What Is an Embossed Film?
Embossed film is a generic term for film with an uneven surface that is processed by heating and pressurizing the film. The name “embossed film” is derived from the term “embossing.” Embossing is applied to improve texture, slipperiness, and peelability. Embossing can also be applied in a variety of patterns, such as diamond, silk, and linen, each with different characteristics. Embossed films are also available in a wide variety of materials, such as polyethylene, silicone, and polyurethane.
Uses of Embossed Films
Embossed film is used for packaging, semiconductor transport, separators, and to provide slipping properties. Uses of embossed film vary depending on the material used. In the case of polyethylene, it is used for diaper backsheets, pocket tissue packaging, liquid containers, and laminating materials. Elastomer films, for example, are used in waterproof suits, transdermal absorbent base materials, clothing materials, wound dressings, and non-slip tapes. Because of this wide range of applications, appropriate materials and embossing methods must be selected.
Principle of Embossed Films
This section describes the embossing method for films. A film of any material is heat-treated to soften it. The softened film is then pressurized with an uneven roll type die to create an uneven surface. After embossing, the film is cooled on a cooling roll and rolled up for production.
Next, we will explain the different types of embossing. Various patterns can be added to embossing, but the following five types of embossing are representative.
- Diamond Pattern (Line Embossing)
This is an embossed film with a diamond pattern (diamond shape) processed with lines. Since it is embossed with lines, the surface is relatively flat, which is a feature of this type of embossing and is often used.
- Diamond Pattern (Uneven Embossing)
This film is not embossed with lines, but with a diamond pattern on the surface, and is characterized by its unevenness. Therefore, it is used for applications requiring high elasticity.
- Silk-Eye Pattern
This processing method is characterized by very small unevenness compared to concavo-convex embossing. It is said to have superior aesthetic appeal and elasticity.
- Hemp Pattern
The hemp grain pattern is an embossing process with a random array of rounded bumps and unevenness, and is often seen in daily life.
- Nashiji Pattern
Nashiji pattern is an embossed pattern with a very fine pattern that cannot be seen with the naked eye. It has a similar feel to frosted glass and gives a luxurious finish.