Economical production of solid cardboard cans

In many areas of cutting-edge research, small and medium-sized enterprises are pioneers of technological progress. In order to further promote this status, technological and mechanical engineering developments in packaging machine construction are also part of the area to be supported by the state and the EU - the goal here: mono-material packaging.

The rule for the production of Cardboard composite cans is still the Manufactured from a mix of materialswhich no longer fulfils the current requirements for environmentally friendly packaging. It is not possible to fully reintroduce this packaging into the material cycle, nor can it be manufactured completely and economically on the basis of renewable raw materials. And this is not just a niche product. Cans made from cardboard composites have a Wide range of applications The most familiar products to consumers are certainly crisps and crackers, soups, sauces and other instant products, spices and tobacco.

If the full carton can is to prevail over the composite carton can in terms of width, there must be no compromises in its properties due to the substitution of various components. For example adequate functionality such as gas tightness, opening behaviour, reclosability and the protective effect of the packaging and thus the shelf life must be guaranteed.

Goodbye material mix!

If we succeed in taking a further step towards single-material packaging for this special packaging material, the result will be Significant sustainability potential. However, the development of such a solution requires a high level of technical performance. This requires packaging machine manufacturers such as Gebrüder Leonhardt GmbH & Co. KG Blema Kircheis from Aue. It can refer to an extensive range of machines through to complete systems for the production of the original packaging and can therefore build on specialist expertise. The company has a strong reputation on the international market for developing new processes and machines.

The core competence of the specialists focuses on the production of packaging made of tinplate, cardboard composites and cardboard. In particular, the business division "Cardboard composite, cardboard" has been greatly expanded over the past five years and has received further impetus through the acquisition of two companies. And there is a willingness to take on the financial risk of such a project and invest accordingly, in addition to receiving a share of the funding from the European Regional Development Fund.

Prerequisites for comprehensive market success

A whole series of changes are planned for the structure of the can: These include replacing the plastic lid and the base of the can with solid cardboard, replacing the aluminium tear-open membrane with paper and creating a barrier in the form of a polymer barrier layer on the body of the can.

Driven by packaging manufacturers and packers, this solution is increasingly being demanded not only for the European market, but worldwide. Blema Kircheis is currently already producing commercially viable results. This concerns the sealing of a deep-drawn cardboard base into a spiral-wound round can body. Work is currently underway to transfer these results to oval can bodies. In addition, there is the transfer of the existing clocked solution to the Sealing of paper membranes in the direction of a continuously operating active principle.

Now it's all about the lid

When producing a two-part cardboard lid, the individual steps must be optimally coordinated: The lid blank is produced in a multi-cavity mould from strip material. At the same time, sections are cut from a spiral-wound tube. These serve as the wall of the two-part snap-on lid. The two parts are brought together in almost parallel moulds arranged around the circumference of a carousel. This is followed by the ultrasonic sealing of the two parts and the final forming of the packaging part. The production of a Slip lid made from solid cardboard is now possible at Blema Kircheis at a rate of up to 300 pieces per minute.

New prototype

The process of replacing the cardboard composite can with a full cardboard can is not only driven by environmental considerations, but also to a large extent by costs, given the issue of disposal fees. The company is currently starting the construction of a Pilot plant for economical production of the new type of packaging. It is also important to maintain the quantity that can be produced per unit of time and to keep unit costs the same, or even better, to reduce them compared to the cardboard composite can. The target completion date is mid-2022, and a well-known customer from the snack sector is interested in industrial testing of this solution afterwards.