Sustainable printing methods: flexo and screen printing, gravure printing, lithography, offset printing

As the manufacturing society moves toward greener practices, it's important to consider whether you're using sustainable printing methods. 

Not only do you want to use sustainable materials like recyclable substrates and low-VOC inks, but you also want to optimize your pressroom to reduce waste. 

So it begs the question, "Which printing method is the most sustainable?" Is it flexo printing, or something else?

very unsustainable printing method

There are many printing methods available to manufacturers in the printing world, but this does not mean that all printing methods are good choices for sustainable printing shops. 

Coincidentally, some popular printing methods are also very unsustainable. for example: 

• gravure printing

• Offset printing

• screen printing

• offset printing

gravure printing

In the long run, gravure printing can be said to be a very unsustainable printing method. 

Gravure printing requires a metal cylinder to carry the ink, which is applied to the depressed portions of the cylinder. The rollers usually only carry one color, and the inks used in the process are highly solvent-based, creating harmful by-products.

Offset printing

While lithography offers some more sustainable practices in terms of the materials used, the multi-step process of lithography adds a lot of extra effort to the print run. Requiring transfer to linerboard , lithography has also been greatly limited in its applications.

screen printing

Screen printing is a valuable printing method because of its ability to produce vibrant colors. However, screen printing is one of the very unsustainable methods available for mass production.

Screen printing inks often contain harmful chemicals such as phthalates, which can easily bleed out after the product cures. Screen printing produces toxic fumes and almost all materials used are non-recyclable hazardous waste. 

As if that wasn't enough, reusing inks and screens is difficult. While screen printing may work well on some substrates, it is an unsustainable method of high-volume production.

offset printing 

Offset printing is a form of indirect printing that uses a printing plate to transfer ink to a rubber cylinder called a blanket, which then transfers the ink to the substrate. 

On the sustainability spectrum, offset printing is somewhere in the middle. It requires more equipment, the blanket roller, and takes longer to set up. In addition, inks used in offset printing are usually oil-based, requiring the cylinder to be cleaned after each use. Oil-based inks often contaminate the water used to clean them.

The Most Sustainable Method: Flexo Printing

Flexo has been proven time and again to be the most sustainable printing method. Flexo printing enables easy printing on flexible substrates, allowing the use of more sustainable and recycled materials . 

Flexo printing can be adapted to water-based inks and methods such as laser cleaning of anilox rolls to further reduce waste and water pollution. 

Additionally, flexo saves printers money by using elastomer hybrid sleeves. Gravure cylinders are expensive (and heavy) and are good for about 50 million prints before needing to be replaced. Elastomeric sleeves can't get such high run runs, but they can be milled, restored and re-etched for new images.

In the past decade, advances in flexo equipment – from incorporating anti-bounce technology to artificial intelligence solutions to ensure print quality – have far outstripped technological advances in other printing methods.

Breaking Down Sustainable Printing Practices

Reusability and adaptability are key to sustainable printing operations. Methods such as lithography and gravure printing severely limit reusability, which can lead to huge storage and waste problems when more than one printing job needs to be done.

Some other considerations regarding sustainable printing practices include:

• ink

• Volatile Organic Compounds

• Energy consumption

• image carrier material

ink 

Many inks contain harmful and toxic chemicals, leading to water pollution and hazardous waste during production. Reduce your operational footprint with sustainable inks. 

Once you print on a substrate, the ink and substrate are connected and cannot be easily separated. Because this adhesive slowly degrades during recycling and disposal, certain inks may prove harmful to consumers.

Volatile Organic Compounds (VOCs)

VOCs are harmful pollutants, usually produced by solvents in harsher inks. Lithographic printing is often classified as oil-based inks that contain high levels of harmful VOCs. 

Using water-based inks is one of the suitable ways to reduce the VOC footprint of printing operations. Flexo printing can accommodate a variety of inks to suit your needs , including water-based inks.

Energy consumption

While energy consumption levels tend to balance out between processes, secondary tasks associated with certain printing methods can drastically alter energy output. Thanks to digital technology, new appliances use less electricity than older ones. This makes flexo printing particularly attractive. 

Using pneumatic mandrel and quick-change sleeve technology, coupled with digital monitoring, flexo is able to run more efficiently than alternatives. In newer flexo printing equipment , carbon fiber cylinders are much lighter than earlier counterparts, further reducing the energy load of printing.

image carrier material

The materials you use also affect the sustainability of your printing operation. Flexo gives you unique flexibility in choosing more sustainable materials. 

Decades ago, flexo sleeves were made from photopolymers, which provided cost-effective, high-quality printing. Today, silicone and elastomeric sleeves offer similar image quality but without the harmful chemicals found in photopolymers. 

While many printing methods require the use of flatbeds, flexo's circular design avoids harmful washout. A comprehensive solution only needs to consider one tolerance, whereas flat panels need to consider three different tolerances.

In addition, post cleaning flexo round sleeves is more environmentally friendly compared to other printing methods. Where plate production requires excessive water or chemicals for cleaning, the elastomeric sleeve only needs to be brushed and rinsed. Any small amount of hazardous VOC waste is converted to smoke by the thermal oxidizer and is easily collected.

future sustainability

While many printing methods offer little to no environmental sustainability, the most responsible printing methods are easily reusable, leave a lighter energy and waste footprint, and are compatible with the most sustainable inks and substrates. 

There is always a way to reduce your operational footprint and improve sustainability.