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“LVL-Ugra” mill is equipped with modern Finnish equipment Raute; the production line is fully computerized. At every stage of the manufacturing process, stability of such parameters as homogeneity, density, moisture, and other physical and mechanical properties crucial for structural materials, are controlled.
Summary process description
LVL production line general description
Summary process description
LVL production technology can be divided into the following stages:
  1. Log handling
The feedstock for LVL manufacturing are softwood blocks of 4-6 m long. The logs are put into conditioning ponds (+ 45Ñ) for 24 hours. After that, they are debarked and cut into 1980+-10 mm pieces, which are automatically transported to the peeling area.
  2. Peeling, clipping and stacking line
The logs are peeled to create veneer sheets of 3,25 + 1 mm in thickness. After that, veneer sheets are cut into a specified size. The wastes here are the heart pith, bark, saw dust, and cut-offs.
  3. Drying and grading
Green veneer is fed into a four-opening drier (two sheets in a storey) heated with thermal oil, goes through sixteen sections of the hot part of the drying system, and then – three sections of the cooling part.
After veneers cool down, they are transported to the grading area. An in-line moisture meter sorts out wet veneer onto a separate tray.
  4. Patching and splicing
A splicing machine trims the veneer, cuts off defects, joins veneer strips with adhesive threads impregnated with liquefied glue, and by means of spot gluing with thermoplastic adhesive, trims and automatically assembles veneers into stacks.
Veneers are fed into the machine manually, cross grain.
  5. Scarfing
A scarf joining machine makes 28+mm wide scarf edges on the both sides of the veneer. Then, it joins veneer pieces into desired veneer sheets. After that, veneer sheets pass through a temposonic grading device “Metriguard”, which defines dry veneer density with the help of ultrasonic waves measurements. The denser veneer, the faster the waves go through it.
  6. Layup station and pre-pressing
Layup and pre-pressing are performed at an automated line with use of a phenol-formaldehyde glue. Layup and pre-pressing processes include the following operations:
stacks feeding to the layup station and their transportation to corresponding trays;
veneer sheets feeding to the gluing kitchen;
glue spreading and layups assembling;
  pre-pressing;
layups feeding to the edge trimming station with simultaneous waste chipping;
sawing into specified length billets.
 
 
  7. Hot pressing
The panels exiting layup station are 1,85 m wide and 27-75 mm thick. They are cut into specified lengths (maximum 18 m) and fed into the hot press (+140Ñ). Time required for final pressing depends on billet thickness and type of the applied adhesive. Thus, pressing of 45 mm thick billets takes 37 minutes.
  8. Sizing and grading
Sizing and grading involve the following operations:
conveying of unsized material to the trimming saw;
trimming and preparing;
beams feeding with a roller conveyor to the multi-blade machine;
ripping to the specified width; chipping of lateral cut-offs.
Finally, the beams are marked.
LVL production line general description
The mill produces LVL beams with length up to 18 m. The production capacity is 39 000 m3 per year.
The manufacturing process includes log handling, peeling, drying, splicing, layup forming, hot pressing, sizing, packing.
The length of press is 18,3 m; ready LVL beam length can vary from 2,5 to 18 m.
The first highly important step in LVL production process is log conditioning prior to debarking, clipping and peeling operations. This way of log handling ensures much higher production volumes.
The log ponds are heated with heat delivered from the drier. Logs are loaded onto a conveyor by an overhead crane.
After conditioning and debarking, the material is clipped to size. The bark is removed from the line with a special conveyor. Wood wastes are chipped and supplied to the boiler station.
Then, the logs are peeled at a high speed line. Sapwood and heartwood veneers are distributed to separate trays. Cut-offs and other wastes are fed into a drum-type hogger.
The veneer is dried in a four-opening drier. At this stage, veneer is graded in terms of moisture content. Dry lump wastes and odd-sized veneers are transferred to the splicing area. Dry veneer goes to the scarf joining line, where scarf edges on the both sides of veneer are made. At this stage, veneer is graded in terms of density. Then, scarf joint veneer is conveyed to the layup station for further pre-pressing.
Pre-pressed layups are fed into the hot press. After that, LVL plates are cut to width in accordance with specified dimensions and assembled into stacks for further packing and storing.
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