Birch-bark is a living organic material with colour tones, patterns and texture that vary widely from tree-to-tree. This makes each bm1 product special – and unique. These differences are much more varied than most wood types. Combining the variations of all these bark patterns during production gives a natural multiplying factor with the number of colour tones, patterns and texture variations already available in nature.
Measurement of dimensions
Rounded cross-sections can be produced with a diameter of 10 to 50 mm for our range of products. In addition, requests for larger sizes can be accommodated. Depending on the construction, centrical borings up to a wall thickness of 2 mm are possible. We make every effort to facilitate customised sizes, so please contact us should you have any special wishes about your product measurements.
The structure of the birch-bark comprises of thin-walled, honeycombed cell layers, embedded between supporting layers of smaller cells. This gives high-stability with an excellent insulating capacity while remaining light in weight. Our patented production process uses these qualities to the fullest.
In contrast to other natural raw materials, bm1 is extremely stable, especially when exposed to humidity and damp. At right angles to the plane level of the bark layers, bm1 is particularly elastic and tough.
Its resiliency, the elastic force, is roughly comparable to hardwood. Mechanical impact on bm1 by harder objects may cause some "stains", particularly parallel to the level of the bark layers.
All products that are exposed to shear stress applied in the direction of the bark layers must be assembled on a core.
bm1 is exceptionally light in weight due to the birch-bark's special honeycombed cell construction. It has a density of 0,38 - 0,55 g/cm³ which is slightly higher than that of, for example, similarly processed cork (0,3 - 0,52 g/cm³). The heat-insulating capacity of bm1 is quite high - even when wet.
With design, we follow nature's prescribed formulae and allow the bm1 to develop its merits to its maximum optimum – so its intended function can be fulfilled even under heavy-duty use. We are continuously looking to expand the scope of potential use and can transform your creative ideas into technical solutions. Our product photographs and drawings will give you a first impression of bm1. Combinations with other materials, in particular wood, have been proven successful. Please let us know what your particular requirements are.
bm1 is handmade according to ecological principles. There are no exceptions. This includes all adhesives and surface refinement treatments used. Our products are fully compostable. However, due to its Properties the breakdown of birch-bark is slow and takes several years.
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