What are the classifications of polypropylene films?

2024-01-15

Polypropylene film can be divided into CPP film, BOPP film,IOPP film and IPP film according to different processing techniques. The relevant information is as follows:

CPP film and characteristics

CPP film, short for Cast Polypropylene Film, also known as "non-stretched polypropylene film" or ", is one of the most commonly used hot-air layer materials in flexible packaging applications. CPP film is manufactured using a melt cast rapid cooling process, featuring no longitudinal or transverse stretching (or only minimal stretching). It is classified as a non-oriented. Compared to BOPP (biaxially oriented polypropylene film), CPP film prioritizes flexibility, heat-sealing capability, and thickness uniformity.

Classification of CPP Film

1.General-purpose CPP film

Thickness: 20-50μm
Features: Balanced properties, high transparency, excellent heat-sealing performance, low cost
Applications: Food packaging bags, gift bags, textile linings, garment linings, hot-air layer in composite films

2. Aluminized Grade CPP Film

Thickness: 20-60μm
Features: Smooth surface suitable for aluminum coating, which significantly enhances barrier properties (oxygen barrier, moisture barrier, light barrier) after application.
Applications: Chocolate, coffee, and tea packaging bags; vacuum packaging base material

3. Retort Grade CPP Film

Thickness: 60-100μm
Features: Using the ternary copolymerization processing method or modified formula, it has high temperature resistance (120℃/30-45 minutes), excellent oil resistance, and high heat sealing strength.
Applications: Convenience food packaging bags, frozen fish and meat packaging bags

Recommendation on the use of CPP film (polyethylene raw material)

Borealis Borstar FB2230 LLDPE

Borouge FB2230 LLDPE is a type of polyethylene raw material specifically designed for the production of frozen film and blown film. It possesses excellent low-temperature resistance and good flexibility

Sabic 118WJ LLDPE

Sabic 118WJ is a linear low-density polyethylene material specifically designed for film production. It contains demolding agents and opening agents, and its melt index is 1g/10min (at 190℃, 2.16kg

BOPP film and characteristics

BOPP film is a polypropylene film produced using biaxial stretching technology.

Biaxial stretching refers to the MD direction and the TD direction.

▶️The MD direction refers to the longitudinal direction of the film, that is, the winding direction of the BOPP film.

▶️The TD direction refers to the transverse direction of the BOPP film.

Why stretch polypropylene film?

The main purposes of polypropylene film stretching include:

Improve the mechanical properties of the polypropylene film. After stretching, the molecular arrangement of the polypropylene film changes, giving it stronger tensile strength, flexibility and impact resistance.
Improved gloss and transparency, the appearance of stretched polypropylene film is significantly better than that of unstretched polypropylene film
Improve the water vapor blocking ability of BOPP film
Improve the dimensional stability of BOPP film, improve heat resistance and cold resistance, and reduce product shrinkage
Easy to produce, effectively improves the production efficiency of polypropylene films

Classification of BOPP films

BOPP film can be divided according to its function:

Anti-static BOPP film, which is obtained by coating an anti-static agent on the substrate or mixing the anti-static agent into the polymer;
Anti-fog BOPP film, which has good fresh-keeping effect and has developed rapidly in the field of packaging products, is obtained by stretching the easy-cut BOPP film in the longitudinal or transverse directions;
Inorganic-filled modified porous BOPP film, which is made by inorganic-incorporated Made from mixed polypropylene;
Easy-to-print BOPP film.

Advantages and application scenarios of BOPP film

BOPP film is highly transparent packaging material with excellent performance.

Due to the orientation of the molecular segments and the increase in crystallinity, the tensile strength, tensile elastic modulus, impact strength, tear strength, flexural life, etc. can be significantly improved, and a strong and tough film with high stiffness can be obtained.

In addition, it has good moisture resistance, high gloss, good transparency, good gas barrier, moisture-proof, light weight, non-toxic, odorless, good dimensional stability, wide range of use, good printability, good electrical insulation, and has excellent It has the advantages of quality stability and processability. Its comprehensive performance is superior to transparent films such as moisture-proof cellophane and polyethylene film. It is known as the "Queen of Packaging" by the packaging industry.

bopp films for packaging of snack foods

Anti-static BOPP film is used for packaging of snack foods such as carp fillets;

Easy-to-cut BOPP film can be used for packaging soups and medicines

Easy-to-print BOPP film can be used for packaging cereals

Inorganic-filled modified porous BOPP film is used for Packaging of deoxidizer and moisture-proof agent.

IOPP film and characteristics

IOPP film (Inverted Oriented Polypropylene Film) is a uniaxially stretched polypropylene film commonly used in food packaging, pharmaceutical packaging and other demanding industrial applications. The IOPP film is mainly stretched in the MD direction, that is, longitudinal stretching, and stretching in the winding direction of the film, thereby improving its mechanical strength, transparency and heat resistance.

Features of IOPP membrane include:

High strength and durability: Due to molecular orientation, IOPP membranes have good tensile strength and resistance to rupture.
Good transparency: Compared with ordinary polypropylene film, IOPP film has higher transparency and is suitable for packaging that needs to display products.
Heat sealing performance: IOPP film has excellent heat sealing performance and is suitable for packaging materials that require sealing.
Temperature resistance and chemical resistance: IOPP membrane can remain stable at higher temperatures and has good chemical resistance.

Comparison of BOPP film and IOPP film

IOPP films are only stretched in the longitudinal direction, so the strength, rigidity and tensile strength are only improved in the longitudinal direction and are weaker in the transverse direction.
IOPP film has lower transparency and clarity than BOPP film
Heat sealing performance is lower than BOPP film
High temperature resistance and chemical resistance are worse than BOPP film
Because the production is relatively simple, the cost is lower than BOPP film

Common applications include food packaging (such as snacks, biscuits, etc.), as well as the packaging of some pharmaceuticals and cosmetics.

PP raw material for IOPP films

20 years PP supplier - Baiyou recommends PP raw material that can be used to make IOPP films

Sinopec F5606 PP

Sinopec F5606, is PP pellets used to make IOPP films and general plastic packaging bags.

F5606 PP pellets has high transparency, low temperature impact resistance, and low heat sealing temperature. It is a high-quality film grade PP granules.

IPP film and characteristics

IPP is a polypropylene film produced using down-blowing water-cooled blown film technology. The optical properties and film thickness deviation of IPP film are slightly lower than those of CPP and BOPP, but the process is simple and the cost is low. It can be packaged by simply sealing at the upper and lower ends. The thickness of packaging film is generally 0.03 ~ 0.05mm. Films with excellent strength at low temperatures can be obtained using copolymer resins. The modified IPP film has low-temperature high impact resistance, high slipperiness, high transparency, high impact strength, good toughness, and anti-static properties. It includes a single-layer polypropylene film, which can be a homopolymer or a copolymer; a multi-layer co-extruded blown film, which is generally made from two raw materials: homopolymerized isotactic polypropylene and copolymerized. IPP is mainly used for packaging of fried snacks, bread, textiles, folders, record sleeves, sea vegetables, sports shoes, etc.

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