Chemicals

The chemistry of sustainability

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Going along with ecological market trends, today additives and auxiliary chemicals support the green transformation of the paper industry, thanks to their renewed role in the papermaking process.

The road that leads the paper industry to sustainability has many paths. Indeed, companies in the sector are questioning themselves on a daily basis about which paths to choose in order to make their production processes increasingly efficient, as well as the availability and use of raw materials, right up to today’s hottest topic of all, the rationalisation of energy consumption.

In addition to these, however, there are issues that relate directly to the papermaking process, highlighting on this front the role of additives and chemical auxiliaries. Well, from a green point of view, the latter are equally decisive for the contribution they can make to the competitiveness of the paper industry, which is now faced with the challenge of achieving those standards of innovation and sustainability that the market and Italian and European legislators are demanding. Technological and scenario aspects become one, as Giuseppe Li Bassi, President of the Intermediate and Specialty Chemicals Group – Federchimica Aispec, explains.  

In general, how is the role of chemical auxiliaries evolving in the papermaking process? What are the main trends?

First of all, it is good to distinguish the different types of auxiliaries and chemical additives that are used in the paper industry and the different materials they involve. Two types of materials are used in the production of paper and board: fibrous material and chemical substances of inorganic and organic nature, i.e. chemical additives and auxiliaries. The percentage of recycled paper that is used in production is also increasing.

Additives are chemical substances that are introduced into the fibrous pulp to give the finished paper specific properties of mechanical, physical, weather, humidity and grease resistance, but also optical and aesthetic characteristics or printability. They can be added to the stock while it is still wet (in which case we speak of internal or wetend addition), or on the finished paper sheet after complete or partial drying (surface or dry end addition).

Processing aids, on the other hand, are chemical substances that facilitate the operating conditions at the various stages of the papermaking process, improving the economy of the process itself. In general, auxiliaries do not appear in the final composition of paper or board, as they do not remain incorporated in the fibrous pulp; however, there are exceptions, such as certain auxiliaries that form stable bonds with the fibrous substrate.

Is the distinction between additives and auxiliaries always so unequivocal?

Of course, the distinction between additives and auxiliaries is not always so clear-cut, as in some cases the same chemical may act as both an additive and an auxiliary. Typically, the role of chemicals in the papermaking process can be divided into four stages: pulp production from wood and annual plants, wet web formation, paper sheet finishing and finally the recycling of paper materials. The most important stage of the production process is certainly the wet phase, in which various chemicals are used that are, both in terms of quality and quantity, the basis of the end result. At this stage, knowledge of the morphological, structural and chemical-physical properties of the fibres together with the characteristics of the entire production system are a priority.

What trends are emerging or consolidating?

The papermaking process requires continuous innovation and chemical auxiliaries play a fundamental role in the papermaking process, not only in terms of quantity, but also as responsible for the outcome of the final product. The trend that has been developing in recent years is an increasing focus on the environmental aspect with more sustainable products. The main trends are focused on proposing performances that have a direct and indirect impact in terms of sustainability, linked to different aspects of the production and use of the products, such as guaranteeing a reduced need for water to mitigate the energy expenditure subsequently used to remove it.

In addition to responding to sustainability needs, there is also a well-established trend to look for alternative chemicals, while keeping performance as much as possible unchanged, to counter the countless supply chain disruptions that occurred during 2022.

Going into more detail, how is paper chemistry changing to support papermaking in terms of quantity and quality?

Paper chemistry is increasingly emphasising the development of products with an increasing renewability content, in order to reduce the use of fossil-based products, thereby improving LCA and carbon footprint indicators. In addition, there is a macro-trend in research and development, directed at the production of functionalised papers for food use, to replace multilayer packaging, which may be less compatible with the requirements of the new European plastics legislation.

From the point of view of additives and auxiliaries, for example, synthetic latex products can be replaced with renewable and recyclable starch-based products, or fluorinated ingredients, used with a barrier effect against fats, with more sustainable products with less environmental impact.

What contribution can paper chemistry make to support the ecological transition and sustainability of the paper industry?

Due to the increasing amount of recycled paper in the production stages, the quality of cellulose fibres decreases and consequently there is a reduction in the mechanical properties of the finished product. With a view to sustainability and ecological transition, the use of additives and auxiliaries derived from starch makes it possible to compensate for this, thus allowing an increase in the proportion of pulp in production.

Furthermore, in addition to the trends in functionalised papers for food use, even in so-called luxury packaging, the focus is increasingly shifting in the direction of products with a high renewability content, while retaining the special quality and customisation characteristics of this specific packaging sector.

Can chemistry for paper also help the paper industry to meet the challenge of rising energy costs?

Like other sectors, the paper industry is also hard hit by the energy increases of recent months. Like other sectors, the paper industry is also hard hit by the energy increases of recent months. The challenge for companies supplying additives and auxiliaries to paper mills is to continue to offer efficient products that allow the paper mill to reduce CO2 emissions and also to search for new ingredients that can drastically reduce the amount of energy needed to dry paperboard. 

What market or technological trends will characterise the future of paper chemistry?

In the light of EU strategies, recently approved or under discussion (Chemical Strategy for Sustainability, European Green Deal, Sustainability by Design, Strategy on Plastics and Packaging), and given the rapid transition from plastic to paper-based packaging, solutions will have to be found to support any changes resulting both from company choices in the supply chain and from the guidelines dictated by the EU legislator.

Generally speaking, the research and development trends that will define the future of the sector are linked to the development of products (auxiliaries or additives) that will allow the paper mill to reduce CO2 emissions, enable the production of finished articles in line with European Strategies (e.g. barrier papers for food use) and the development of products with an LCA/Carbon footprint increasingly aimed at all-round sustainability.