As developing regulatory pressures exert an increasing influence on materials selection in flexible packaging design, Paramelt has continued to develop its Aquaseal™ range of water-based heat seal and barrier coatings to meet these ongoing demands.
One particular area of market concern relates to the use of solvent-based vinyl lacquers in a range of applications, particularly on aluminium foils. The use of vinyl chloride monomer is limited to an SML of 1mg/kg in all direct food contact applications on a pan European basis and continues to have a negative environmental image.
In addition the presence of residual solvents from these lacquers can give a detrimental effect on both organoleptic properties and food safety.
In addition the presence of residual solvents from these lacquers can give a detrimental effect on both organoleptic properties and food safety. This combination of factors is driving an increasing demand from both food producers and the retail chain to discontinue the use of these materials.
Bluewave™ technology platform
In two particular areas Paramelt has recently introduced some exciting new products within the Aquaseal range, produced using the new Bluewave™ technology platform developed in partnership with Dow.
- For aluminium lidding foils, a fully water-based combi-lacquer dispersion, based on chlorine free, high molecular weight thermoplastics, has been developed offering excellent sealability to both polypropylene and polystyrene substrates. This product, particularly targeted at the dairy sector gives, excellent seal and peelability characteristics combined with the necessary resistance properties against water, fat and lactic acid.
- For thinner heat seal foils, intended for diverse applications such as soup cubes, processed cheese and chocolate wraps, Paramelt has developed a range of aqueous, ethylene copolymer emulsions which provide excellent adhesion to aluminium combined with good lay down, film formation, flexibility and crease resistance.
Offering superb barrier characteristics and tailored minimum sealing temperature, Paramelt can provide a comprehensive range of alternatives to the use of plasticised vinyl systems.
For further technical information please contact Mr Leon Krings.
Bluewave™ is a trademark of The Dow Chemical Company
Aquaseal™ technology platform
Paramelt established the world’s first commercial capability for the mechanical dispersion of high molecular weight, thermoplastic polyolefins and styrene block copolymers in water.
Aquaseal™ technology platform
At Paramelt we have licensed the unique DOW Bluewave™ technology platform which enables us to disperse a broad range of thermoplastic materials at high solids in water. These consists of mainly polyolefinic materials which have only previously been processable by extrusion technology.
This unique capability opens up an innovative range of new potential applications for water-based coatings. Paramelt is able to offer these polymer dispersions either as binder system or additive into traditional water-based coatings but also as fully formulated aqueous coatings for diverse of applications.
Until now, access to the true capabilities of these materials has only been possible by extrusion, lamination or hot melt coating. Where application via printing or liquid coating techniques were required, the formulator had to compromise on polymer selection or was limited to high melt index (waxy) materials whose performance was substantially below that of the extrusion grades.
In packaging for example, this extends the range of materials available to the converter using standard printing and coating methods; i.e. the same materials which are typically applied by film lamination, extrusion coating and high-performance hot melt formulations can now be directly coated from dispersion in water.
The introduction of this new technology opens up the full formulatory envelope, allowing the coating designer to completely optimise target properties, without the need to compromise for dispersibility.
In essence, the Aquaseal concept offers:
- Unique aqueous high shear dispersion technology
- Production of high molecular weight, thermoplastic polymer dispersions in water
- Revolutionary potential for innovation in coatings, sealants & adhesive layers on a large variety of substrates.
- Application of extrusion grade polymers using printing & coating techniques
- Water-based, safe and reliable technology
- Access to totally new markets and applications for polyolefins
- Expanded design space to create totally new product concepts
Benefits of Aquaseal™
The introduction of the novel Aquaseal technology opens up the full formulatory envelope, allowing the coating designer to completely optimise target properties, without the need to compromise for dispersibility.
Benefits of Aquaseal™
The introduction of the novel Aquaseal technology opens up the full formulatory envelope, allowing the coating designer to completely optimise target properties, without the need to compromise for dispersibility.
This versatility in material selection enables product property optimisation based on application requirements rather than material limitations. In this way, products can be designed to achieve the best balance of characteristics such as:
- low in-reel blocking
- effective barrier
- direct food contact
- adhesion to both polar and non-polar substrates
- tailored seal initiation temperature and sealing range for maximal operating window
- effective wetting and lay-down of coating
- controlled coefficient of friction (CoF)
Once the base binder dispersion has been validated for the application, Aquaseal dispersions can be further optimized using common formulatory components, in order to deliver the full package of application requirements:
- rheology and surface modifiers
- flow and levelling additives
- wetting agents, defoamers
- fillers and colorants
- cross-linkers
- stabilizers and biocides
Aquaseal™ polymer dispersions and formulated coatings offer numerous economic and environmental benefits:
- suitability for heat sensitive substrates
- potential for significantly lower coating weight compared with extrusion
- possibility for partial coating to provide functions only where needed
- high solids (up to 60%) offering reduced supply chain costs and environmental impact
- application using standard printing/coating methods: flexo, gravure, rotary screen, air knife etc
Solvent free alternatives to solvent-based lacquers:
- reduced environmental impact
- lower processing hazards
- regulatory compliance
- reduced solvent costs