The moisture content of pallets is considered a key parameter for wooden containers. The natural, “living” material used has special properties that must be taken into account.
Wooden pallets are standardized products that have strict tolerances in geometric dimensions, strict requirements to the degree of cleanliness, allowable weight. These characteristics directly depend on the humidity of the product, so this parameter is regulated by the state standard, violation of which is not allowed.
Moisture content of lumber for pallet manufacturing
Different species of wood are used for pallets, their initial moisture content is not the same and is determined by the specifics of a particular wood plant (alder, birch, linden, pine, etc.). This parameter is also influenced by the time of year in which the wood was harvested and the climatic features of the area.
Freshly cut wood is not suitable for making pallets, as its humidity is very high – it can reach 80-100%. This is a favorable background for the reproduction of microorganisms of fungal nature, including mold fungi. Infested wood attracts specific insect pests, high humidity is comfortable for many of them, so their reproduction can have a flurry character.
During natural processes, the moisture content changes and the material is transformed. The following types of deformation are observed:
- Shape change – lumber warps. It may occur in different directions and may be accompanied by cracks;
- volume increase – swelling. In this case, the linear dimensions do not increase uniformly, but depending on the direction of the fibers. This occurs when the wood is wet for a long time, during which it absorbs moisture. The weight increases at the same time;
- shrinkage – a decrease in moisture content. Volume and linear dimensions decrease, while shrinkage is also uneven. Weight decreases.
When manufacturing, selling and using wooden pallets, different moisture content of lumber is used.
- Natural Humidity. The normal value is 30-70%. Moisture of wood after cutting, before drying. Dangerous values in terms of the possibility of deformation and damage by pests and pathogens.
- Transport humidity. Varies within the range of 20-22%. Wood dried to this degree can be transported in open railroad cars and trucks without a tent.
- Humidity according to GOST. It is regulated by document number 33757-2016 (“Flat wooden pallets”). The indicator for dry pallets can not exceed 22%. It is achieved by long drying of lumber at a temperature of +56℃ in special chambers, according to a special technology.
Determination of moisture content with a moisture meter
There are various instruments for measuring moisture content. When determining this indicator for wooden pallets, the needle-type instrumentation is used because it provides the most accurate values.
When checking moisture content, measurements are taken in all parts of the pallet structure. The values are then summed up and an average value is calculated, which is taken as the total moisture content of the wooden pallet. In order to keep it within the permissible limits, transportation decks should be stored in well ventilated areas under a roof or waterproof awning, or in closed warehouses. The conditions of keeping such containers are described in GOST 15150-69.
Applications and features of dry pallets
Dry wooden pallets are in demand among manufacturers in various industries. Such containers meet phytosanitary norms and safety requirements for storage and transportation of goods, they are resistant to mold and pest infestation. Dry pallets are characterized by high strength, they are durable, not subject to deformation and fluctuations in environmental conditions. Pallets made of softwood do not emit resin after proper drying.
All this guarantees the preservation of the packaging of goods, as well as safe use in automatic production lines, in large warehouses.
The most actual use of dry pallets for transportation of the following goods:
- food and beverages in cartons;
- pharmaceuticals, cosmetics and hygiene products;
- equipment for medical institutions, etc.
Ruspallet Company produces and sells wooden pallets of high quality in standard sizes. You can order new pallets of 1200×1000 size (1, 2 and 3 grades), as well as Euro pallets 1200×800 (1, 2 and 3 grades). We also sell wooden pallets of different grades, used pallets: standard and lightweight. To order, please contact our specialists in any convenient way.