The function and requirements of beverage packaging
The function of beverage packaging
- Protect food
- Convenient storage and transportation
- Promote sales
- Increase the value of goods
Classification of beverage packaging
- Waterproof packaging,
- moisture-proof packaging,
- shock-proof packaging,
- mildew-proof packaging,
- dust-proof packaging,
- radiation-proof packaging,
- thermal insulation packaging,
- inflatable packaging,
- anti-theft packaging and aseptic packaging, etc.
- Liquid packaging
- and solid packaging.
- Vacuum packaging,
- inflatable packaging,
- deoxygenated packaging,
- moisture-proof packaging
- and shrink packaging.
- Refrigerated packaging,
- freezing packaging,
- sterilization packaging.
Requirements for beverage packaging materials and containers
- easy to open,
- easy to carry,
- easy to drink.
Beverage packaging containers and materials
- Paper packaging materials
- Plastic packaging materials
- Metal packaging materials
- Glass packaging materials
Glass packaging materials for beverage bottle
The characteristics of glass
Glass is a non-crystalline material.
The main components are：
- soda ash (sodium carbonate, co-solvent),
- limestone (calcium carbonate, stabilizer),
- clarifying agents,
- coloring agents,
- decolorizing agents,
Molten by the high-temperature furnace (1400 ~ 1600 ℃) and then condensed.
- Good transparency
- Good chemical stability
- Good airtightness
- Strong pressure resistance
- Diversified shapes
- Wide range of applications
- Heavy and brittle
- Light transmittance causes deterioration of contents
Types and specifications of glass bottles
There are many glass bottles, which can be classified according to their usage, manufacturing method, and purpose.
According to the size of the bottleneck
- Smallmouth bottles (or ampoules):﹤20mm
- middle mouth bottles: 20-30mm
- and wide-mouth bottles: ﹥30mm
According to the shape of the bottle mouth
- intermittent spiral,
- crown type.
According to whether to recycle or not.
Disposable bottles and recycled bottles.
According to the size of the capacity
- Small volume bottles (below 150ml),
- medium volume bottles (150-500ml)
- and large volume bottles (above 500ml).
Common defects of glass bottles and methods of quality inspection
Common defects of glass bottles
1. Defects of the glass itself
- Air bubbles
2. Defects in the production process
- Uneven thickness
- Not full
Quality inspection methods of glass bottles
According to the national standard (GB/T 4545-2007), the inspection items for glass bottles include the following:
- Capacity and quality inspection.
- Inspection of bottle mouth, bottle body, dimensional tolerance, thickness, and the seam line.
- Inspection of thermal stability, chemical stability, and internal pressure.
- Inspection of the degree of annealing of bottles and cans, cracks, bubbles, colour, etc.
Glass bottle cap
(1) Yellow crown cap
(2) Screw cap
Screw caps are divided into
- ordinary screw caps,
- twisted screw caps,
- and screw caps.
Metal Packaging Material for Beverage Bottle
Steel-based packaging materials:
- Tin plate (tinplate),
- chrome plate (TFS plate),
- coated plate,
- galvanized plate,
- stainless steel plate.
Tinned steel sheet
Tin-plated sheet steel is a product made of low-carbon thin steel plate with tin plating on the surface, referred to as a tinplatetinplate. They are commonly known as tinplatetinplate.
It is widely used in the manufacture of various containers for packaging food. Moreover, it can also be used for containers made of other materials with lids or bottoms.
Tin-plated plate consists of five parts, from the inside to the outside of the steel substrate, tin-iron alloy layer, tin layer, oxide film and oil film.
The mechanical properties of tin plate
The degree of quenching and tempering is usually used as an index to indicate tinned plates’ comprehensive mechanical properties. Including strength, hardness, plasticity, toughness, and so on.
Corrosion resistance of tinplate
The tin plate’s corrosion resistance is related to the corrosion resistance of each layer structure of the tinplate.
The steel substrate’s corrosion resistance mainly depends on the steel substrate’s composition, the number of non-metallic inclusions, and the surface condition. The presence of inclusions on the surface of the steel substrate is primarily harmful. When they appear at the dew point of the tin plate, they will accelerate the tin layer’s corrosion in a corrosive environment and then accelerate the steel plate’s corrosion.
The tin plating is required to completely cover the steel substrate’s surface, but the actual tin plating layer has many small holes, among which the pores that expose the steel substrate are called dew points.
The number of exposed iron spots on the tin plate is expressed by porosity: the number of pores or pore area per square decimeter.
The influence of tin layer continuity on corrosion resistance is expressed by iron dissolution value: it refers to measuring the dissolution of iron after a certain area of tin plate is kept in a simulated acid solution for a certain temperature and time.
Tin-iron alloy layer
The tin-iron alloy layer’s main component between the steel substrate and the tin layer is the tin-iron metal compound FeSn. Which not only has a mediating effect, makes tin firmly adhere to the surface of the steel plate, but also makes the tin layer bright and compensates for the existence of tinplated porosity improves the corrosion resistance of the steel plate.
There are two kinds of oxide film on the surface of the tin plate. One is SnO and SnO2 formed by oxidation of tin layer itself; the other is passivation film of a chromium-containing compound formed by passivation treatment of tin plate. snO2 is a stable compound, while SnO is an unstable compound, so both will affect the corrosion resistance of the tin plate.
The chromium-containing passivation film makes the corrosion resistance of tinplated plate greatly improved, and the more chromium contained in the passivation film, the better the corrosion resistance, which can effectively inhibit the oxidation of tin to yellow and sulphide to black, but the passivation film is easy to fall off in the environment of pH <5.
The oil film on the tinplate’s surface separates the plate from the corrosive environment and prevents the tin layer’s oxidation. The oil film acts as a lubricant in the use of tinplated plates and cans, which can effectively prevent the tin layer from scratches and damage during processing and transportation, leading to corrosion in tinplated plates.
The oil film will also hurt can processing and surface finishing.
Chrome-plated steel sheet
The chrome plate comprises a steel substrate, a chromium layer, a hydrated chromium oxide layer and an oil film.
(1) Mechanical properties are not much different from tinned steel sheets;
(2) Corrosion resistance: Good corrosion resistance, but slightly worse than tinplate.
(3) Processing performance The chrome plate cannot be soldered, and the seam must be welded or bonded when making cans. It is suitable for making can bottoms, lids and two-piece cans.
(4) Inexpensive price The corrosion resistance of chrome-plated plates after the coating is higher than that of tinplated plates, and the price is about 10% lower. It has better economic efficiency, and its usage is gradually expanding.
Galvanized steel sheet
It is a metal sheet formed by plating a zinc layer of 0.2mm or more on a low-carbon steel substrate’s surface. Galvanized sheet is mainly used as a large-capacity packaging barrel.
Low carbon steel sheet
Low-carbon steel plate refers to ordinary carbon steel or high-quality carbon structural steel with a carbon content of less than 0.25% and a thickness of 0.35-4.0mm.
The low-carbon composition determines that the low-carbon steel sheet has good plastic properties, is easy to form and process and weld the seam, and the made container has better strength and rigidity, and the price is low.
Special coatings are applied to the steel plate’s surface to be used for filling beverages or other products. It can also be made into narrow belts for binding cartons, wooden boxes or packages.
Types of metal cans
The structure of the metal tank
The can is divided into three-piece cans and two-piece cans according to the structure.
It composed of 3 parts: can body, can bottom and can lid. The can body has seams, and the can body is rolled and sealed with the can lid and can bottom (double rolled edge).
The body of a large tank has convex and concave reinforcement rings to enhance the tank body’s strength and rigidity.
The basic structure of the tank bottom and the tank lid is the same, and its structure is composed of the rounded side of the lid hook, the shoulder blade, the external rib, the slope, the lid core and the sealant. There are two types of can lids: regular lids and easy-open lids.
The two-piece can is a metal can with a can body and a bottom as a whole. There is no seam on the can body, only a can cover, and the can body are rolled and sealed, and the airtightness is better than that of a three-piece can.
The characteristics of two-piece cans compared with three-piece cans:
- The two-piece can has only one seal, no side seams, and good airtightness;
- No welding seam, pollution-free, smooth and beautiful surface, and can reduce the joint material by 25%-30%;
- Two-piece cans can be printed and decorated in a circle
- Lightweight, saving materials, and easy to open;
- Two-piece cans are more suitable for short-term, high-temperature sterilization;
- However, the equipment investment for the two-piece can is relatively large, about eight times that of the three-piece can.
Tank type and specifications
According to the shape, it can be divided into round cans, round cans with flushed bottom, square cans, square cans with flushed bottom, oval cans, oval cans with flushed bottom, trapezoidal cans and horseshoe-shaped cans.
Packaging container “Steel pail” GB/T13252-2008
Can lids mainly include ordinary can lids and easy-open lids.
Advantages and disadvantages of metal cans
Metal cans have the following advantages as beverage packaging: First, they have excellent barrier properties. It can not only block gas but also block light. This feature allows beverages to have a longer shelf life. The second is that it has excellent mechanical properties, mainly manifested in high-temperature resistance, humidity resistance, pressure resistance, insect resistance, and resistance to harmful substances. The third is not easy to break, easy to carry and adapt to modern society’s fast-paced life. Fourth, the surface is well decorated, which can stimulate consumption and promote sales. Fifth, it can be recycled and reused.
Metal packaging containers also have certain shortcomings, mainly manifested in poor chemical stability, poor alkali resistance, poor internal coating quality, or poor technology, making the beverage taste bad.
Paper Packaging for Beverage
The characteristics and types of paper containers
The main advantages of paper containers include: low cost, more economical, lightweight, conducive to logistics, no metal leaching and other phenomena occur, waste can be recycled, no white pollution, instantaneous autoclaving technology, no preservatives, etc.
The main shortcomings of paper containers are: pressure resistance and sealing precision is not as good as glass bottles and metal cans, can not be heated to sterilize pre-formed cartons in the preservation process will reduce the heat sealing performance due to polyethylene oxidation, due to creases and paper fibre hardening and loss of elasticity two become uneven, to the filling machine caused by feeding difficulties.
Commonly used paper containers for beverages
1. Classification and structure of composite cartons
- Tetra Pak
- Gable top pack
2. The use and application of composite carton
Starting from the raw materials, sterilization, moulding, filling, and sealing are all completed in one filling machine. This kind of cartons are collectively called post-formed cartons, such as Tetra Pak in Sweden.
Composite cartons are mostly used for packaging milk, milk beverages, lactic acid bacteria beverages, fruit and vegetable juice beverages, and tea beverages.
Tetra Pak and Kangmei’s paper container packaging can be seen everywhere in the beverage packaging market. The “Tetra Pak” brick carton was initially developed as a milk container, and has now been used for the packaging of fruit and vegetable juices, soft drinks, and wine; Bacteria carton packaging is used to reposition the popular Nestle NESTEA iced tea brand.
3.Innovative performance characteristics of paper packaging
With the continuous advancement of science and technology, paper and paper containers are developing in a multifunctional direction. Paper packaging has multiple functions: dehydration, moisture prevention, sterilization, preservation, temperature sensing, edible, visible, flame retardant, toughening, water resistance, oil resistance, acid resistance, deodorization, etc. For beverage packaging, special functions such as sterilization, temperature sensing, and toughening can be applied.
Plastic Packaging Material for Beverage Bottle.
25% of the world’s total output of plastic products is used for packaging, and plastic packaging materials account for about 25% of the total consumption of packaging materials. These two data fully illustrate the importance of plastic packaging materials. GB/T10004-2008 “Plastic Composite Film”
Plastic is a polymer material composed of resin and added with various additives to improve its performance. It is moulded into a particular shape at a specific temperature and pressure and can maintain a predetermined shape at room temperature.
The performance of plastic packaging materials
The most prominent feature of plastic packaging materials is that they can conveniently adjust the material properties through various methods to meet various needs; they can also be made into composite films and multi-layer plastic bottles, which are light in weight, not easy to break, and convenient to transport and carry.
Types and characteristics of plastics used in beverage packaging
Polyethylene is the world’s largest production of synthetic resin, and the largest consumption of plastic packaging materials, accounting for about 30% of plastic packaging materials. Low-density polyethylene (LDPE) has better transparency, softness, high elongation, better impact resistance and low-temperature resistance than HDPE. It is still used in various packaging materials, but it has obvious shortcomings as a food packaging material. High-density polyethylene (HDPE) has a high degree of crystallinity, allows a higher use temperature, and its hardness, airtightness, mechanical degree, and chemical resistance are good, so a lot of blow molding is used to make bottles and other hollow containers. Its high oil resistance is widely used for serving milk, milk products, and packaging natural juices and jams. However, the fragrance retention of HDPE is poor, so it is not suitable to store food and beverages for a long time. However, it can be used as the composite film’s inner layer material with good heat-sealing performance characteristics. For example, two-layer and three-layer composite materials have been widely used in beverage packaging. The United States adopts cellophane/adhesive/PE composite bottles to hold lemon juice.
Polyvinyl chloride (PVC)
PVC can be roughly divided into three categories: hard products, soft products and paste products. The seamless line of PVC bottles produced by the injection stretch-blow method has uniform wall thickness and can hold carbonated beverages such as cola and soda; the PVC bottles produced by the extrusion blow molding method are only suitable for holding fruit juice and mineral water.
The vinyl chloride content in the resin should not be higher than 1×10-6. 1 kg of PVC resin is only allowed to contain 1 mg of vinyl chloride monomer. Bottles produced with this kind of PVC resin are used for packaging beverages, and the vinyl chloride monomer cannot be detected in food.
The Coca-Cola China Company disclosed that since October 2011, PVC beverage bottle labels had been completely banned in China and replaced by new environmentally friendly non-PVC film labels, because PVC labels “may be harmful to the environment during the recycling process. influences”.
Polypropylene film has a high crystalline structure with a permeability of 1/4 to 1/2 of that of polyethylene. It has high transparency, smoothness, and high processing performance. It is widely used in the preparation of fibres and molded products, but mainly plastic films.
Currently, polypropylene coated films with airtightness and easy heat sealability and composite materials composited with other films, cellophane, paper, aluminium foil, etc., have been mass-produced, and containers made of PP composite materials can be used for beverage packaging.
All types of PP have a common feature of static electricity. To solve this problem, it is common to coat an antistatic agent on the film or mix the film’s antistatic agent. Coating polyvinylidene chloride resin with good airtightness on the film can improve the oxidation resistance of PP.
Polyester (PET or PETP)
PET is a material with good crystallinity, colourless and transparent, and extremely tough. It has the appearance of glass, is odourless, tasteless, non-toxic, flammable, has a yellow flame with a blue edge when it burns, and has good airtightness. PET has a small expansion coefficient and a low molding shrinkage rate of only 0.2%, which is 1/10 of that of polyolefin, which is smaller than PVC and nylon, so the product’s size is stable. The mechanical strength can be described as the best, and its expansion is similar to aluminium. The film strength is 9 times that of polyethylene, 3 times that of polycarbonate and nylon, and the impact strength is 3 to 5 times that of ordinary films. The film also has moisture-proof and fragrance-preserving properties. In recent years, the production of PET bottles has developed rapidly. Heat-resistant PET bottles are widely used in beverages that require hot cans such as tea beverages and fruit juice beverages.
At present, China is in the rapid development of PET beverage packaging, including the demand for polyester bottles with double-digit growth every year. The application proportion of PET bottles in domestic carbonated beverage packaging accounted for 57.4%, while carbonated beverages accounted for about 46% of the total soft drink production. Polyester bottle packaging has accounted for the main share of the domestic beverage packaging market. Consumers widely believe that PET bottles have the characteristics of “large capacity, transparency, intuitiveness, lightness and ease of opening, refrigerated, convenient to carry, strong, and recyclable”, all of which provide a broader perspective with the development of PET bottled beverage.
Polyvinylidene chloride (PVDC)
Its softness characterizes PVDC and shallow air and water permeability, which can avoid the penetration of peculiar smell, has good freshness and fragrance retention performance, and is suitable for long-term preservation of food; it has good acid, alkali, chemical and grease resistance, and has good heat resistance. Shrinkage, suitable for airtight packaging, and is a good heat-shrinkable packaging material. The disadvantages of PVDC are that it is too soft and has poor operating performance; it has strong crystallinity, is easy to crack and perforate, and has poor aging resistance; its monomer is also toxic, so it is mainly used as a coating material or manufacturing composite materials. PVDC is often combined with paper, aluminium foil and other plastic films to make composite materials or PVDC coating materials. A good bond can be obtained by solvent bonding. These composite materials have good
Its moisture-proof, oxygen-proof, and airtight properties are easy to heat seal and suitable for packaging water-containing foods.
PC is a colourless, transparent, bright and beautiful plastic. Because PC is non-toxic and odourless, it has good ultraviolet transmission performance, moisture-proof and fragrance-preserving performance, wide temperature resistance, no brittleness at -180℃, and long-term use at 130℃, so it is an ideal Food packaging materials. Taking advantage of PC’s excellent impact resistance and easy forming characteristics, it can be manufactured into bottles, cans, and various containers for packaging beverages, alcohol, milk, and other fluid substances. The most significant disadvantage of PC is stress cracking. In addition to selecting high-purity raw materials and strict control of various processing conditions, the use of resin modification with low internal stress, such as a small amount of polyolefin, nylon, polyester, etc., melt blending, can significantly improve stress crack resistance and water resistance.
Polyamide, commonly known as nylon, is the first resin developed by DuPont in the United States for fiber, and it was industrialized in 1939. In the 1950s, the development and production of injection molding products began to replace metals to meet downstream industrial products’ requirements to reduce weight and reduce costs.
PA has good comprehensive properties, including mechanical properties, heat resistance, abrasion resistance, chemical resistance and self-lubrication, low friction coefficient, certain flame retardancy, easy processing, suitable for glass fibre and Other fillers are filled to enhance modification, improve performance and expand application range.
PA film products are widely used in food packaging. To improve its packaging performance, stretched PA film can be used and combined with PE, PVDC or CPP to improve moisture resistance and heat-sealing performance. It can be used for high-temperature cooking and packaging of animal meat products. And deep-frozen packaging. 8. Bioplastics
Bioplastics refer to plastics produced under the action of microorganisms based on natural substances such as starch. It is renewable and therefore, very environmentally friendly. Bioplastics are not only environmentally friendly. They are also very adaptable to the body, and are expected to be used to produce postoperative sutures and other medical products that the body can absorb.
Types and characteristics of composite materials
Composite material: It is composed of two or more materials with different properties through physical or chemical methods to form a material with new properties on the macro (micro). Various materials complement each other in performance and produce a synergistic effect, so that the comprehensive performance of the composite material is better than that of the original constituent materials to meet various requirements.
Characteristics of composite materials
- Enhanced protection of commodities
- Mechanical packaging adaptability
- Strong commodity
- Conducive to the full use of materials, extensive resources, reducing energy consumption and costs
Recycling of packaging materials and environmental protection:
At present, the world produces 45 billion tons of waste each year. China annual industrial solid waste is about 600 million tons, and urban waste is 100 million tons. According to preliminary estimates, packaging waste is about 16 million tons, accounting for all urban waste. 25% by volume, 15% by weight. It is the harsh facts that have sounded the alarm to the world. It strongly illustrates the reserve for environmental pollution control and the recycling and reuse of packaging waste is indeed imminent.
Packaging waste recycling and environmental protection standards and regulations
(1) Requirements for the recycling and treatment of packaging waste In June 1996, the “China Environmental Protection White Paper” pointed out that the Chinese government implemented the “China Trans-century Green Project Plan” during the “Ninth Five-Year Plan” period, which pointed out the direction for the creation of green products and green packaging. Make enterprises have rules to follow and rules to follow.
(2) Packaging waste recycling and environmental protection standards and regulations. The United Nations held the first human environment conference in Stockholm, Sweden in 1972, and adopted the “Human Environment Declaration”, “Human Environmental Behavior Plan” and other documents, and established the United Nations Environmental Planning Summer (UNEP) June 5th of each year is the “World Environment Day”; in 1980, the United Nations Environmental Planning Summer and Nature Conservation Union drafted the “World Natural Resources Protection Program.”
In 1983, the UN General Assembly and UNEP authorized Mrs. Brundtland to form the “World Commission on Environment and Development.” In 1987, “Our Common Future: From One Earth to One World” was published, which put forward the viewpoint of sustainable development.
The status quo of recycling and reuse of packaging materials
At present, recycling and processing packaging waste is an important measure to deal with the global shortage of resources and to control global environmental pollution. There is no garbage in the world, there are only resources, only resources that are misplaced, and those that can be recycled should be recycled. Paper, plastic, metal, and glass are the most commonly used packaging materials. The paper packaging waste can rot within 7 days under appropriate conditions. It decomposes within a few years under normal circumstances, while plastic waste can exist for 200 to 400 years. According to a Gallup Institute of Public Opinion survey in the United States, plastics accounted for 72%, glass 8%, steel 5%, aluminum 4%, paper 4%, other 1%, and unidentified garbage. It accounted for 6%.
Recycling and reuse of packaging materials
Recycling of glass bottles
There are three main types of waste glass recycling and reuse
- Circular reuse
- Refurbishment and melting
- Direct reprocessing
Recycling of metal packaging products
- Recycling and reuse
Recycling of paper packaging
After the waste packaging paper is recycled, it is mainly used to produce recycled paper, cardboard and pulp molded products for various purposes.
Recycling of packaging plastics
Recycling and reuse: It is no longer a process of processing, but directly reused after cleaning.
Mechanical treatment and regeneration: including two categories: direct regeneration and modified regeneration.
- Incineration method
- Landfill method
Packaging material recycling and environmental protection measures
(1) It is necessary to establish a recycling and processing company under the supervision of the State Environmental Protection Administration and purchase advanced equipment to form a network across the country to provide a one-stop service for recycling, processing, and recycling.
(2) It is necessary to increase publicity on environmental protection awareness and cherishing resources to make people aware of the environmental and resource crises facing the earth on which humans live, and form people’s conscious behavior.
(3) Borrowing from Western developed countries’ successful experience, implementing a green environment, setting up company recycling devices, and ensuring it through legislation.
(4) It is necessary to establish and improve the legal system and operating mechanism of green packaging. On the one hand, environmental protection departments, packaging industry competent departments and material departments should perform their duties and cooperate under relevant national policies, laws and regulations, and do an excellent job in the development of green Packaging and packaging waste disposal work. On the other hand, we must improve the green packaging legal system, and promote the development of green packaging with laws and regulations.
New trends in beverage packaging
The latest developments and research results of beverage packaging are reflected in the following aspects
The lightweight of glass bottles. The most significant disadvantages of glass bottles are poor mechanical beauty, fragility and weight.
As far as the current beverage packaging market is concerned, metal cans are still widely used beverage packaging materials, divided into two-piece cans and three-piece cans.
The largest amount of plastic containers is PET bottles.
Development Trends of Paper Containers
Paper packaging is the most traditional form of packaging. In recent years, as green packaging has gradually become the mainstream of packaging, paper packaging has been more widely used. There are four main types of paper packaging containers: paper, cartons, paper tubes and pulp.
New beverages packaging
- Automatically heated steel cans
- Pressurized aluminium cans
- Disposable polypropylene cups for instant brewing
- Plastic cups with filters on the mouth of the cups
- Low-cost steel cans
- Three pieces of metal with rolled edges tank.
Please click below to watch the production process of bottled water production.