The initial cut that squares and prepares the log for downstream processing is the heartbeat of the sawmilling process.
A common requirement in many timber production lines is the efficient removal of two sides of a log or cant in one pass. Wood-Mizer’s Twin Vertical Saw (TVS) has been a proven log breakdown option in sawmilling for more than half a decade with numerous units delivering sterling results worldwide.
The success of the TVS has been built on providing a robustly engineered log breakdown sawmill where high output, accuracy, reduced labour, improved price/performance ratio and more efficient electricity consumption, combine to deliver a sawmill that achieves good results on all these important issues.
The TVS can work as a stand-alone unit or can be integrated into an existing sawmilling line to increase production even more. It is designed to work with Wood-Mizer’s SLP processing system that largely automates the production of similarly sized logs into a consistent final product. Log diameters from 100 to 400 mm and lengths of between 900 and 3600 mm can be processed.
The core efficiencies of the TVS include: Dependable Performance
The robustly built and CE certified TVS sawmill is designed to provide long years of consistent and quality in a high production sawing environment.
The use of two, industrial strength 11.2 kW electrical motors that power the belted blade wheels ensures smooth and accurate power transfer to where it is needed – the blades. Industrial size blade guide rollers ensure cutting consistency. The use of belted blade wheels that do not require crowning means less maintenance and costs, less blade fatigue and less costly breakdowns.
The use of Wood-Mizer manufactured and approved thin-kerf, narrow band blades ensure significantly improved log recovery stats. Wood-Mizer’s wide range of blade brands and profiles cover the whole range of sawing applications – from knotty softwoods to dense tropical hardwoods.
The twin sawmill heads are set at an angle to the in-feed bed which reduces the initial impact on the blade as it makes contact with the timber. This lets the blade stays sharper for longer and limits damage to the blade body.
Hydraulic blade tensioning also ensures that the blade is easily and accurately strained to specification. The blade tracking system accurately centres the blade on the wheel in one easy step.
Various industrial material handling options make easy work of heavy logs going into and out of the TVS and beyond, which reduces labour and improves productivity.
Computer controlled sizing makes it easy to adjust the cutting widths quickly and accurately.
The TVS’s design means that it can easily slot into an existing layout or form part of a line when the entire SLP line is commissioned.
Three (3) options of in-feed and out-feed tables are available to feed the timber through the cutting heads, namely:
• A standard dog feed system (the dog spacing intervals can be adjusted to suit the sawmiller’s standard log lengths)
• A spiky chain feed system with spiked top rollers (adds greater stability to the log as it goes through the sawmill, as well as increased productivity due to the ability to load logs with little or no gaps between them onto the chain.)
• A flat feed chain system (for timber with an already flat cut surface).
• Additional in/out-feed options:
- Pneumatic spiky side discs keep the offcuts in place on the log until they are ready to be dropped away.
- The addition of a spiral roller option on the out-feed of the new flat bed TVS ensures the easy removal of offcuts.
The price/performance ratio of the TVS now for the first time allows entry level, medium and large sawmills access to industrial scale sawmilling capacity.Proven Results
Since its roll out internationally, the use of the TVS by mills has increased consistently.
CRS Timbers outside Sabie puts 70m3/day through a TVS as primary breakdown unit in their crate and pallet manufacturing operation breaking down Saligna logs of between 120 and 250 mm in a mixed sawmill line that still includes circular multirips.
JRM Pallets in Mpumalanga also run a TVS in their pallet manufacturing set-up. The only factor limiting them from feeding 100 m³ of Saligna into their TVS is the availability of timber. The current input of 70 m³ per day into the TVS delivers between 40 and 50 m³ per day of timber.
Ngodwana Motors t/a Webco Sawmill outside Sabie use three TVS’ as primary breakdown point for Pine going into crate and pallet material. Average diameters fed into the TVS stand at between 135 and 300 mm while an average of 110 m³ is fed into and some 60 m³ eventually exists from the mixed line. Electricity consumption has gone down and labour has also been reduced.By Etienne Nagel
Top photo: A spiky chain and flatbed TVS running in a mill in the Kenyan rift valley.