Stalatube’s ongoing goal is to be able to decrease the amount of waste and improve the effectiveness of raw material use. Scrap percentage is a concrete and clear measure for those activities. Scrap (the material going to waste) is created during the whole production chain – production planning, cutting, production lines, and possible additional processes, e.g. special saw cutting, all play an important role in minimizing the scrap amounts. Low scrap percentage is seen straight away as savings in material costs, shorter delivery times, and reduction of the environmental load caused by the operational activities. From the year 2018 to 2022 Stalatube has succeeded in reducing the scrap percentage by over 42 %, which means about 1500 tons of saved material. It also means a huge improvement in Stalatube’s CO2 footprint. During this year 2023, a new record will be made also in the scrap reduction during the actual welding of the tubes.
The professionalism of our staff and commitment to a common goal have a crucial role in our ability to reduce scrap amounts. Each week possible improvements related to scrap reduction are viewed with the production staff and in daily management the focus is on implementing the corrective actions together with the operators.
“The motivation and corrective actions done by our operators are important, if not the most important part in being able to successfully reduce the scrap percentage”, says Tuukka Juhanila, production director of Stalatube.
Together, production and production planning have learned finding the best suited production lines for different product types and optimizing the lengths of production runs. Experienced professionals make a well-functioning production process possible and are able to focus on critical process phases that can potentially lead to significant scrap amounts. Especially the start of tube welding and possible web changes during a production run are critical points. Additionally the operators are able to evaluate when minor faults can be fixed with tube straightening or manual welding to achieve all the quality criteria for acceptable tubes.
Another important factor are investments and improvements related to the machinery. Also adjustments and improvements that have been made to gas-networks and welding machines in the mill have had an important role. Latest investment that had a positive effect in scrap reduction was updating the welding method on production line 10 to laser-welding on 2022. With laser technology the scrap percentage during welding is lower than with tig-plasma welding method. It also enables production of ferritics on this line as a new material option.
“We will be investing in our two other production lines, that will enable us to produce 12 meter long tubes. After the investment, due to capacity increase the possibilities to optimize scrap percentage improve by choosing best suited production lines for different products and production batch sizes”, Juhanila comments on near future investment plans.
In the meantime, excellent work to reduce and optimize the scrap percentage continues and for this year 2023 the goal is to reach less than 9 % total scrap.
Teppo Lassila
EQHS Manager IWE & IWI-CStalatube Oy (Finland)
Technical support