Which adhesive is used in Bopp tape?
When it comes to packaging, one of the most commonly used materials is Bopp tape. It is widely appreciated for its durability, strength, and versatility. But have you ever wondered what makes Bopp tape so effective in sealing packages? The answer lies in the type of adhesive used. In this article, we will explore the adhesive used in Bopp tape and understand its properties, composition, and application. So let's dive in!
1. Understanding Bopp Tape:
Bopp tape, also known as Biaxially Oriented Polypropylene tape, is a widely used packaging material. It is made from polypropylene film that is stretched in both the machine and cross directions to enhance its properties. Bopp tape is known for its high tensile strength, excellent clarity, resistance to moisture, and low cost, making it a popular choice for various industries.
2. The Role of Adhesive in Bopp Tape:
The adhesive used in Bopp tape plays a crucial role in its performance. It is responsible for creating a strong bond between the tape and the surfaces it is applied to. The adhesive should exhibit excellent adhesion, cohesion, and tackiness to ensure optimal sealing strength. Different types of adhesives can be used in Bopp tape, but the most commonly employed is pressure-sensitive adhesive (PSA).
3. Pressure-Sensitive Adhesive (PSA):
PSA is a type of adhesive that forms a bond when pressure is applied to it. It does not require heat, water, or solvent activation. This makes it convenient for immediate use without any additional processing. PSA is composed of three main components: a viscous polymer, a tackifier, and a plasticizer. Together, these components provide the necessary adhesive properties to Bopp tape.
4. Composition of PSA:
a. Viscous Polymer:
The viscous polymer forms the backbone of the PSA and provides cohesive strength. The most commonly used viscous polymers in PSA are natural rubber, synthetic rubber, and acrylic. Each polymer offers different properties, such as heat resistance, chemical resistance, or UV stability, allowing for customization based on the application requirements.
The tackifier gives the adhesive its initial tackiness, allowing it to stick to various surfaces. Tackifiers are typically made from resins, such as rosin or hydrocarbon-based resins. They enhance the adhesive's ability to wet out the surface and provide initial adhesion, ensuring a reliable bond.
Plasticizers are responsible for making the PSA softer and more flexible. They prevent the adhesive from becoming too rigid and losing its cohesive strength. Common plasticizers include phthalates and esters, which help maintain flexibility even at low temperatures.
5. Application of PSA in Bopp Tape:
PSA is applied to Bopp tape during the manufacturing process. It is typically coated onto the non-adhesive side of the Bopp film using a coating machine. The adhesive layer is then dried and cured to achieve the desired tackiness and adhesion properties. The thickness of the adhesive coating can vary depending on the application requirements, but it is usually around 15 to 30 microns.
In conclusion, the adhesive used in Bopp tape plays a critical role in its performance. The pressure-sensitive adhesive (PSA) provides excellent adhesion, cohesion, and tackiness, ensuring reliable sealing strength. Composed of a viscous polymer, tackifier, and plasticizer, PSA offers flexibility and customization options for different applications. Understanding the composition and properties of the adhesive used in Bopp tape helps appreciate its superior sealing capabilities, making it a trusted choice for packaging needs across various industries.