have relating to these products.