Being shatter-resistant, torsional-resistant and heat-resistant, phenolic resin is a popular product in industrial applications for decades. The material is a thermosetting plastic and e. g. in use as filter material. It demonstrates the high level of temperature and pressure resistance that is necessary for filtering aggressive media. However, less and less phenolic resin is being produced due to negative impact of the production process on the environment. Due to the decreasing availability of phenolic resin, prices of the filter cartridges are rising, and delivery times of up to 20 weeks are now becoming the norm. Levaco, a company based in Leverkusen, Germany, has also had to contend with this growing challenge. In order to prepare its production processes for the future and to reduce its ecological footprint, the former member of the Bayer Group started looking for alternatives early on. The chemical company found everything it was looking for at Eaton. The filtration specialist was able to offer Levaco a solution that can outperform phenolic resin filter cartridges, both in terms of cost and environmental impact.
Filters for homogenisation
The Levaco Chemicals GmbH headquarters and production facility are located at Chempark Leverkusen, Germany. Levaco is engaged in the contract production of specialty chemicals for well-known chemical companies. The Coating Solutions division primarily serves customers from the paint, coatings and ink industries, but wood preservatives, industrial coatings and pigment preparations can also be optimised using the chemicals from this division.
One of the intermediate products in the Coating Solutions division is an amine condensate agglomerated with dichloroethane. Filter cartridges made from phenolic resin have long been an essential process component for manufacturing this product. This gel-like fluid also serves as a base material for pigments and fillers. It particularly helps to improve the protective properties of paints and coatings.
To achieve the desired consistency, the amine condensate is mixed with water. This produces inhomogeneous agglomerates, which have a negative influence on product quality. The filter cartridges are therefore primarily used in the process to distribute the particle sizes evenly, so that a homogeneous product can be produced. In addition to the poor availability and the resulting price increases for the phenolic resin filter cartridges that had been used up to that point, the environmental impact of these cartridges motivated Levaco to search for alternatives. The company has been a customer of Eaton for many years and so the filtration specialist receives the inquiry about the filtration technology for amine condensate.
Polyamide as an alternative
However, the exceptional properties of phenolic resin filter cartridges did not make it easy to find an alternative. High temperature and pressure resistance, strong chemical resistance — all this is standard for phenolic resin. For this reason, filter cartridges made from this all-rounder material have been the standard for a long time.
Eaton suggested polyamide as a possible alternative. Polyamide can withstand greater pressure and higher temperatures than polyester or polypropylene, for example. The available filter ratings are approximately equal to those for phenolic resin and may even be better in some cases.
Loftrex Nylon filter cartridges were therefore good for the company‘s application. The melt-blown filter cartridges made from polyamide can withstand high operating temperatures of up to 120 °C and a differential pressure of up to 2.5 bar at ambient temperatures. The filters are made from a polyamide-6 polymer material using efficient melt-blown technology. The result is a powerful and durable filter cartridge made of a fine-pored material. Its particularly smooth surface also reduces fibre migration. This is also beneficial for the process at Levaco as any filter fibres that are released form impurities which can reduce the product quality.
Service live nearly doubled
Eaton‘s filtration engineers chose Loftrex Nylon filter cartridges with a retention rating of 100 µm to provide the ideal homogenisation of the amine condensate. This turned out to be the right choice: with optimised differential pressure and flow rate, Levaco can use the same filter cartridges for up to five batches of the product. A total of 75 filter cartridges are in use at the company, spread across a 50-cartridge housing and a 25-cartridge housing. Together, they enable a high throughput of 10 m3/h. By using a number of filter cartridges in parallel, the excellent performance of the filter cartridges very quickly begins to have noticeable economic benefits.
The service life of the polyamide filter cartridges is about double that of the old phenolic resin filter cartridges. For Levaco, this means that product quality remains the same, while considerably fewer consumables are required. As polyamide is an easily available filter material short delivery times can be provided without any problems.
After Levaco‘s coating experts contacted Eaton with a request for new filter media, it took less than two weeks for them to receive the first sample shipment for testing. Following trial runs, Eaton received the order for the filter cartridges a few months later.
The fact that this process was so straightforward is mainly due to the confident relationship between the solution provider and the customer. Levaco has thoroughly tested the Eaton filter cartridges. They now help to maintain the consistently high product quality that Levaco customers are accustomed to. Homogenised with the Loftrex Nylon filter cartridges, the amine condensate gives the end products precisely the desired properties.
Eaton Technologies GmbH, Langenlonsheim
Author: Jenö Inderfurth
Eaton Technologies, Germany