When do cemented carbide saw blades need to be sharpened, precautions and methods of sharpening

1. In the following situations, the carbide saw blade needs to be sharpened in time a) When the cutting quality no longer meets the requirements. b) When the energy consumption of the sawing machine increases significantly. c) When the edge of the cutting material has obvious burst. d) It is very important to grind the saw blade in time when the edge wear of the sawtooth alloy reaches 0.2mm, because the saw blade with a passivated edge is likely to cause the jitter of the saw blade due to the increase in resistance when working, and increase the load of the motor. Both the saw blade and the machine can cause damage. In passivation 1. When there are the following conditions, the carbide saw blade needs to be sharpened in time a) When the cutting quality no longer meets the requirements. b) When the energy consumption of the sawing machine increases significantly. c) When the edge of the cutting material has obvious burst. d) It is very important to grind the saw blade in time when the edge wear of the sawtooth alloy reaches 0.2mm, because the saw blade with a passivated edge is likely to cause the jitter of the saw blade due to the increase in resistance when working, and increase the load of the motor. Both the saw blade and the machine can cause damage. Passivation

2020-09-06

How to correctly choose the series parameters of carbide circular saw blades

How to choose the series parameters of carbide circular saw blades? To 　　 Carbide saw blade is composed of saw board and carbide saw teeth. To 　　 Hard alloy saw teeth are basically imported at present, our company uses Luxembourg DERMETBL hard alloy. To The alloy particles used in high-quality saw blades are thicker and larger, because such alloy saw teeth can be sharpened repeatedly and have a long service life. The welding quality of cemented carbide is also very important. The weld seam should be thin and well-proportioned so that the teeth can withstand Greater cutting force. To 　　 The quality of the saw blade is very important. Because the saw blade adjusts its rotation, it has to transmit cutting force and maintain working stability. A good saw blade not only has static geometric dimensions and accuracy, but more importantly, its dynamic characteristics. To When the saw blade is continuously cut, the heat generated by the alloy saw tooth cutting will be transmitted to the saw board, which will increase the temperature of the saw board. In this case, the high-quality saw board can maintain the precision of the statement, while the poor-quality saw The saw blade will warp and affect the precision of sawing. To 　　The dynamic stability of the saw board is particularly important for the precise condition of several saw blades used in groups. To 　　 How can the quality of longitudinal cutting be guaranteed when a set of unstable saw blades are used for multi-blade saw equipment? To 　　The saw board and the cutter head are an integral part of the high-quality saw blade. To 　　 Carbide saw blade manufacturing generally does not make so many specifications of saw blades. According to the optimization rules and according to the current wood processing enterprises' equipment, materials and other specific factors, it is composed of the current common carbide saw blade specifications. This is not only conducive to our choice of carbide saw blades, but also conducive to the large-scale production of alloy saw blade manufacturers. To 　　 Under normal circumstances, the right and left teeth should be selected for sawing particleboard and medium-density boards, flat ladder teeth (flat teeth, trapezoidal teeth combination) should be selected for sawing veneer panels and fireproof boards. The outer diameter of the saw blade is mostly Ф300-350mm according to different circular saw models, and the thickness of the saw blade is related to the diameter. Ф250-300mm thickness 3.2mm, Ф350mm above 3.5mm. To Due to the large cutting rate of the computer cutting saw, the diameter and thickness of the carbide saw blade used are relatively large, the diameter is about 350-450mm, and the thickness is between 4.0-4.8mm. Most of them use flat stepped teeth to reduce edge chipping. , Saw marks. To 　　Alloy saw blades for sawing real wood usually use a left and right tooth shape combined with cymbals. Because this combination has a large rake angle, it can sharply cut the wood fiber structure and make the cut smooth. For slotting that needs to keep the bottom of the slot flat, use a flat tooth profile or a combination of left and right flat teeth.

2020-09-06

Selection of Grinding Wheels for Hard Alloy Woodworking Tools

Reasonable selection of sharpening wheels is one of the key factors to ensure the quality of tool sharpening. Hard alloy saw blades with welded teeth should be sharpened with diamond grinding wheels. The performance indicators of diamond grinding wheels include abrasive grain size, binder type, grinding wheel hardness, grinding wheel structure, grinding wheel shape, grinding wheel size, diamond concentration, diamond layer thickness and material layer Width etc. The abrasive of the diamond (JR) grinding wheel is a synthetic diamond synthesized under high pressure and high temperature with graphite as raw material under the action of a catalyst. Its main component is carbon (C), which is colorless and transparent, light yellow, yellow-green and black. Wait for several colors. Synthetic diamond abrasives have extremely high hardness and are currently commonly used abrasives for sharpening carbide tools. Compared with silicon carbide, the sharpening productivity is 5 times higher, the roughness is 1 to 3 higher, and the tool durability is 1 to 3 times higher. Diamond grinding wheels are expensive and have poor toughness, especially strong affinity for iron group elements, and poor thermal stability. They will graphitize when the temperature reaches 700-800℃ in air medium, so they cannot be used to sharpen steel tools. Diamond grinding wheel is expensive, so only the working part of the grinding wheel is composed of diamond and bond abrasive layer. The thickness of the material layer is usually only 1.5mm, 2mm, 3mm and 5mm. The particle size standard of diamond grinding wheels is the same as that of ordinary grinding wheels. Generally, the particle size is 80～120# when sharpening carbide teeth, and the hardness of the grinding wheel is intermediate. The concentration of diamond grinding wheel refers to the mass of diamond contained per unit volume in the material layer. The standard is 0.879g (4.39 carats)/cm3, and the concentration is 100%. The concentration of 50% or 100% is generally used when sharpening carbide serrations. Table 1 shows the shape and code of commonly used diamond grinding wheels. There are four types of bonding agents for diamond grinding wheels: bronze (Q), resin (S), ceramic (A) and electroplating (D). The resin bond diamond wheel is generally used for dry grinding, and the bronze bond diamond wheel for wet grinding with coolant. The marking sequence of diamond grinding wheel is: abrasive-particle size-hardness-bond-concentration-shape-size. The size injection method is: outer diameter×thickness×aperture×diamond material ring width×material layer thickness×angle. For example, the abrasive is a diamond grinding wheel with synthetic diamond, particle size 100#, medium hardness, resin bond, concentration 50%, disc-shaped grinding wheel, outer diameter 80mm, thickness 13mm, aperture 20mm, material ring width 3mm, material layer thickness 3mm The mark is: JR100#Z50D180×13×20×3×3. Before using the grinding wheel, check whether the grinding wheel has no gaps, concentricity, vibration, etc. and whether the surface is clean. When using a diamond grinding wheel to sharpen a carbide saw blade, it should not be in contact with the saw blade body of tool steel material, otherwise the grinding wheel will be blocked. The saw blade body of tool steel material should be ground with corundum or silicon carbide abrasive wheels. Because of the high hardness of cemented carbide, greater grinding pressure is required during sharpening, and because of its low thermal conductivity, it is not allowed to generate excessive heat. Therefore, it is required to have good cooling and heat dissipation conditions during sharpening, which is usually required. Coolant to reduce the occurrence of grinding cracks. When using a diamond grinding wheel to sharpen cemented carbide saw teeth, the total grinding amount should be controlled below 0.1mm. If the grinding amount is too large, the diamond consumption of the grinding wheel is too high and the cost is too high. For sharpening YG6 and YG8 cemented carbide serrations, when the coolant supply is within the range of 3~4L/min, the grinding wheel with bronze bond, particle size 100~120# and concentration 100% can be used.

2020-09-06