Food Packaging Film:Everything you should amply know
Food Packaging Film:Everything you should amply know
Food packaging films are used to wrap around food surfaces, mainly to isolate and decompose microbial bacteria and foreign contaminants from entering, and to prevent and prolong food spoilage. Food packaging film can ensure food safety and extend the shelf life of food. It enables us consumers to enjoy a higher quality of life.
Table of Content:
The advantages of food packaging film?
What are the food packaging film materials?
What are the processes of food packaging film?
What are the quality requirements of food packaging film?
How to choose best food packaging film?
The advantages of food packaging film
1.High transparency
The packaging film is made of high polymer resin imported from the United States and blown by multi-layer co-extrusion, with high gloss.
2.Good extension performance
The film can fit tightly in the appearance of seafood steak and other food, just like a layer of transparent skin, so that the product has a sculpture-like three-dimensional sense, the wonderful shape of the product called out, so that customers increase the sense of closeness and desire to buy.
3.Good oxygen barrier characteristics
Compared with the ordinary packaging, the paste body packaging generally has good oxygen barrier characteristics, so it has obvious advantages in the freshness and quality of fresh and fast food – below 4 degrees Celsius, the paste body packaging can keep the food fresh for 4-8 weeks.
4.Strong temperature and water resistance
The body of the packaging of this divine “film” has excellent temperature resistance, good water retention, so it is not only convenient for refrigerated transport, but also to retain the juice and nutrition of the food when heated.
5.Can be directly into the microwave heating
When the package is heated in the microwave oven, it will automatically expand and form a natural steam environment inside the film, and then slowly lapse to accelerate the heat and ensure hygiene. After heating, the package can be easily torn clean, very convenient, and the food will not dry.
What are the food packaging film materials?
With the continuous development of packaging technology, high-barrier plastic packaging materials that can preserve quality, freshness, taste and extend shelf life are widely used in the food packaging industry, especially composite films (bags) are widely used in the packaging of milk powder, tea, steamed food, meat, flavorful snacks, beverages, milk, etc. Food quality, freshness, taste preservation in addition to the food itself, the processing technology, sterilization methods, how to choose the right packaging materials, to ensure food quality and safety has a very important impact.
Currently in the market more widely used plastic packaging materials are.
1. polyamide (PA) commonly known as nylon, it has a strong gas barrier, but the poor barrier to water vapor, water absorption, and with the increase in water absorption and expansion, so that the gas barrier, moisture resistance has dropped sharply, its strength and stability of the packaging size is also affected.
It has good mechanical properties, good toughness and wear resistance, cold and heat resistance, the normal use temperature range of -60 ℃ ~ 130 ℃, the highest temperature up to 200 ℃. Chemical properties are stable, good printability and good puncture resistance. The material meets the requirements of food packaging regarding safety and hygiene. Therefore, it is widely used in frozen packaging and steaming packaging of food. Due to its good printability and puncture resistance, most of the refined rice and other nylon packaging bags sold in the market today.
2. Polyester (PET) . it has High transparency and good gloss,excellent gas barrier, oil barrier and fragrance retention properties. Good rigidity and toughness, high tensile strength. Good chemical stability, resistant to alkene acid and alkali. Wide range of use temperature, normal use temperature range is -70℃～120℃, can be used at 150℃ for a period of time. because of good hygiene and safety,it is widely used in poultry meat packaging. PET-based laminated film can be used for steamed food packaging.
3. polyethylene (PE) has certain air permeability, tensile strength and tear strength, certain flexibility and good moisture resistance. He has good chemical stability and is a non-toxic packaging material. Therefore, it is often used as the heat sealing layer and moisture-proof coating of composite materials.
4. Polypropylene (PP) is made of propylene polymerization, it is a very light plastic with high transparency, good gloss, good physical and mechanical properties such as tensile strength, hardness and toughness, good heat resistance, can be used continuously at 120℃ and can be steamed in boiling water. Chemically stable, stable to acid, alkali, salt and many solvents within a certain temperature range. Health and safety, in line with the requirements of food packaging.
As we all know, the materials used for food packaging must have appropriate barrier properties, such as greasy food requires high oxygen and oil resistance; dry food requires high moisture resistance; aromatic food requires high odor resistance; and fruits, vegetables and fresh food requires packaging with a certain permeability to oxygen, carbon dioxide and water vapor; at the same time to have good physical and mechanical properties, mainly including Material tensile strength, tear strength, impact strength, etc.; also has good chemical stability, should not have any chemical reaction with the internal food, in order to ensure the safety of food. Also has high temperature resistance, suitable for high temperature sterilization and low temperature storage of food and other characteristics.
Therefore, most of the food packaging on the market today is based on composite plastic film packaging, especially high barrier materials have become the main body of food packaging. So in the selection should first consider the quality of the contents, freshness, flavor requirements. At the same time in the choice of plastic film (bag), must fully understand the relevant properties of plastic, to get a reasonable choice.
What are the processes of food packaging film?
To be a good buyer in the market, you need to have an overall thorough understanding of the product you need to purchase, including the entire process from material selection to production to packaging and shipping, and also to understand the market characteristics of the product so that you can do a good market analysis as a whole, and then choose a manufacturer with good quality and fair price according to your needs. Purchasing. So, what are the production methods of food packaging film?
- Blow molding method
Through the direct contact of water and film surface cooling, so it can be quickly cooled, spherical stretching, its flatness is slightly inferior to the cast method, but the transparency is better, while spherical stretching on the production of high-barrier food stretch film ductility has a go impact.
- Flow calendering method
Through the cooling roller cooling, the food type high barrier stretch film made longitudinally has specific stretching, transversely has no stretching, the overall flatness is good, the transparency is second to the blowing method, but the stretching ductility is better.
What are the quality requirements of food packaging film?
Due to the wide use of food packaging film, a wide variety of different requirements, the contents being packaged from raw to cooked, from low to high temperature, from easy to corrupt fresh fruit to hard nuts, from vacuum packaging bags to inflatable packaging bags, basically covers the range of composite packaging bags.
1. requirements of isolation; most of the food category is rich in fats and oils, fats and oils are susceptible to oxidation and deterioration, so the strict requirements for oxygen barrier, and the requirements for moisture gain or loss within the food packaging film is also very high.
2.moisture activity; food all contain specific moisture, when the packaging material is selected, in the case of food processing conditions, the formula remains unchanged, the moisture content of food changes very little. When the conditions change, it will directly affect the original moisture activity value of the food, and moisture is one of the important factors causing food spoilage, as long as there is a specific moisture content, microorganisms can grow. For different moisture content foods, different materials and methods should be used.
1) Moisture low activity food. Bacteria are not able to survive in food with moisture activity below 0.65, for dry food with moisture activity below 0.60, as long as it can be kept dry for a long time can be free from spoilage caused by bacteria in food.
2) Food with medium moisture activity. For moisture activity in the 0.60-0.90 intermediate moisture food, to maintain food quality methods are, vacuum packaging, nitrogen packaging, deoxidizer packaging, etc., placed in the food fatty oxidative deterioration, food discoloration, etc.
3) Moisture higher activity food. For moisture activity in 0.9-1.0 multi-moisture system of food, quality maintenance methods: 100 ℃ or more heating sterilization, the use of hydrogen peroxide, radiation and other sterilization of aseptic packaging.
3. food packaging film inflatable packaging role. The role of inflatable packaging is to extend the shelf life, the type of inflatable packaging bags with different requirements.
4.grain packaging bag requirements. Grain has a respiratory effect, different grains on the oxygen adsorption capacity varies greatly, in each grain packaging bags, can be used in the excellent isolation of food packaging film filled with oxygen to the better preservation of food inflatable packaging bags.
5. vacuum requirements. Evacuated packaging isolated oxygen, moisture-proof, both to protect the quality of materials and make the appearance of goods look good, generous.
How to choose best food packaging film?
So how should we choose food packaging plastic film? We can judge from the following six aspects.
- Food packaging film must fully comply with health standards. That is, the film itself does not occur in the migration of toxic substances, non-toxic, odorless, odorless.
2. The film must have a certain mechanical strength, smooth surface, no water absorption, corrosion resistance and other excellent properties. Moisture-proof packaging of food, vacuum packaging and inflatable packaging, to have the function of blocking the environment of water vapor, oxygen penetration into the packaging bag and prevent the inert gas inside the bag from escaping. Frozen food packaging, to have low-temperature freezing performance. For the production of “cooking bag” with the film, the requirement of high-temperature cooking performance. For oil and fat food packaging, require oil resistance and UV penetration resistance (such as a single film does not meet the required performance, we must selectively take the composite or coating and other technological means)
3. The film should have good printability, or be able to adapt to printing after pre-press treatment.
4. The film should have good sealability and mechanical packaging adaptability.
5. The film should be economical, under the premise of effective protection of commodities, choose materials that are easy to obtain at low prices.
6. without static electricity or anti-static treatment to remove static electricity.
However, any single plastic film can not have the above-mentioned excellent characteristics.
Therefore, according to the different nature of the packaging items and the choice of appropriate film. Avoid improper selection of packaging materials and food deterioration or mechanical operation in the process of bad adhesion, blockage, wrinkling, perforation, broken bags and other disadvantages.
For more detailed types or questions about food packaging films, please refer to: https://www.kxpack.com/product-category/plastic-film/
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