For the time being, solid wood bending processing methods are mainly sawn and pressurized bending two major types. Sawing processing is to use the band saw directly in the sawn wood or glued patchwork plate sawed out of the curved shape, and then milled. Although the production process is simple, no need to add new equipment, the fibre of the wood is cut off, the strength of the parts is reduced, and the coating is more difficult, curvature and ring-shaped parts also need to splice, will cause the rate of low material and many other problems
Pressurized bending can overcome the above shortcomings, with the pressurized method of straight square or veneer directly pressed into a variety of curved parts. The lines are natural and smooth, retaining the rich natural texture and colour of the wood, in addition to simplifying the furniture structure, saving labour and materials and improving the strength.
Solid wood bending machine is achieved by softening and bending of an entire solid wood which can be processed as bent part with multiple shapes, such as L,U,O and S shapes which can be applied in the furniture industry.
The solid wood bending process is mainly: a selection of materials → raw material processing → softening treatment → pressure bending → drying and shaping → final processing. How to attach the force of man to the natural material, which is the principle of what? The author says a few examples in life, you will understand.
Wood is supported by cellulose, like the steel skeleton in the building; lignin plays a fixed role, like the cement infused in the skeleton, or asphalt in more graphic terms, will become viscous flow state in the presence of heat or chemical action, without the fixed role will be softened.
Assuming that the wood is a uniform material, bending will form a concave and convex surface, the concave side of the pressure, the convex side of the tension, there is a layer of stress in the middle of zero called the neutral layer. After softening, the square lumber, with the grain compression deformation increased a lot, but the tensile deformation does not change much. That is, when a certain pressure is applied, a large deformation will occur. It is like a plastic bag, especially the common thin black plastic bags in the grocery store, tearing one to both ends of the pull, you will find that at first need to force, but then without force will become thinner and thinner, is a reason.
In order to use the wood compression deformation is large, not easy to damage this characteristic, you need to move the above-mentioned neutral layer to the outside. This is why a metal strip is tightly attached to the outside of the tensile surface to carry the tensile force and protect the wood, thus improving the bending properties.
Wood at moisture content of 15% or more, lignin will soften at 90 ℃, but after drying, the moisture becomes very small, it takes 230 ℃ to soften back. That is to say, drying and shaping is mainly to reduce the moisture content to reach different lignin zero boundary point, rather than heating to make lignin become solid.
As a wood bending machine manufacturer, Shijiazhuang Cangao High Frequency Machinery Co., Ltd. is a professional manufacturer of R&D and manufacturing of complete sets of high-frequency machinery. Products are used in many industries and fields such as furniture, wood-based panels, flooring, packaging, musical instruments, handicrafts, bamboo processing, etc. . The main products are: high frequency machinery series, high frequency assembly machine series, high frequency jigsaw machine series, high frequency heat press series, high frequency vacuum dryer series, solid wood bending series and various customized high frequency equipment.