Bangbang, pongpong, or bongbong: it went by different names in each region in Korea.
Jumping on it was so fun that it has always been a popular ride for kids in the playground. It's trampoline.
Nowadays, it's often found in indoor amusement facilities.
Trampoline provides great exercise for losing weight and gaining muscle strength.
Because it can be used indoors, adults also use it as fitness equipment.
In essence, it is an elastic mat connected to springs.
Mats help you jump higher through the recoil of the spring and also relieve the shock after the jump.
To make this elastic mat, polypropylene (PP) is often used for the excellent tensile strength (maximum stress that can be withstood when pulled)
and impact strength. PP is a synthetic resin made by polymerizing propylene.
It's one of the most widely used general-purpose plastics that can transform into various products depending on the properties and processing method,
including films, textiles, and automotive parts.