Sawmilling Technologies: yesterday, today, tomorrow
23 July 2013
Scientific and technical progress, with its temps rapidly increasing in the second half of XXI century, involved forest machinery building, including equipment for woodworking. Frame saws that replaced hand labor and served the man from times immemorial were gradually made way for new technologies. By the way today many sawmills particularly in Russia solve their production tasks with the same frame saws, with it becoming, however, more and more difficult with every passing day.
“The frame saw has good precision and it’s not a bad technology, but it has limitations due to low capacity and primitive measuring if compared with the modern technologies,” says Kari Kiiskinen, Managing Director of Heinola Sawmill Machinery – a leading Finnish producer of sawmilling machinery. - When Heinola Sawmill Machinery Inc started operations in the late 1960s, the technology most commonly applied at sawmills was frame sawing.
When a frame saw broke down, it was always a big concern. The typical maintenance shutdown was very long.The greatest obstacle however was the limited capacity. If large production output was required, several frame saws had to be installed side by side. This took up a lot of space and manpower. Frame sawing came to the end of its road in the 1980s, when the growing demand for sawn goods and increased quality requirements forced sawmills to consider new technologies.
It was impermissible to stand still, that is why producers of sawmilling machinery have been always developing. The same can be watched today. Although sawn goods may look almost the same as 50 years ago, sawmill processes have become speedier, more precise and more reliable.
Thus, old frame saws were replacing with saw lines, with their appearance marking a quality breakthrough. In bandmill technology with blades set in an unbroken string, continuous sawing is enabled and speeds are significantly higher than with the frame saw. The thin blade of the bandmill provides a clean cut, and little wood is wasted in sawdust. Heinola has produced bandmills since the early 1980s. And today having a rather wide range of machinery, HEINOLA band saw lines remain one of the leading sectors for large investments.
“A merry-go-round saw line with a bandmill is the first investment for a small sawmill. It’s your basic tool.But bandmills also play a role at a large sawmill facility,” says Kari Kiiskinen.
Edging and trimming go hand in hand with bandmilling. The plank that comes through the unit can be scanned on both sides for knots or other irregularities.It is then sawn into goods as required.
One more step ahead
Another popular modern sawing method is profiling, which means cutting board profiles into the plank before sawing.
“On profiling lines, knots and other faults in the boards are only detected in the finished goods. Profiling has other benefits though: speed, simplicity, small space requirements, low overall cost of investment and easy maintenance,” underlines Kari Kiiskinen. However, profiling itself requires high precision , that is why it is only possible at circular – moreover double arbour sawing. Precision in bandmill technology is not enough for profiling.
Profiling lines have quickly gained ground in the 2000s, with profiling itself being introduced at the market in 1970-s. Today HEINOLA product range also includes several saw lines equipped with profiler units.
Future in precision
Managing Director Kari Kiiskinen of Heinola Sawmill Machinery Inc.believes that there will still be demand for both bandmills and profiling lines in future. The type of wood, product range and market conditions determine which saw line best meets the demand.
“The focus will be increasingly on yield volume and the quality of sawn goods. Two issues will stand out:the accuracy of dimensions and the level of automation,” Kari Kiiskinen expects. - Optical imaging might be a built-in feature of saw lines, enabling visual detection of knots before sawing”.
Measuring instruments have improved at an amazing rate, which has speeded up lead times and improved the quality of final products. Sawing can be optimized by shape, and each log can be optimally positioned for sawing. Improved optimization has increased yield volumes.
The increased role of automation is evidenced in quicker response times.Sawmills that are able to adjust operations based on orders no longer produce goods for stock; their operation reflects the orders on hand. As an example, a line recently delivered by Heinola Sawmill Machinery to Japan was this kind of a smart, self-adjusting facility.
Secret of leadership
Heinola has been at the leading edge of sawmill technology for nearly 50 years. As sawmilling trends evolve, quick responses are key to offering solutions that clients need and desire. Managing Director Kari Kiiskinen cites the latest saw line range, HEINOLA SL, as a good example of meeting current demand. The efficient and compact saw line includes precise measuring instruments for saw line optimization and active crook-sawing. A HEINOLA SL line can have an annual output of 400,000 cubic metres of sawn goods at a 95 percent capacity utilisation rate. Although these figures already display a superb level of excellence, Heinola continues its efforts to ensure even better results through sawmill technology.