Packaging in today's world has emerged as an integral part of brand promotion. Aluminum is a metallic element that is available throughout the globe. Aluminum was used to make vessels, tins, tubes, etc. but it is also used for foil sheets and containers for packaging food and other articles.
The aluminum foil manufacturing business seeing a steady GDP growth in recent years. Aluminum foils are produced by continuously casting and cold rolling aluminum sheets. They are prepared in thin metal leave. Aluminum foil sheets are rapidly used in the manufacturing of various kinds of containers as per packaging requirements.
Consumers can heat or freeze food items in the foil container directly. The global aluminum foil market size is valued at 24.54 US Billion dollars for the year 2021. The global aluminum foil packaging market is estimated to grow at a CAGR of 5.5% from 2022-2030.
Consumption of aluminum foil is growing fast in India. Consumers can directly heat or freeze food products in the foil container. To overcome the demand for aluminum foil in India, there is an introduction of a new aluminum manufacturing plant in Jaitapur, Indore. To make it successful, USD 5.6 billion has been approved by the board of SRF.
Key Properties of Aluminum as Packaging Material
Advantages of Using Aluminum Foil Container
Requirements
Production of Aluminum Foil
Printing and Embossing
Using Aluminum Foil as a Laminate
Aluminum Metalized Films
Key Properties of Aluminum as Packaging Material
| Property | Advantages |
|---|---|
| Appearance | Bright, reflective gloss makes for an attractive appearance |
| Stability | When exposed to air, aluminium forms an oxide layer that prevents further oxidation. It is also inert and does not form toxic compounds when exposed to most chemicals, including most foods and cosmetics |
| Barrier Properties | Heavier gauges form a complete barrier to gases and water. Aluminium reflects light, making it a suitable material to protect light-sensitive products |
| Hygienic Properties | Aluminium’s smooth metallic surface is non-absorbent. It can be easily cleaned and sterilised |
| Formability | Aluminium’s ductility makes it easy to form. It has excellent deadfold properties. Its friability (ability to crumple) makes it useful for blister packaging |
| Conductivity | Aluminium conducts electricity and heat, making it useful for applications such as induction heat sealing of containers |
| Recyclability | Aluminium can be recycled at relatively low cost (recycling requires about 5% of the energy required to refine aluminium) |
Souvik Dey
Advantages of Using Aluminum Foil Container
There is more than one advantage of using aluminum foil containers as alternatives to other materials. Because of this only the need for aluminum foil is increasing day by day. Given below are some of the most common advantages of using an aluminum foil container.
Recycling and Recovery
The use of aluminum can be proved as an environmentally safe solution for plastic. As aluminum is easily recycled and has no higher toxic danger to the environment. Overall aluminum foil can be counted as an eco-friendly material.
Formability and Strength
Aluminum has a good strength under its characteristics. Aluminum foil is nothing else but aluminum only. Hence they also carry good strength and formability under their characteristics.
Heat performance of the product
An aluminum foil container can successfully preserve the temperature of the product to a great extent. They are quite common to use for keeping food items hot.
Decorative characteristics
Aluminum foil can also be used as a decorative alternative due to them being easily molded in the shape as per the need.
Safety and product security
Aluminum has higher strength than a few other materials. Hence, the strength provided by aluminum foil is better than others. It also provides good security to the product and saves them from any additional damages.
Chemically neutral and non-toxic
Aluminum foil is void of any toxic chemicals in it that can be found naturally within it or can be introduced while the manufacturing process. However, aluminum foil is so safe that it can be used as a covering material for food products due to its nontoxic nature.
Light in weight making it easy and economical to transport
Aluminum foil is a light weighted product. And hence easy to carry and transport from one place to another. This characteristic of aluminum foil helps most in its use for day-to-day life and makes transporting easier of the foil.
Can be printed, coated or embossed
aluminum foil can be printed, coated, or embossed as per the requirement. All these procedures can be successfully applied to aluminum foil without any issue.
Requirements
Aluminum foil is used in many day-to-day activities. It also has a definite plan for the manufacturing of aluminum foil. The requirements for an aluminum foil manufacturing company can be divided into two parts.
The first part will include the machinery requirements whereas the next part will include the raw materials.
The basic machinery requirements are Aluminum foil container machine – Single cavity, Decoiler (Max foil width: 450mm. Nsk bearing), Control cabinet, Press for a single cavity, Air compressor, Counter & Stacker, Mold lifter, Scrap collector, Collecting table, Mould/dies.
The raw material requirements can vary on many factors. The basic requirements are Aluminum alloy, Lubricants, Packaging materials, etc.
Production of Aluminum Foil
Aluminum foil is typically less than 150 mm in thickness. A typical water vapor transmission rate (WVTR) for 9 mm foil is 0.3 g/m2 per 24 hours at 38°C and 90% RH. As thickness is reduced, foil becomes more vulnerable to tearing or pinholing.
The most economical means of manufacturing reroll stock. The system continuously feeds, casts, chills, and coils the reroll stock. After the foil stock has been manufactured, it must be further processed on a rolling mill. The work rolls have finely ground and polished surfaces to ensure a flat, even foil with a bright finish.
Each time the foil stock passes through the rolling mill, it is squeezed, its thickness is reduced and its length increases, but its width remains the same. This means the required width for the final foil product must be set at the beginning of the process. The addition of lubricants to the aluminum surfaces also maintains the workability of the material.
Piyush Mishra
Foil Finishes, Coatings, and Lacquers
Rolling produces two natural finishes on foil: bright and matte. The foil surfaces in contact with the work rolls are polished to a bright and shiny finish. If thinner foils are rolled together, the foil-to-foil face of each web develops a satin-like matte finish.
Other finishes can be produced with special patterns on the work rolls or, more commonly, by using separate or in-line mechanical finishing machines. See the below table
| Type of finish | Description |
|---|---|
| Bright both sides | Uniform bright specular finish, both sides |
| Extra-bright both sides | Uniform extra-bright specular finish, both sides |
| Matte one side | Diffuse reflecting finish, one side |
| Matte both sides | Diffuse reflecting finish, both sides |
| Embossed | Pattern impressed by engraved roll or plate |
| Annealed | Completely softened by thermal treatment |
| Chemically cleaned | Chemically washed to remove lubricants |
| Hard | Foil fully work-hardened by rolling |
| Intermediate temper | Foil temper between annealed and hard |
In most packaging applications, aluminum foil is combined with other materials such as coatings, inks, papers, paperboards, and plastic films. A very useful characteristic of aluminum foil is that it can readily accept many different types of coating materials such as inks (for printing), varnishes and lacquers (for embossing), adhesives, and polymers (for heat sealing, etc.).
Coatings generally can be classified as protective or decorative. Protective functions for coatings include:
- Making the foil more heat-resistant
- Increasing tensile strength
- Increasing resistance to potentially corrosive agents
- Enhancing the barrier properties of low gauge foil
- Increasing resistance to scratching or scuffing
- Increasing the UV resistance of a printed foil
Printing and Embossing
If the foil is to be printed, it is important to be aware that its glossy surface may make small print difficult to read. The reverse type is best avoided unless it is large. It is sometimes necessary to print a matt white background on which black type will be more visible. It is given a primer or washes coat to ensure a clean surface and to provide a foundation for the ink.
Aluminum foil is particularly suited to embossing. This gives both a three-dimensional quality to a design and increases the number of reflective surfaces able to reflect light to create a more eye-catching effect. It also increases stiffness and allows cut pieces of foil to be easily separated.
Using Aluminum Foil as a Laminate
Lamination involves combining sheets of different materials into a single layer, using a mixture of adhesives, pressure, and sometimes temperature to bond the materials together. Aluminum foil is laminated on web-fed rotary equipment which sometimes includes a coating unit to add further protection.
Four methods are used to laminate aluminum foil named Wet bonding, dry bonding, extrusion bonding, and hot-melt bonding.
Rishita Jain
Aluminum Metalized Films
Aluminum is the only metal used for vacuum metalizing in packaging applications. Initially used for decoration, is now widely used in flexible packaging. It improves the points like gas and moisture, creates better barrier properties, it allows good heat and light resistance with better electrical conductivity.
Metalized films are often a component in a laminate. Batch processing is the most widely used approach to metalizing. Typical examples of laminates using metalized films are shared below.
| Product | Type of laminate |
|---|---|
| Coffee | 12 mm metallised BON/50 mm LDPE |
| Savoury snacks | 18 mm OPP/adhesive/18 mm metallised OPP |
| Condiments/spices | 12 mm metallised PET/38 mm MDPE |
| Bag-in-box wine | 50 mm ionomer/12 mm metallised PET/75 mm EVA |
| Biscuits | OPP/18 mm metallised OPP |
| Medical products | paper/adhesive/18 mm metallised OPP/ionomer |
| Cold meats | metallised PET/PE |
Conclusion
The popularity of aluminum foil, especially for flexible packaging, will continue to grow. Even aluminum foil is being scrutinized in regard to its environmental 'friendliness.' Hence, manufacturers are increasing their efforts in the recycling area.
Aluminum foil also uses less energy during both manufacturing and distribution. The global demand for aluminum foil is forecast to report strong growth driven by consumption in major emerging markets. More growth opportunities will turn up between 2019 and 2025 as compared to the past five years.
FAQs
What is the raw material for aluminum foil?
Aluminum foil is made up of aluminum alloy. The alloy used for making the foil has 92-99 percent aluminum.
Who invented aluminum foil?
Aluminum foil was introduced in the year 1825 by Hans Christian Oersted.
What is the difference between aluminum foil and tin foil?
The differences between the two can be listed under many categories. However, the main difference between both of them is that aluminum foil is made up of aluminum whereas tin foil is made from tin.
Does aluminum foil expire?
Aluminum foil is made from aluminum alloy and hence no possible expiration date to it.
