Glass factory Lesní Brána was originally founded in 1872. At its site in Dubi in the Czech Ore Mountains, typical glass products as beverage bottles, plate glass or glass blocks were produced. The first production line for insulation “FIBREX” made from glass fibers was built in the mid-1960s. During more than 50 years of glass wool production two big changes of fiberizing technology took place, in 1993 and 2013.
Increasing heating costs and high energy efficiency drive the growth of the industry. The Czech government promotes the energetic improvement and the restoration of new and old buildings. These factors result in a high demand of insulation materials. Thanks to a continuous innovation and improvement of the production processes, ULB has been able to reach a high quality standard that is the foundation of the success of the traditional Czech company.
The mixture of raw materials is prepared in batch house and fed to the melting furnace where is melted at temperature almost 1,300° C to glass with defined chemical composition . The liquid glass is forced through centrifugal spinners with thousands of small orifices on peripheral wall. A primary fibers which were generated by the rotary movement are attenuated further by flow of compressed air to final fine fibers. Afterwards, a small quantity of binding agents is added to the fibres. After binding, hardening takes place in a curing oven at temperature approx. 200° C. The thickness and the density of the product can be adapted exactly to the requirements of use. The glass wool is now cut to the requested shape and size.
A challenges of production are the complexity of whole production process and sensitivity of final quality of products on precision settings of all production parameters as well as wide range of products. The multitude of products and the resulting variables make a control of the production based on the visual judgement and the feeling of the operator impossible. One of the biggest challenges of manufacture is the uniform distribution of the fibre material before curing. If the fibre material in the glass fibre mat is insufficient, the finished insulation material plate has a poorer insulation and mechanical performance and fails to comply with the European standard for mineral fibre insulation materials (DIN EN 13162:2001-10). This, in turn, leads to expensive complaints. The consequences are not only increased costs, but above all damage to the image. If too much fibre material is used, efficiency of production is falling.
An exact review of the mass per unit area of the glass wool mat is necessary to guarantee a precise distribution of the material. Based on a state-of-the-art X-ray technology, the DIEFFENSOR checks the mass per unit area of the measured material on the entire surface without any contact. The measurement of the mass per unit area is adapted to the production needs. Besides the current cross profile, it is also possible to generate a long-term trend according to the type of production. Different statistic evaluations are available to analyse the material distribution as well. Any fluctuations are visible and can be regulated by the system control.
- Complete non-contact measurement of the weight per unit area
- High accuracy and flexibility due to fine resolution
- Optimisation of material consumption thanks tothrough analysis of longitudinal and cross profile
- foreign opject detection for protection against damages (e.g. hot spots, wet spots, etc.)
- Material, glue and energy can clearly be reduced
"The demand for our insulation materials is high. We are always interested in an improvement of our production and product quality."
"We manufacture approx. 100 different products – rolls and boards with different thicknesses, widths, and densities,- for 365 days per year and 24 hours per day."
Since beginning of cooperation and commissioning of the DIEFFENSOR, we have achieved a significantly better distribution of fibres but our target is completely avoid impact of operators on distribution."
Pavel Gromus - Chairman of the Board of Directors, ULB