Plastic antistatic

There are many static phenomena in life, such as snapping sound when the synthetic fiber clothes are taken off, sparks can be seen sometimes in the dark, and in the dry winter, the human body is easy to carry static electricity, when touching the door handle will produce discharge phenomenon. Plastic materials are easy to produce static electricity in the process of production and use, which is mainly due to friction, and once brought with static electricity, it is difficult to eliminate, charge accumulation will cause production difficulties, scrap products, electric shock, discharge and even fire. Whether the use of external antistatic agents, or internal antistatic agents for material antistatic treatment, environmental relative humidity, temperature and surface concentration and other factors have a certain impact on the antistatic performance, this paper will be introduced in detail.

Humidity and temperature

The antistatic effect of plastic treated with antistatic agent is related to its ambient temperature and humidity. The higher the humidity and temperature, the better the antistatic effect. In fact, at room temperature, the change of temperature has little effect on the antistatic effect, but the increase of temperature tends to increase the antistatic performance, because with the increase of temperature, the mobility of antistatic agent molecules increases. The change of humidity has great influence on the antistatic effect. The surface charge leakage of polymer treated with antistatic agent is usually not only electron conduction, but also ion charge movement. The charge shift is caused by the formation of hydrogen bonds in the hydrophilic group of the antistatic agent. Because antistatic agent has hygroscopicity, and can produce ionized group after hygroscopicity, the electrical conductivity of plastic surface is greatly increased, promoting the play of antistatic effect. Therefore, the higher the ambient humidity, the better the antistatic effect.

The use of surfactant as plastic internal antistatic agent, mainly using this kind of surfactant through the internal molecular migration, the formation of conductive film on the surface. If plastics and the choice of antistatic agent had good compatibility, because both the antistatic agent can force between the molecules of migration is more difficult, and loss of the surface of the antistatic agent can't get the supplement in time, it is difficult to play a good antistatic effect, excessive antistatic agent must be added, but add too much, and will affect the other performance of the plastic. If the compatibility is very poor, it is often difficult to process. At the same time, a large number of antistatic agents will be precipitated, which not only affects the appearance quality of products, but also the precipitated antistatic agents will be quickly lost, and it is also difficult to maintain lasting antistatic effect.

Therefore, the selection of appropriate hydrophilic and oleophilic base collocation, try to seek suitable compatibility between antistatic agent and resin, antistatic agent, especially internal antistatic agent molecular design should be considered first. Usually the two are required to have a proper mutual compatibility, but also to be able to seep a certain amount of surface, once the surface can be stopped. When the surface antistatic agent loss, the internal antistatic agent can quickly seep out of the surface, restore the antistatic effect, this is the ideal durability antistatic agent.

The compatibility of antistatic agent and resin depends on the molecular structure of polymer material and the polarity of antistatic agent, similar polarity compatible, polarity difference is not only difficult to mix, but also affect the quality of plastic surface and processability. In practice, choosing the right compatibility can be quite difficult and requires a lot of experimentation.