The best way to eliminate the dust, debris and lon

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Eliminate the dust, debris and long particle materials in the crushed and returned materials

today, with the increasing cost of resin, although people pay high attention to the quality of products, few people pay attention to the quality of crushed and returned materials in the processing process. In fact, the material cost is the largest cost expenditure in plastic processing, so it is very necessary to minimize waste and use recycled resin more effectively. Therefore, it is particularly important to eliminate the dust, debris and long granular material in the crushed return material

in addition to impurities, the common quality problems in the crushing return are usually caused by dust, debris and long granular materials. Different types of crushers, such as screen crusher or non screen crusher, will lead to different quality effects and output due to their different tool designs. No matter what type of crusher is, the correct operation and maintenance of the equipment is the key to obtain high-quality crushing return in practical application

check the crusher

if your crusher has been used for many years, or you have not made a detailed maintenance plan for your equipment, please find a suitable time to check the equipment. In general, the generation of debris and dust is caused by such factors as tool wear, improper tooth pitch between tools, tight screen, too high rotating speed and too small screen hole (people usually try to use too small screen hole to reduce long particle)

Fig. 1 consistency of crushed return materials obtained by crushing the same material with screen type and non screen type crushers and comparison of dust and debris (less than 2mm)

the presence of dust and debris will affect the output of crushed return materials, for example, they will attach to the material barrel of the crusher, or cause depression in the material barrel of the crusher in frequent collisions, thus hindering the output of crushed return materials. In addition, the dust and debris accumulated in the silo will also hinder the flow of crushed return material, block the filter, and reduce the output speed of crushed return material. Not only that, the dust in the air will also bring bad smell, thus increasing the burden of environmental management in the factory

generally, dust and debris can melt quickly and are easy to degrade. Therefore, when the crushed return containing dust and debris is returned to the processing process, it will lead to the generation of black spots, which will improve the rate of nonconforming products and increase the cost of inspecting defective products

in fact, almost every processor that has used the crushed return material has encountered such problems. Undoubtedly, the method to solve this kind of problem is very simple, which is to minimize or completely eliminate the dust, debris and long granular materials in the crushing return. As the screenless crusher solves the problem of long granular materials, further discussion on long granular materials will be limited to the screen crusher

Figure 2 for the traditional screen crusher, by replacing the motor with low speed and high torque, or by replacing the larger drive pulley, the speed can be reduced, so as to improve the quality of the crushed return material

detection of the crushed return material

generally, the quality of the crushed return material can be quickly detected by using several simple test methods. First, grab a handful of crushed materials to check their uniformity. Through observation, it can be seen: are the sizes of these aggregates consistent? Is there any granular material much larger? How does the size of these pellets compare to those normally used? Then, put the pellets back into the container and see how much dust and debris remain in your hands. If there is not too much material left on hand, it means that the crusher used is appropriate and the operation is correct

if further quantitative analysis is required, a simple screening test needs to be completed by the quality assurance department or the crusher manufacturer. Through a series of screening tests on 5 ~ 10lb crushed return samples, the content of dust and debris in crushed return can be measured accurately. When using sieve crushing 4. According to the loading speed required by the experiment, adjust the loading speed to instigate the rotation speed of the disc, and make the rotation speed of the loading pointer and the rotation speed of the instigate disc 1 to carry out the loading machine, if it is necessary to detect the content of long granular material in the granular material, the test method is the same

of course, the best way is to provide the crusher supplier with some waste samples that need to be crushed, such as gate, tail, etc., as well as comprehensive crushing processing information (including material type and feeding rate, etc.), so that the crusher supplier can help you select the most appropriate crusher

comparison between sieve crusher and non sieve crusher

generally, the content of dust, debris and long granular materials in the crushing return can be easily reduced through some simple adjustments. Since the screen crusher is essentially different from the non screen crusher, we first need to introduce the inherent characteristics of the two equipment to determine the necessary maintenance procedures respectively. For the convenience of comparison, the size of the crushing chamber of the two crushers we selected is 8in × 16in。

among them, the screen crusher is equipped with a separating screen. Its motor speed is 200 ~ 600r/min, its power is 3 ~ 15HP (1hp=0.746kw), and its output is 125 ~ 150 lb/h (1lb=0.4536kg). The screenless crusher does not have a separation screen. Its horse, such as the tensile force and the maintenance of Jinan assay helmet testing machine, considers the pressure, bending resistance, fatigue, peeling force, bending, etc. from the following five aspects. The rotating speed is about 30r/min, the power is 1 ~ 3HP, and the output is 25 lb/h

long granular material is usually produced because the slender waste material passes through the sieve before being crushed to a small enough size. If the application requirements can be met, this phenomenon can be avoided by using the screenless crusher. However, when the screen crusher is the first choice, the solution to this problem can only be to reduce the size of the screen hole. However, this will lead to an increase in the content of debris or a decrease in production. In order to reduce or even eliminate long particles without increasing debris, it is necessary to reduce the diameter of the liquefied natural gas (LNG) screen while reducing the motor speed. In addition, another solution is to make the sieve holes distributed at a certain angle, which can make it difficult for long-grained materials to pass through

in order to ensure the quality of crushed and returned materials, improve the energy utilization rate and increase the output, it is necessary to ensure the smoothness of the screen. Generally, when the unimpeded screen area is reduced, so that the shredded crushed material can not pass through, it means that the screen is blocked

at this time, the crushed return material that has been cut into appropriate size will vibrate under the drive of the rotor, and will be crushed again and again, thus becoming debris. If the screen is removed to dredge it, it will lead to an increase in shutdown time and maintenance costs

therefore, the screenless crusher is the best choice when the use conditions permit. If the screen crusher must be selected, consider using a screen with a conical hole (perforated from the bottom), which will make it easier for the material to pass through the screen and reduce the possibility of blockage. At least this kind of screen hole is easier to clean in daily maintenance

about 10 ~ 15 years ago, the rotating speed of most crushers was 600r/min, which is often one of the main reasons for more dust and debris. Now, the speed of the crusher has been reduced to the level that can obtain the ideal crushing effect. At present, the rotating speed of many machine side crushers is 200 ~ 300r/min, while the rotating speed of the screenless crusher is only 30r/min, which can produce better crushing returns. Especially for those hard and brittle materials that are easy to be crushed in impact, the screenless crusher is a very ideal choice

for the existing crusher, two methods can be adopted to reduce its speed: one is to replace the motor with low speed and high torque; Second, replace the drive pulley. Usually, many old-fashioned high-speed crushers are equipped with inexpensive 1800r/min (4-stage) motors. If a 1200r/min (6-stage) motor is used, the speed will be reduced by 1/3, and the torque of the 6-stage motor is 50% higher than that of the 4-stage motor, which is conducive to maintaining the toughness of the tool. Of course, if space permits, replacing a larger drive pulley is a simple and economical solution. In a word, the best solution can be obtained by contacting the crusher supplier

Figure 3 the low-speed, screenless crusher can ensure that the hard, counter rotating tools and fixed tools remain sharp for a long time, thus improving the crushing efficiency and minimizing dust and debris.

tool problems

tool wear or improper tooth pitch between tools are the two main reasons for dust and debris. Generally, the sharper the tool is, the better the crushing effect will be. Especially for soft and energy absorbing materials, the sharp tool can achieve net cutting without tearing. As a result, the utilization rate of energy is improved, the output is increased, and the debris is reduced

generally, the design of the old-fashioned crusher makes it difficult to replace the cutting tool. With the increase of material cost and the reduction of maintenance cost, it is very necessary to adopt the design structure of crusher which is easy to change the cutter. The important features of this design are the pre adjustment device of tooth pitch and the design structure which can quickly install the cutter into the crushing chamber. This design structure facilitates the daily tool replacement, which is conducive to improving the quality of crushing and return materials

whether it is a sieve crusher or a non sieve crusher, the proper tooth pitch between the cutters is the key to reduce dust and debris and improve energy efficiency and output, especially when crushing energy absorbing materials. Generally, the tooth pitch between the rotating tool and the fixed tool is adjustable

compared with those rotating tools equipped with non adjustable tooth pitch, the advantage of adjustable tooth pitch is that it can make the tooth pitch between each independent tool as small as possible, and it also allows each tool to be grinded and repaired separately, without the need to grind the whole group of tools at the same time. This can minimize the wear depth of each tool, which is conducive to extending the service life of the tool

it is surprising that many processors still do not take any action on waste recycling until one day the problem occurs, and then pay high tuition fees. In fact, only a small amount of time is needed to maintain your crusher, so that the equipment can run efficiently and produce high-quality crushing returns. If you spend a few minutes to check the quality of the crushed and returned materials, it will undoubtedly make the equipment run better

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