- The new Mespack machine produces stick packs made of oneBarrier recycle-ready monomaterial; the laminated metalized MDOPE film has a high-performance sealant web developed by Bobst and Dow (printed by Poplast)
The most optimal stick pack solution for the pharmaceutical industry has been collaboratively developed by: Mespack (a leading manufacturer of innovative and sustainable flexible packaging solutions); Dow (a global materials science company); and Bobst (the world’s leading suppliers of substrate processing and printing for the packaging industry); and Poplast (a major national player in flexographic and rotogravure printing as well as laminating and slitting processes for packaging).
The sustainable stick pack is produced with a revolutionary pharma vertical form-fill-seal machine and made of oneBarrier recycle-ready monomaterial; the stick packs have a laminated base with a high-performance sealant web metalized MDOPE film developed by BOBST and DOW.
The basic concept of the oneBARRIER project is the following: to be operable, it must completely be end-to-end, in order to ensure exemplary interaction and integration of each stage of the production process, in reference to materials, consumables, equipment, mechanical and electronic components, connectivity, waste streams, ongoing recyclability legislation, among others. The objective is to ensure that the output is the best quality in terms of functionality, attractiveness, and safety; the process must be the most efficient, productive, and profitable. Furthermore, both packaging and process should be the most sustainable and operable, in terms of being produced on an industrial scale, and comply with recyclability guidelines and legislation.
Although obtaining the targets on all counts is challenging, oneBARRIER BOBST has succeeded in creating solutions with current pre-established commercially available solutions. OneBARRIER BOBST is not alone, as forward-thinking companies understood that progress entails collaboration. The oneBARRIER project exemplifies not only the importance of collaboration, but also the importance of beginning with raw materials, before recycling re-circulation under a different form.
OneBARRIER comprises of two streams addressing fibre-based and polyolefin-based flexible packaging substrates that are viable replacements for incumbent multi-material non-recyclable substrates, including metallized polyester:
- FibreCycle – high barrier paper-based mono-material structures coated with functional layers that can be recycled in existing paper/cardboard streams.
- PrimeCycle – high barrier polymer-based mono-material structures that are EVOH- and topcoat-free.
Occasionally, the oneBARRIER solutions can offer the option of clear AlOx as well as the opaque AluBond vacuum metallizing deposition. The selection of either one is dependent on the application and specified requirements: AlOx enables the consumer to view the packaged product; AluBond is especially suited when light or UV barrier is needed; and AluBond if the aesthetic of the metal remains a requisite for the application.
The breadth of the oneBARRIER PrimeCycle project: The vast majority of high barrier multi-material flexible packaging is unsuitable for single stream recycling infrastructures, particularly in areas or regions where recovery streams are self-contained, fractured, and disconnected. This mono-material structure has been created to perform at an equivalent level, rather than that of incumbent structures, such as metallized polyester.
Of what is PrimeCycle made? The PrimeCycle high barrier structure comprises of the following: an MDOPE outer layer (including the package printing surface); a primer coating applied to the film in preparation for metallization; a thin barrier layer applied through paper metallization with either the transparent AlOx or the opaque AluBond technology; and a sealant PE web laminated to the MDOPE outer layer. There is no need for EVOH or additional top coating.
Partners of the pharma stick packs project have jointly overcome the following primary challenges: the PE has critical impediments in relation to heat-sensitivity, extensibility, and low polarity substrate. In comparison to other packaging films such as polypropylene or polyester, it has less thermal resistance, hence maximizing thermal resistance is necessary. The sealant web properties are also optimized in regard to stiffness and dimensional performance. The process encompasses a distinct procedure:
- Resin optimization is fundamental, particularly in reference to the chemistry required to offset polyolefins’ lack of polarity (Dow). Each PE film layer was tailor made for the subsequent MDO machine direction orientation, in order to improve the stiffness and optical properties of the film.
- As a result of the MDOPE web’s low surface energy, the film surface must be coated with primer. A water-based primer formulation (Michelman) provides oxygen and water vapour barrier; it also confers good polarity to the non-polar base film.
- In regard to the primer, coating trials were run on the BOBST oneBARRIER EXPERT COATER to test for the optimal coating method, in order to prevent foam formation when the primer is metered at high speed; the coated film must be uniform (in reference to width thickness) and have no visible coating-related defects. In order to avoid stretching of the PE film when heated, drying must simultaneously ensure rapid water evaporation and maintain a low film temperature. Barrier testing for pinholes were performed after metallization.
- AluBond metallizing on a BOBST EXPERT K5 vacuum metallizer: The AluBond opaque metallizing promotes chemical anchoring (chelation) of the first aluminium particles, thus creating a metallized seeding layer on the web that provides superior bond strength properties. Barrier testing for pinholes were performed before and after metallization.
- Afterwards, the film is laminated to the PE sealant web, which was optimized in regard to stiffness and dimensional performance (Dow); a solvent-free barrier adhesive (developed and produced by Sun Chemical) is used and applied to the substrate with a solventless BOBST NOVA SX 550 LAMINATOR.
- Gravure surface printing with oneECG + OPV on a BOBST RS 6003 platform press installed at Italian converting company Poplast: Film machinability, as well as tenure of the barrier properties that were considered during the substrate development, significantly contributed to offsetting challenges of printing PE in gravure. Subsequently, not only were the highest quality graphic reproduction achieved, but it also benefited from the advantages of BOBST oneECG extended color gamut.
- Vertical form-fill-seal machine by Mespack: The MSPH series, a full servo and stainless-steel machine is available to produce 840 sticks per minute. It perfectly suites to the pharmaceutical industrie due to it complies with specific regulations, such as GMP, GAMP5, FDA, and 21 CFR Part 11. In reference to documentation focused on pharmaceutics, this solution not only offers the execution of DQ, IQ, OQ, RA, but also the preparation of PQ and EN1020 standard 2.1 as well as 3.1 material certificates. Upon request, other forms of documentation can be prepared as well.
To highlight the results obtained: The PrimeCycle packaging substrate delivers a barrier of AlOx OTR + WVTR <0.1 (ultra-high barrier) and eliminates the need for EVOH and topcoat applications. Furthermore, it satisfies the market requirements: a minimum of 2-3 N/15 mm with laminate bond strength.
The oneBARRIER PrimeCycle PE AluBond mono-material stick packs have been certified by the German institute Cyclos-HTP with a recyclability level of 88%, which is well above the target of 70% set by the most recent regulations. OneBARRIER PrimeCycle PE AlOx mono-material, which has been prepared for a variety of applications, has been certified by the German institute Cyclos-HTP with a recyclability level of 98%.
The growing demand for pharmaceutical products that entail strict requirements for compliance with specific regulations, together with the growing sensitivity to sustainability, indicates that companies are working together to innovate and develop solutions that not only integrate these concepts, but also sufficiently meet the needs of the pharmaceutical industry.
