杏吧原创

SOMETIMES it鈥檚 the simple things in life that are the most
annoying鈥攍ike trying to wrestle the lid off a jam jar. But now scientists
have found a way to make jars easier to open. Their solution? Don鈥檛 screw lids
on so tightly in the first place.

Many people, particularly the elderly, have great difficulty opening jars,
says Liek Voorbij at Delft University of Technology in the Netherlands. They can
be so tough to open because makers don鈥檛 seal them to a set torque. Instead they
twist a lid to a particular angle.

Voorbij and Bea Steenbekkers at the Wageningen Agricultural University
measured the lid-twisting prowess of 750 volunteers. The aim was to find a
maximum tightness that everyone can open. With the help of a strain gauge
attached to a jar, the team calculated the optimum tightness that would allow
people to open the jar, without leaving it so loose that the seal risks being
broken prematurely. They found that a torque of 2 newton-metres was the ideal
tightness. All the 20 to 40-year-olds they tested could manage this, as could 97
per cent of 50 to 94-year-olds.

Voorbij now challenges manufacturers to use his data to produce easy-to-open
jars.