A screw cap, in particular for bottles of liquid

摘要

The plastics bottle plug comprises a top wall and a skirt including an internal thread. There is an internal annular recess where the skirt joins the wall to accomodate a cast joint. One or more flexible annular lips (7) are moulded integrally with the plug and extend from the top wall into the recess accomodating the joint (6). The lip can be of triangular section, its outside and inside faces being inclined to the plug axis at approximately 15 and 45 deg. respectively. The lip secures the joint in place once cast.