Environmental performance: label materials selection and usage

In the case of FSC – which is probably the most widely used worldwide – label converters that become certified are eligible for an on-product FSC logo use that ensures CoC certification and provides their customers with a guaranteed FSC product. Essentially, the basis of the CoC certification is that any FSC labeled product can be traced back to a certified source (see flow chart above).

A brief outline of the main organizations that label paper mills work with for certification and chain-of-custody verification are:

Forest Stewardship Council - The Forest Stewardship Council (FSC) is also a non-profit organization that encourages responsible management of the world’s forests and provides global standards for forest management which cover a balance of environmental, social and economic aspects. The well-being of forest communities and ecosystems is as important as replacing trees in ensuring the future of the world's forests.

The FSC system also provides a way of tracking forest products through independently verified and documented CoC certification. This has to cover every stage in processing, conversion, distribution and printing before the final product can carry the FSC logo.

The FSC's international headquarters are located in Bonn, Germany, but contact persons and national offices can be found today in more than 40 countries, thereby creating a truly global FSC network.

Carrying the FSC certification logo on a label converter’s products tells the label industry, customers and market that they support the highest social and environmental standards in the markets and applications where the labels are produced and used. However, for a label to carry the logo it must be printed on FSC paper by an FSC certified label converting company.

FSC certification is supported and encouraged by major worldwide trusted environmental organizations that include well-known names such as Greenpeace, National Wildlife Federation, The Nature Conservancy and the World Wildlife Fund.

Label users and consumers wishing to support healthy forests and communities should look and ask for FSC, or other certification, labels when purchasing label paper products.

Sustainable Forest Initiative - SFI Inc. is a fully independent, charitable organization dedicated to promoting sustainable forest management. Its forest certification standard is based on principles that promote sustainable forest management, including measures to protect water quality, biodiversity, wildlife habitat, species at risk and forests with exceptional conservation value. The standard is used widely across North America, and has strong acceptance in the global market.

SFI chain-of-custody certification extends into the market by tracking fiber content from certified lands through production and manufacturing to the end product, so that consumers who buy products with the SFI ‘percent-content’ label know they are buying products from responsible sources.

The SFI labels are recognized globally and provide a visual cue to help customers source certified forest products.

Programme for the Endorsement of Forest Certification (PEFC) schemes - The PEFC Council is an independent, non-profit, non-governmental organization founded in 1999 which promotes sustainably managed forests through independent third party certification. PEFC provides an assurance to purchasers of paper products which ensures that they are promoting the sustainable management of forests.

There is also a Finnish Forestry Certification Scheme (FFCS) that was developed by the forestry sector and forest owners. This scheme is one of a number that now operate under the PEFC umbrella.

USING PAPER WITH A RECYCLED CONTENT

An increasing number of label papers now have some level of recycled fiber content. However, paper cannot be recycled indefinitely as the fibers will gradually get shorter and weaker. This means that some virgin tree pulp must be introduced into the process so as to maintain the strength and quality of the fiber and finished paper.

Using recycled paper fibers in label papers is claimed to use between 28 percent and 70 percent less energy, save up to 55 percent in water consumption and also substantially reduce carbon emissions – in some label paper mills by up to 20 percent. The use of recycled content label papers therefore already makes sound economic and environmental sense.

In addition, recycled paper also produces fewer polluting emissions to air and water. It is not usually rebleached and where it is, oxygen rather than chlorine is usually used. This reduces the amount of any dioxins which are released into the environment as a by-product of the chlorine bleaching processes, and also keeps waste out of landfills. So, using recycled paper in label grades is seen as being particularly environmentally friendly.

However, it should be noted that there are different sources of paper waste fibers that can be used as a source material for manufacturing recycled paper grades and the label converter may wish to be aware of which sources are the most acceptable:

• Mill broke for example is ‘waste’ paper which has never been used by consumers and may include paper mill waste, laminator waste, printer waste, reel ends, off cuts or rolls damaged during production. When mixed with water the fibers from this waste are freed into pulp.

However, it should be noted that the National Association of Paper Manufacturers does not recognize a paper as recycled if it contains more than 25 percent mill broke and/or virgin wood pulp.

• Post-consumer waste (PCW) is waste paper which has been printed on and used and then collected for recycling; it is seen as more problematic because it needs to have ink and other contaminates removed from it during the pulping stage – but still it is worthwhile. Although the de-inking process uses water and chemicals, it is still less harmful to the environment than the manufacturing process of new paper. Indeed, detergents are used to float-off the ink, where it is removed, solidified and then used for the production of products such as cat litter and soil conditioners.

• Release liner waste is now starting to be collected by organizations such as cycle4green in Europe and recycled into new liner grades, in this case, by Lenzing Papier in Austria. The liner is desiliconized and separated in a newly developed process. This is a cost-free collection service for a minimum single pick-up of three tons.

Modern label papers using recycled paper fibers are visually indistinguishable from 100 percent virgin fiber papers. Good quality labelstock grades containing recycled paper are produced by a number of label paper mills and also incorporated into pressure-sensitive laminates.

Apart from certification for papers made from 100 percent certified virgin fibers, the FSC also operates certification for papers which contain 100 percent recycled post-consumer waste (PCW)  – another for papers with at least 85 percent post consumer; the balance preconsumer, and a third being a credit account of post and preconsumer (no virgin fiber).

Arjowiggins, for example, now offers an eco-friendly one-sided label paper that combines 60 percent certified recycled pulp with 40 percent FSC-certified virgin fiber pulp. Other suppliers, such as Avery Dennison, offer label grade papers that are, say, 30 percent post-consumer waste.

With such possibilities on the market, label converters should review the ranges of recycled content label paper grades available from their labelstock or laminate producers and assess their possible usage and applications with their customers.

USING THINNER, LIGHTER AND REDUCED BASIS WEIGHT PAPERS

In recent years considerable work has been undertaken by paper mills to reduce the amount of fiber that goes into label grades, gradually reducing the basis weight, making the papers thinner and lighter – but without affecting the paper’s performance during printing, converting or application.

Constant quality improvements over the years have permitted the use of lower grammage/basis weight papers for labelstock and label liner applications. A reduction from 67 to 60 g/m. for example, can save over ten percent of liner material for each million square meters of labels converted. Some label grades of face or liner paper may today be as low as 50 g/m. or even down as low as 25 g/m.. Such reductions also mean more paper will be on rolls. In turn, longer rolls allow considerable savings on core and wrapping materials as well as on roll-change-related waste in the manufacturing process – and longer running between reel changes.

In addition, improvements in surface properties of, say, pressure sensitive liner grades have enabled significant reductions of silicone coat weight over the years, and/or lower curing temperatures. Add all these elements together and that’s quite an achievement in today’s environmentally challenged world. It therefore makes sense for both label converters and buyers to use thinner labelstocks wherever feasible.

USING CHLORINE-FREE OR OTHER CHEMICAL-FREE PAPERS

A number of different chemicals are involved in the pulping stage of papermaking. Of these, chlorine – which has traditionally been used for bleaching wood pulp to make it white – is amongst the most damaging. 

However, most paper mills, especially those found in Europe and North America, now produce ‘Elemental Chlorine Free’ (ECF) papers which are bleached through the use of oxygen, chlorine dioxide or other chemicals instead of using chlorine gas. This is a much less environmentally damaging pulp producing process and is an important consideration in the gradual elimination of dioxide created by chlorine bleaching.

Even better for the environment are those paper mills that use a Totally Chlorine Free (TCF) technology. These are papers bleached without the use of any chlorine compounds at all. Indeed, in countries like Sweden and Germany, chlorine-free papers are regularly produced. Sweden, for example, has a law that requires the elimination of organochloride emissions from paper.

There is arguably little difference between paper grades that are ECF and TCF in their environmental impact on the pulp bleaching process, and both are significantly less polluting than traditional chlorine gas methods. Tremendous progress has been made in these areas in recent years. Any paper brands carrying the Blue Angel mark are certainly required to be TCF.

In terms of recycled paper, a Processed Chlorine Free (PCF) process is used for some recycled grades. Blue Angel is perhaps recognized as the most stringent labeling system for recycled paper. This requires a minimum of 51 percent printed and domestic/office waste and also requires companies to report on the energy used in the manufacturing process.

While chlorine free papers are now widely used, there is also a requirement for some other types of paper that are free of certain other chemicals. Acid-free label papers, for example, have specific applications and have also gained increasing interest. These are papers which contain no free acid and have a pH value of 7.0 or greater. Such papers may be produced from cotton fibers or chemical wood pulps, or virtually any other fiber.

However free of acid the paper may be after manufacture, it must also not have aluminum sulfate (alum) sizing applied to the surface. Unless the paper has been buffered with a substance capable of neutralizing acids (calcium carbonate), it is still possible that pollution in the atmosphere will make the paper acidic over time. 

The term ‘acid-free’ does not necessarily mean the paper is safe to use in, say, archival applications. The label converter will need to look for additional specification on what the paper is made of, cotton or purified wood pulp, buffering content and  whether neutral or alkaline sizing is used.

In general, acid-free specified paper grades are required for archivists, conservators, curators and other collection-care specialists who need a variety of acid-free label formats for their laser printers. Stickers for children and foods may also need to be acid-free. It is said that acid-free papers are brighter and cheaper than acid-containing papers.

CO.-free papers are also available, but on a limited basis due to the number of certifications held. The CO. footprint for the paper is calculated using the IPCC method which accounts for the most important greenhouse gases.

Label converters and their customers should again be reviewing the label papers that they use to determine, if possible, their chemical content and use or recommend those EFC, TCF, PCF, CO.-free or acid-free grades most suitable to the their products and applications.

USING COMPOSTABLE AND BIODEGRADABLE PAPERS

In some label applications today there is a need for a (self-adhesive) roll-labelstock that is biodegradable or compostable so as to comply with ISO 14855 or EN13432. ISO 14855 is the standard that determines the ultimate aerobic biodegradability of materials under controlled composting conditions. EN13432 is the European compostable standard, if the label represents less than one percent of the total packaging weight, and where biodegradability certification is required.

According to the EN13432 standard, for example, a compostable material must meet three conditions:

• Biodegradation - The compostable material must break down through microbial action producing only carbon dioxide, water and humus (soil). The standard dictates that this process must be 90 percent complete within six months

• Disintegration - The compostable material must satisfy a disintegration test three months after the composting process begins. The standard demands that no more than 10 percent of the original mass of material have particle sizes greater than 2mm after this three month period

• Absence of toxic materials - When fully composted the compostable material must have no negative effects on the composting process. This is checked by a composting test

Some label material suppliers now offer materials to meet these standards; in particular, materials that are suitable for organic food packaging and branded products where the label needs to be compostable with the packaging, as well as for shelf-stable and chilled products that need to be environmentally friendly.  Label substrate options include white elemental chlorine free (ECF) non-coated, semi-gloss and kraft natural unbleached papers. These substrates need to be used with a fully biodegradable/compostable, environmentally benign, eco-friendly adhesive, such as products described under the next heading.

USING ECO-FRIENDLY, ENVIRONMENTALLY BENIGN ADHESIVES

Over the past few years there have been increasing numbers of inquiries for adhesive products that have any kind of ‘green’ attributes, and that certainly includes things like environmentally benign adhesives, adhesives for recycling compatibility, adhesives that can be composted, bio-degradable adhesives, adhesives that can be easily removed or washed off, etc. See Figure 3.3.

• We encourage and promote with our customers the use of chain-of-custody certified face and liner papers that provide a guaranteed product has been tracked from its point of origin to the point of it being printed and dispatched. The papers are either produced from a recycled fiber content and/or virgin fiber obtained from sustainable forests (FSC, FSI or PEFC certified

• We encourage and promote with our customers the use of papers with stringent environmental specifications that include ECF, TCF or acid-free characteristics

• We continue to evaluate and review the use of tree-free papers made from agricultural waste and encourage their use where appropriate

• We constantly review and promote the availability of thin film constructions that reduce waste, enable more labels per roll, reduce reel changes and encourage shipping efficiencies

• We specify recyclable plastics (PP and PET) where technical requirements allow and continually trial and encourage the use of bio-plastic, cellulose and surfaced layered cellulose films that offer biodegradability and compostability to meet the appropriate international EN 13432 or ISO 14855 standards

• We use environmentally friendly 100 percent solvent-free adhesives – whether water-based acrylic adhesives or hot-melt adhesives – for the majority of applications in preference to solvent-based adhesives

• We are evaluating the use of bio-friendly adhesives and look to encourage their use where technical requirements allow