Hüttenes-Albertus CZ, s.r.o.

We offer Kaltharz resins for standard and quick curing of the molding sands using different types of base sands (high-silica sands, chromite sands, etc.) for both grey and nodular graphite iron, and for steel we offer resins with nitrogen content of 1 % and less. There is also a full range of proven modifications: some for grey and nodular graphite iron with reduced, but not completely low nitrogen and water content as for steel as well as variants with an optimized price level.

Owing to their high quality, our standard resins allow low additions and are characterized by good strength, low development of gas and odour and good flowability of the molding sand and thus also optimum homogenisation of molding sand components due to low viscosity of these products.

By choosing the suitable quantity and type of activators used, resins can be very well adjusted, in order to easily optimize their reactivity and thus also the subsequent speed of curing of the manufactured molding sand with respect to the type of foundry sand used and the curing conditions given especially by the temperature of this system as well as of the environment.

At the moment, this activity is often performed automatically when preparing molding sands, i.e. by dosing the appropriate quantity and type of activator with respect to immediate temperature of the base sand and environment. An example may be the AUTOFEEDER which we constructed in cooperation with Elkoso.

For special purposes, we furthermore offer the following systems from our production:

Low-sulphur systems by using reactive resins and corresponding slow activators containing lactic acid, which reduce the amount of sulphur in reclaim. In this way we are able to prevent graphite degeneration in parts close to the surface in nodular iron castings as well as strong odour during casting caused by SO2 emissions in reclaim. Problems with the odour may also be caused by outdoor storing of the reclaim, particularly in summer. That is why these systems are being applied in many cases despite their higher price.
Kaltharz products with faster, but due to additives used, still plastic curing process, which are well suitable for steel castings due to their nitrogen content amounting to 0.5% and less.

Due to the enormous price increase of furfuryl alcohol (FA), the main raw material for manufacture of furan resins, we have alternatively developed a whole range of new Kaltharz products, for which we have been gradually substituting FA by other components while maintaining our existing recipes. This process allows the customers to test, without a risk, several variants under their own conditions and to decide, which rate of substitution of furfuryl alcohol suits them best.

These are primarily our Kaltharz products of the TF range, where FA has been substituted by a high-quality phenolic resin. Where it is not desirable to use phenol, e.g. due to waste disposal, we offer the phenolic free products within the TP range.

Pure phenolic resins from the holding’s production are also available.

Unfortunately, this step in developing new types for furan-phenol-formaldehyde binders is inevitable in the sense of constantly increasing prices of FA, as mentioned above. However, we are still encountering the deep-routed mechanisms of individual foundries that are afraid to undergo practical tests of these new binders under the supervision of HA CZ, but they would like to buy existing binders at the much lower old prices. This situation is very critical and leads us constantly to a certain type of persuasion... however, here in the Czech Republic as well as in the neighbouring countries there are already many practical examples of series production, which is fully functional. This is all a compromise in long-standing habits where price of the final product plays the main role. The HA CZ solution rests upon different content of the phenolic resin in the final product. All our suggestions on the applicability of these furan-phenol-formaldehyde binders are based on practical discussions with foundries where we rely on the existing state of functionality. It has to be said that by using the furan-phenol formaldehyde system, we do not only bring a solution in the form of a price alternative, but also this technology is an adequate solution for applicability in foundries.

Suitable activators can control the system of molding mixture lifetime, mold curing and stripping of the model equipment. The environment, temperature of the environment as well as temperature of the sands also play a role, so in terms of usability we look at this system with the same eyes as at the classic furan system. Kaltharz products with a 30% substitution of FA are already being used in series; other products with up to a 50% substitution are being tested.