SYNTHETIC RESIN CAP, CLOSURE DEVICE, AND CLOSURE DEVICE WITH BEVERAGE

摘要

PROBLEM TO BE SOLVED: To provide a synthetic resin cap which facilitates an opening operation and is free from making a user pain when the user grips and rotates the cap.SOLUTION: There is provided a synthetic resin cap 1 having a top plate portion 2 and a cylindrical portion 3 hanging from the peripheral edge thereof. A knurl portion 12 formed of a plurality of knurl projections 12a extending in a handing direction is formed on the outer peripheral surface of the cylindrical portion 3. The knurl portion 12 is divided into a plurality of knurl regions 13 at intervals in a circumferential direction of the cylindrical portion 3. A knurl projection group 12A each formed of three or more knurl projections 12a is formed in the knurl region 13. A width W2 of a blank area 14 between the adjacent knurl projection groups 12A is 1.5 mm or more. The total of a width W1 of the knurl projection group 12A and the width W2 of the blank area 14 is 7 mm or less. A ratio W1/W2 is set at 0.6 to 3.SELECTED DRAWING: Figure 1