A Study Conducted by the Van Dyk Technology Center and Commissioned by the Foil & Specialty Effects Association

Editor’s note: The Foil & Specialty Effects Association (FSEA) has been proactive in providing clear, supported evidence that transfer metallic decoration (hot stamp, cold transfer and digital transfer processes) is recyclable. The association’s latest study is of interest to those with decorated plastic products, providing broad direction and pointing consumers, Consumer Products Groups (CPGs), Municipal Recycling Facilities (MRFs) and marketers toward resource-efficient recycling data for plastic packaging. This study demonstrated how metallic transfer decorated plastic materials can be collected, separated and recovered from the waste stream to be efficiently recycled.

Through extensive testing at the Van Dyk Technology Center, located at the Van Dyk Recycling Solutions headquarters in Norwalk, Connecticut, a study commissioned by the FSEA demonstrated that transfer foil decorated plastic materials currently are being sorted by the Municipal Recycling Facilities (MRFs) to be included in the recycling stream.

Details of study
The Van Dyk Technology Center was commissioned to assess two plastic materials with metallic transfer finishes based on the Association of Plastic Recyclers (APR) sorting protocol. The goal was to mimic various functions found in Municipal Recycling Facilities (MRFs) sorting plants in a laboratory setting. The Van Dyk testing center is designed to provide a setting for those involved in the recycling and solid waste industry to implement tests that mimic real sorting challenges.

The equipment used for testing was a TOMRA Autosort 5. The TOMRA Autosport is a multifunctional sorting system used to recover a wide range of valuable materials from different waste streams. The advanced near infrared (NIR) spectrometer-based detector recognizes materials based on their specific and unique spectral properties of reflected light. In combination with NIR, a metal detection sensor allows the Autosort to determine the difference between paper and aluminum/ferrous metals.

Figure 1 outlines the working principle behind the TOMRA Autosort. Input material (1) is evenly fed onto the conveyor belt, where it is detected by the NIR and/or VIS spectrometer-based detector (2). If the sensors detect material to be sorted out, it commands the control unit to blow the appropriate valves of the ejection module at the end of the conveyor belt. The detected materials are separated from the material flow by jets of compressed air. The sorted material is divided into two fractions in the separation chamber (3).

Procedures
Van Dyk received four samples of plastic containers with varying degrees of transfer metallic coverage. The APR SORT-B-01 protocol was followed to determine the recyclability of the transfer metallic decorated samples. This evaluation is a multistep process that involves two main components. The first consisted of a compression test. All articles were compressed with a compression device made as per APR’s compression documentation. Each article was assigned a variable number (1 through 4) for identification purposes.

After the articles were compressed, trials were staged to measure the recovery rate of the sample articles when mixed with a base-mix of materials (see Table 1)..

Before testing the articles, the base-mix was run through the system to determine the baseline performance of the optical sorter so that the results could be compared to this baseline. For PET, it was determined that the recovery rate was 97.4%. For HDPE, it was determined that the recovery rate was 97.8%.

In accordance with APR’s protocol, the base-mix combined with the test articles was passed under the optical unit five times. For each pass, the number of successfully sorted articles was recorded and summarized.

The results shown in Table 2 were obtained by following the procedures outlined in APR’s NIR sortation protocol (Sort-B-01). Each repetition of the test, also referred to as a run or pass, was combined to arrive at a final capture rate for the article. Using the article capture rate and its variance from the baseline, each article was categorized into one of APR’s recyclability categories (APR Result in Table 2).

Conclusion

• The four plastic samples were evaluated at the Van Dyk Testing Center to mimic various functions found in the Municipal Recycling Facilities (MRFs) sorting plants in a laboratory setting.
• The four samples had an estimated range of coverage from 25% up to 75% of transfer metallic foil decoration.
• The summary of the test results for each of the four plastic transfer metallic decorated samples demonstrated that the samples were sorted to be included in the recycling stream with a variance of less than 1.6% from the base recovery rate.
• Brand owners and product decorators have testing conclusions that show transfer metallic decoration most likely is being recycled by Materials Recovery Facilities (MRFs).
• The test results of the Van Dyk sorting study with the preferred design recommendation from the APR indicates that plastic containers decorated with metallic transfer are recyclable and most likely are sorted by the Municipal Recycling Facilities (MRFs) to be included in the recycling stream.

Notes:

1. See the APR Design® Guide for specifics on metallic coverage and materials.
2. For a copy of the study, Recyclability of Plastic Containers with Metallic Transfer Decoration, please email Jeff Peterson at jeff@petersonmg.com.