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Post-delivery testing important to Valutec’s way of working
Valutec has recently conducted “final acceptance” tests, including quality and capacity testing at a number of sawmills, including Mercer in Germany, Pauls in Belgium, Gran Tre in Norway, and Vida Vimmerby and Rödins in Sweden.
The purpose of the final acceptance testing is to ensure not only performance relative to the dimensions to be dried, but also that the stated requirements and tolerances for capacity, checking and target moisture content are met.
“Commissioning is always followed by a test phase. Once everything is stable, we begin our post-delivery testing. The operators help out with the initial measurements and setting up the measuring system, then I visit the customer to analyze the results and to check that everything is working as promised in the contract.”
The testing protocol that Valutec follows was originally drawn up in the mid-1990s at the the Swedish Wood Research Institute (SP Trätek), with Thomas being one of the people responsible for its creation. Although measurement techniques have evolved, this testing process has stood the test of time.
Data difficult to interpret
The measurement process requires a certain degree of expertise. Anyone who has worked intensively with lumber drying knows that there is a lot of natural deviations that can make measurements complicated and difficult to interpret.
“This can be noise from the lumber itself, such as lumber with varied moisture content when it enters the kiln, but even from a boiler that isn’t performing at its best. The results aren’t always perfectly clear in the first instance, and it’s important that they are interpreted correctly and that all circumstances concerning the kiln are as they should be.”
On occasion, quality managers also attend the tests.
“This could be to discuss, for example, issues such as deformation and warping. These matters are related the lumber and aren’t encompassed by our contracts, making it difficult to promise anything linked to them. Although naturally we like to help out with such matters where possible within the process. Together with the kiln operators, we want to ensure that the process itself works as it should, such as by achieving the right moisture content and reducing turnaround times.”
Gathering
For Thomas Wamming, the test phase is also a chance to meet the customer and bring the project to a close. As Head of R&D, he can act as a neutral party once the project managers and the installation crew have completed their work. It becomes a gathering of sorts, providing an opportunity to discuss areas for development.
“Many customers like to make the most of the opportunity to take extra measurements in conjunction with testing. These could be linked to aspects in which they have a particular interest or that concern them specifically, such as new sensor positions or test pieces at the top of the package. These are opportunities I truly appreciate. Curious customers help us accumulate knowledge that aids us in our own development work.”
The testing process is also a chance to assist the customer in the handling of a new kiln, with the model being tested a key consideration.
“The TC continuous kiln is so powerful that it’s easy to get things terribly wrong if you’re not careful. We need to monitor the initial moisture content as well as work effectively with air and heat. It’s important to gain a good grasp of all these aspects.”
Operators key
Valutec’s success in recent years has resulted in a great deal of business travel, in both Europe and North America. This has provided new insights into both different types of lumber and how it is handled before it enters the kiln.
“In Europe, felled forest is bucked with a cut-to-length approach. This affects leakage air and airflows inside the kilns. Then there are major differences in the lumber itself. German spruce is much like Nordic spruce, while Austrian spruce is clearly different as it grows on slopes. The tension in that lumber is very particular,” says Thomas, who believes that these visits also help form an understanding of the central role of lumber drying in achieving the right production quality.
“It’s important that drying is also carefully considered during the planning stage. The more people realize how taking a broad approach to the process at an early stage benefits quality, the better the wood products we’ll see in markets across the world.”
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