Roy Planck, the father of fluororesin, began to study Freon's substitutes at DuPont in the United States in 1936.
Roy Planck, ພໍ່ຂອງ fluororesin, ໄດ້ເລີ່ມຕົ້ນການສຶກສາທົດແທນ Freon ທີ່ DuPont ໃນສະຫະລັດໃນປີ 1936.