Modern board processing and finishing were the focal points of the dfv symposium "Folding box production.”
The full title of the symposium was "Folding box production – Harnessing new growth potential through process optimization."
It was organized at this year’s FachPack by PackReport and PackMittel in cooperation with the dfv-academy of the Deutscher Fachverlag (German Technical Press), and it was a huge success. About 70 attendees watched the program of presentations, which included four technical talks on all different aspects of modern folding box production, with great interest. The Heidelberg company was a co-organizer of the event.
After a welcoming address and introduction to the topics by facilitator Carlos Lange-Prollius, the editor-in-chief of the trade journals PackReport and PackMittel, Wolfgang Suerbaum, CEO of Smurfit Kappa Carton and member of the Executive Committee of the Trade Association of the Folding Box Industry (FFI), began with an overview of the economic situation of the German folding box industry. In view of a 5 percent increase in 2006 sales, the mood in the industry is optimistic. Sales are also expected to continue to increase, at least in the near future. In addition to highly qualified employees and speed, flexibility and logistics in production, the high
level of innovation among manufacturers undoubtedly also played a key role in this positive development. Germany is the recognized leader when it comes to new developments in production processes and in further processing and high quality finishing.
"Today, folding box packs must offer substantially more than just functional utility," the speaker stressed. He described everything from psychological aspects ("Folding boxes can create emotional added value") and neuro-economic properties ("Brands and packaging induce insensitivity to pain") to thoughts on how the brain reacts to prices and brands.
Hot embossing versus cold film transfer
Jens Niemann, applications engineer at Leonhard Kurz GmbH & Co. KG – by its own account the world’s leading producer of hot and cold films – gave a technically highly detailed and practical presentation on the subject of "Cold film transfer as enhancement of conventional hot film embossing." After describing the basic characteristics of the two finishing processes, he then compared advantages and processing constraints. Hot embossing as practiced for many years in the relief printing process is generally carried out offline in three variants: flat to flat,
round/flat or round/round. The first of these methods in particular is a highly robust technology with high accuracy of register.
It can easily achieve outputs of 7,500 sheets/per hour. The rotary process allows even higher speeds of as many as 10,000 sheets/hour, with certain limitations with regard to accuracy of register. Embossing punches are generally necessary for all three variants.
Cold film transfer is a combined printing/lamination process which is normally implemented online with offset printing plates, but is also used in flexographic or letterpress printing. There are two versions: rotary processing with UV curing and sheet processing.
In offset sheet printing, conventionally hardening adhesives are traditionally used, with the disadvantage that further processing, especially die cutting, takes longer. The use of UV curing is under development. The speaker believes that progress can be expected early in the months ahead.
Classic application areas for hot embossing as well as for cold films are self-adhesive and wet adhesive labels, packaging, greetings cards, magazines, calendars, posters, visiting cards and advertising articles. Niemann stressed that only a professional would be able to spot differences in the application from the processing result.
As he sees it, the advantages of hot embossing are in effects such as gloss and haptic finishes. The finishing method can also be applied on most materials. Embossing or debossing are realized in one step with perfect register. Savings in the amount of film used are also possible.
The hot embossing process has its limitations, for example with regard to the reproduction of half-tones and the combination of large areas with fine negatives, which result in a lower production speed.
Key points in favor of cold film transfer are the high production speed due to inline processing and the design options ranging from full area to half-tones. Embossing punches are not needed, so the printed material does not become deformed. What’s more, short make-ready times and job changes that can be implemented within minutes also have a positive impact.
The process is subject to constraints when used for finishing absorbent print materials. A slightly lower degree of gloss of the applied film must also be tolerated depending on the type of surface of the print material, the print quality of the adhesive and the overlacquering, for example with matt lacquer. Consumption of film can be as much as 30 percent higher with offset sheet printing, which also does not allow inline embossing/debossing.
Weighing the pros and cons of the two finishing methods, the speaker came to the conclusion that there are arguments to justify both processes.
Hot embossing cannot be replaced by cold film transfer in every case. Use of the conventional process is advisable especially for large runs, on paper or board with an absorbent surface and when haptic effects and embossed designs with perfect register accuracy are required.
Cold film transfer is recommended for small and medium-long print runs of up to 5,000 sheets/hour on materials with limited temperature stability.
It can be used for creating specific color tones and innovative metallic print color effects with a high gloss finish.
To sum up, Niemann believes that hot embossing will continue to be used in offset sheet printing. In the rotary printing sector, on the other hand, there is a certain trend towards cold film.
Technical advances in the cutting and grooving of folding boxes were explained by Klaus Linhardt, CEO of Karl Linhardt Stanzformen GmbH.
His main focus was on the so-called counterplate technology. This grooving device method, which is the main rival of groove die milling, is not new.
However, until about 15 years ago very limited use was made of counterplates because electric discharge machining was used for their production and this resulted in higher costs.
In 1992, this mid-sized company which specializes in making flat dies was the first manufacturer to start producing milled steel counterplates on a machine of its own design. Market acceptance increased in the period that followed, with the result that this production division now accounts for more than 50% of sales at Linhardt.
According to the speaker, there are a number of reasons for using a steel counterplate as an alternative to a grooving die.
These include improved machine performance, reduced tensile forces due to smoother sheet travel, flat blanks and uniform groove quality.
In addition, marks are avoided, counterscoring lines and embossing punches are easy to integrate and there are fewer holding points.
Depending on the application, two plates of different hardness (35 or 50 HRC) are used in practice. In the case of the 35 HRC plate, a life of 1 million sheets can be expected, and as many as 3 to 4 million die cutting operations with the fully hardened version. To complete the range there is also a soft version with 15 HRC.
Last but not least, Karl-Heinz Freund, managing partner of the corrugated board, carton packaging and display manufacturer Friedrich Freund GmbH, reported on the technology partnership between his company and printing machine manufacturer Heidelberg which has lasted since 1998.
He showed how a close cooperation between machine builder and board processor can lead to profitable growth in practice.
This goes back to the decision taken at that time to switch production at the Krefeld location from sheet format VI to III B. This also involved the purchase of a Speedmaster CD 102-6+L. Cooperation intensified over the following years, not least due to the expansion of the Heidelberg Group through the acquisition of a sheet die cutting machine manufacturer and a producer of folding box gluing machines.
True to the saying "everything from a single source," a second Speedmaster CD 102-6+L, a Diana Pro 74 folding box gluing line and 2 Dymatrix 106 CSB die cutting machines were acquired in 2004 among other investments, after the idea of converting from sheet offset to flexographic printing had been rejected again after brief consideration.
Back in 1999, a first step was taken towards networking the workflow by supplying the printing machine with CIP 3 data via Prinect Data Control.
This incorporates automatic transmission of order data and presetting data, automatic feedback of production data and central storage of OK values for recurring orders.
In 2004, work began on expanding the IT network under the lead management of Heidelberg. The following year the ERP system Boxsoft was installed, and in 2006 Prinect Data Control based on JDF was partially integrated in Boxsoft. Further expansion of the JDF workflow is planned in the future.
Bernd Neumann has worked as an author for PackReport in Leverkusen for many years The speakers at the dfv Symposium "Folding box production" (from the left)
Wolfgang Suerbaum, CEO Smurfit Kappa Carton and member of the Executive Committee of the Trade Association of the Folding Box Industry (FFI), Jens Niemann, Technical Engineer Graphics at Leonhard Kurz GmbH & Co. KG,
Karl-Heinz Freund, managing partner of Friedrich Freund GmbH and Klaus Linhardt, CEO of Karl Linhardt Stanzformen GmbH.
Photos: Bernd Neumann
Wolfgang Suerbaum, CEO Smurfit Kappa Carton and member of the Executive Committee of the Trade Association of the Folding Box Industry (FFI).
Jens Niemann, Technical Engineer Graphics at Leonhard Kurz GmbH & Co. KG. Carlos Lange-Prollius, editor-in-chief of the trade journals PackReport and PackMittel, facilitated the symposium.
" Today, folding box packs have to offer substantially more than just functional utility." Wolfgang Suerbaum, CEO Smurfit Kappa Carton.
"Hot embossing will continue to be used in offset sheet printing. In the rotary printing sector, on the other hand, there is a certain trend towards cold film." Jens Niemann, Technical Engineer Graphics at Leonhard Kurz. GmbH & Co.KG.
Source: PACKREPORT No. 11, 19 November 2007, page 026