Abstract: A cap which has a female screw in the inner peripheral surface and which is to be screwed on a port neck part of a container main body holding a predetermined liquid, wherein a plurality of ribs radially extending astride from an inner surface of a top surface part of the cap to an inner surface of a peripheral wall part and integrally projecting inwards are formed on a peripheral edge part of the inner surface part. A female screw is a screw in the form of two threads composed of spiral mated ridges of two threads, for example. The liquid held in the container main body is, for example, a chlorine-based bleach which contains a surface active agent and a sodium hypochlorite. The mated ridges each are 80 to 120 degrees in thread angle ? and 1 to 15% of a valley radius of the female screw in thread height H.

Abstract: A cap which has a female screw in the inner peripheral surface and which is to be screwed on a port neck part of a container main body holding a predetermined liquid, wherein a plurality of ribs radially extending astride from an inner surface of a top surface part of the cap to an inner surface of a peripheral wall part and integrally projecting inwards are formed on a peripheral edge part of the inner surface part. A female screw is a screw in the form of two threads composed of spiral mated ridges of two threads, for example. The liquid held in the container main body is, for example, a chlorine-based bleach which contains a surface active agent and a sodium hypochlorite. The mated ridges each are 80 to 120 degrees in thread angle ? and 1 to 15% of a valley radius of the female screw in thread height H.

Abstract: A cap 10 which has a female screw 14 in the inner peripheral surface and which is to be screwed on a port neck part 13 of a container main body 11 holding a predetermined liquid, wherein a plurality of ribs 18 radially extending astride from an inner surface of a top surface part 16 of the cap 10 to an inner surface of a peripheral wall part and integrally projecting inwards are formed on a peripheral edge part 17 of the inner surface of the top surface part 16. A female screw 14 is a screw in the form of two threads composed of spiral mated ridges 14a, 14b of two threads, for example. The liquid held in the container main body 11 is, for example, a chlorine-based bleach which contains a surface active agent and a sodium hypochlorite. The mated ridges 14a, 14b each are 80 to 120 degrees in thread angle ? and 1 to 15% of a valley radius of the female screw 14 in thread height H.

Abstract: A cap 10 which has a female screw 14 in the inner peripheral surface and which is to be screwed on a port neck part 13 of a container main body 11 holding a predetermined liquid, wherein a plurality of ribs 18 radially extending astride from an inner surface of a top surface part 16 of the cap 10 to an inner surface of a peripheral wall part and integrally projecting inwards are formed on a peripheral edge part 17 of the inner surface of the top surface part 16. A female screw 14 is a screw in the form of two threads composed of spiral mated ridges 14a, 14b of two threads, for example. The liquid held in the container main body 11 is, for example, a chlorine-based bleach which contains a surface active agent and a sodium hypochlorite. The mated ridges 14a, 14b each are 80 to 120 degrees in thread angle &thgr; and 1 to 15% of a valley radius of the female screw 14 in thread height H.

Abstract: A parison length control method for a blow molding machine in which a parison is extruded vertically, the end of the parison is closed, and a blowing gas is blown into the closed parison. The method includes the step of deriving a relationship between parison length and extruder screw rotation speed during a test molding process. Current parison length is then detected during normal molding operation, and the difference between the current parison length and a target parison length is derived. The extruder screw rotation speed is then controlled by calculating a correction amount for the extruder screw rotation speed based on the parison length difference in combination with the relationship between parison length and extruder screw rotation speed. The extruder screw rotation speed is then adjusted by the correction amount so as to attain the target parison length.

Abstract: The invention resides in a rotary blow molding machine in which under an extruder for extruding a parison, a turntable is arranged which has plural sets of molds mounted thereon for holding the parison therebetween and blow-molding the parison, the turntable is rotated by a motor, an annular driven gear is provided on the turntable, and one pair of idle gears are made to intervene between the driven gear and a driving gear for transmitting the rotation of the motor so as to intermesh with both the gears.

Abstract: The invention resides in a rotary blow molding machine in which under an extruder for extruding a parison, a turntable is arranged which has plural sets of molds mounted thereon for holding the parison therebetween and blow-molding the parison, the turntable is rotated by a motor, an annular driven gear is provided on the turntable, and one pair of idle gears are made to intervene between the driven gear and a driving gear for transmitting the rotation of the motor so as to intermesh with both the gears.