wd-40

jar opener

JarKey

• "necessity is the mother of invention," and the practice of preserving food is no exception to this rule. During the early years of the Napoleonic Wars, the French army had such a problem keeping food from going bad that in 1795, the government offered a cash reward of 12,000 francs, which was huge at the time, to any person who could find a way to preserve food safely in order to feed the troops

It took quite a while, but the incentive worked. Fourteen years later, a young chef and candy maker named Nicolas Appert finally cracked the code and won the prize, earning him the title of "The Father of Canning." With a lot of trial and error, he eventually figured out that food cooked inside a champagne bottle would not spoil if it was sealed tightly. Interestingly, at the time, he had no idea why his method worked, as the concept of pasteurization was not discovered for another 50 years. Unfortunately, despite his modern-day esteem, he never got to enjoy the fruits of his labor.
another Frenchman by the name of Philippe de Girard expanded upon the original method. He recognized that glass jars were not only heavy, but also expensive and hard to transport, so he came up with the idea for the tin can, and a British merchant named Peter Durand helped him patent it in 1810. By the mid-19th century, canned goods had become somewhat of a status symbol in Europe, and the increased demand led to the invention of machine-made steel cans in the 1860s.

When a jar is heat-processed, its contents expand, which causes the internal pressure to become lower than the atmospheric pressure outside the jar. This difference in pressure pulls the lid tight to the top of the jar, creating a vacuum seal. And while that's great for preventing contamination, it can also make the jar really hard to open.
Sometimes, jars that have already been opened and refrigerated are even harder to open for the second time than they were the first. That's because the cold makes the lid contract, which tightens the seal. This explains why running a jar under warm water can help loosen it up and make it easier to open.

a Japanese glassmaker and an engineer from the Shibaura Institute of Technology have discovered how to make a glass jar that's easier to open. After studying men and women of all ages, from their 20s to their 80s, they found that the shape of a bottle and how it fits in the user's hands has a big impact on how difficult it is to open. They learned that a jar shaped like a parallelogram makes it easier to apply the necessary force to twist off the lid.
https://wiki.ezvid.com/best-jar-openers

disassembling telve