Wood chipper is the production of wood chips, a special equipment, wood chipper, also known as wood slicer, is one of the series of wood processing equipment. Widely used in the textile, paper, pulp, plywood and other industries in the production process of preparation steps. The main raw material cutting machine is peeled trails wood, bamboo, wood and skins fuelwood harvesting times more than other materials. But for too thick (350mm or more) too small (30mm or less) is too short (250mm or less) is too thin (5mm or less) and irregular materials (not decomposed stump, twigs, etc.) does not have a uniform cutting function adequately, or just the raw material based on the original cut of the wall thickness of less than 5 mm slice bamboo insufficient cutting function with layered forest harvesting and wood processing residue in the process cutting into chips forestry machinery. Wood chipper and more as pulp, hydrolysis and Wood raw materials. Overview: 1870s, Northern Europe, North America, forestry production and use in developed countries first chipper equipped with only three to four knife. 1940s, the emergence of six or more multi-cutter sliced machine. The 1950s and the emergence of new multi-spiral sliced face cutter machine, to further improve the performance of wood chipper. China Forestry Machinery Research Institute of Forestry in the 1970s developed into a joint mobile chipper, can simultaneously chipping, chip screening, and will be qualified to install wind wood silo or truck jobs, thereby greatly improving the timber chipping productivity. Category: wood chipper fixed and mobile two categories. Fixed used for factories; generally used for mobile Forest Hill Field. Structural components in the form of work fragmentation machine disc chipper two drum chipper and, according to the feed way points have beveled feed peace-feed of two types. ①drum chipper. Mainly used cutting diameter or thickness of 120 mm below the branches, small trees, slab, lath and other chips after cutting, is used as fiberboard, pulp materials. The cutting mechanism is a rotating drum mounted above a number of the knife, the knife when the rotation will be processed into wood chips technology. On the outer edge of the drum has a plurality of rectangular through holes, the chips can be discharged smoothly; feed mechanism comprises a feed port, the upper and lower feed rollers and feed gap adjustment bodies, from the feed interface enters the timber into upper and lower feed rollers suppress, and to a certain speed into the cutting mechanism to control the size of the cutting chips; thick timber during processing, from the feed gap adjustment mechanism to adjust. After the wood by screening, the larger must re-enter between the blades and baffles crush (Figure 1). This lower wood chipper cutting quality. ② disc chipper. By the cutter, cutter, bottom knife, cutter blades and other components (Figure 2). Cutterhead front mounting the cutting insert has grooves, radially offset 10 ° ~ 15 ° arrangement. Bottom blade adjustment block wedge pad to adjust the amount of projection of the blade; rear mounted pad pitch for sharpening compensation after adjusting the length of the blade. On the cutter along the edge direction through the slit, cut a good wood to go to the other side of the cutter head. Uniform configuration of the outer edge of the cutter blade, blade air flow generated by the chips are blown from the discharge port, after screening, is too large to enter another crusher crushed. The machine has a small knife, multi-tool and screw the three types of knives, cutting wood evenness of the first two are poor, Helical knife disc chipper all contact with the cutting surface of the cutter in the cutting process, the unit less stressful, wood cut neatly, little wood chips, cutter wear, consistent cut into chips length, cutting wood up to about 97 percent pass rate. Manufacturing trends around the world wood chipper's now all attention on improving the cutting mechanism, the blade quality and chucking method to reduce time sharpening and replacement of permit. Reduce the world to promote the development of forest resources in cutting area mobile chipper; and cutting area combined with chipper and the whole tree chipper adopt joint machine, the economic effects will be further enhanced.