Recently, the use of tumblers has increased as a way to cope with the climate crisis, and each brand is releasing new products in various forms and designs. In response, Seoul YWCA (Chairman Cho Yeon-shin) tested and evaluated the main quality and performance (warm, cool, airtight, safety), ease of use, and environment of 13 tumblers sold on the market.
As a result of the test, there were differences in thermal insulation and cooling performance and ease of use by product type (semi-sealed, sealed) and by product. All of the products to be tested complied with safety and labeling standards, and it was found that the abrasive used in stainless steel manufacturing could be removed by washing.
As for the main performance of the tumbler, 'thermos (carry loop tumbler)' was the best among the 13 products. By product type, the sealed type with a completely sealed and narrow entrance had relatively better thermal and cooling performance than the semi-sealed type, and the difference between the products was large (maximum 17.3℃). On the other hand, the semi-sealed type had a wide inlet and a drinking port, so the thermal insulation performance was low, but the difference between the products was not significant. The sealing performance, surface temperature, and adhesion of the painting all satisfied the relevant criteria.
Calculating the carbon emissions of each stage once a day for a year, it was found that plastic cups emit 16.5 times more carbon than tumblers and paper cups emit 12.9 times more carbon than tumblers. While tumblers account for most of the carbon emissions in the pre-manufacturing stage, disposable cups repeat the use and disposal of new cups each time, so the longer the period of use, the higher the carbon emissions.
As a result of user evaluation on the five conveniences of use, such as sealing force, grip, condensation, portability, and ease of cleaning, the sealing force and grip were generally satisfied, but the ease of cleaning and portable reason were relatively low. Overall, the satisfaction of the sealed type was relatively high, but the ease of cleaning was higher in the semi-sealed type.
As a result of checking caps, packing, detection of harmful substances by body material, and heavy metals in surface paint, all products met safety standards. In the case of the abrasive used in stainless steel manufacturing, some products had abrasives before cleaning, but they did not remain after washing using detergent and cooking oil.
The capacity of the entire product was more than 95% of the mark, which met the mark criteria, and the entrance diameter was wider than that of the "semi-closed type" (78~86mm), making it easier to hold ice or drinks. The difference between the product with the widest entrance (Glass lock clip type tumbler, 86mm) and the narrowest (thermos carry loop tumbler, 50mm) was about 1.7 times, and the weight difference between the heaviest product (Stanley Go Vacuum Bottle, 346g) and the lightest product (thermos carry loop tumbler, 236g) was about 1.5 times.