Before the introduction of bamboo floor types, it's important to know some basic characteristics of bamboo
1. The distributing of bamboo (Moso) fibers
The numbers of fiber from outside to inside are gradually decreased, the quantity of fibers rate is 6:2:1 (outside to middle to inside). The more close to outside, the higher quality of bamboo material. This is why we always use bamboo outside as the "face".
2. Shrinkage and expansion
The shrinkage or expansion comparing
The tangent of bamboo strip has the biggest shrinkage or expansion, the radial is the second, the height is the smallest, the rates are 4.5%, 3%, 0.32% respectively. This shows the vertical floor is more stable than horizontal
The shrinkage or expansion of inside wall is almost the double of outside skin, this is the reason when bamboo strips are dried, all strips are introflexion. This is why we design the structure of symmetry.
Bamboo floor types
1. vertical
Bamboo strips are glued together along radial, strips are face to face (pole's outside) and rear to rear (pole's inside) glued together.
2. horizontal
horizontal floor is made by two methods, that is one time hot press to form the plank and two times hot press to form the plank. One time forming is widely used by the manufacturers, two times forming is normally applied for across laminated plank or some special width of floors (width of 96mm is standard)
The structure of one time forming:
5-5-5: three layers are all used with 5 pieces of bamboo strip. It's the simplest way to process horizontal floor, one time hot press to form the plank, and strips are only one width of 20.5mm.
5x5x5: all three layer are same wide strips (20.5mm), except middle layer is added a half wide (12.3mm) strip to make glue line detached.
5-6-5: top and bottom layers are used with 5 pieces of 20.5mm wide strips, middle layer is used with 6 pieces of 17.1mm wide strips.
The structure of two times forming:
Two times forming is first to press single layer, then glue single layer together. Two times forming is able to build all structure here.
5-5-5
5x5x5
5x6x5
5xHx5
Three layers are horizontal, across laminated.
5-V-5
Middle layer is vertical, parallel laminated.
5xVx5
Middle layer is vertical, across laminated.
Compare one time forming and two times forming, the two times has higher quality of gluing. Compare different structure, across laminated has advantage to make wide floor plank.
3. Strand woven
Strand woven is made by irregularly bamboo slices, random mixed with glue, than to be pressed by high pressure (50-60kg/sq.cm., vertical and horizontal floor are pressed with 15-20kg/sq.cm.), under this high pressure, bamboo is compressed, so the density of the material is very high, it's about 1.1g/cm3 , the hardness along with density is much better than vertical and horizontal, and the shrinkage and expansion rate is less than vertical and horizontal as well.
