Current situation of research of processing technique of woodiness material cutting

The classification of 1 woodiness material normally the lumber of the meaning is the truncal part that points to tree, weigh log or real wood again, it is the material of natural and organic high polymer that waits for composition by cellulose, semi-cellulose and Mu Su, it is natural generate, grain nature, colour and lustre feels kind character, bigger than intensity, machine easily, sex of adiabatic, sound insulation is good, it is the indispensable material in furniture. Woodiness imitation stuff includes man-made plank, man-made square and expect into profile. Woodiness composite material includes lumber plastic, model is changed break makings board and woodiness are compound structural board. As a result of the buildup of the consciousness of environmental protection of in short supply, mankind of lumber resource and the progress of production technology, come nearly 10 years, stuff of world woodiness imitation and woodiness composite material especially development of man-made board industry is swift and violent. Constant use man-made board to include: Plywood, particieboard and beaverboard (low density, medium density, high density) . Next watches listed among them a few kinds of typical man-made board classification of type, utility and treatment function. The man-made plank that expresses a model expects man-made board type - material is comprised - exterior quality - frontier department machines function - utility classification - typical utility - special utility conifer lumber plywood - conifer material veneer - the surface after arenaceous light is slick - poorer - the structure is used; Wheat straw - the surface when using excelsior is very slick - good - use to be not a structure more - footplate of scaleboard of furniture, joinery, floor, stair - beaverboard of the density in notting have (MDF) - lumber fiber, fasciculus, straw - the surface is very slick - very good - blame structure is used - line of furniture, joinery, adornment - without 2.

The treatment characteristic of 2 lumber machines the research of function domestic and internationally to had compared maturity to lumber. Lumber and metallic property are different, it is a kind of model have blame all pledge the material of gender and different tropism, its cutting characteristic basically has: (1) lumber material property and intensity because direction each different, the action when cutting differs at the included angle of lumber fiber direction, the stress of lumber and destroy load to also differ, the form cutting bits that produces consequently and workpiece surface quality are different also. When arranging grain cutting for example, material lead is broken off crack happen in point inclined upper part, bend easily break off, cutting appearance is good; When the cutting that go against grain, material lead is broken off crack happen in point inclined lower part, break off not easily, cutting surface is poorer. All pledge as a result of the blame of lumber gender and different tropism, cutting way is different the cutting tool that needs different structure. (2) lumber hardness is not tall, mechanical intensity limit is inferior, separative good. (3) heat-resisting ability is poorer, its cooking temperature cannot exceed when treatment (110 ～ 120 ℃ ) . (4) comfortable at high speed cutting: Lumber cutting speed is in commonly 40 ～ 70m/s, highest can amount to 120m/s, the rotate speed of general cutting cutter shaft is in 3000 ～ 12000r/min, highest can amount to 20000r/min. High speed cutting makes cut bits to have not enough time to be broken off along fiber direction crack by cutting tool cut away, can obtain taller geometrical precision and exterior surface roughness. (5) the factor that affects lumber cutting performance is very much, different tree is planted the physics of material is mechanical property is different, the tree is planted, direction of grain of density, moisture content, lumber, fiber, annual ring, temperature, mechanical intensity, may produce different cutting motivation to use up, or produce the treatment limitation such as burr. For example document [3] studies through milling means region and material density are opposite the intermediate zone between lumber early material and late material the influence of cutting force; Document [4] considers to be affected to cutting tool tatty through density of the micromechanism of different lumber, lumber, the analysis makes clear lumber quartz content and lumber density and cutting tool wear away to concern without apparent linear, point out cannot use quartz alone content and size and density will explain circumstance of cutting blade wear rate. 2.

The sort of stuff of imitation of treatment characteristic woodiness of stuff of 3 woodiness imitation is various, involve a lot of influencing factor again, bring certain difficulty to undertake to its the system studies. The systematic development that still does not have this respect at present considers to report. It is main raw material with lumber more as a result of these material, cutting becomes different figure, size form unit, add adhesive to wait to make and be become again, accordingly, the blame of lumber all pledges gender and different tropism still have very big effect to the cutting function of these material. Study to its main end is domestic and internationally at 2 o'clock: (1) the environment other condition impact to material function. Document [5, 6] considered to differ relative humidity (65%RH and 85%RH) the environment is beaverboard of the density in, directional particieboard and particieboard are the static strength strength of these 3 kinds of material, hardness, fatigue of life and creep different, the result shows, the static strength strength of MDF is the greatest, particieboard is the smallest, what and 65%RH issues the static strength strength of 3 kinds of material compare 85%RH to fall is big. Additional, because the fiber of MDF is smaller than paring dimension, namely its material qualitative uniformity is better, so the stretch model to OSB and particieboard measures higher relative humidity and fatigue life causes the ground adverse effect is more apparent than the influence to MDF; (2) the influence that material function wears away to cutting force, cutting tool and machines quality. For example, document [7] had a test to MDF cutting force, the influencing factor that studies MDF cutting force offers formula of experience of cutting force calculative; The moisture content of man-made board, density and cutting function have very big concern, document [8] experiments through a series of cutting, measure cutting force and exterior surface roughness, study cutting tool wear away. Get with what sell aperture to get pair of MDF cut an experiment to consider to make clear: The influence gets cut element to basically have feed, rotate speed and cutting speed. Power of axial direction cutting is the greatest, as the addition of cutting speed, cutting force increases, when cutting speed achieves 60m/min, cutting force begins to reduce. MDF getting is cut cut bits to be petty powder, its are exported and entrance quality becomes as the addition that bore counts poor, but bore diameter change is very little, in bore 17400 hind, bore diameter still did not exceed treatment deviation. The structural characteristic of broach of treatment of 3 woodiness material and milling cutter 3.

Cutting tool of treatment of 1 woodiness material is main structural characteristic (1) the place before be like is narrated, the cutting of woodiness material needs the cutting tool of different structure when way is different. For example, of lumber auger cut cent to be transverse auger cut and fore-and-aft auger cut. Transverse auger cut should use sharp angle 180 ° (broach the included angle between two cutting blade) , have heavy the broach that cuts a knife, sink among them cut a knife to be used at be in advocate lumber fiber is cut off first before blade participates in cutting in order to assure the quality of hole wall. And fore-and-aft auger taper is used when cutting (namely sharp angle is less than 180 ° ) broach. (2) horn of cutting tool wedge (before knife face and hind the included angle of knife face) small: Lumber intensity is smaller than the metal much, accordingly, in its cutting process, as a result of the action of cutting force, lumber happens above all be out of shape, depart next and eliminate to cut bits, the proportion that the separate force place of cutting holds is large, the pointed pitch bisect of cutting tool is very big from the influence of force. So interest of small wedge part departs at lumber. 3.

The dosage of broach of industry of treatment of 2 broach lumber is very big, basically use at machining all sorts of blind aperture, via and dig up blemish (section child) etc. Make cutter hub with 45 steel commonly, hard alloy makes the crucial point, solder of cupreous silver-colored drill steel and into. The form that solders according to alloy razor blade can be divided to set a type and integral pattern, set a type to only knife head is hard alloy, head of integral type knife and helix chamfer are club of one whole hard alloy, solder to grind a technology with blade the demand is higher. If integral hard alloy is straight,the via that metallic treatment uses is gotten power twist drill, sharp angle is more than 80 ° commonly, in order to assure the intensity of broach. And the sharp sex of carpentry broach is more important. Set a pattern hard alloy sells Kong Zuan to be used at transverse auger cut, diameter of general blade ministry 3 ～ 16mm, have Shuang Ren, 3 needles, the central needle of broach should be compared 2 delimit blade makes an appointment with tall 1mm, delimit blade is compared advocate blade is tall 0.

5 ～ 1.

0mm, its standard overall length is 57mm. Via of hard alloy of whole form of characters or letters broach can be used at fore-and-aft auger cut, sharp angle is 60 ° ～ commonly 80 ° , 60 ° are gotten cut the result optimal, cutting force is small, mao Bian is little. Carpentry broach is gotten in average platoon use the component that has Zun Xuan, dextrorotation. What grind as installation and blade with petiole is fiducial, diameter of general requirement petiole is 10mm, through stretch clip first class is placed at drilling machine, include a platoon to get, stand auger, bench drill, drilling machine rotate speed is in commonly 3000 ～ 5000r/min. 3.

Treatment of material of woodiness of 3 milling cutter basically is used at be on machine of mill of milling machine, engrave and of all kinds machining center with milling cutter, treatment shapes chamfer of the surface, tenon, sealing side, rotate speed 20 thousand R/min of 1 ～ . By configuration cent is the following 3 kinds: (1) integral type milling cutter: Make cutter hub with 45 steel commonly, hard alloy makes the crucial point, solder of cupreous silver-colored drill steel and into. Bit highlights cutter hub 1 ～ 1.

5mm, hind horn 15 ° of 10 ° ～ , before horn 35 ° of 25 ° ～ . This kind of milling cutter is used blunt hind face of the knife before general blade grinds his, its cutting is round after be being ground for many times again diametical general taper, and line radian can be changed subsequently, consequently the influence machines quality. Integral type milling cutter is so comfortable the line that does not need to cooperate at treatment. The sealing side knife that place of sealing side machine uses attributes this one kind. (2) assemble type milling cutter: Its razor blade is regular polygon commonly, go up in cutter hub with bolt installation directly, and but dislocation is used. Bit is used after becoming blunt, turn bit to another blade (namely the across of bit) , can continue to use. Classics of this kind of milling cutter is adjusted, change or initiative outline appearance still can maintain after maintenance changeless, rose to machine quality consequently, return usable and same cutter hub additionally, through providing different clue model bit will satisfy different model the treatment requirement of the face. (3) combined-type milling cutter: Integral type and assemble type milling cutter to be able to combine combined-type milling cutter to differ in order to machine model face. For example, odd piece show the combination that receive a knife is used can machine point to tenon. Joining together pointing to tenon firm, versatility is good, it is to make full use of the important step of lumber raw material. Can ask to adjust deepness of bit amount, cutting according to material width and joining together degree of tightness. This kind of razor blade standardizes batch production commonly. Material of cutting tool of treatment of 4 woodiness material reachs his to wear away hard alloy cutting tool is used extensively at cutting density of all sorts of lumber, plywood, particieboard, high school board wait for different material, its not only can rough machining also can finish machining, also can machine the plank sticking a face of all sorts of material. The wear extent of PCD carpentry cutting tool is carbonization tungsten about the 1/5 left and right sides of hard alloy cutting tool, consummate century 90 time evening, 40% what the portion of PCD carpentry cutting tool already occupied his to always apply. The value of PCD cutting tool that the whole world machines every year with Yu Mu material 4000 ～ 50 million dollar, with 15% ～ the rate of 20% will rise henceforth. Cutting tool of carpentry of our country PCD basically uses Yu Jiang to change the CNC Machining of compound floor and tall hardness beaverboard at present. Also divide like the wear process of carpentry cutting tool and metallic cutting tool wear away for initial stage, wear away continuously and wear away at high speed 3 phase. Study the analysis knows, of carpentry broach wear away to basically give side of the knife after now, when with hard alloy cutting tool getting cuts MDF, after machining 15000 aperture, wear away the area is very small still, along with the addition that bore counts wear extent is shown slow the trend that increase by degrees, after bore quantity arrives at 9000, wear extent tends smooth, still did not enter quickness to wear away level. Object of treatment of carpentry cutting tool is much constituent, complex mixture system, 3 kinds when the characteristic of woodiness material decided carpentry cutting tool is common wear away the characteristic of mechanism. (1) abrasive wears away: Nod mechanical abrade to cause by woodiness material horniness, these hard particle include: Colophony, quartz arenaceous, section child wait with agglutination material; (2) chemistry corrodes wear away: Particieboard and in the solidify agent that density beaverboard uses glue process to add (ammonium chloride) chloric oxidation corrodes the high temperature that produces chloric oxygen reaction to cause with cutting tool; The Chan Ning that perhaps exists in environment of woodiness material cutting, acetic acid and multivariate phenolic compound reacts to the chemistry of cutting tool; (3) electrochemistry corrodes: Because of cutting tool material the aqueous solution in each constituent and lumber, organic weak acid, multivariate phenolic compound contact, make a lot of small galvanic cell and happen. Accordingly, the wearability that raises carpentry cutting tool basically has two ways: It is to increase capacity of tatty of makings of cutting tool wear-resisting; 2 it is to raise cutting tool to fight corrode tatty ability. Use technology of exterior ooze layer boron of hard alloy ooze, vanadium, chromic to carbonization tungsten, nitrogen, advantageous to raising cutting tool wearability. Wearability of film cutting tool also has the improvement of different level. Coating TiN, ti(C, n) , zrN, (Ti, zr)N, tiAlN the hard alloy material that wait, cutting tool life can rise severalfold. Make coating can improve the attrition obstruction of cutting tool and woodiness material apparently with CrN or Cr2N. Diamond penetrate hardness tall, wearability is chemical and good, inert good, cutting tool of diamond coating carpentry is a kind of ideal fight grind a method. NCD(Nanocrystalline Diamond) coating also can reduce coefficient of friction, reduce sort of quantity and coating ply, lumber even its micromechanism has close tie. The geometrical appearance of cutting blade also is the crucial factor of reliable coating. Material of 5 epilogue woodiness and our production and life are having inseparable connection, its processing technique is built to our country and raise people living standard to having the place that cannot ignore. Turn the development tide with automation as woodworker high speed, treatment of woodiness material cutting has favorable development trend and perspective. Accordingly, produce efficiency and treatment quality to rise further, reduce finished cost; Material of woodiness of comprehensive promotion our country machines a level, increase in the competition ability on the international market, urgent to the pertinent question of domain of woodiness material processing technique need has development research and solve, basically wait for solve a problem to include at least: (1) the research of material cutting mechanism, especially dosage is mixed greatly difficult treatment material (if aggrandizement is compound floor) the research that machines mechanism; (2) the cutting tool that machines in the light of different material wears away the thorough research of mechanism, material of actor choosing cutting tool, optimize cutting tool structure; (3) the CAD/CAM technology that improves cutting tool design; (4) those who improve bit solder to grind a technology with blade; (5) cutting tool uses rationalize research: Include the cutting tool of the different structure that different treatment means should use; And the reasonable cutting parameter when different cutting tool is used. 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