01. 

Composite packaging containers and materials 

(1) Composite packaging containers 

The composite packaging containers can be classified by materials into paper/plastic composite material containers, aluminum/plastic composite material containers, and paper/aluminum/plastic composite material containers. They have excellent barrier properties. 

2. Paper/plastic composite containers are classified by shape into paper/plastic composite bags, paper/plastic composite cups, paper/plastic composite paper bowls, paper/plastic composite plates, and paper/plastic meal boxes, etc. 

3. Aluminum/plastic composite containers can be classified by shape into aluminum/plastic composite bags, aluminum/plastic composite barrels, aluminum/plastic composite boxes, etc. 

4. Paper/aluminum/plastic composite containers can be classified by shape into paper/aluminum/plastic composite bags, paper/aluminum/plastic composite cylinders, and paper/aluminum/plastic composite packages. 

(2) Composite packaging materials 

Composite packaging materials can be classified by material into paper/plastic composite materials, aluminum/plastic composite materials, paper/aluminum/plastic composite materials, paper/paper composite materials, plastic/plastic composite materials, etc. They possess high mechanical strength, barrier properties, sealing ability, light-blocking capability, hygiene properties, etc. 

2. The paper/plastic composite materials can be classified by materials into paper/PE (polyethylene), paper/PET (polyethylene terephthalate), paper/PS (polystyrene), paper/PP (propylene), etc. 

3. The aluminum/plastic composite materials can be classified by materials into aluminum foil/PE (polyethylene), aluminum foil/PET (polyethylene terephthalate), aluminum foil/PP (polypropylene), etc. 

4. The paper/aluminum/plastic composite materials can be classified by materials as paper/aluminum foil/PE (polyethylene), paper/PE (polyethylene)/aluminum foil/PE (polyethylene), etc. 

02. 

Abbreviations and Descriptions 

AL - Aluminum Foil 

BOPA (New York) biaxially stretched polyamide film 

BOPET (PET) biaxially oriented polyester film 

BOPP bidirectional stretched polypropylene film 

CPP cast polypropylene film 

EAA ethylene-acrylic plastic 

EEAK ethylene-acrylic acid ethyl ester plastic 

EMA ethylene-methacrylic acid plastic 

EVAC Ethylene-Vinyl Acetate Plastic 

IONOMER - Ionic copolymer 

PE polyethylene (collectively referred to, it can include PE-LD, PE-LLD, PE-MLLD, PE-HD, modified PE, etc.): 

-- PE-HD High-density Polyethylene 

-- PE-LD Low-density Polyethylene 

-- PE-LLD Linear Low-Density Polyethylene 

-- PE-MD Medium-density Polyethylene 

-- PE-MLLD Metal-Lined Low-Density Polyethylene 

PO polyolefin 

PT glass paper 

VMCPP - Vacuum Aluminized Cast Polypropylene 

VMPET - Vacuum Coated Aluminum Polyester 

BOPP (OPP) - namely, biaxially oriented polypropylene film. It is a type of film made from polypropylene as the main raw material, obtained through the flat film method and biaxial stretching. It has high tensile strength, high rigidity, good transparency, excellent glossiness, low static electricity performance, excellent printing performance and coating adhesion, as well as excellent water vapor and barrier properties. Therefore, it is widely used in various packaging industries. 

PE - Polyethylene. It is a thermoplastic resin obtained by polymerizing ethylene. In industry, it also includes copolymers of ethylene with a small amount of α-olefins. Polyethylene is odorless, non-toxic, has a waxy feel, and has excellent low-temperature resistance (the lowest usable temperature can reach -100 to -70°C), good chemical stability, can resist the erosion of most acids and alkalis (not resistant to oxidizing acids). At room temperature, it is insoluble in common solvents, has low water absorption, and excellent electrical insulation properties. 

CPP - namely cast polypropylene film, also known as unextruded polypropylene film. Depending on the application, it can be classified into general CPP (General CPP, abbreviated as GCPP) film, aluminized CPP (Metalize CPP, abbreviated as MCPP) film, and retortable CPP (Retort CPP, abbreviated as RCPP) film, etc. 

VMPET - refers to polyester aluminum-coated film. It is used as a protective film for packaging of dry and expanded foods such as biscuits, as well as for the outer packaging of some medicines and cosmetics. 

Aluminum-coated film possesses the characteristics of both plastic film and metal. The purpose of coating the surface of the film with aluminum is to block light and prevent ultraviolet radiation. This not only extends the shelf life of the contents but also enhances the brightness of the film. To a certain extent, it replaces aluminum foil and has the advantages of being inexpensive, aesthetically pleasing, and having good barrier properties. Therefore, aluminum-coated film is widely used in composite packaging. Currently, it is mainly applied to the packaging of dry and expanded foods such as biscuits, as well as the outer packaging of some medicines and cosmetics. 

PET - also known as high-temperature resistant polyester film. It possesses excellent physical properties, chemical properties, dimensional stability, transparency, recyclability, and can be widely applied in fields such as magnetic recording, photosensitive materials, electronics, electrical insulation, industrial films, packaging decoration, screen protection, optical-grade mirror surface protection, etc. High-temperature resistant polyester film models: FBDW (single-sided matte black) FBSW (double-sided matte black) High-temperature resistant polyester film specifications: Thickness Width Roll diameter Inner diameter of the roll core 38μm - 250μm 500 - 1080mm 300mm - 650mm 76mm (3") 152mm (6") Note: The width specifications can be produced according to actual requirements. The conventional length of the film roll is equivalent to 3000m or 6000m of 25μm. 

PE-LLD - Linear Low-Density Polyethylene (LLDPE) is a colorless, odorless, and tasteless milky white granule with a density of 0.918 to 0.935 g/cm³. Compared to LDPE, it has a higher softening temperature and melting temperature, and has advantages such as high strength, good toughness, high rigidity, good heat resistance, and cold resistance. It also has excellent resistance to environmental stress cracking, impact strength, tear strength, etc., and can withstand acids, alkalis, organic solvents, etc., making it widely used in industries, agriculture, medicine, hygiene, and daily necessities. Linear Low-Density Polyethylene (LLDPE), known as the third-generation polyethylene resin, in addition to having the general performance of polyolefin resins, has particularly superior tensile strength, tear strength, resistance to environmental stress cracking, low-temperature resistance, heat resistance, and puncture resistance. 

BOPA (NYLON) - This is the English abbreviation for biaxially oriented polyamide (nylon) film. Biaxially oriented nylon film (BOPA) is an important material for producing various composite packaging materials. Currently, it has become the third largest packaging material after BOPP and BOPET films. 

Nylon film (also known as PA) is a very tough film with good transparency, excellent luster, high tensile strength and elongation strength, good heat resistance, cold resistance, oil resistance, and resistance to organic solvents. It also has excellent wear resistance, puncture resistance, and is relatively soft. It has excellent oxygen barrier properties, but poor water vapor barrier properties. It has high moisture absorption and permeability, and poor heat sealing performance. It is suitable for packaging hard items such as greasy foods, meat products, fried foods, vacuum-packed foods, and steamed foods. 

03. 

Composite 

The compound symbol "/", and the compound methods include: 

-- Dry bonding, symbol "/dr."; 

-- Solvent-free lamination, symbol "/sf." 

-- Wet composite, symbol "/wt."; 

-- Extrusion compounding, symbol "/ex."; 

-- Co-extruded composite, symbol "/co." 

04. 

Classification 

The plastic and aluminum foil composite films and bags used for food packaging are classified into four categories based on their material structure. 

05. 

How should different products be selected for their packaging materials? 

Recently, I have received many inquiries from friends about what materials should be used for certain products. I took some time off to summarize them. These are the materials that our previous customers have ordered and used. I hope this will be helpful to everyone. 

06. 

Question Answering 

Question 1: How should one choose the material for frozen food? 

Answer: The plastic soft packaging used in the frozen food industry is mainly divided into three categories: The first category is single-layer bags, such as PE bags, with poor barrier effect and commonly used for vegetable packaging, etc.; the second category is composite soft plastic bags, such as OPP//PE (of slightly lower quality), NYLON//PE (better than PA//PE), etc., which have good moisture-proof, cold-resistant and puncture-resistant properties; the third category is multi-layer co-extruded soft plastic bags, where different functional raw materials, such as PA, PE, PP, PET, etc., are separately melted and extruded, then merged at the main die head and formed by blow molding and cooled for composite. Currently, the second category is the most commonly used. 

Question 2: What material is suitable for making biscuit products? 

Answer: For biscuits, generally use OPP/CPP or OPP/VMCPP. If you want better preservation of aroma, you can use KOP/CPP or KOP/VMCPP. 

Question 3: I need a transparent composite film. The requirement is that it should have good barrier properties. So, which one has better barrier performance between BOPP/CPP k-coated film and PET/CPP? 

Answer: The K coating has good barrier properties, but its transparency is not as good as that of PET/CPP.