The future of monomaterial flexibles

Recyclable packaging that protects

Concern around natural resource depletion has increased for businesses and consumers alike. In turn, this concern increases the drive toward a circular economy – where recycling is a basic fact of life. For the packaging industry in particular, recyclability is no longer a ‘nice extra’, but an essential.

Achieving circularity can be challenging for packaging manufacturers however, especially when it comes to flexible barrier packaging, such as retort pouches and multilayer laminate. Recycling these types of packaging often requires separating various polymers and metal foils – which can be expensive or impractical. Manufacturers face the challenge of simplifying their flexible barrier packaging. This often involves moving toward monomaterials constructed from similar, or identical, polymer grades that can be recycled in a dedicated single stream.

Nevertheless, many traditional monomaterial packaging solutions fail to deliver the levels of functional performance that consumers expect. Specifically, maintaining sufficient barrier performance – the ability to keep food or other perishable goods safe – is a key concern in reduced-material or monomaterial designs. In line with the growing need for monomaterial solutions that retain functional performance, we offer a portfolio of resins for respective adhesive and coating solutions. These enable manufacturers to replace extra material layers with thin functional layers – enabling high-performance monomaterial packaging.

What is a monomaterial?

A monomaterial contains predominantly one material type, such as polyethylene (PE), Low density polyethylene (LDPE), linear low-density polyethylene (LLDPE), high density polyethylene (HDPE), polypropylene (PP), polyester (PET) or paper. (Ceflex) For plastics, this should mean over 90% of one polymer type, as this is the upper threshold when adhesives, additives, and inks are included.

Film and flexible packaging substrates

In contrast to multi-functional multi-material laminates,  monomaterials’ functional performance has been particularly limited in flexible packaging, as alternatives are needed to replace the function of a layer to be replaced. Whatever packaging monomaterial solution you are aiming for, we can provide an approach for you. Our coating resins can add protective features to a wide range of film and flexible packaging substrates.

Biaxially oriented polypropylene (BOPP).
Biaxially oriented polyethylene (BOPE).
Biaxially oriented polyethylene terephthalate (BOPET).
Polylactic acid (PLA).

Excellent functionality in key performance areas

Packaging manufacturers also need to ensure high functionality in areas besides barrier performance and recyclability. Our resins and crosslinker for monomaterial packaging offer all the key properties our customers expect, including:

• Non-blocking properties
• Heat-sealability
• Good adhesion
• Printability
• High transparency
• Surface enhancement
• Food contact compliance

Building on a tradition of innovation

Building on our history of creating high-performance resins, we developed new solutions that meet emerging customer and market needs. We have long been at the forefront of innovating adhesive and coating solutions for the packaging sector. High-performance monomaterial packaging using the latest coating resin technology is just one example of the type of global trend we continue to help set.

And we are not stopping there: we are already developing the next generation of monomaterial solutions through our core research program. What is more, because all our innovation is guided by our customers’ needs, we actively involve our customers in our R&D efforts. 

An extensive range of raw materials for adhesives and coatings 

Our portfolio of resins and crosslinkers for adhesives and coatings in monomaterial designs addresses the requirements derived from the European Packaging and Packaging Waste Regulation (PPWR). It includes recycling compatible raw materials for laminating adhesives, for primers utilized on difficult olefinic substrates, for protective and barrier coatings, as well as for inks, heat seals and topcoats. 

Primers (for topcoat adhesion or for metallization)

Primers are initial coatings applied to a substrate to improve the adhesion of subsequent layers or coatings, to increase their durability, and to provide additional protection for the substrate. In particular, primers are always required with heat-sealable coating layers, which can enable sealing on stretched and oriented BOPP and BOPET film. This is done in order to achieve the required strength and consistent adhesion.

Exemplary grades for primers: NeoCryl® A-1127 (EMEA & NMA) (metallization), NeoCryl® BT-36 (EMEA & NMA) (metallization), NeoRez® R-605 (EMEA & NMA) and NeoRez® R-670 XP (EMEA).

Topcoats

Packaging has a long journey to make before it reaches the shelves. While being handled or transported, its protective features might be weakened through scratching, condensation, or extreme temperatures. In particular, the barrier properties of film packaging can severely deteriorate in these conditions. For this reason, the protective topcoat layers that protect the barrier are as important as the barrier itself.

Exemplary grades for topcoats for protection/ heat-sealing or with aroma and flavor barriers/ mineral oil barrier: NeoCryl® A-1127 (EMEA & NMA), NeoCryl® A-1129 (NMA), NeoCryl® A-2092 (NMA), NeoCryl® BT-67 (EMEA & NMA), NeoCryl® BT-36 (EMEA & NMA), NeoCryl® FL-715 (EMEA & NMA), NeoCryl® FL-721 (EMEA & NMA) and NeoCryl® FL-736 XP (EMEA) and NeoCryl® XK-14 (NMA).     

Adhesives for lamination

Materials can be combined to customize packaging functionality so as to suit particular characteristics of the product or environment where it will be used. This offers a lot of flexibility, and adhesives play an important role in this. Keeping the total amount of adhesives used below certain thresholds reduces the impact upon the recyclate quality. Adhesives can reportedly cause gel formations during the extrusion process, which can reduce the recyclate quality, and block the screen filters on the extrusion line. Adhesives, such as polyurethane, acrylic, or natural rubber latex adhesives as well as non-polyethylene (PE)- or non-polypropylene (PP)-based tie layers, can comprise a maximum of 5% of the total structure’s weight. The limit is to optimize the quality of the recyclate and to avoid disruption of the recycling process.

Check out our broad portfolio for laminating adhesives.