A brief comparison of common laboratory grinders

A brief comparison of common laboratory grinders

In recent years, with the accelerating progress of scientific research work, the basic workload of the laboratory has been increasing, which has made the previous manual work have to be replaced by machines. In the case of sample grinding, the most traditional way is to deal with it through mortar. . No matter which type of laboratory, mortar is the most common tool. The mortar can meet the basic requirements when handling small samples and some samples with extensive conditions, but the sample size is increasing in many laboratories.

Moreover, the independence of the samples is also higher. When using the mortar to process, the workload is very large, and it is difficult to ensure that there is no cross-contamination between the samples, which makes the work efficiency and effect are not ideal. Laboratory grinders have solved this contradiction very well.

The original grinders were industrial products and were large machines. Laboratory grinders have been around for more than a decade, and the time to enter the domestic labs has been shorter. The time to actually start popularizing is nearly three years. Although the time is short, there are already many types and types. Various types of laboratory grinders have emerged and new products are constantly emerging.

At present, there are many kinds of laboratory grinding machines, but basically they use the grinding beads to move at high speed, collide with the sample, and finally achieve the purpose of pulverizing and homogenizing the samples. It can be roughly divided into three types (the classification is mainly based on the oscillation method), and this article focuses on comparing the three types of laboratory grinders.

The first category, vertical oscillation

This type of laboratory grinder was first used in the seed testing industry because the amount of grinding for seed testing is usually very large, and each seed must have at least 100 replicates. If it is manually processed with a mortar, The workload can be imagined. The most famous representative is a brand in the United States, and several in the country have adopted the same method. The advantage of a vertically oscillating mill is that the throughput can be very large, and up to 4 x 96 samples can be processed at the same time, which is a good helper for those laboratories with a large number of samples. However, due to its movement mode and structural constraints, it also brings some inconvenience to its use, because it is vertical movement, so its fuselage is a vertical structure, in order to stabilize the center of gravity, the bottom will be heavier, and also because of its The vertical movement produces longitudinal vibration, which makes it less suitable for placement on the table, and its operation panel is at the lower part, so that the user needs to kneel or bend to operate the button. Still cause fatigue. Therefore, it is not very suitable for use on the test bench.

The second category, horizontal reciprocating oscillation

This kind of laboratory grinding machine was first introduced by a German grinding machine manufacturer. Most of the products of this factory are concentrated in the industrial field, but the laboratory grinding machine designed by it is also very professional, which makes a clever use of the level. The relative movement method is used for grinding, so that the structure of the instrument can be flattened and does not occupy space, and the relative movement of the pair of rocker arms at the same speed can just cancel the force, and the movement in the horizontal direction does not occur. The longitudinal oscillation wave is very suitable for placement on the test bench and will not affect other equipment. The rocker arm of the horizontal oscillating grinder is in front of the instrument, so the state of the work can be seen at a glance, but the noise will be transmitted relatively more directly. With the improvement of the motor by domestic manufacturers, the brush motor will become Brushless motors have also improved noise. The horizontally oscillating mill has the same interaction force, so it can use a larger container, the grinding tank. Because the grinding tank is generally hard metal, the mass is large, and if it uses other movement methods, it needs to overcome its own gravity effect. , which makes the grinding effect bad and affects the life of the instrument. Therefore, the scope of the horizontal grinder is much wider due to the grinding pot, perhaps because the manufacturer of the grinder hopes to balance some industrial applications. With the increasing application of laboratories, especially for freeze-grinding applications, it has been found that another benefit of the horizontal grinder is the convenience and safety of the freezing operation. The convenience is that the adapter is easy to install and only needs to be tightened by the knob. The adapter is ready, eliminating the need for additional fixtures, which saves a lot of time and a greater degree of pre-cooling. The safety is reflected in the fact that the condensed water will only exist around the rocker arm at the front of the instrument after freezing and grinding, and will not flow backward to the inside of the instrument, which ensures the absolute safety of the internal motor. Therefore, such grinders are more suitable for biological laboratory applications and are widely used.

The third category, three-dimensional (also known as octagonal) oscillation

Representatives of such laboratory grinders were introduced by a reagent company in the United States to complement their extraction reagents. The movement mode is different from the first two reciprocating motion modes, which is a kind of motion similar to vortex oscillation. Therefore, the grinding machine can reach a high rotation speed, but its flux cannot be reached due to its structure limitation. It is very high, and its grinding tube is generally a special consumable, mainly because its adapter is a disc structure, and the grinding pot is stuck on it. Ordinary sample tubes will loosen or even rupture from the adapter during high-speed oscillations. The advantage of a special tube is that the texture is hard and the sample can be well ground. The splayed type grinder is mainly used with the reagents. Therefore, the design does not take into account the need of freezing and grinding. The adapter cannot be pre-cooled in a liquid nitrogen environment. The method of cooling is to pass the cryo shield to the cavity. Cooling, but the temperature is generally around 0 ° C, which makes it less suitable for dry grinding of plant tissue. However, the wet grinding effect of animal tissues is still ideal. Therefore, such grinders are more common in some animal and medical research laboratories.

In short, the vertical oscillating grinder has a large volume and the highest flux; the horizontal oscillating grinder is easy to operate and has wide adaptability; the eight-character oscillating grinder has the fastest speed and is suitable for wet grinding. These three types of grinders are all visible in the laboratory, and each type of grinder has its own use.

From the perspective of the cost of the instrument, the imported laboratory grinding machine is generally more than 100,000 yuan, and the domestically produced is about 30,000-60,000. The technology and quality of the domestic laboratory grinding machine is shorter than the imported one, such as vertical. The first domestic model has been around for about 5 years, and the first domestic laboratory grinder (Beijing Dingyuan) is only about 3 years old. However, due to the lack of technical difficulty, the gap is actually very small. The gap is more in the details of the operational experience, the rich experience of the application.

The final choice is to take into account the needs and budget of the laboratory.