20. April 2023
“Why are plastic canisters handed in without lids?”
Collecting and storing drained and emptied plant protection product and liquid fertiliser packaging until it is handed over at PAMIRA® collection points has become a matter of course for farmers. RIGK GmbH has been organising PAMIRA® collection operations for 25 years now. The collection service network has been steadily expanded during this time and the return process has been optimised. The fact that the system is accepted by farmers is illustrated by the fact that it collects nearly 3,000 tonnes of packaging nationwide every year. Farmers can bring their rinsed and emptied plastic canisters to more than 400 collection points in Germany.
There are some criteria to be considered for orderly drop-off. For example, it is important that the containers are handed in without a closure, i.e. a lid.
Many farmers regularly ask the RIGK inspection staff about this acceptance criterion: “Why are the lids not allowed to remain on the empty plastic canisters? These are also made of plastic, like the canisters, aren't they?”
In principle, this is a correct observation. However, there is a big “but” here: Firstly, there is a seal in each lid of a container to ensure that nothing leaks out. The seals are made of a wide variety of materials. Secondly, the lid itself is generally a plastic material that is significantly different from the plastic used for the container (canister, bottle). This differentiation is necessary for safety reasons. The crop protection and liquid fertiliser containers are almost exclusively made of HDPE plastic. This is a special type of plastic that requires a manufacturing process in order to produce the canister or bottles in large quantities at low cost. The lids are usually made of the plastic types PP or HDPE. These are manufactured in an injection moulding process. Associated with this are other properties of the plastic that are influenced by the processing method. The plastic canisters must be rinsed and delivered empty of residues. This level of cleaning cannot be achieved with the lids. This aspect as well means that canisters and lids need to be treated differently to ensure optimised recycling. After collection, the emptied canisters are compressed into plastic bales. This achieves around a 15-fold compaction, which in turn enables efficient transport to the recycling partner. If the lid were to remain on the canisters here, compression would be significantly impeded. The bales would quickly burst open after compaction and make recycling impossible. Once the compressed plastic bales have arrived at the recycling partner, they are processed into a regranulate. The process is essentially a simple one. The plastic bales are crushed to the size of a fingernail. This is followed by washing and density separation. During the separation process, only the floating parts, i.e. the plastic part HDPE, of which the crop protection and liquid fertiliser canisters are made, are used for further processing. Other parts that also float move on to the next process step, which is extrusion with melt filtration. In this process, the cleaned ground material is melted and pressed through a fine sieve (melt filter). The latter filters the finest residual particles from the melt in order to yield a very pure plastic granulate as a recycling product. If unscrewed lids and their foamed rubber seals were allowed to enter the recycling process, the cleaned plastic ground material would be mixed with them. It would then no longer be technically possible to sieve off these rubber particles in the filter. Due to the high temperature of the plastic melt, the rubber particles would become very soft and elastic and be pressed through the screen. They would then be present in the regranulate as inclusions, and even a small quantity would lead to a significant reduction in quality.
So there can only be one approach for PAMIRA collection:
Lids must be unscrewed before being dropped off at the collection point so that the containers can be handed over without any problems in order to ensure an optimised recycling process. The lids are then disposed of separately in an environmentally friendly manner.
PAMIRA® is a registered trademark of Industrieverband Agrar e. V. (IVA). RIGK GmbH is responsible for carrying out collections and recycling the collected packaging.
Contact RIGK-Team:
Thorsten Heil
System Manager PAMIRA
Phone: +49 611 308600-17
heil(at)rigk.de
Ingo Köhler (Author)
Recycling Manager
Contact IVA:
Maik Baumbach
Communication, Deputy Press Officer
Phone: +49 69 2556-1268
baumbach.iva(at)vci.de