PVC-free inks: WhatPackaging's jargon buster

Disha Chakraborty (DC):  In India, flexo usage is about 10-15% and gravure printing is about 80-85%. But there is no solvent restriction in gravure as a process. Therefore the usage of toluene / PVC in inks and on the press is a five-decade old norm in India. How do we start this journey in the Indian packaging industry? Are there any lessons we can learn from other territories? 
Thomas Haas (TH): Toluene-free and PVC-free are two different topics. The elimination of toluene is a product safety and HSE driven topic. Nowadays, regulations for food packaging are in place in India. Also, a majority of food packaging worldwide is printed with toluene-free systems and there are multiple solutions available. Siegwerk offers toluene-free solutions and we can support you on this journey.

DC: What about PVC-free?
TH: The phase out of PVC or other chlorinated binders is a recycling driven topic. Here respective solutions are available and Siegwerk can support you on this journey as well.

DC: What if the packaging firm still relies on toluene-based inks?
TH: In case the printing house still operates with toluene-based inks and wants to eliminate at the same time also PVC as a binder, the solution is to go for a PVC-free solution directly which is at the same time toluene-free, as Siegwerk only offers toluene free solutions.

DC: There is a follow up question. What are the lessons from Europe or South East Asia which the Indian packaging industry should be made aware of? 
TH: The transition to a PVC-free solution is only one part to make a packaging better recyclable. There are other measures such as a change in packaging structure to monofilm solutions or paperisation. The whole topic is complex and we recommend we have detailed discussion about this.

Thomas Haas: The quality of the PVC-free and PVC-based inks are on par

DC: How easy is it to use PVC-free ink? 
Dipshikha Banerjee (DB): There is no difference in terms of handling of the PVC-free ink as compared to other solvent-based systems.

DC: What about assembly line speed?
DB: Well, the speed of printing and assembly line are something that the converters should not compromise when they switch to a PVC-free system. In short, a comparable speed of the process can be expected for PVC-free and existing ink systems.

DC: Which industries is it suitable for? 
DB: PVC-free inks qualify for NPH (Nutrition, Pharma, Hygiene) applications and meet the necessary compliances. Of course one can use the PVC free inks for non-food applications as well.

DC: What has been your experience with brands in Europe? Is the packaging sustainability drive being driven by EU policy or by brands or packaging manufacturers? 
DB: The drive to become more circular is coming along the whole packaging value chain. This includes brand owners and converters, as well as NGOs and state policies.

DC: Do you think there is any quality difference between PVC and PVC-free inks? Any tweak to the press etc?
TH:  With the experience we have so far, we are confident that the quality of the PVC-free and PVC-based inks are on par. However, this needs to be checked and validated for the particular application one is producing.

DC: Among Polyurethane (PU) inks, a high share is based on aromatic PU, which in some applications are under scrutiny for recycling-compatibility. Do you regard aromatic PU as go-to technology, or prefer aliphatic PU inks?
TH: In general, inks will impact the recyclability of a material. The discussion is around the level of impact. As we have seen during the webinar presentation, minor ppm amounts of PVC will disturb any recyclability. Therefore the ideal way is de-inking.

DC: Do-able?
TH: However this technology is not available at a large scale for the entire packaging industry. This is the situation, right now.

DC: You touched upon how PVC co-polymers are not compatible with flexo photopolymer plates. Can you elaborate?
TH: The problem is rather indirect. The PVC copolymers are soluble in acetates and acetates are used as a solvent for PVC-based ink systems. Acetates in turn can damage the photopolymer plates flexography.

DC: Does one need a different type of doctor blade or rubber rollers or shore hardness while running PVC Free inks on a gravure press? 
TH: No.

DC: What kind of applications are we looking forward to when it comes to PVC-free inks?
DB: When we talk about Asia, the reverse lamination applications are usually produced by using PVC-based inks. Therefore, we need to target those sectors when we consider the transition to PVC-free.

Dipshikha Banerjee: There is no difference in terms of handling of the PVC-free ink as compared to other solvent-based systems

DC: How can we control the print component on the press if PVC is used in the inks and overprint varnishes (OPV)?
TH: As mentioned before PVC-free systems do not require any special handling as compared to PVC-based systems, controlling printing components should not be a matter of concern.

DC: Are pigments an issue for recycling? In what way?
TH: Any material containing ink will be coloured. And so, you have an impact.

DC: So, what is the solution?
TH: The best option is de-inking.

DC: If packaging is de-inked, how important is the binder base of the ink?
TH: If the packaging would be completely de-inked, you are right, the binder system will not play a role. However, the problem is, de-inking is under development. We do not have infrastructure to facilitate de-inking as of now. And of course, there is no clear collection and sorting process which exists today. So, going PVC-free to support and enable sustainability pro-actively would be the step in the right direction.

DC: Is this ink manufactured in Siegwerk’s factory Bhiwadi?
DB: The Indian PVC-free inks and coatings are produced locally in the Bhiwadi factory.

DC: And finally, Dipshikha Banerjee, you mentioned the Nestle-initiated process for PVC-free inks. Can she shed more light about this project and its importance ...
DB: EU and NA recycling associations like CEFLEX, RecyClass, APR disapprove the use of any PVC-containing components in packaging. PVC has been listed as Class F which means low compatibility to recycling or not recyclable at all. Following these findings, Nestlé sustainability packaging vision has included PVC removal from both plastics and printing inks.

If you want to see the webinar - PVC-free systems – improving the quality of recycled material, then please click here