Glue for laminated veneer lumber - application features
Surely any of you knows about the existence of laminated veneer lumber, and from this material of modern times they build beautiful houses from wood.
But few people think about what kind of glue is used for laminated veneer lumber, and to what extent is its composition safe for humans?
Unfortunately, very often residents expect to get an environmentally friendly private home, but in fact, human health may suffer due to the use of poor quality adhesives.
Most often, this type of timber is made from coniferous wood, most often from pine. To begin with, raw materials (round logs) should be processed, bark removed, cut off the slab, and then sawed. Typically there are 3 planks (i.
e. lamellas) that will be cut radially. Large-sized boards are obtained using a special method that will take into account the angle of inclination of the rings (annual), which removes excess stress and makes it possible for the wood to dry out as soon as possible.
Further, for the final drying of the lamellae, it should be subjected to the following actions:
- High temperature treatment.
- Pressure effect.
After that, the lamellas should be processed again by using machines to achieve smoothness, ideality of shape, and then glued under a press at a temperature of +210 degrees. For gluing, special compounds are used, which, under pressure, fall into the deepest wood pores, which gives it a high strength reserve. After the final hardening of the adhesive, the material should be planed, cut, and elements of the required size should be created. Glued laminated timber can serve for many decades without damage, delamination, but its quality may vary.
When ordering a house from such material, be sure to pay attention to the shape and appearance. Certain manufacturing companies make beams that consist of pieces from 0.2 to 0.4 meters in size, which greatly reduces the aesthetic qualities. It is better when, when creating, one lamella extension was made for everything from 10 to 15 meters.
Please note that not all varieties adhesives are suitable for the production of timber. Some of them will contain a large amount of harmful substances as well as toxins. For this reason, glued laminated timber can be considered an environmentally friendly material only with strict compliance with the method of its creation in accordance with GOST, SanPiNam and with the use of suitable adhesives. In general, after hardening, most adhesives do not release volatile substances, but some will have a long and final hardening in the deep layers of the wood.Such products are not suitable for gluing timber, and the most dangerous ingredient in them is formaldehyde.
Please note that several safety classes can be distinguished according to how phenol-formaldehyde is released by adhesive compounds - E1, E2 and E3. Each adhesive composition must be tested by manufacturers, and then a conformity class is affixed on its packaging (the safest is E1).
At the moment there are several types of adhesive that are used for the production of building materials:
They do not include formaldehyde at all, as well as other harmful substances (for example, urea). They allow you to work with bars at temperatures from +6 degrees, and still do not respond to high levels of humidity, but they are very expensive.
Adhesives based on polyurethane will also be expensive.
Other compositions for the production of laminated veneer lumber are not used, because they are not ways to ensure the reliability of adhesion of wood. For this reason, PVA, carpentry adhesives are not useful for such a purpose.
Most often, the type of adhesive does not play a decisive role - harm to the human body causes a violation of the technology for creating a bar. For example, with insufficient temperature or even a decrease in the gluing time, the full degree of polymerization of the adhesive composition does not occur, and it will release toxins for a long time.
Different means for creating glued laminated timber may be with different parameters and characteristics. Below we have discussed the main features of the three most popular formulations.
|Name of the adhesive||External signs||Hardener||Consumption, kg per square meter||Average price, rubles|
|Polyurethane||Light brown, liquid||None|| 0. |
15 to 0.225
|Melamine||Milky white, liquid||Yes||0.3 to 0. 45||480|
|EP I||Transparent, liquid||Yes|| 0 .. |
. 25 to 0. 4
As can be seen from the table, only polyurethane compounds are sold as one-component adhesives. The remaining types of products are sold in two-pack form and require mixing with a hardener before use.
Formaldehyde (aka phenol-formaldehyde) is a gas with a pungent odor.
It is considered a toxic and poisonous substance, and in medicine it is referred to as strong allergens, as well as carcinogens. Some scientists also say that the substance has mutagenic properties, and it can negatively affect both the person himself and his future children. The relationship of formaldehyde with the development of tumors of the lungs and other organs of the respiratory system, as well as bronchial asthma, has been proven. Since poisoning and the development of serious problems for a person requires a regular intake of a substance into the body, it is important to exclude living in a house that is made of laminated veneer lumber. The active release of such a harmful substance as formaldehyde is in cheap materials, the cost of which is due to the minimum price of a low-grade adhesive composition.
The conclusion will be simple - when buying a timber, it is important not to save money and you always need to carefully study the certificates for the purchased products.
There is an adhesive on the market for the manufacture of glued timber that will meet safety requirements, and therefore the timber produced on their basis can will be used for housing.
Here are the most popular ones:
Suitable for the production of laminated veneer lumber.
The development of the Russians, in which there are no toxic components, and it is considered harmless to human health. The advantage will be the lower cost in comparison with analogues of foreign production.
With the right choice of adhesive composition, wood can remain a "breathing" material, and still will not emit toxins, and the house will become an excellent safe place for human living. If you still have doubts, it is better to buy more reliable materials for construction - a profile solid bar, which is 100% natural and will not cause doubts about the quality.
Posted By: Work Style |13, Nov 2020
Posted By: Work Style |09, Nov 2020
Posted By: Work Style |13, Nov 2020
Posted By: Work Style |12, Nov 2020
Posted By: Work Style |02, Nov 2020