There are many arguments around the features and environmental benefits of different materials, and as we have all experienced, it can be very hard to reach a clear conclusion.
In every situation, the only correct answer is to look at a lifecycle analysis and assessment for your specific product, taking account of the primary, secondary and tertiary packaging requirements. This will give you a clear vision on the environmental impact of your product, and how to minimise the impact factors that are most important to you.
Aluminium is often considered to be a very sustainable product, as, although there is a high energy cost in the initial extraction from bauxite, it is infinitely recyclable, meaning minimal waste to landfill, and spreading the initial extraction costs over multiple uses. Recycling uses 5% of the energy required for the initial extraction, and also releases just 5% of the greenhouse gases. The recycled material loses none of the qualities of the initial material.
To add to this, it is collected by all UK councils through standard kerbside recycling schemes, and is widely recognised by consumers as a recyclable product, which all helps to ensure that waste is minimised.
When considering closures, bear in mind that due to tolerances involved in working with aluminium, an element of plastic is almost always required to achieve a seal, although this does not necessarily stop the product from being recyclable.
You should also consider the options for creative design – aluminium does have some interesting options for embossing or screen printing for customisation, however it is worth checking specifically whether your design can be achieved.