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product overview |
| Our Product | Visual Characteristics | Strength | Dimensions/Profiles | Stress Data/Physical Properties |
Strength
In keeping with DIN 4074.1 "Grading of coniferous timber in terms of bearing capacity" there are two ways in which wood is appraised through visual and mechanical grading. The lamella used for glue laminated wood production are appraised on the basis of grading features such as branches, slope of grain, cracks, annual ring widths etc.
Mechanical grading also grades by modulus of elasticity which with the naked eye would not be possible. This makes possible a more precise and even grading of the lamella. In keeping with the above DIN, distinctions are made based on the following grading classes:
GRADING | DIN/EN | STRENGTH CLASSES | GRADED BY | |||
visual | DIN 4074 | S 7 | S 10 | S 13 |
| trained specialists |
mechanical | DIN 4074 | MS 7 | MS 10 | MS 13 | MS 17 | DIN 4074.3 approved machine |
* EN 338 only available as a draft | ||||||
STRENGTH CLASSES DO NOT SAY MUCH ABOUT THE OPTICAL CHARACTERISTICS OF GLUE LAMINATED WOOD.
The four possible strength classes of glue laminated wood are composed of the raw lamella possible grading classes:
CLASSES | BS 11 / GL 24 |
grading class as per DIN 4074 | S 10 |
grading classes as per EN 338 | C 24 |
modulus of elasticity grain/parallel | 11.000 |
permissible tension z II | 8,5 |
use | normal standard quality |
AT BULLINGER | STANDARD |
BULLINGER floor elements are generally produced in the strength class BS 11 (GL 24).
As one of the most up-to-date glue laminated wood production centres in Europe, the BULLINGER mill is equipped with a mechanical strength grading system. This enables all strength classes up to BS 18 to be produced, but only to be made with MS graded lamella.