The quality system

Step-by-step quality control is carried out during the production of glulam:

• The first stage is the control of incoming materials;

• The second stage is technological control;

• The third stage is the control of finished products;

• The fourth stage is pre–shipment control and shipment control of finished products.

Control of incoming materials

At the initial stage, the quality of lumber and glue for wooden structures is assessed. The verification takes place according to interstate standards. 

Each batch of incoming lumber is checked according to GOST 8486 "Softwood lumber. Technical conditions" for the quality of wood boards by visual inspection and according to GOST 24454 "Softwood lumber. Dimensions" for compliance with the geometric parameters of the board.

The glue used for gluing wood undergoes visual inspection for the presence of foreign inclusions and a visual assessment of the color of the glue, declared by the supplier. The conditional viscosity of the glue is determined, since it is the conditional viscosity that determines the speed of distribution of the adhesive composition over the surfaces and the quality of penetration of the adhesive mass into the pores of the connected wooden components of the timber.

The control of incoming materials makes it possible to exclude the use of low-quality materials in the production of timber.

Technological control

At the stage of technological control, the execution of the technological discipline  for the manufacture of glued structures is monitored. Inconsistencies are identified and eliminated. The factors of their occurrence are analyzed in order to prevent them.  

Technological control includes:

• Monitoring compliance with the drying modes of the board to the required humidity. The moisture content of the board is an indicator on which the quality of gluing wood depends. The dried board is monitored for the presence of residual stresses and deformations;
• The procurement stage of production. At this stage, the board is being prepared for several processing streams: the breakdown and designation of the material into types of projects; preparation of the board for splicing into a whole lamella; preparation of the board for gluing into a blank wooden structure;
  
• The stage of splice of the board for compliance with the criteria. The quality criteria are stipulated by GOST 19414 "Solid glued wood. General requirements for toothed adhesive joints";
  
• Quality control of wood gluing modes for compliance with regulatory and technical documentation. At this stage of production, the ratio of the proportions of the adhesive and the hardener of the adhesive used is monitored. Laboratory tests are carried out under conditions of temperature and humidity stresses for the strength of adhesive joints of adhesive structures in accordance with the requirements of GOST 20850 "Glued wooden load-bearing structures. General technical conditions" and GOST 33121-2014 stipulated in it "Glued wooden structures. Methods for determining the resistance of adhesive joints to temperature and humidity influences". In production, two main methods are used to control the durability of glued joints of wooden structures. Initially, tensile stresses occur in the wood of the tested samples, causing compression deformations in the glued seams. Then, under the influence of a change in the stress sign  glued seams experience tensile deformations.  With these test methods, an assessment of the strength of  both adhesion – the connection of adhesive layers with wood, and cohesion – the strength of the joints of the adhesive layer is given;


• Instrumental control of manufactured wooden structures. The quality of manufactured products is checked for compliance with regulatory documentation, and a visual assessment of the surface quality of products for compliance with the technical conditions of the enterprise is also carried out.
  

Control of finished products

The technological process of manufacturing wooden structures completes the control of finished products. At this stage, a final decision is made on the shelf life of the products. If appropriate, the products are packed and delivered to the warehouse. 

Before shipment, a certain number of pints are selectively opened, depending on the volume of products shipped, all products in a pint are inspected. Only after the conclusion of the inspection commission, the products are fully transferred to the customer for shipment.

Control of the process of shipment of finished products

At the final stage of control, the process of shipment of finished products is monitored. This type of control excludes the possibility of delivery to the customer of structures damaged during loading at the enterprise.

The implementation of step-by-step control ensures the stability of the high quality of the products manufactured by the company.