Production of glued laminated timber

The Sokol Timber Processing Plant (TM Sokol) has a guaranteed supply of timber (round timber / sawlog). Since 2011, the company has been leasing forest plots with a total area of 159,681.8 hectares with an estimated logging volume area of 364,600 cubic metres. Logging is performed by a special purpose independent business unit operating out of Vologda.

SOKOL saws timber on a special timber sawing line that uses a HewSaw R 250SE timber-sawing machine manufactured in Finland. The product of this stage of the process is sawn timber.

Sawn timber is dried in BOLLMANN (Germany), MULBOK (Italy), Jartek (Finland), Baschild (Italy) Vаlutek (Finland) to reduce the moisture content to 12±2%.

• Dry sawn timber is moved from the drying chambers to the laminated timber shop.
  
• It is aged for at least 2 days there and is then supplied to Sistem TM optimization line.
  
• The temperature and relative humidity in the shop are continuously maintained and recorded by the thermohydrograph. The moisture content must not exceed 14 % when producing glued laminated timber (beams). Timber moisture content (minimum timber temperature is 150 °C) is measured by an automated timed moisture meter. Timber that is outside moisture content norm is automatically rejected.
  
• The timber for the beam production is sorted according to the European standards EN 14081-4, with characteristic values for bending strength, tensile strength, compression strength, shear strength, modulus of elasticity and density, which are determined by the Golden Eye 702 scanner made in Switzerland.
  
• Sawn timber for the wall timber (houses) manufacture iis sorted by quality according to exterior and interior surface requirements.
  

• The calibrated, strength- and quality-sorted blanks are delivered to the Ducet splicing line (Canada).
  
• The studs required to join the lamellas are cut parallel to the width of the workpiece on the tenoning machine, first on one side of the workpieces and then on the other.
  
• Apply adhesive to the entire length of the cut tongue (separately on both sides of the parts to be joined with combs).
  
• The pieces to be joined are pressed together at pressures up to 10 N/mm².
  
• The lamellas are cut to lengths of 12 and 13.5 m and stacked on the storage table.
  
• The adhesive system used for bonding is that of global leader Akzo Nobel. Adhesive consumption rate for wooden laminated beams according to Akzo Nobel recommendations.
  

• After splicing, the calibrated lamellas, with glue applied to them in the form of cords, are formed into so-called lamella packages, which are fed into a Kallesoe HF press (Denmark).
  
• The FIS (Forward Integration System) allows for the calculation and optimisation of press parameters depending on the technological production conditions.
  
• The HFI press is complemented by a heat chamber (HeatCamera), eliminating potential rejects due to "cold" zones in the press. The camera also optimises the cost of HFI heating.
  
• It is imperative that the adhesive joint temperature requirements are observed during pressing.
  
• A cold hydraulic Ducet press is used to increase the cross-section of the timber, where the timber is pressed in two planes.
  

• Planing of timber and beams is performed on a Ledermac LMC 840 planing machine.
  
• Each girder (beam) is visually inspected (visual inspection by staff) and repaired if necessary. The strength of the product is not reduced, only the optical defects are removed.
  

• The timber arrives at the prefabricated housing shop.
  
• Wall trimming is performed on a Hundegger machining centre (Germany) and Kruzi cup-cutting machines (Switzerland).
  
• The accuracy of processing parts is within +/- 0.5 mm, the production time of one set of houses (about 150 m²) takes not more than 1 day.
  
• All wall parts are labelled according to the house specifications.
  
• The equipment works with CAD-based engineering software.
  
• Reading the information from the designer's drawings ensures that all parts are highly accurate and conform to each other.
  

• Production control is carried out continuously to ensure the strength of the spike groove joints, the quality of the glue joints, and the functioning of the glued laminated timber production equipment.
  
• The production control system is regularly checked for efficiency and suitability.
  
• The results of the product tests are documented and stored in the laboratory.