An efficient recycling of PET bottles: “Participants screening” through the slightest unwillingness toward cap removal

Efficient recycling of PET bottles absolutely needs sufficient sorting and cleanness of collected bottles. However, bottles are contaminated due to no bottle washing and poor sorting. Therefore, psychological factors of recycling behaviors play an essential role for efficient recycling. The authors developed a low-biased valuation method of unwillingness (botheration, tediousness) toward recycling behaviors of PET bottles (cap and label removals, bottle washing and crushing). Valuated unwillingness was validated by sorting survey results of 54,593 bottles. The results suggest that even slight unwillingness toward cap removal (1.77 JPN-yen) could clearly divide recycle-conscious and non-conscious people. Although non-conscious people were discouraged to perform recycling behaviors sensitively by unwillingness, recycle-conscious people could complete the necessary behaviors in spite of elevated unwillingness. It was also validated by a web questionnaire with statistical test. When unwillingness is implemented appropriately in PET bottle collection system, it allows only high-quality PET bottle collection via participants screening.