There are several main purposes and benefits of applying silicone oil on the surface of PET blister sheet:
Anti-adhesion: Silicone oil can effectively prevent adhesion between sheets, especially during stacking and transportation. This is very important for improving production efficiency and reducing scrap rate.
Lubrication effect: Silicone oil provides lubrication effect, making the sheet smoother during subsequent processing (such as thermoforming, cutting, etc.), reducing friction and static electricity.
Dust and anti-fouling: Silicone oil has dust and anti-fouling effects, which can keep the surface of the sheet clean and prevent dust and impurities from adhering, thereby improving the appearance quality of the product.
Extend mold life: Sheets coated with silicone oil have less wear on the mold during thermoforming, which can extend the service life of the mold and reduce maintenance costs.
Improve demolding: Silicone oil is a good lubricant that can reduce the friction coefficient between PET blister sheet and mold, making it easier for the sheet to be demolded from the mold and reducing breakage and scratches.
Improve antistatic property: Silicone oil can reduce the static charge on the surface of PET blister sheet and prevent static adsorption of dust and dirt.
There are mainly the following processes for applying silicone oil on the surface of PET blister sheets:
Coating method: Silicone oil is evenly applied to the surface of the sheet by a coating machine. This method is usually carried out on a sheet production line, and the coating thickness and uniformity of the silicone oil can be controlled.
Spraying method: Silicone oil is sprayed onto the surface of the sheet using a spraying device. It is suitable for situations where local areas need to be coated.
Roller coating method: Silicone oil is applied to a roller, and then the PET blister sheet is passed through the roller so that the silicone oil is evenly applied to the surface of the sheet. The roller coating process is simple to operate, efficient, and suitable for mass production.
Impregnation method: The sheet passes through a silicone oil solution so that a layer of silicone oil is evenly coated on its surface. This method is less used in industrial production and more used in laboratories or small batch production.
Difference between single-layer and double-layer silicone oil coating
Single-layer silicone oil coating refers to the coating of silicone oil on one side of the PET blister sheet, while double-layer silicone oil coating refers to the coating of silicone oil on both sides of the sheet. The demoulding, anti-sticking, wear and scratch resistance, anti-static and optical properties of double-layer silicone oil are better than those of single-layer silicone oil, but the cost is also higher.
The difference between single-layer and double-layer silicone oil is mainly reflected in the amount and effect of silicone oil. The amount of single-layer silicone oil is less and the cost is lower, but the anti-sticking and wear resistance are poor. The amount of double-layer silicone oil is more and the cost is higher, but the anti-sticking and wear resistance are better.
Single-layer PET sheet silicone oil:
- Simple process: The single-layer silicone oil process is relatively simple and the cost is low.
- Applicability: Suitable for application scenarios that do not require high anti-adhesion and lubrication effects.
- Consistency: The uniformity and consistency of coating are easier to control.
Double-layer PET sheet silicone oil:
- Complex process: Silicone oil needs to be applied separately on each layer, the process is relatively complex and the cost is high.
- Excellent performance: Provides better anti-adhesion effect and more uniform lubrication effect.
- Multi-purpose: Suitable for application scenarios with high requirements on sheet performance, such as frequent stacking, handling or molding in complex molds.
How to choose?
Whether to choose single-layer or double-layer silicone-coated PET sheet depends mainly on specific application requirements and cost considerations. If you have high requirements for lubrication and anti-adhesion properties of the sheet and want better performance in subsequent processing, you can choose double-layer silicone-coated sheet. If it is a general packaging or molding requirement, a single-layer silicone-coated sheet is usually sufficient.
