Protocol on the releasability of labels and adhesives on PP and PE packaging

Publication date: July 15, 2021

When recycling packaging, it is important that the material flows are as homogeneous as possible. In the recycling process, packaging is washed so that any product residues disappear and labels and adhesives are removed. In practice, however, not all labels and adhesives are removed properly during the washing process. The National Test Centre for Circular Plastics (NTCP) has therefore developed a test protocol for this purpose on behalf of the Netherlands Institute for Sustainable Packaging (KIDV).

Protocol on the releasability of labels and adhesives on PP and PE packaging

Using this protocol, companies can test whether the labels and adhesives they use on PP and PE rigid packaging separate properly during the washing process. This can be tested in their own laboratory or at a test facility, such as the NTCP. KIDV uses this protocol as a supplement to the Recycle Check Rigid Plastic Packaging. "We received many questions from companies about this part of the Recycle Check. Packaging made of PP and PE is often washed in cold water. However, companies do not know what requirements the adhesives and labels have to meet in order to be washable. A protocol already existed for PET packaging that is washed in warm water. We hope that with this new test protocol for rigid PP and PE packaging, we can help companies even better in making their packaging recyclable," says Nynke Arntzen, packaging expert at KIDV.

Protocol development

When packaging is recycled, it is chopped up into shreds. These shreds enter the washing process and are cleaned by friction, among other things. Friction in the process plays a role in the release of adhesives and labels. To develop the protocol, the NTCP conducted experiments in their test environment. Existing protocols for washable adhesives (from EPBP and Recyclass) were also used and coordination with the University of Vienna and Recyclass took place. For example, Recyclass has recently released a low-key QuickTest Procedure to investigate on a smaller scale the release of labels and adhesives in the cold water washing process.

The challenge when developing a protocol is to find a balance between practicality and accuracy. Recyclass offers with the QuickTest an accessible way to get a first insight in the release of adhesives. The NTCP protocol is more extensive and therefore more in line with reality, among other things because of the increased friction. Recyclass recognises the important role of friction.

For the development of this protocol, KIDV and the NTCP set up the Adhesives Working Group, in which various chain parties participated. With among others: Albert Heijn, Altrif Label, Avery Dennison, Eshuis, Geostick, Optimum Group, Royal Sanders, Veolia and Wibra. Participants supplied samples for the experiments.

About the Recycle Check

The Recycle Check Rigid Plastic Packaging is a tool that can be used to determine to what extent rigid plastic packaging is recyclable under the current Dutch system. By going through the decision tree on the basis of a number of questions, various insights are obtained into the recyclability of the packaging. For each question, KIDV provides background information on the various aspects of collection, sorting and recycling. This Recycle Check appeared for the first time in 2018 and is updated annually. The Recycle Check is used by the Dutch Waste Fund ('Afvalfonds Verpakkingen') when granting the modulated fee for rigid plastic packaging.

Download the protocol

The protocol is only available in English and consists of two documents. The first document is a description of the steps you must take in order to carry out the test and the material you need for this. The second document is a calculation tool in Excel. This offers an extra tool to follow the protocol.

Click here for Measurement protocol for the releasability of adhesives in the cold water washing process of rigid PP and PE packaging with plastic labels.
Click here for the corresponding calculation tool.


Related news and events