1. What is a wood chipper?
Wood chipper is also called wood slicer, which belongs to a series of wood processing equipment.
It is widely used in the material preparation section of the production process of textile, papermaking, pulping, wood-based panels and other industries. The main cutting materials of this machine are small-diameter wood, bamboo, board skin material and leftovers of felled firewood after peeling. However, it does not fully have the function of uniform cutting for over-thick (above 350mm), over-thin (below 30mm), over-short (below 250mm), over-thin (below 5mm) and irregular raw materials (undecomposed stumps, branches, etc.), or just cuts the raw materials on the original basis, and does not fully have the function of layered cutting for slices of bamboo with a wall thickness of less than 5 mm. At this time, a re-crusher can also be used to re-crush the oversized wood chips to achieve the ideal size.
Wood chippers can process pine, miscellaneous wood, poplar, fir, and raw bamboo. Due to its compact structure, small area, good cutting quality, low power consumption, and suitable for mobile operation, it is more suitable for small and medium-sized particleboard and fiberboard manufacturers, and can also be used for commercial wood production. In order to meet the different requirements of papermaking, fiberboard, and particleboard industries for wood length, the wood length can be adjusted within a certain range.
2. What are the categories of wood chippers? What are the advantages and disadvantages of each?
Wood chippers can be divided into two categories: fixed and mobile according to the usage scenario. Fixed types are mostly used in factories, and mobile types are generally used in forest areas and mountain fields.
Wood chippers are divided into drum chippers and disc chippers according to the structural form of the working parts.
- Drum chippers
Drum chippers are mainly used to cut branches, small-diameter wood, board skins, laths, etc. with a diameter or thickness of less than 120 mm. The cut wood chips are used as raw materials for fiberboard and pulp.
The cutting mechanism is a rotating drum with several flying knives installed on it. When the flying knives rotate, the wood is processed into craft wood chips. There are multiple square through holes on the outer edge of the drum, which can make the wood chips discharged smoothly. The feeding mechanism consists of a feeding interface, upper and lower feeding rollers and a feeding gap adjustment mechanism. The wood entering from the feeding interface is pressed by the upper and lower feeding rollers and fed to the cutting mechanism at a certain speed to control the size of the cut wood chips. When processing thick wood, the feeding gap adjustment mechanism is used for adjustment. After the wood chips are screened, the larger ones must be crushed again between the blade and the baffle.
- Disc chipper
The disc chipper consists of a cutter disc, a cutting knife, a bottom knife, a cutter disc blade, etc. There is a groove for installing the cutting blade on the front of the cutter disc, which is arranged at a radial angle of 10° to 15°.
The bottom of the blade is padded with a wedge-shaped adjustment block to adjust the extension of the blade. The rear is equipped with a distance adjustment pad to adjust the compensation length of the blade after sharpening. There is a through gap along the blade direction on the cutter disc, and the cut wood chips can be transferred to the other side of the cutter disc. Blades are evenly arranged on the outer edge of the cutter disc. The airflow generated by the blades blows the wood chips out from the discharge port. After screening, the oversized ones enter the crusher for crushing. The machine has three types: less blades, more blades and spiral blades. The uniformity of the wood chips cut by the first two types is poor. Since the cutting surface of the spiral blade disc chipper is in contact with the cutter disc during the cutting process, the unit pressure is small, the wood chips are neatly cut, there are fewer broken wood chips, the blade disc wear is small, the length of the cut wood chips is consistent, and the qualified rate of the cut wood chips can reach about 97%. In order to meet the different requirements of the papermaking, fiberboard and particleboard industries for the length of wood chips, the length of the wood chips can be adjusted within a certain range. The disc wood chipper has a compact and reasonable structure, is easy to operate, has a large production capacity, a high qualified rate of wood chips, and low energy consumption per unit of wood chip output. It is an ideal equipment for producing high-quality wood chips.
Disc chippers are mainly used for cutting logs, and the quality of wood chips is good. They are widely used in pulp and paper mills.
3. Maintenance and care of wood chippers
Before installing the chipper, the site should be leveled first, and the ground can be hardened if conditions permit. The equipment should be placed stably, and the installation direction should be determined according to the actual situation of the site and raw materials.
The wood chipper tool should be regularly inspected and replaced. For example, if the material is large in size and the wood material is good, the self-rotation of the wood chipper will also have a certain impact on the tool after it is turned on. The blade of the chipper is made of alloy steel. If it is worn or the angle changes after long-term use, the fastening screw of the blade can be loosened, and the blade can be removed for grinding and adjustment. If it is worn too much, a new blade of the same specification should be replaced.
The shaft of the chipper bears the entire load of the machine, so good lubrication has a great relationship with the bearing life. It directly affects the service life and operation rate of the machine, so the injected lubricating oil must be clean and the seal must be good.
If the oil temperature of the chipper bearing rises, the machine should be stopped immediately to check the cause and eliminate it. If there is an impact sound when the rotating gear is running, the machine should be stopped immediately to check and eliminate it.
In the initial trial operation, several straight raw materials with a length of about 2-4 meters within the processing range should be selected according to the different small, medium and large models. Try to avoid using special hard miscellaneous wood and oversized diameter and overly curved raw materials for trial operation.
4. How to choose a wood chipper?
The factors to be considered when purchasing a wood chipper are as follows.
- Is the wood chipper double-chamber water-cooled? Because the wood chipper is a high-speed crushing equipment, it is easy to heat up after long-term production, thereby damaging the bearings and causing the wood chipper to stop production. Therefore, water cooling is essential for wood chippers. The double-chamber water-cooled wood chipper can not only greatly reduce the heating time to ensure long-term production, but also protect the internal parts of the wood chipper from damage due to overheating of the machine.
- When buying a wood chipper, you must consult the bearing performance of the wood chipper, whether it is suitable for high-speed operation, and whether the bearing is filled with butter or engine oil. In general, it is best to buy a wood chipper with engine oil, because when the wood chipper is running at high speed, the engine oil can better lubricate and maintain the bearing. The best choice of bearing is imported high-speed bearing, because general bearings cannot withstand the long-term high-speed operation of the wood chipper.
- The selection of wood chipper blades is crucial and affects the output of the wood chipper to a large extent. Be sure to understand in detail the material of the wood chipper blade and whether the blade is plated with wear-resistant welding rods. The blade material is generally better for manganese steel, because manganese steel is harder and has greater crushing force. And the wear-resistant welding rod is best to use carbide welding rods. It is both wear-resistant and high in strength.
- Can the wear-resistant ring inside the wood chipper be replaced? Because some wood chipper shells are disposable, you must pay attention to buying the kind that can be replaced as much as possible when purchasing, so as to save investment. The disposable wood chipper wear-resistant ring is scrapped after use, which is not cost-effective.
- Check the circuit and oil circuit to confirm whether they are safely connected, and the tension of each chain, V-belt and transmission mechanism. Check them frequently during future use.
- When the chipper is feeding normally, pay attention to whether the pointer of the chipper ammeter is within the allowable current range. If it exceeds the allowable current range for a long time, the motor will be damaged, which is usually called motor burnout. When the pointer exceeds the allowable current, the wood should be reduced or stopped immediately.
- The conditions of various parts of the chipper should be checked frequently. If there is any abnormality, it should be handled or replaced in time.
