Some Views on Increasing the Production Capacity of Barrel Plating Line

Nov. 22, 2022   |   11 views

 

Preface

In barrel plating production, the shorter the plating time, the better. One way to achieve this goal is to try to reduce the impact of the mixing cycle of parts.

However, factors such as driving beat time and process formulation also affect the improvement of production capacity.

These aspects are described below.

02

Mixing period

The mixing cycle is the time required for parts to turn in and out of the stack of parts in the roller during barrel plating.

The reason why it can be produced is that the parts are piled up, and the parts keep rolling.

The mixing period of the parts is related to many factors such as the shape, size, speed and loading capacity of the drum.

  1. Speed

Increasing the rotating speed of the drum is undoubtedly beneficial to shortening the mixing cycle of the parts.

This is because when the rotating speed of the drum is increased, the turning force of the drum on the parts is strengthened, so that the parts have more opportunities to appear on the surface layer. For example, in order to improve the consistency of the whole parts, the method of increasing the roller speed is often adopted in production.

Practice has proved that this method is effective.

Increasing the rotating speed of the drum can shorten the mixing cycle of the parts, but the rotating speed of the drum is limited.

If the rotating speed of the drum is too high, the reduction of electroplating time caused by the shortening of mixing cycle may be offset by the strong grinding effect between parts.

The principle for selecting the drum speed is that the higher the drum speed is, the better it will be without any other influence.

In addition, the shape of the parts is also an important factor affecting the speed of the drum.

For example, the rotary speed of barrel plated sheet parts is usually higher than that of conventional drums. This is because sheet parts are easy to stick to each other, resulting in coating quality problems. Increasing the roller speed can reduce the probability of sticking between parts.

As a rule, the rotational speed of the roller for galvanization is 5r/rain, while the rotational speed of 6~10r/rain is often used for the washer galvanization according to the size of the roller.

On the premise of ensuring that the part surface is not damaged or is slightly damaged, high roller speed can be used to shorten the mixing cycle of parts as much as possible.

The rotation speed of the drum is generally different according to the hardness of the coating metal and the process characteristics.

In addition, the size of the drum, the surface property and shape of the parts, the performance and roughness of the coating, and the diameter of the drum will also affect the speed of the drum.

Therefore, the selection of drum speed in production should be made according to the specific situation, rather than being fixed.

Otherwise, the production efficiency and product quality of barrel plating will be adversely affected.

  1. Loading capacity

The greater the loading capacity of the roller, the longer the mixing period of the parts during barrel plating.

In general, the cylinder loading capacity of common parts is 1/4-2/5 of the cylinder volume. Less than 1/4, the loading capacity of the roller is too small, which not only has low production efficiency, but also may not be able to contact the cathode conductive head normally due to too few parts.

If it is greater than 2/5, the loading capacity of the drum is too large. On the one hand, the mixing cycle of parts is long, and the production efficiency may not be improved; On the other hand, due to the relative reduction of the amount of solution in the drum, the mass concentration of metal ions will drop too fast, which will adversely affect the stability of the plating solution.

The loading capacity of the drum is in the range of 1/4~z/5, and the optimal value is about 1/3.

In production, it is often encountered that when the whole electroplating process is about to be completed, the remaining parts are sometimes not divided into two drums, so they are installed in one drum for electroplating, which makes the loading amount exceed the standard. As a result, the coating thickness and quality are not as good as before in the same electroplating time, so the electroplating time has to be extended, and the final product quality cannot achieve satisfactory results.

03

Driving beat time

The shorter the travel time, the greater the electroplating capacity.

However, if the electroplating time of the product is long and needs to be delayed, shortening the driving beat time will not increase the production capacity, on the contrary, it will lead to other situations that are not conducive to the product quality.

For example, the time delay causes a drum to spend too long in the pickling tank and stay in the washing tank for too long before electroplating.

04

Process development

After determining the driving beat time and the total electroplating station, the longest electroplating time without delay is determined. In order to improve the production capacity, the electroplating time of products should be controlled within the maximum electroplating time when formulating the process document.

If the electroplating time exceeds the maximum electroplating time, it will need to be delayed, which will affect the production capacity and may have other adverse effects; If the electroplating time is shorter than the maximum electroplating time, the electroplating tank will need to be empty, which will also reduce the electroplating capacity.

Take the current zinc rolling line as an example. The beat time is 5min, the maximum number of stations is 19, and the maximum electroplating time is 95min. If the loading capacity of product A is 80kg and the electroplating time is 80min, then only 16 stations will be used and 3 stations will be empty. In order to increase the production capacity, the loading capacity of product A can be increased to 90kg.

At this time, all stations are used, and the capacity increases when the loading capacity increases but the driving beat time does not increase.