Plastic packaging is a common way to keep food fresh. Appropriate packaging can not only better protect products but also bring more sales opportunities. Since plastic packaging is in direct contact with food, the choice of material is extremely crucial. Non-toxicity and cleanliness are fundamental requirements. Considering practical applications, most current food packaging is made of multiple layers of materials combined. Today, we will analyze the common materials and bag shapes of food packaging bags.
I. Materials
The materials of food packaging bags are mainly as follows:
Polyethylene (PE): Polyethylene is a very common food packaging material with good flexibility, abrasion resistance, and barrier properties, and is suitable for packaging various foods.
Polypropylene (PP): It has high heat resistance, acid resistance, and alkali resistance, and is very suitable for packaging food that undergoes high-temperature processing and can be heated in a microwave oven.
Nylon (PA): It has good abrasion resistance, high temperature resistance, and chemical stability, and is an ideal choice for packaging food that requires high-temperature heating or has a more active chemical nature.
Polyester (PET): It has high strength, rigidity, and transparency, and performs well in the packaging of light products such as beverages and cosmetics.
Polyvinylidene chloride (PVDC): With its excellent moisture-proof, oil-proof, and anti-corrosion properties, it is widely used in the packaging of meat, baked goods, and other products.
Ethylene/vinyl alcohol copolymer (EVOH): It has good oxygen barrier and light-blocking properties, making it suitable for packaging food with high moisture content and prone to oxidation.
II. Multiple film composite methods
BOPP/LLDPE: Moisture-proof, cold-resistant, with strong low-temperature heat-sealing tension; suitable for instant noodles, snacks, frozen pastries, powdered products, etc.
BOPP/CPP: Moisture-proof and oil-resistant, with good hand feel, high transparency, and good rigidity; suitable for dry foods such as instant noodles, biscuits, and candies, but not suitable for packaging refrigerated foods and high-temperature sterilized foods.
BOPP/MCPP: Light-blocking, moisture-proof, oil-resistant, and oxygen-barrier, with good sealing performance; suitable for dry foods and fried foods.
BOPP/VMPET/LLDPE: Moisture-proof, oxygen-barrier, and light-blocking; suitable for various snacks, tea, soup ingredients, etc.
PET/CPP: Moisture-proof, oxygen-barrier, fragrance-preserving, and high-temperature resistant; suitable for cooked foods, alcoholic foods, and fragrant foods.
PET/PET/CPP: Moisture-proof, high-temperature resistant, and easy to seal; suitable for soy sauce, liquids, shampoo, etc.
PE/PP: It has good barrier properties, mechanical strength, and flexibility, and is widely used in packaging fields such as various foods, medicines, and cosmetics.
PE/PA: It has high strength, abrasion resistance, and chemical stability, and is suitable for packaging food that requires high-temperature heating or has a more active chemical nature.
PET/PE: It has high strength, rigidity, and transparency, and is suitable for packaging light products such as beverages and cosmetics.
III. Common bag shapes
Three-side seal: A bag with two side seams and a top seam. The bottom edge is formed by horizontally folding the film. Three-side seal bags are widely used in food packaging, mask bags, tea bags, candy bags, powder bags, cosmetic bags, snack bags, medicine bags, pesticide bags, and other fields.
Back seal bag: Also known as a middle seal bag, it is a packaging bag with the seal on the back of the bag. It has a very wide range of applications. Candy, bagged instant noodles, bagged dairy products, etc. mostly use this packaging form. In addition, back seal bags can also be used to store food, medicines, cosmetics, frozen foods, postal items, etc. It has the functions of moisture-proof, waterproof, insect-proof, and preventing things from scattering. It has good sealing performance, is non-toxic and odorless, and has good flexibility.
Four-side seal bag: The four sealing edges are sealed together to seal the four sides, and the two sides and the bottom edge are sealed. In the cosmetics industry, four-side seal bags are widely used in the packaging of products such as creams, lotions, and perfumes.
Stand-up pouch: It has a horizontal support structure at the bottom and can stand on its own without relying on any support whether the bag is opened or not. It is mainly used in products such as fruit juice beverages, sports beverages, bottled drinking water, squeezable jelly, seasonings, etc.
Spout pouch: As an emerging packaging bag for beverages and jelly, it is developed on the basis of stand-up pouches. Usually, a spout is added for convenient pouring and multiple uses. It is mainly used for liquid packaging such as beverages, jelly, ketchup, salad dressing, shower gel, shampoo, etc.
Zipper bag: It has excellent sealing performance and convenience and is suitable for packaging various foods such as candies and biscuits.
Good packaging bag materials can not only better protect products but also beautify product appearance and enhance consumers’ purchase desire. Therefore, customizing packaging bags is as important as purchasing packaging equipment. According to factors such as one’s own needs, product characteristics, and market positioning, carefully select appropriate materials and bag shapes to meet packaging needs in different fields.