Most of us have struggled to open a glass jar. Whether you’re desperate to add some jam to your toast, mayonnaise to your sandwich or pickles to your burger, those tightly screwed-on lids can prove a real nuisance.
But Japanese researchers have come up with a solution through the development of a glass jar whose lid can be removed with ease.
And it turns out the fundamental problem lies in the shape of those pesky glass containers.
Noriko Hashida, a professor at the Shibaura Institute of Technology, and Hakuyo Glass, which is based in Tokyo, have developed a container that can be opened by men, women, children and the elderly.
The body of the jar has a parallelogram-shaped cross-section so that the user can tightly grip it, Nikkei Technology Online reported. Additionally, a weaker force is required to remove the lid.
Hashida asked men and women in their 20s to 80s to remove the lids of 15 different glass containers and evaluate “the ease of opening a lid” and “the ease of holding a bottle”.
The results showed that glass jars that fir the shape of users’ hands are easier to hold, while a glass container that is smooth from its neck to its body is easier to open.
Further tests revealed that a parallelogram was the optimum shape for the cross-section of a glass jar.
Hakuyo Glass now plans to use the design to package its products, including jam and tsukudani (seafood, meat or seaweed preserved in soy sauce and mirin).
Meanwhile, back here in the UK you'll have to keep on struggling...