PVC-free closures

A vessel cap made of metal or plastic for a vessel for receiving foods or beverages, comprising a seal insert made of a seal material which comprises at least three different polymers mixed with further substances, wherein

• the seal material contains no PVC;
• the seal material is substantially free from components that are liquid at room temperature;
• the seal insert can be pasteurized at temperatures up to 98° C.;
• the seal material has a Shore A hardness between 40 and 95;
• and the seal material comprises at least three different polymers,
• wherein the first polymer is polypropylene in an amount from 10% by weight to 50% by weight,
• the second polymer comprises an olefin block copolymer, a styrene ethylene butylene styrene block copolymer (SEBS), or a combination thereof, in an amount from 10% by weight to 50% by weight, and
• the third polymer comprises a polyolefin elastomer in an amount from 15% by weight to 40% by weight.