Logs arrive normally by lorries to the log sorter, where the whole load can be unloaded to the sorting table or to the unsorted log area.
Log sorting line is a long conveyor with sorting trays on both side. Movement and storage space is needed around the log sorting line.
Log sorting line at UPM Seikku sawmill in Pori.
© UPM
Log sorting plans
Log sorting plants do not vary much from one mill to another with their operations and design, because the procurement and cross cutting methods for logs are similar in the whole country. Most striking differences can be found in the capacity and the number of pockets.
In practice the process begins when the cross-cut logs are loaded sideways on the log sorting table. From there the logs are moved along conveyor lengthwise.
With the advanced technology the sorted log information from each pocket can be directly conveyed to the loaders operating at the log sorter. The loaders can also be equipped with a GPS map system, indicating the location of each sorted log batch in the log yard.
Storage of sorted logs
There is not any need for long storage periods of logs at the mills. On the contrary, if the log stock turns fast it reduces possible storage damage to them and also ties down less working capital.
Also, the sorted logs are cut soonest possible. For the summer stoppages the log stocks are minimized.
However, even the short-term storage of logs requires a vast, well founded and paved storage area, which is kept dry from rain water and the melting of snow. There must be clearly indicated routes ensuring safe and functional operations at all times, which can be kept tidy as well.
Logs are moved around by
- loaders
- telehandlers
Telehandlers can reach up to seven meters high log piles.
Large wheel loaders are needed for the carrying of logs.
© Metsä Group
Internal logistics from the log yard to sawmill is steered by the production plans and the resulting log requirements. The aim is to keep the sorted log stocks at a sufficient level in relation to the sawing needs.
The numbers and capacity of machinery is dependent on the capacities of the log sorter and sawmill, and the travel distance between the two. The machinery must be capable of taking care of the sorted log stock and to transport logs to sawmill’s feeding table. Logistic costs of this part of sawmilling is made up from the distance between the log yard and sawmill, efficiency of the machinery and other related costs.
