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Stand-up pouches are one of the fastest growing packaging concepts, which are replacing the traditional packaging formats. In this study, stand-up pouch prototypes are prepared from cellulose fatty acid coated heat-sealed virgin kraft paper with leak proof seals. This study demonstrates that molar mass controlled cellulose ester (C6-C16) coatings can significantly improve the barrier properties of virgin kraft paper. All cellulose ester coatings performed better compared to that of PLA. Cellulose ester coatings also improved the resistance of virgin kraft paper against tested nonpolar oil and grease compounds. In addition, the cellulose ester coatings had no antimicrobial activity, and fewer microbes adhered to them than to the PLA surface. The results demonstrate that cellulose fatty acid ester coatings have high potential in future applications requiring good barrier properties.

According to an example aspect of the present invention, there is provided bio-based mineral oil barrier coatings and films usable for decreasing mineral oil migration, for example in food packaging materials, and thus improving the safety of the materials facing the mineral oil containing environment.Patent family as of 17.12.2021EP3411231 A1 20181212 EP20170747055 20170203 EP3411231 A4 20190904 EP20170747055 20170203 FI127441 B 20180615 FI20160005075 20160203 FI20165075 A 20170804 FI20160005075 20160203 US2019001647 AA 20190103 US20170063300 20170203 WO17134345 A1 20170810 WO2017FI50058 20170203Link to current patent family on right

Pakkausmateriaalien kehityksessä on mielenkiinto viime aikoina voimakkaasti lisääntynyt vaihtoehtoisia, biopohjaisia ratkaisuja kohtaan. VTT panostaakin omassa liiketoiminnassaan tälle alueelle, ja on jo saavuttanut tuotepilotoinnissaan maailmanluokan tuloksia.

The aim of this presentation is to demonstrate totally bio-based multilayer barrier packaging films. These films were prepared with a thin coating of fibrillated cellulose as an effective barrier against oxygen and/or mineral oil residues. It is shown that such films are feasible for packing of dry foods in formats such as bag-in-box, flexible pouches, and most recently in paper-based stand-up pouches. The cellulose fibrils can provide the films with a barrier suitable even for demanding products and for modified atmosphere packaging (MAP). For example, the bio-based MAP pouches containing ground hazelnuts were able to retain both their shape and internal atmosphere, while maintaining the original product quality. However, processes such as irradiation and aggressive compounds from the food product were found to impair the oxygen barrier provided by the fibrillated cellulose.

The aim of this presentation is to demonstrate totally bio-based multilayer films. These films were prepared with a thin coating of fibrillated cellulose as a barrier against oxygen and mineral oil residues. Such films are feasible for packing of dry foods in formats such as bag-in-box, flexible pouches, and most recently stand-up pouches. The cellulose fibrils can provide the films with a barrier suitable even for more demanding products and for modified atmosphere packaging.

The present invention relates to a continuous roll-to-roll process for improving the water tolerance of bio-based polymers, in particular cellulose nanofibrils (CNF) films. Furthermore, the invention provides a method, which combines surface modification/functionalization for improving water stability and wet strength, UV/Ozone treatment, corona treatment or plasma activation for purifying and activating the surface and thus increasing the reaction efficiency, and further hydrophobization of the surface of CNF film.Patent family as of 30.11.2021DE602015030549 D1 20190606 DE201560030549T 20151130 EP3224305 A1 20171004 EP20150862244 20151130 EP3224305 A4 20180606 EP20150862244 20151130 EP3224305 B1 20190515 EP20150862244 20151130 ES2739478 T3 20200131 ES20150862244T 20151130 FI126761 B 20170515 FI20140006044 20141128 A 20160529 FI20140006044 20141128 US10786829 BB 20200929 US20150528522 20151130 US2017266693 AA 20170921 US20150528522 20151130 WO16083674 A1 20160602 WO2015FI50835 20151130Link to currentpatent family on right

Several standard or material specific methods for grease barrier testing are being used. Results are expressed either as the time in which a test liquid has penetrated through a packaging material or as the amount of liquid which has penetrated through the material during a certain time period. However, such tests are not accurate, and there was a need for a new and more quantitative test method. A new test method developed by integrating two previous standard methods will be presented. Dyed oil or grease is placed on the food contact side of the sample under a specific weight. The reverse side is then scanned after pre-selected time intervals. This method combines visual data with a numerical result obtained by image analyses. Likewise, there are several methods for testing mineral oil hydrocarbon (MOH) barrier of packaging materials. Such mineral oil residues in food have raised concern as potential genotoxic carcinogens during the recent years, especially in Europe. These contaminants may originate from printing ink residues from recycled paperboard, certain additives, processing aids, and lubricants. A test method for MOH barrier will be presented in which the mineral oils are introduced to the test system in the gas phase. The amount of MOH diffused through a packaging material and absorbed into a food simulant is determined by gas chromatography. Focus was on compounds of relevant molecular weight, and using equipment and materials which are commercially available.

Nanocellulose, also referred to as cellulose nanofibrils (CNF) is one of the most studied innovations for the modern forest sector. Until very recently, CNF films have been produced at small-scale using slow filtration methods. In this presentation, the first steps towards continuous CNF film production are presented. VTT’s semi-industrial roll-to-roll pilot-line was successfully utilized in producing high quality CNF films with some promising technical properties (oxygen barrier, temperature resistance, tensile strength). However, as single layer CNF films have relatively weak moisture resistance, flexibility and zero sealability, the multilayer structures were also produced. Tempo-oxidized CNF was first dispersion coated onto PET film and further extrusion coated with LDPE resulting in a 3-layer structure: PET/CNF/LDPE. 3-layer structure had excellent technical properties which fulfilled the requirements of modified atmosphere food packaging. Demonstrator pouches filled with nitrogen were produced with the packaging machine and the oxygen concentration inside the packages was monitored as a function of time. As a result, CNF containing multilayer films performed better as compared to commercial 3-layer multilayer films containing EVOH barrier layer. The developed films could be used as a packaging material for dry or low moisture content food products such as dry snacks, dried fruits, nuts, spices etc.

Cellulose nanofibrils were produced from various biobased raw materials by grinding and high pressure homogenization. Films were produced by Erichsen lab-scale coater from banana, sugar beet, hemp, softwood and hardwood pulps, and plasticized with 30 wt% of sorbitol. Water vapor transmission, grease penetration, oxygen transmission, and mechanical properties including tensile strength and strain were measured and compared against each other. All films had high water vapor transmission rates varying between 20-24 g×mm/m2/day. Due to high number of polar hydrogen bonds in CNF, the films were impermeable to grease. All films had excellent oxygen barrier properties (2/day) at dry conditions, whereas at 80% relative humidity (RH) the transmission rates increased rapidly. There was not much difference between the oxygen transmission rates (OTR) of different films, thus, all OTRs were ranging between 2.9-5.2 cc×mm/m2/day at 80% RH. All films were strong, translucent and easy-to-handle. Unbleached softwood CNF films had the best mechanical properties (tensile strength of 150 MPa and strain of 16%).

Properties of nanocellulose vary according their method of production and composition of raw materials. Recently, alternative raw materials such as sub-products of agroindustry and industrial crops have gained significant attention for the production of nanocellulose. This implies an important addition to the biorefinary concept, increasing the value chain of products such as sugar and ethanol. In this work, several raw materials like sugar cane, hemp and banana fibers were used to produce nanofibrillated cellulose (CNF). These CNF were characterized in terms of their suspension behaviour, chemical composition, rheology, morphology and structural behaviour and such properties compared to the nanocellulose traditionally obtained from bleached wood fibres. The suitability of the different materials in application tests such as paper additives and nanocellulose film production will be discussed.

Cellulose nanomaterials have unique properties that make them potential for numerous applications. One of their most promising applications is transparent cellulose films with excellent strength, density and smoothness. Cellulose films could be utilized as gas barriers in packaging, substrates for printed electronics, in diagnostics or even as electronic displays instead of oil-based plastic films. From the safety point of view, the advantages of cellulose nanomaterials have been argued to be their benign nature towards humans and the environment as well as their biodegradability. However, when used in products, the biodegradability of cellulose nanomaterials might differ from that of pure materials. For example, during film preparation, the hydroxyl groups in the surface of cellulose nanofibrils form strong hydrogen bonds, which upon drying of the film could make it more resistant towards degradation. Results on the biodegradability of different grades of cellulose nanofibrils (CNF) and their products, namely CNF films and papers coated with CNF are presented in this paper. In addition, results on the toxicity of cellulose nanofibrils to humans as well as ecotoxicity during biodegradation in the composting environment are reported. The results of biodegradability tests (OECD 301B) of two different grades of CNF indicate that their biodegradability is dependent on the fibrillation degree, the finer grade degrading faster than the coarser grade. The biodegradability test (EN 14046) of CNF films and papers containing CNF showed that all the CNF products tested were biodegradable according to the requirements set in the standard (EN 13432). In the composting test (EN 14045) disintegration of CNF products was observed in the composting environment with no acute ecotoxicity during biodegradation. Regarding toxicity to humans, some indication of cytotoxicity was observed for nano-scale cellulose fibrils. However, all the other toxicity tests results, including in vivo tests with Nematode, showed no sign of toxicity.