The basic knowledge of tape type-structure- adhesive-release paper

I. Definition of adhesive tape
Pressure sensitive tape means that the tape adheres easily to the surface being adhered by touch and light pressure. Pressure sensitive tape is a viscoelastic polymer with both liquid and solid properties. Therefore, compared with glue, adhesive tape does not need to be cured during bonding, which can save man-hours. Tapes are used in a wide range of fields. In addition to daily office tape products, tapes are also used in many industrial fields such as automobiles, electronics, paper printing, construction, home appliances, new energy, and rail transit.

II. The structure of the tape
Adhesive tapes generally consist of coatings with various functions. The adhesive is applied to one or both sides of the substrate (to make single- or double-sided tapes). The following diagrams show typical constructions of single-sided or double-sided tapes.

III. Types of substrates
The task of the substrate is to hold the adhesive and primer. The base material is very rich, from paper to plastic film, etc. Different materials have different characteristics and are suitable for various application scenarios.

Common substrates:

1. Film tape (PP, PET,PVC)
   Dimensionally stable, chemically stable, temperature resistant (PET), transparent or white
   Non-woven tape
   Docile, heat-resistant, hand-tearable, transparent
2. Foam tape (PE)
   Vibration and noise reduction, suitable for rough surfaces, compensates for thermal expansion and contraction between different materials (such as glass and metal), black or white
3. Cloth/fabric tapes are compliant, scratch-resistant, hand-tearable, and have a high amount of glue.
4. Asymmetric Tape
   Differential adhesives are coated on both sides of the substrate, resulting in different peel forces on both sides.
5. Non-backing tape
   There is no base material, only the adhesive is attached to the release paper, which has excellent conformability and is very thin.

IV. Types of adhesives
The coating weight (g/m2) and formulation of the adhesive depends on the application for which the tape is designed.
Common adhesives are acrylic adhesives, natural rubber adhesives and synthetic rubber adhesives. Different adhesives have different basic characteristics, and acrylic adhesives are generally better suited for permanent and outdoor applications.
Comparative analysis of two main adhesives:

Acrylic Adhesive:

1. Advantages
   Excellent adhesion to polar materials (PET, PC, glass, metal)
   Heat resistant
   Aging resistance
   Can withstand various environments
   Typically higher shear resistance at elevated temperatures
2. Limitations
   Final bond strength is achieved after a rest period, so repositioning is possible
   low initial bond strength
   Relatively low adhesion to polar materials

Rubber adhesive:

1. Advantages
   High initial viscosity
   Realize fast bonding with the adherend
   Excellent adhesion to non-polar surfaces such as PP, PE, or EPDM
2. Limitations
   Relatively low high temperature resistance
   Relatively low aging resistance
   Relatively low environmental performance
   Relatively low chemical resistance
   Relatively low moisture resistance

V. Types of release paper/film
The type of material of the release paper determines its physical properties, such as tensile strength, elongation, tear resistance, moisture resistance stability, cutting debris… The release force of the release paper/film should not be too large to cause tape It is difficult to peel off, and it should not be too small to fall off.

Common release paper/film:

1. Cellophane
   tearable
   good tensile strength
   Good electrostatic discharge performance
   The paper core is relatively hard and has strong compressive stability
   die cut
   cost-effective
2. PE coated paper
   high dimensional stability
   PE coating prevents moisture absorption
   tearable
   good tensile strength
   Good electrostatic discharge performance
   die cut
3. MOPP film
   Dimensionally stable, good tensile strength
   Moisture-proof
   Small thickness tolerance
   die cut
   translucent
4. PE film
   Good elasticity, suitable for wrapping thicker products
   Moisture-proof
5. PET film
   High temperature resistance (up to 150°C)
   Small thickness tolerance
   dimensionally stable, thin
   die cut
   transparent