Mixing method of high-voltage ceramic capacitor powder

Abstract

The invention discloses a mixing method of high-voltage ceramic capacitor powder, and relates to the technical field of preparation of electronic ceramic materials. The device is used for solving the problems of low control precision, poor mixing uniformity, low production efficiency, high manufacturing cost and unstable product quality of manual granulation in existing high-voltage ceramic capacitor powder manufacturing. Comprising the steps that powder is flatly laid in a container, pure water is metered and evenly sprayed to the powder through a sprinkling can, a release agent is added to the powder, the water content of the powder ranges from 0.8% to 1.5%, and the mass ratio of the release agent ranges from 0.5% to 1%; adding release agent powder after water spraying into a sealing bag provided with polyethylene hollow light balls, and sealing and shaking to form preliminary mixed powder; the diameter of the polyethylene hollow light ball is 5-10 mm, and the volume ratio of the polyethylene hollow light ball is 30%-40%; placing the sealing bag filled with the preliminary mixed powder in a rotating body of a swing machine, and obtaining uniformly dispersed powder after the swing machine works for 30-60 minutes; and the rotating speed of the swing machine is 50-80 r / min.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electronic ceramic material preparation, and more particularly to a mixing method of high-voltage ceramic capacitor powder. BACKGROUND

[0002] In the field of high-voltage ceramic capacitor powder manufacturing, the granulation link as a key step directly affects the forming quality and performance stability of the product. At present, the manual granulation method is widely used in the small batch test stage. This technology relies on the experience of the operator to mix the powder, add water and stir, etc. Although it has the advantage of flexible adjustment, but with the continuous improvement of the performance requirements of high-voltage ceramic capacitors, its technical limitations are increasingly prominent.

[0003] From the aspect of water content control, manual granulation lacks precise quantitative control means. The operator mainly judges the water content of the powder through experience methods such as hand feeling and visual observation. This method is easily disturbed by factors such as individual operation habits and changes in environmental temperature and humidity. When the water content is lower than the process standard, the high-voltage ceramic capacitor forming body is insufficient in the binding force between particles during the pressing process, the internal stress distribution is uneven, and then the layer cracking phenomenon is caused. In severe cases, the surface of the body may even appear "uncovering" problem, resulting in body scrap, greatly reducing the product qualification rate and production efficiency. When the water content is too high, the adhesion of the powder increases significantly, and in the process of mold pressing, it is easy to adhere to the surface of the mold, not only causing demolding difficulty and prolonging the production cycle, but also causing scratches and wear on the surface of the mold due to forced demolding, greatly shortening the service life of the mold and increasing the production cost.

[0004] In terms of release agent mixing, the stirring intensity and time during manual granulation are difficult to keep consistent, resulting in uneven distribution of the release agent in the powder. In the area where the local release agent concentration is insufficient, the lubrication effect between the forming body and the mold is poor, and more external force needs to be applied during demolding, which aggravates the wear of the mold; while in the area where the release agent is excessive, the excess release agent will be left on the surface of the body, affecting the subsequent sintering process, resulting in defects such as pores and cracks on the surface of the product, and reducing the electrical performance and reliability of the product. In addition, the low efficiency and unstable product quality of manual granulation have made it difficult to meet the needs of rapid verification of process parameters and shortening of the development cycle in the small batch test of high-voltage ceramic capacitors, becoming a bottleneck restricting the technological innovation and product upgrading of the industry. SUMMARY

[0005] The embodiment of the present application provides a mixing method of high-voltage ceramic capacitor powder, which solves the problems of low control precision, poor mixing uniformity, low production efficiency, high manufacturing cost and unstable product quality in the manual granulation of the existing high-voltage ceramic capacitor powder manufacturing.

[0006] The embodiment of the present application provides a mixing method of high-voltage ceramic capacitor powder, which solves the problems of low control precision, poor mixing uniformity, low production efficiency, high manufacturing cost and unstable product quality in the manual granulation of the existing high-voltage ceramic capacitor powder manufacturing.

[0007] The powder is laid in a container, pure water is sprayed on the powder by using a watering can, and a release agent is added on the powder, wherein the water content of the powder is 0.8%-1.5%, and the mass ratio of the release agent is 0.5%-1%;

[0008] The powder with the release agent added after water spraying is put into a sealed bag provided with polyethylene hollow light balls, sealed and shaken to form a preliminary mixed powder; the diameter of the polyethylene hollow light balls is 5-10 mm, and the volume ratio of the polyethylene hollow light balls is 30%-40%;

[0009] The sealed bag provided with the preliminary mixed powder is placed in a rotating body of a swing machine, and the swing machine is operated for 30-60 minutes to obtain uniformly dispersed powder; the rotating speed of the swing machine is 50-80 r / min.

[0010] Preferably, the sealed bag is made of wear-resistant polyethylene.

[0011] Preferably, the powder is a barium titanate-based ceramic powder.

[0012] Preferably, when the swing machine is operated, the rotating body swings up and down and left and right.

[0013] The swing machine is operated for 45 minutes, and the rotating speed thereof is 60 r / min.

[0014] In summary, in the method provided in the embodiment of the present application, the powder with the release agent added is placed in a sealed bag, and the sealed bag, hollow balls and a simple swing machine are used to replace the precision equipment in the prior art, so that the test cost can be reduced. Furthermore, the hollow balls are arranged in the sealed bag, and when the swing machine drives the sealed bag to swing up and down and left and right, the hollow balls roll on the powder, so that the powder and the release agent can be mixed more uniformly, the problem of uneven mixing of the release agent in the prior art is solved, and the advantage that multiple batches of mixing have consistency can be achieved. Furthermore, by adjusting the rotating speed and operation time of the swing machine, the water content and mixing effect of the powder can be accurately controlled, and the uniformity of the powder is improved. DETAILED DESCRIPTION

[0015] The technical solutions in the embodiments of the present application will be described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

[0016] The high-voltage ceramic capacitor powder provided by the embodiment of the present application is mainly suitable for the preparation of the powder of high-voltage ceramic capacitors, multilayer ceramic capacitors (MLCC), piezoelectric ceramics and other electronic components, and can be extended to the mixing process of special ceramic and metal powder.

[0017] When small batches of materials are prepared in the laboratory, the traditional mixing technology has the following problems: manual operation depends on human experience, the moisture content of the powder and the release agent are unevenly distributed, which causes the ceramic body to produce defects such as layer cracking, mold sticking and microcracks, affecting the electrical performance of the product; the cost and efficiency of the equipment are imbalanced: the cost of using large precision equipment for small batch test products is too high, and because the material is less, the use of large equipment is relatively large; in addition, the traditional manual mixing takes a long time to mix the material uniformly and has poor uniformity, and cannot meet the mixing needs of nanoscale powder (<10 mu m). Resource waste is serious: the increase of waste caused by uncontrollable process increases the production cost.

[0018] In order to solve the above problems, the embodiment of the present application provides a mixing method of high-voltage ceramic capacitor powder, which systematically solves the above problems by providing innovative mixing medium (polyethylene hollow lightweight ball), optimizing process parameters (moisture content 0.2%-0.4%, swing machine speed 50-80 rpm) and low-cost device design, and provides an efficient, economical and green manufacturing trend-compliant mixing solution for the electronic ceramic industry.

[0019] Specifically, the mixing method of high-voltage ceramic capacitor powder provided by the embodiment of the present application mainly includes the following steps:

[0020] Step 101, the powder is laid flat in a container, and pure water is uniformly sprayed on the powder using a watering can, and a release agent is added on the powder, wherein the moisture content of the powder is 0.8%-1.5%, and the mass fraction of the release agent is 0.5%-1%;

[0021] Step 102, the powder with the added release agent after water spraying is loaded into a sealed bag provided with polyethylene hollow lightweight balls, and the sealed bag is shaken to form a preliminary mixed powder; the diameter of the polyethylene hollow lightweight ball is 5-10 mm, and the volume fraction of the polyethylene hollow lightweight ball is 30%-40%;

[0022] Step 103, the sealed bag provided with the preliminary mixed powder is placed in the rotating body of a swing machine, and the swing machine is operated for 30-60 minutes to obtain uniformly dispersed powder; the speed of the swing machine is 50-80 r / min.

[0023] Specifically, in step 101, the powder is laid in a container, and according to the difference between the measured water content of the powder and the target required water content, pure water is uniformly sprayed on the powder by using a watering can, and then a release agent is added on the powder sprayed with pure water; in actual application, the water content of the powder is between 0.8% and 1.5%, and according to different powder requirements, the mass ratio of the release agent is between 0.5% and 1%.

[0024] It should be noted that the watering can here can be a common watering can, which can only spray mist water.

[0025] In step 102, the powder after adding the release agent is loaded into a sealed bag provided with polyethylene hollow light balls, and then the sealed bag is sealed and shaken for 1-2 minutes to form a preliminary mixed powder; it should be noted that the diameter of the polyethylene hollow light ball is between 5-10mm, and the volume ratio of the polyethylene hollow light ball is between 30%-40%.

[0026] In step 103, the sealed bag is arranged in the rotating body of the swing machine, and since the rotating body can swing up and down and left and right, when the swing machine is started, the sealed bag arranged in the rotating body also swings up and down and left and right accordingly, and the uniform dispersion of the powder is realized through the rolling friction of the hollow balls arranged in the sealed bag. It should be noted that the rotating speed of the swing machine is between 50-80r / min, and the working time is between 30-60 minutes.

[0027] For example, the powder is barium titanate-based ceramic powder.

[0028] For example, the sealed bag is made of wear-resistant polyethylene material.

[0029] For example, the swing machine is made of metal material, and the hollow rotating body is arranged in the swing machine, the sealed bag can be arranged in the hollow rotating body, and when the swing machine is working, the rotating body can swing up and down and left and right, and the swinging speed can be adjusted. Preferably, the rotating speed of the swing machine is 60r / min, and the optimal working time is 45 minutes.

[0030] In the embodiment of the application, the powder with the release agent is placed in the sealed bag, and the sealed bag and the hollow balls and the simple swing machine replace the precision equipment in the prior art, which can reduce the test cost; further, by arranging the hollow balls in the sealed bag, when the swing machine drives the sealed bag to swing up and down and left and right, the hollow balls roll the powder, which can make the powder and the release agent mix more uniformly, solve the problem of uneven mixing of the release agent in the prior art, and achieve the advantage of consistent mixing of multiple batches; further, by adjusting the rotating speed and working time of the swing machine, the water content and mixing effect of the powder can be accurately controlled, and the uniformity of the powder is improved.

[0031] The following table is an example of 12kV-300pF products, using a precision special mixer, the simple mechanical mixing of the embodiment of the application and the performance changes after manual mixing of three different processes:

[0032]

[0033] As shown in the above table, the test product prepared by the simple mechanical mixing process provided by the embodiment of the application has no great difference in product appearance and product electrical performance from the product prepared by the professional mixer process, and fully meets the normal product requirements. The mixing method provided by the embodiment of the application uses low-cost tools to approximate the effect of precision instruments. The product prepared by traditional manual mixing has many fine cracks on the side of the product after sintering, and the product capacity uniformity and dielectric loss are quite different from normal products; in addition, the high voltage resistance and partial discharge performance of the product are greatly reduced, which cannot meet the electrical performance requirements of the product.

[0034] In summary, in the method provided by the embodiment of the application, the powder with the release agent is placed in a sealed bag, and the sealed bag, the hollow ball and the simple rocking machine are used to replace the precision equipment in the prior art, which can reduce the test cost. Furthermore, by arranging the hollow ball in the sealed bag, when the rocking machine drives the density bag to swing up and down and left and right, the hollow ball rolls the model powder, which can make the powder and the release agent mix more uniformly, solve the problem of uneven mixing of the release agent in the prior art, and achieve the advantage of consistency of multiple batches of mixing. Further, by adjusting the rotating speed and working time of the rocking machine, the water content and mixing effect of the powder can be accurately controlled, and the uniformity of the powder is improved.

[0035] Although the preferred embodiments of the present application have been described, those skilled in the art can make further changes and modifications to these embodiments once they know the basic inventive concept. Therefore, the appended claims are intended to be interpreted as including all changes and modifications falling within the scope of the present application.

[0036] Obviously, those skilled in the art can make various modifications and variations to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A method of mixing a high voltage ceramic capacitor powder characterized by, The application relates to a method for preparing a barium titanate-based ceramic powder. The method comprises the following steps:

1. Spreading the powder in a container, spraying pure water on the powder by using a watering can, and adding a release agent on the powder, wherein the water content of the powder is 0.8%-1.5%, and the mass proportion of the release agent is 0.5%-1%; 2. Sealing and shaking the powder added with the release agent in a sealed bag provided with polyethylene hollow light balls to form a preliminary mixed powder, wherein the diameter of the polyethylene hollow light balls is 5-10 mm, and the volume proportion of the polyethylene hollow light balls is 30%-40%; 2. The method of claim 1, wherein, 3. Placing the sealed bag provided with the preliminary mixed powder in a rotating body of a swing machine, and obtaining uniformly dispersed powder after the swing machine works for 30-60 minutes, wherein the rotating speed of the swing machine is 50-80 r / min.

3. The method of claim 1, wherein, The sealed bag is made of wear-resistant polyethylene.

4. The method of claim 1, wherein, The powder is a barium titanate-based ceramic powder. When the swing machine works, the rotating body swings up and down and left and right. The swing machine works for 45 minutes, and the rotating speed is 60 r / min.

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