BOPP vs CPP: A Guide to the Differences

CPP and BOPP films are packaging films. There are differences in performance and application. They have different roles and properties. This guide will analyze their differences. Tell you how to choose.LetUnincorporatedUnToLet Enhance revenue and efficiency of your business

What is biaxially oriented polypropylene (BOPP) film?

BOPP film is a biaxially oriented polypropylene film. First, polypropylene is extruded through a narrow mold in a molten state to form a thick sheet. Then, it is processed in a specific machine at a specified temperature and speed. Longitudinal stretching and transverse stretching are performed in sequence. It is then cooled or heated.Finally, it undergoes corona treatment and coating to complete the manufacturing process. BOPP film has many advantages due to its biaxial stretching. For example, it has high transparency and strength. It is also highly durable and has excellent stretchability. In addition, it is waterproof. As a result, it is one of the most widely used packaging materials today. It has many uses and is often used in food packaging bags, gift packaging, printing materials, and other fields. It is convenient, practical, and effectively protects products.

Main Characteristics of BOPP Film:

BOPP film is a commonly used flexible packaging material. It is colorless, odorless, and non-toxic.It has high stretchability and impact strength. It is tough and highly transparent. After longitudinal and transverse stretching, it becomes more durable and does not break easily. It also has good moisture and gas barrier properties. It protects products from spoilage and has good printability. After corona treatment, it can be printed with beautiful patterns. It is commonly used as a surface material for composite films. High definition and glossiness make products more attractive.

However, BOPP film is prone to static electricity. An electrostatic eliminator is required for high-speed production. It does not have heat sealability and requires special treatment before heat sealing. It is made by the tube film method or flat film method, and products made by the flat film method have high strength and uniform thickness. In order to improve performance, multi-layer lamination is usually chosen. It can be laminated with LDPE and PE to enhance barrier properties and used for packaging oil-containing foods.

What is CPP film?

CPP film is cast polypropylene film or unstretched polypropylene film. It is a polypropylene film made by the Cast extrusion process.

During production, polypropylene is melted and poured onto a Chill roll, which is then cooled to form a film. There are many types of CPP film.

Common types include GCPP (general-purpose CPP), MCPP (metalized CPP), and RCPP (re-sealable CPP). CPP film offers numerous advantages, including transparency, glossiness, smoothness, moisture resistance, heat resistance, and low static electricity. It is widely used in daily life, such as packaging for bread, vegetables, stationery, and more. It is also suitable for both traditional and non-traditional packaging applications.It is also used in non-traditional packaging materials such as laminated stacking designs, side-sealed bags, vertical bags for food and textiles, candy twist packaging, and document protection.

This material is non-toxic, odorless, heat-resistant, and moisture-proof, meeting various safety, hygiene, and food safety standards, making it a reliable choice.

Main characteristics of CPP film:

CPP film is highly transparent and glossy. It looks very attractive. It is a very good packaging material.

It has good heat sealing performance and can be used for various types of packaging.

It also has strong tear resistance. It can provide strong protection for packaged products.

Customized production is available. The cast process can produce films of different thicknesses, making it suitable for a wide range of applications.

Excellent heat resistance, can be used for hot filling, cooking bags, and sterile packaging.

Resistant to acids, alkalis, and oils. Can come into contact with food without changing its taste. Suitable for packaging bread and other foods.

Supports a variety of printing styles. Widely used in clothing, food, medicine, clothing, and document confidentiality fields.

Main Differences Between CPP and BOPP Films

CPP films and BOPP films are manufactured differently and have different properties. They differ in strength, durability, barrier properties, physical properties, and heat sealability.

Manufacturing process:

The main difference between CPP and BOPP films is the stretching direction and forming method.

CPP film is manufactured using a cast extrusion process. Polypropylene particles are extruded in a molten state and then rapidly cooled to form a film. The film is stretched in a single longitudinal direction, giving it excellent physical properties, high transparency, and glossiness in the longitudinal direction.

BOPP film is produced through a biaxial orientation process. Polypropylene sheets are stretched simultaneously in the longitudinal and transverse directions at high temperatures. This improves the strength, rigidity, and barrier properties of the film and enhances its physical properties. However, the process is complex and the cost is relatively high.

Strength and Durability:

CPP film has good tear resistance but weak tensile strength.

BOPP film has high tensile strength due to biaxial stretching, making it more puncture resistant and durable.

Barrier Properties

CPP film has average barrier properties and is suitable for applications with low protection requirements.

BOPP film is highly moisture-proof and oxidation-resistant, and is more suitable for preserving perishable items such as food.

Physical Properties

CPP and BOPP films each have their own advantages.

BOPP film has high transparency and glossiness. It has strong ink and coating adhesion and good tensile properties.CPP film is unidirectionally stretched and slightly less transparent than BOPP. However, it has better longitudinal stretching and tear resistance. It has better glossiness, moisture resistance, heat resistance, barrier properties, and mechanical adaptability.

CPP film is suitable for high-temperature retort and low-temperature heat sealing, and is resistant to acids, alkalis, and oils. It is often used in food packaging and is safe for food contact, as it does not alter the flavor of the packaged food.

Heat Sealing Performance

BOPP film has poor heat sealing performance. A coating needs to be added.

CPP film has good heat sealing performance and does not require a coating.

This is because CPP is unidirectionally stretched, so its heat sealing performance is relatively better.

Simply put, BOPP film is not as good as CPP film in terms of heat sealing and requires additional processing to improve its heat sealing performance.

What are the types of BOPP film?

There are many types of BOPP film, each with its own characteristics.

• Heat-Sealable Film: There are single-sided and double-sided heat-sealable films. They have a wide range of applications. They are used in food, tea, and beverages. They need to have good heat sealing performance, feel soft to the touch, and have a wide heat sealing temperature range.
• Anti-Fog Film: Prevents condensation and water vapor, and has antibacterial properties. Commonly used for food and fresh fruits and vegetables.
• Ultra-Thin Matte Film: Attractive appearance, excellent printing and lamination properties. Suitable for paper-plastic composite packaging such as books and gift bags. During production, high requirements are placed on the combination of materials and additives.
• Twist Film: Good twistability, stiffness, glossiness, and aluminum plating properties.Can be used for candy and products that require twisted packaging.
• Straw Packaging Film: Requires good optical properties, a suitable friction coefficient, and sufficient heat sealing strength.
• Release Film: Good dimensional stability and relatively stable in heated environments. Commonly used to protect adhesive products such as band-aids.
• Barrier Protective Film: Excellent dimensional stability and high tensile strength. Suitable for isolation and protection during industrial product winding and molding.

Applications

Applications of BOPP film:

• BOPP film is a biaxially oriented polypropylene film. It has high strength, good barrier properties, and is particularly suitable for printing, so it has a wide range of applications.
• Food packaging: It is commonly used for packaging snacks, baked goods, frozen foods, etc., and can protect food well.
• Labeling: It is also commonly used for labels on containers such as bottles and cans.
• It can also be used for cigarette packs, CDs, and DVDs, serving as a transparent display and protective layer.

Additionally, it is used in food containers, packaging labels and stickers, high-performance textiles, medical plastics, plastic ropes, personal care products, textbook covers, tapes, and moisture-wicking clothing. It plays a significant role in numerous industries.

CPP Film Applications

CPP film is transparent and heat-resistant, making it widely used across various fields.

• Soft packaging: stationery, textile packaging.
• Food packaging: commonly used for snacks, candies, fruits, and vegetables.
• Stationery: can be used to package notebooks and books.
• Textiles: provides excellent protection for clothing and also prevents dust.

Summary

Choose CPP film or BOPP film. It depends on the performance requirements of the packaging and its safety performance. CPP film has excellent transparency, glossiness, and heat sealability, making it ideal for applications that require these characteristics. BOPP film is tough, has good moisture retention, and allows for more refined printing patterns, so it is often used in food packaging and labels. Which one to choose depends on where it will be used.