Oriented strand board
OSB, and OSB ( oriented beach english board or oriented structural board, " board oriented strand " ) are wooden materials, consisting of long, thin shavings ( strands ) are produced. They were originally a waste product of veneer and plywood industry.
OSB panels are manufactured in industrial plants as follows.
- Particle preparation: From the debarked wood are cut lengthwise through the rotating blades beach.
- Drying: The natural moisture of the chips is reduced at high temperatures. This is necessary in order to subsequently coat the chip with a sufficient adhesive ability. Moreover, it should during the pressing process is not too much moisture in the chips be present, otherwise the resulting vapor pressure could bring the raw panel to the burst.
- Gluing: The adhesive is applied finely dispersed in a gluing machine on the chips.
- Spread: The 100-200 mm long, 10-50 mm wide and 0.6-1.5 mm thick chips are along in the litter and process oriented transversely scattered so that they are arranged crosswise in three layers.
- Press: Under high pressure and high temperature ( 200-250 ° C press temperature ), the beach mostly produced on continuous presses.
For bonding to PF adhesives (USA), MUPF adhesives ( melamine - urea-phenol - formaldehyde) and PMDI adhesives used, mainly for reasons of quality outweighs the proportion of PMDI. Very often is used in the middle layer PMDI and in the outer layers MUF or MUPF adhesives.
The flexural strength is higher due to the long and slender chips than normal flat pressure plates (chipboard ). Due to the high content of gluten, the OSB board on a high vapor diffusion resistance. The chip structure gives the OSB her signature look, which makes them not only useful for the "invisible " use, but also for decorative applications. Note in this regard the effect of Formaldehydausdünstung the indoor air quality. The density is depending on the use of the plates about 600-700 kg / m³ and subject to production variations.
OSB panels are used as building panels in the building shell and interior finishing as wall or roof panel. In the floor area they serve as installation plate ( tongue and groove profile). However, special panels should be installed for mounting on underfloor heating, because the risk of default is very high plate by one-sided drying of the plates. In view floors, in roof extensions and as a facade you can find decorative use because of their striking appearance, so also in furniture for shelves and racks. In addition, they will for packaging (boxes ) and used as formwork for concrete.
Have OSB in America is of great economic importance. 95 % of all OSB panels are manufactured in the USA and used mainly in construction. In Europe 2008, the OSB production 3.3 million m³, of which in Germany around 1 million m³.
The standard EN 300 defines according to their mechanical properties and the relative humidity resistance following classes:
- OSB / 1: panels for interior applications ( including furniture) for use in dry conditions
- OSB / 2: panels for load-bearing purposes in dry areas
- OSB / 3 panels for load-bearing applications in humid conditions
- OSB / 4: Heavy-duty plates for load-bearing applications in humid conditions
Another way to allow for OSB structural use, is to monitor as part of a general type approval of the German Institute for Building Technology ( short form Z -9.1 -XXX). Here, the technical requirements are summarized at the disks in a vendor-specific authorization document that is the basis for further production monitoring.
In the harmonized standard ( EN 13986 ) for OSB following two formaldehyde - classes are given (determined in accordance with EN 120 " perforator ", ENV 717-1 " bottle method " and EN 717-2 " gas analysis method" ):
- Class E1 ≤ 8 mg/100 g
- Class E2 from 8 to 30 mg/100 g
In Germany timber materials the emission class E2 are not admitted.