Con­tact­less sealing makes formed packs tighter

A com­pletely new method for the con­tact­less sealing of water-sol­uble multi-chamber pouches enables more com­pact sealing seams, better hap­tics and a more ­effi­cient pro­duc­tion process. Ini­tated by market demands, the “water sealing with inkjet printer” project was ­devel­oped and real­ized by the cre­ative minds and makers of Harro Höfliger’s Engi­neering & Inno­va­tion Services.

The new process enables a greater design variety of multi-chamber prod­ucts as well as greater safety during han­dling by the consumer.

Good is not good enough – this phi­los­ophy moti­vates people at Harro Höfliger and in par­tic­ular the Engi­neering & Inno­va­tion Ser­vices team. When it comes to improving estab­lished solu­tions or devel­oping promising tech­nolo­gies for the future, the 16 employees go beyond their daily rou­tine, bring out their cre­ativity and lit­er­ally put processes to the test.

They also scru­ti­nized the heat sealing of water-sol­uble multi-chamber polyvinyl alcohol (PVOH) formed packs filled with deter­gents or cleaning agents. The result: For the pro­duc­tion of the pouches, Harro Höfliger now counts on an inno­vative water sealing process based on a mod­i­fied inkjet print­head. With the help of this device, water is applied with utmost pre­ci­sion and con­trol to the lid film which then begins to dis­solve. A roller then accu­rately applies it to the ther­mo­formed base film filled with powder or gel.

Con­tact of the films results in a very homo­ge­neous, dense and extremely durable sealing seam, which is much nar­rower than with heat sealing. Not only does this increase the design variety of the multi-chamber prod­ucts, it also allows a more com­pact shape. Con­se­quently, more packs can be pro­duced per cycle with the same film width. In ­addi­tion, the con­tact­less water appli­cation causes no con­t­a­m­i­na­tion and thus reduces the cleaning and main­te­nance efforts and expenses for the system. For con­sumers, the improved pres­sure sta­bility means even more safety in handling.

Cre­ativity first, fol­lowed by process optimization

“And yet cre­ativity is not some­thing we do for our­selves. We always develop with a focus on appli­ca­tions to meet the needs of the market,” empha­sizes Achim Wolf, Head of Engi­neering & Inno­va­tion Services.“The dri­ving force behind this inno­va­tion project were our cus­tomers’ new require­ments for hap­tics and the design of multi-chamber prod­ucts. We wanted to pro­vide more attrac­tive options for formed packs and make pro­duc­tion even more efficient.”

“Cre­ativity is not some­thing we do for our­selves. We always develop with a focus on appli­ca­tions to meet the needs of the market.“Achim Wolf, Head of Engi­neering & Inno­va­tion Services 

In accor­dance with the internal inno­va­tion man­age­ment processes at Harro Höfliger, the team approached the water sealing project sys­tem­at­i­cally in sev­eral phases.

“We start with proof of con­cept tests. Four dif­ferent ideas were put for­ward for water sealing and we tested them all exten­sively. The print­head turned out to be ideal because every single drop of water can be pre­cisely con­trolled and the con­tact­less appli­ca­tion offers many advan­tages,” explains Wolf.

In the next phase, testing the process capa­bility on the pro­to­type, his team ­focused on the need for 24/7 pro­duc­tion at high speed right from the start. The Omni FS semi-auto­matic machine pro­duced water-sealed sam­ples that had to pass pres­sure, drop and dis­so­lu­tion tests. Only then was the system inte­grated into the cus­tomer’s pro­duc­tion line. “If nec­es­sary, my team is on site at the cus­tomer’s premises until opti­miza­tion is com­plete. Our in-house tests have resulted in com­plex knowl­edge that we are happy to pass on. We start with cre­ativity, then we tran­si­tion into process optimi­zation,” explains Wolf.

More accu­racy, less material

How­ever, water sealing is only one piece of the puzzle in the con­stant opti­miza­tion of pro­duc­tion processes for multi-chamber pouches. Achim Wolf’s team is also working on tech­nical solu­tions and process para­me­ters for the forming process, for example to reduce the mate­rial con­sump­tion of PVOH films. A new dosing process, enabling the filling of the powder for­mu­la­tion even more pre­cisely and cleanly, has already been devel­oped. In the next phase it will be adapted for cus­tomized appli­ca­tion. Achim Wolf: “We are con­stantly revising the entire process and are always devel­oping new prod­ucts for our customers.”

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Photos: Helmar Lünig,, Harro Höfliger