Wood-Mizer HR250 resaw increases Lowveld sawmill productivity
Wood-Mizer HR250 resaw increases Lowveld sawmill productivity
A Wood-Mizer HR250 twin horizontal resaw has a significant impact on the productivity and profitability of a prominent pallet component producer.
The HR250 now easily exceeds the volumes that Mitrek’s primary breakdown saws can throw at it.
Mitrek Sawmill, owned and operated by veteran sawmiller Peet Groenewald near Whiteriver in South Africa’s Mpumalanga Province, is no stranger to change.
These changes or innovation cycles as Peet calls it has one goal in mind – increased efficiency.
Mitrek’s growing efficiency has gone hand-in-hand with Wood-Mizer from the start. In 1997, the mill’s first Wood-Mizer LT20 laid the foundation for its success.
More Wood-Mizer’s followed, two hydraulic LT40’s, two single-head HR200 resaws and a Wood-Mizer EG300 multi-blade edger broadening Mitrek’s efficiency. A Wood-Mizer LX450 twin rail sawmill that started working in 2017 with the remaining LT40, drove Mitrek’s efficiency even higher.
The next innovation cycle followed in 2019 with Peet’s decision to replace the two Wood-Mizer HR200 single head resaws with a Wood-Mizer HR250 twin horizontal resaw. The resaws are key to Mitrek’s operation to resaw blocks and boards into pallet components.
Peet’s critical eye immediately told him that the old resaws were struggling to match the mill’s improved primary breakdown capacity after the LX450 was commissioned.
“I also knew I could improve the quality of the output from the HR200’s. If the quality at the end of the process is down, my income goes down and my costs go up.
“Since I took the HR250 into production, my overall efficiency has shot up,” Peet says.
The accurately resawn component exiting the HR250 driven by two 15 kW motors.
“I immediately recognized the benefits that the HR250’s single-head twin-blade configuration allows for,” Peet Groenewald says.
“The HR250’s ability to produce up to three resawn boards in one pass meant that I had a winner. I could now replace two single-head, single-cut resaws with one machine and still match and exceed the output that I previously got.
“A reduced wage and electricity bill was just the start. I could also use the remaining HR200 elsewhere for increased flexibility.
“The sizing accuracy delivered by the HR250’s digital setworks now provides for a product where size consistency is measured with a vernier. My customers are prepared to pay a premium for that accuracy,” Peet smiles. “My staff can now make size changes on the fly where manual size changes previously didn’t allow for that.
“The HR250 cuts much faster than the single head resaw using a 50 mm blade. The higher beam strength that the wide blade offers provides for fast, accurate and wave-free cutting,” Peet surmises.
“I also cut Eucalyptus Grandis, which is a heavy, tension-filled hardwood grown commercially in South Africa. The four large and heavy, 720 mm diameter blade wheels that HR250 has, is also contributing to cutting accuracy and speed.
“When the blade enters the cut, the heavy wheels also carry enough energy to immediately cut deep, which then combines with the motors to provide for precise, accurate and fast sawing,” Peet says enthusiastically.
“The overhead in and outfeed roller system of the HR250 and its single head, twin blade configuration, is especially important when you cut Eucalyptus.
“Let me explain,” Peet says.
“The tension in Eucalyptus makes the timber want to move when you cut it. The hold-down rollers close to the cut prevents any movement or fishtailing during the cut when the tension is released. Because it can make two cuts in one pass, movement is limited further, which is not the case with multi-head resaws where movement happens when the board passes from one head to the next.
“The hold-down rollers also hold the component firmly in place, this allowing me to cut down on staff and my wage bill. Staff at the outfeed end now needn’t check sizing or accuracy anymore,” Peet continues.
Another area of significant improvement after the HR250 was installed, is Mitrek’s bottom line.
“We previously produced 18m³/day with the two HR200’s,” Peet explains. Out of this total, we had a 75-80% cutting accuracy rate, which impacted on the total volume of sawn timber we could sell.
With the HR250, we’re producing 25m³/day with a 100% accuracy rate, which has had a dramatic impact on our overall profitability,” Peet concludes.
The HR250 twin horizontal resaw working at Mitrek Sawmill near Whiteriver in Mpumalanga
What is in the machine
The affordable heavy-duty Wood-Mizer HR250 offers a resaw solution for industrial and professional sawmillers to improve output and recovery.
The HR250 features two horizontal bandsaw blades in one compact head to resaw cants and boards into two or three pieces in one pass.
Four crowned steel band wheels measure 710 mm in diameter can accommodate a 37 mm and 50 mm wide Wood-Mizer bandsaw blade.
Two standard 15- or optional 18-kW electric motors drive each set of steel band wheels for consistent power and precision through the cut. The accurate and precise up/down movement of the saw heads is controlled by two 0.75 kW motors with the simple setworks control panel with digital blade position controls ensuring the accurate height adjustment of the saw wheels when the cut thickness is set. Each blade has its own setworks panel and is run independently using the digital controls or manual up/down buttons
A 1.5 kW variable speed electric motor drives a heavy-duty belt conveyor for feed speeds of between 0 and 27 m/minute.
A pneumatic hold down roller at the infeed end and an idle top roller at the outfeed end, keep material secure during the cut.
Blade tension is automatic and is controlled by a pneumatic/oil hydraulic system for longer blade life.
Material up to 292 mm wide by 254 mm high can be placed onto the rugged rubber conveyor with variable feed options for optimal processing of various types of material.
The heavy-duty and driven overhead infeed roller firmly holding the component down in the cut.
High-value final product exiting Mitrek Sawmills to customers.