At LIGNA 2013
, Wood-Mizer is exhibiting a new concept for converting small logs into boards efficiently and quickly. Wood-Mizer’s SLP2 is an automated line made up of three sawmills connected by a material handling system. The SLP2 line processes the logs that are 10-40 cm in diameter and 1.2-3.6 m length into any square material, and is primarily used to produce pallet lumber.The case history
Quite often businesses do not have a way to make a profit from low-value small logs. And in many cases, such logs are considered only good for firewood or mulch. With this problem in mind, in 2007 Wood-Mizer developed a system of products that could process small logs into a commercial product that is marketable and profitable.
This first successful SLP line was made possible through the use of Wood-Mizer’s well known narrow-band blade sawmill technology that they have employed worldwide since 1982. Narrow band (thin-kerf) blades conserve more raw material, require less energy, are cheap to purchase and maintain, and are the key to sawing small logs profitably.
Dozens of SLP systems in operation around the world are proving the profitability of small logs every day. Through the feedback and suggestions Wood-Mizer collects from customers, the company has improved the SLP system by adding yet advantage crucial to profits – a reduction in labor requirements to run the system. The new automated SLP2 line reduces the manpower requirements by two times: the line can now be managed by 2 or 3 people depending on the size of the material being processed.Innovative design
"To automate the SLP technology we redesigned all the sawmills in the line, created one new machine and developed three
types of conveyors – belt, roller and chain," - says Roman Frontczak, director of Wood-Mizer’s R&D Department.
Wood-Mizer engineers made four objectives their goals with the new system.
1) The whole line is controlled by one central operator’s station
2) Material flow through the system would be seamless and reliable
3) Cutting accuracy would be improved by more precise material positioning
4) Comprehensive slab removal would be integrated into the design
Improvements in safety and operation of each unit in the line has been accomplished. For example, all the sawmills are now equipped with hydraulic blade tension systems with safety switches that stop the entire line in the case of a broken blade.SLP2 Overview
In the SLP2 layout presented at LIGNA
, the line operates in this way:
• Log loading
is made from an inclined ramp equipped with the chain log feeder.
• Twin Vertical Saw
. The first sawmill’s function is to cut two slabs from the left and right sides of the log resulting in a two-sided cant. The log is moved through the cutting heads by a spiky-chain conveyor. Six overhead spiked rollers ensure straight movement of the log through the saw. After they are cut, the two slabs drop directly onto an inclined chain conveyor that removes them for further processing.
• The Single Horizontal Saw
is a brand new mill in the line. This machine comes after the TVS and the two-sided cants are fed into it by the same spiky-chain conveyor. Here, the third slab is cut off the bottom, resulting in three-sided cant. The sawn log is moved on to an area where the bottom slab is removed for further processing, while the three-sided cant is guided by special fences and roller conveyors into clamps that pneumatically position the cant from both sides.
• The HR500 Horizontal Resaw
can be installed with up to six cutting heads depending on productivity requirements. In its maximum configuration, this resaw will produce six pallet boards plus one slab in a single pass. The material is positioned precisely by side pneumatic clamps and top pneumatic rollers that operate together to keep the three-sided cant secure during sawing.
• After the HR500 the material handling system
removes boards to the next stage in the production line.
• The central operator console
is installed at the beginning of the line. From here, the operator controls all sawmill functions
and power switches.Increase efficiency while decreasing costs
Wood-Mizer recommends that customers order the SLP2 line after considering the size of the raw material which they are need to process. "Shorter log lengths require shorter conveyors which means less metal is used and the equipment is then less expensive, features a more compact layout, requires less maintenance and therefore uses less energy," Roman Frontczak shares.
Wood-Mizer reports that installation of the SLP2 line is fairly simple and is usually completed within two days. During installation, Wood-Mizer technicians ensure that each sawmill is properly adjusted. Wood-Mizer recommends that the system should be checked once a week during operation.
"The demands of our increasingly modern global economy requires that all businesses make decisions to increase efficiency, and see how they can reduce costs in a smart way," continues Roman Frontczak. "The automated SLP2 line gives our customers an additional benefit by greatly reducing the necessary manpower as labor costs continue to rise."
The new automated small log processing technology is designed to assist wood producing businesses to become more successful and competitive in the markets they serve.