Recycling of Post-Consumer Polystyrene Packaging Waste into New Food Packaging Applications—Part 2: Co-Extruded Functional Barriers
Abstract
:1. Introduction
- Co-extruded structures with a virgin polymer layer of the same polymer in contact to food;
- Co-extruded structures with the post-consumer recyclate behind a suitable barrier polymer layer;
- Laminated structures with post-consumer recyclates behind a suitable barrier polymer;
- Coating of the surface with barrier lacquers or inorganic structures.
- Input concentration of potential contaminants in post-consumer polymers;
- Cleaning efficiencies of the (super-clean) recycling processes;
- Exposure scenario of the consumer.
2. Results
2.1. Study Design
2.2. Spiking of the Yogurt Cups
2.3. Experimental Migration Kinetics
3. Discussion
3.1. Migration Kinetics
3.2. Exposure Evaluation
4. Materials and Methods
4.1. Manufacturing of HIPS Sheet and Cups Spiked with Model Compounds
4.2. Quantification of Spiking Levels in the PS Cups
4.3. Migration Kinetics into the Gas Phase
4.4. Diffusion Modelling
5. Conclusions
Funding
Institutional Review Board Statement
Informed Consent Statement
Data Availability Statement
Acknowledgments
Conflicts of Interest
References
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Sample | Spiked Mean Concentrations in the Yogurt Cups (mg/kg) | ||||||
---|---|---|---|---|---|---|---|
Toluene | Chlorobenzene | Styrene 1 | Methyl Salicylate | Phenyl Cyclohexane | Benzophenone | Methyl Stearate | |
Sample 0 | 872 ± 11 | 935 ± 18 | 736 ± 20 | 1290 ± 19 | 1389 ± 19 | 1370 ± 10 | 1098 ± 9 |
Sample 1 | 561 ± 6 | 588 ± 8 | 677 ± 2 | 754 ± 10 | 807 ± 8 | 805 ± 10 | 654 ± 4 |
Sample 2 | 472 ± 12 | 503 ± 13 | 691 ± 18 | 651 ± 20 | 699 ± 17 | 693 ± 11 | 563 ± 6 |
Sample 3 | 379 ± 3 | 406 ± 8 | 677 ± 5 | 525 ± 6 | 564 ± 8 | 554 ± 7 | 447 ± 6 |
Sample 4 | 264 ± 10 | 282 ± 7 | 660 ± 20 | 354 ± 9 | 382 ± 8 | 369 ± 4 | 301 ± 3 |
Sample | Migrated Amount (µg/cm2) | ||||||
---|---|---|---|---|---|---|---|
Toluene | Chlorobenzene | Styrene 1 | Methyl Salicylate | Phenyl Cyclohexane | Benzophenone | Methyl Stearate | |
Sample 0 | 0.230 | 0.297 | 0.0562 | 0.0224 | 0.00145 | 0.00627 | 0.000709 |
Sample 1 | 0.0952 | 0.157 | 0.0658 | 0.00366 | 0.00608 | 0.00335 | 0.000168 |
Sample 2 | 0.0442 | 0.0892 | 0.0685 | <0.0001 2 | <0.0001 2 | 0.00119 | 0.000767 |
Sample 3.1 | 0.0119 | 0.0307 | 0.0426 | 0.000676 | 0.000152 | (0.0769) 3 | 0.0136 |
Sample 4.1 | 0.00389 | 0.0126 | 0.0377 | <0.0001 2 | <0.0001 2 | 0.00336 | 0.000809 |
Sample 3.2 | 0.0250 | 0.0506 | 0.0414 | 0.000237 | 0.000116 | 0.00113 | <0.0001 2 |
Sample 4.2 | 0.00463 | 0.0117 | 0.0166 | <0.0001 2 | <0.0001 2 | 0.000160 | <0.0001 2 |
Sample | Migrated Amount (µg/cm2) | ||||||
---|---|---|---|---|---|---|---|
Toluene | Chlorobenzene | Styrene 1 | Methyl Salicylate | Phenyl Cyclohexane | Benzophenone | Methyl Stearate | |
Sample 0 | 1.65 | 2.09 | 0.430 | 0.317 | 0.0174 | 0.0604 | 0.0149 |
Sample 1 | 0.653 | 0.983 | 0.452 | 0.0119 | 0.00260 | 0.0834 | 0.000150 |
Sample 2 | 0.337 | 0.587 | 0.354 | 0.000196 | <0.0001 2 | 0.00166 | 0.00189 |
Sample 3 | 0.126 | 0.284 | 0.286 | <0.0001 2 | <0.0001 2 | 0.00103 | 0.00165 |
Sample 4 | 0.0416 | 0.111 | 0.334 | 0.000324 | <0.0001 2 | 0.00720 | <0.0001 2 |
Temperature | Diffusion Coefficient DP (cm2/s) | ||||
---|---|---|---|---|---|
Toluene | Chlorobenzene | Styrene 1 | Methyl Salicylate | Phenyl Cyclohexane | |
5 °C [13] | 2.50 × 10−16 | 3.80 × 10−16 | 3.40 × 10−16 | / | 1.87 × 10−19 |
20 °C [13] | 1.41 × 10−15 | 7.67 × 10−15 | 3.08 × 10−15 | / | 8.30 × 10−19 |
40° (this study) | 5.85 × 10−14 | 8.45 × 10−14 | 4.88 × 10−15 | 2.23 × 10−16 | 9.10 × 10−19 |
40 °C [13] | 5.15 × 10−14 | 1.64 × 10−13 | 8.00 × 10−14 | / | 5.70 × 10−17 |
60 °C (this study) | 3.00 × 10−12 | 4.20 × 10−12 | 2.87 × 10−13 | 5.06 × 10−16 | 1.32 × 10−16 |
60 °C [13] | 2.35 × 10−12 | 1.65 × 10−11 | 2.63 × 10−12 | / | 2.19 × 10−15 |
EA (kJ/mol) | 134.0 | 138.0 | 108.2 | / | 112.7 |
D0 (cm2/s) | 1.84 × 109 | 2.42 × 1010 | 4.76 × 104 | / | 1.24 × 102 |
r2 | 0.9802 | 0.9679 | 0.8479 | / | 0.7560 |
Sample | Migrated Amount (µg/kg) | |||||
---|---|---|---|---|---|---|
Toluene | Chlorobenzene | Methyl Salicylate | Phenyl Cyclohexane | Benzophenone | Methyl Stearate | |
Sample 0 | 7.74 | 9.34 | 0.512 | 0.0306 | 0.135 | 0.0190 |
Sample 1 | 4.99 | 7.87 | 0.143 | 0.222 | 0.122 | 0.00754 |
Sample 2 | 2.75 | 5.22 | <0.00452 | <0.00421 | 0.0504 | 0.0401 |
Sample 3.1 | 0.925 | 2.23 | 0.0379 | 0.00795 | (4.08) 1 | 0.896 |
Sample 4.1 | 0.433 | 1.31 | <0.00831 | <0.00770 | 0.268 | 0.0790 |
Sample 3.2 | 1.94 | 3.66 | 0.0133 | 0.00607 | 0.0602 | <0.00658 |
Sample 4.2 | 0.516 | 1.22 | <0.00831 | <0.00770 | 0.0127 | <0.00977 |
Sample | Migrated Amount (µg/kg) | |||||
---|---|---|---|---|---|---|
Toluene | Chlorobenzene | Methyl Salicylate | Phenyl Cyclohexane | Benzophenone | Methyl Stearate | |
Sample 0 | 0.774 | 0.934 | 0.0512 | 0.00306 | 0.0135 | 0.00190 |
Sample 1 | 0.499 | 0.787 | 0.0143 | 0.0222 | 0.0122 | 0.000754 |
Sample 2 | 0.275 | 0.522 | <0.000452 | <0.000421 | 0.00504 | 0.00401 |
Sample 3 | 0.0925 | 0.223 | 0.00379 | 0.000795 | (0.408) 1 | 0.0896 |
Sample 4 | 0.0433 | 0.131 | <0.000831 | <0.000770 | 0.0268 | 0.00790 |
Sample 3.2 | 0.194 | 0.366 | 0.00133 | 0.000607 | 0.00602 | <0.000658 |
Sample 4.2 | 0.0516 | 0.122 | <0.000831 | <0.000770 | 0.00127 | <0.000977 |
Sample | Sheet Thickness | Barrier Thickness in Cup | Composition | ||
---|---|---|---|---|---|
Nominal | Measured | Nominal | Measured | ||
Sample 0 | 800 µm | 790 µm | 0 µm/ | 112 µm | 0%/100%/0% |
100 µm/ | |||||
0 µm | |||||
Sample 1 | 720 µm | 163 µm/ | 20 µm/ | 23.1 µm/ | 22%/56%/22% |
422 µm/ | 50 µm/ | 54.0 µm/ | |||
165 µm | 20 µm | 21.3 µm | |||
Sample 2 | 880 µm | 242 µm/ | 30 µm/ | 31.5 µm/ | 27%/46%/27% |
405 µm/ | 50 µm/ | 58.7 µm/ | |||
231 µm | 30 µm | 36.0 µm | |||
Sample 3 | 1040 µm | 320 µm/ | 40 µm/ | 47.6 µm/ | 30%/40%/30% |
431 µm/ | 50 µm/ | 67.1 µm/ | |||
300 µm | 40 µm | 47.4 µm | |||
Sample 4 | 1200 µm | 405 µm/ | 50 µm/ | 53.6 µm/ | 33%/33%/33% |
406 µm/ | 50 µm/ | 55.9 µm/ | |||
382 µm | 50 µm | 55.0 µm |
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Welle, F. Recycling of Post-Consumer Polystyrene Packaging Waste into New Food Packaging Applications—Part 2: Co-Extruded Functional Barriers. Recycling 2023, 8, 39. https://doi.org/10.3390/recycling8020039
Welle F. Recycling of Post-Consumer Polystyrene Packaging Waste into New Food Packaging Applications—Part 2: Co-Extruded Functional Barriers. Recycling. 2023; 8(2):39. https://doi.org/10.3390/recycling8020039
Chicago/Turabian StyleWelle, Frank. 2023. "Recycling of Post-Consumer Polystyrene Packaging Waste into New Food Packaging Applications—Part 2: Co-Extruded Functional Barriers" Recycling 8, no. 2: 39. https://doi.org/10.3390/recycling8020039