Manufacture of Poroton bricks
Permeable bricks
Brickwork is used in the construction of about 90 percent of all homes in Germany. One of the most progressive construction materials is the Poroton brick. In the factory's own laboratory, Schlagmann Baustoffwerke in Zeilarn, Germany puts the natural high-tech material through its paces. An important component in this process is the BINDER KBF series constant climate chamber.
Although a construction material with thousands of years of tradition, modern bricks today are considered technical masterpieces. The interaction between the four elements earth, water, air and fire results in high-performance construction elements such as the familiar Poroton brick. It combines excellent thermal insulation with the ability to handle humidity particularly well. Schlagmann Baustoffwerke GmbH & Co. KG headquartered in Zeilarn, Germany also fills the conventional blocks with perlite, an insulating material made of mineral volcanic rock. The result is a natural living environment with low energy costs.
Microscopic pores
By drying and firing them at 950 °C, Poroton bricks form an efficient pore and capillary structure, i.e., fine channels that absorb and whisk moisture away. The faster water vapor escapes from the material, the better the brick protects against cold and heat. The so-called sorption behavior of Poroton bricks far surpasses that of other construction materials because humidity condenses and evaporates on the walls of many thousands of microscopic pores.
Consistently high quality is important for the reliability of construction materials. Based on the standard EN ISO 12571, Schlagmann Baustoffwerke determines in regular product samples how high the so-called moisture sorption behavior of the Poroton bricks is. Its ability to absorb and whisk away moisture is measured under constant climate conditions of 23 °C and 80% humidity over a test period of approx. 21 days. To do so, the company stores bricks in the BINDER KBF series constant climate chamber for several weeks.
Impressive values
Although from the heart of nature, Poroton bricks filled with perlite are genuine high-tech materials. They are thermally conductive from 0.07 to 0.09 W/mK in wall thicknesses of 30 to 49 cm. In comparison, the thermal conductivity value (λ) of bricks at the beginning of the 1970s was still 40 W/mK. The impressive values and a high annual production volume of 500,000 tons of bricks and 100,000 m³ of perlite, corresponding to bricks for about 11,000 single-family homes, demonstrates how important constant quality control of the natural material is. A large number of individual elements must always be available in the same proportions. The base material of clay consists of varying proportions of so-called layer silicates, as well as organic and inorganic materials such as quartz, calcite, dolomite, feldspar, oxides, hydroxides, silicic acid, iron hydroxide gels and organogels.
Nature on the test bench
In developing factory production controls, Schlagmann Baustoffwerke sets new standards with the BINDER KBF series constant climate chamber. Short test intervals ensure proven safety at consistently high quality levels. The BINDER constant climate chamber is particularly well-suited for this purpose because of its homogeneous climate conditions with uniform horizontal air circulation even when loaded. This makes it extremely valuable according to Dr. Jens Gedhuhn, research and development chemist at Schlagmann Baustoffwerke. "The glass door of the BINDER constant climate chamber is a big advantage," stresses Dr. Gedhuhn. "It allows preliminary orientation in the storage of samples without affecting the chamber climate." The Poroton expert also sees another plus in the rapid climate recovery after opening the door. In a temperature range of -10 °C to 100 °C, the BINDER KMF series constant climate chamber is an ideal complete solution for stability testing across industries. In addition, it offers Schlagmann optimum process safety. Reliably and safely, the KMF is in use at Schlagmann 360 days a year. Although the chamber can be found in the production area where different ambient temperatures prevail, it always maintains the required working temperature thanks to its high-performance cooling system. The Multi-Color Screen (MCS) controller makes adjustment of settings simple. A target/actual comparison of the setpoint can also be quickly performed. The log memory and integrated line recorder are also available for monitoring, a completely safe package.
