Why Does the Printing Industry Need Static Eliminators?
The printing industry generates significant amounts of static electricity, primarily due to the accumulation and amplification of static electricity generated by the materials themselves during printing (through repeated friction).
The main hazards of static electricity in the printing industry are dust attraction and color bleeding.
The static electricity removal process in the printing industry mainly consists of three parts:
1. Static removal treatment of semi-finished products before printing;
2. Controlling the accumulation and amplification of static electricity during the printing process;
3. Static electricity elimination during the cutting and storage of finished printed products.
The following addresses the three questions mentioned above... A brief explanation of static electricity handling methods, causes, and hazards:
1. Why is static electricity removal necessary before printing?
Because the main substrates used in the printing industry are materials such as plastic and paper, these materials themselves carry strong static electricity and are insulators, making it difficult for them to transfer static electricity to other media. Therefore, once static electricity is present, it easily accumulates, causing the substrates to attract each other and become difficult to separate before entering the printing press. Therefore, it is essential to remove static electricity from the substrate surface before printing. There are two main methods for removing static electricity in this step: 1. Increasing the conductivity of the material itself, but this reduces its lifespan... The process is short-lived and expensive. 2. First, dust removal and static electricity removal are performed simultaneously when picking up the substrate to ensure that the substrate can be smoothly peeled off and fed into the printing press one sheet at a time. Then, static electricity removal is performed again at the paper inlet of the printing press to ensure that the substrate itself does not carry static electricity before printing, thus preventing color bleeding during the subsequent printing process.
2. Since the static electricity of the object has already been removed before printing, why is static electricity removal still needed during the printing process?
Because the main printing processes in the domestic market are currently divided into three types: gravure printing, offset printing, and screen printing. All of these processes involve multiple frictions. This results in a significantly higher static electricity level on the surface of the object. If static electricity is not properly controlled during printing, it can easily lead to static ink spots and color bleeding on the printed product. Furthermore, the high-speed friction and peeling during printing generate static electricity, and the accumulation of static electricity can easily lead to air discharge, causing electric shock or fire. So how can we effectively control and eliminate static electricity during the printing process? It's crucial to ensure that the substrate is free of static electricity before contacting the printing plate and that the finished printed product is also free of static electricity. This process is very complex; simply put, it requires ensuring that there are absolutely sufficient positive and negative ions to neutralize the static electricity on the object being printed.
3. Why do finished printed products need static electricity elimination?
The answer is simple: to prevent finished printed products from being difficult to neatly store and arrange after cutting. The solution is to install static electricity elimination equipment during the cutting process.
Another point that needs special attention is that:
Most manufacturers of static electricity elimination equipment currently use a point discharge method to eliminate the generation and elimination of static electricity.
The operation involves a high-voltage generator producing high voltage, which is then used to ionize air molecules into positive and negative ions via a discharge electrode. These ions neutralize ions on the surface of objects. (Incidentally, static electricity is caused by a localized imbalance of positive and negative ions.) Therefore, any conductor that comes into contact with the discharge electrode will generate sparks. If these sparks come into contact with flammable or explosive materials, it can cause unnecessary industrial accidents.
However, in the modern printing industry, some printing processes require the use of flammable and explosive auxiliary materials. Therefore, it is crucial that manufacturers using flammable or explosive materials never use point-discharge type static eliminators.