Relationship between antifogging agent and film antifogging property
DATE：2019/11/13 9:07:37 / READ： / SOURCE：This station
Relationship between antifogging agent and film antifogging property
The self-adhesive packaged food contents evaporate on the surface of the film. When the temperature is below the dew point, the evaporated water will condense on the surface of the film into fine water droplets. The diffuse reflection of the water on the surface of the film causes the temperature of the surface of the film to be below the dew point. When evaporated, the evaporated water will condense into fine water droplets on the surface of the film. The diffuse reflection of the water droplets on the surface of the film will make the surface of the film foggy, and the transparency will be greatly reduced. The packaged product will not be seen and the packaging will be affected. There are many methods for anti-fog, and currently there are mainly two types suitable for plastic films.
1) Surface hydrophobic method, which is to make the surface of the film form a highly hydrophobic structure, which is not wetted by water. Even if it is dew condensation, only large water drops are formed and fall off, and the transparency of the film is maintained.
2) Surface hydrophilic method, which makes the contact angle of the surface of the film to water small, and the surface wettability becomes good, and the water droplets condensed on the surface of the film can be expanded into a transparent water film, thereby maintaining the transparency of the film.
The above two methods are further divided into an external processing method and an internal adding method. The internal addition method adds an appropriate amount of antifogging agent to the formulation to make the surface hydrophilic. The mechanism is preliminarily believed that the antifogging agent added in the formulation forms a liquid layer on the surface of the film after being formed into a film. The lower layer of the liquid phase layer is distributed with the lipophilic group and the plasticizer affinity, and the upper layer is distributed with the hydrophilic group and the water affinity, so that the surface of the film is hydrophilized to achieve the purpose of anti-fog. In actual use, two or more antifogging agents are generally used in combination. After the anti-fogging agent is added to make the surface of the film hydrophilic, the film surface is easy to absorb and wet, and the water is a conductive substance, thereby preventing the surface area from being statically charged, thereby preventing static electricity and dust.
The self-adhesive packaged food contents evaporate on the surface of the film. When the temperature is below the dew point, the evaporated water will condense on the surface of the film into fine water droplets. The diffuse reflection of the water on the surface of the film causes the temperature of the surface of the film to be below the dew point. When evaporated, the evaporated water will condense into fine water droplets on the surface of the film. The diffuse reflection of the water droplets on the surface of the film will make the surface of the film foggy, and the transparency will be greatly reduced. The packaged product will not be seen and the packaging will be affected. There are many methods for anti-fog, and currently there are mainly two types suitable for plastic films.
1) Surface hydrophobic method, which is to make the surface of the film form a highly hydrophobic structure, which is not wetted by water. Even if it is dew condensation, only large water drops are formed and fall off, and the transparency of the film is maintained.
2) Surface hydrophilic method, which makes the contact angle of the surface of the film to water small, and the surface wettability becomes good, and the water droplets condensed on the surface of the film can be expanded into a transparent water film, thereby maintaining the transparency of the film.
The above two methods are further divided into an external processing method and an internal adding method. The internal addition method adds an appropriate amount of antifogging agent to the formulation to make the surface hydrophilic. The mechanism is preliminarily believed that the antifogging agent added in the formulation forms a liquid layer on the surface of the film after being formed into a film. The lower layer of the liquid phase layer is distributed with the lipophilic group and the plasticizer affinity, and the upper layer is distributed with the hydrophilic group and the water affinity, so that the surface of the film is hydrophilized to achieve the purpose of anti-fog. In actual use, two or more antifogging agents are generally used in combination. After the anti-fogging agent is added to make the surface of the film hydrophilic, the film surface is easy to absorb and wet, and the water is a conductive substance, thereby preventing the surface area from being statically charged, thereby preventing static electricity and dust.
Author：admin