A strand manufacturing apparatus capable of reducing variations among diameters of resin strands without stopping the operation of an extruder is provided. A strand manufacturing apparatus includes a die in which an outflow hole for discharging a resin material contained in an extruder as a string-shaped resin strand is formed, an adjustment valve configured to adjust opening of the outflow hole, an image acquisition unit configured to acquire an image of the resin strand extruded from the outflow hole, a diameter acquisition unit configured to acquire a diameter of the resin strand in the image, and an opening adjustment unit configured to adjust the opening by driving the adjustment valve based on the diameter of the resin strand acquired by the diameter acquisition unit.

A process for preparing a waterborne dispersion of a silicone pressure sensitive adhesive base includes the use of a solventless polyorganosiloxane pellet containing a polyorganosilicate resin and a polyorganosiloxane gum. The waterborne dispersion of the silicone pressure sensitive adhesive base can be combined with a free radical initiator, and dried and cured to form a silicone pressure sensitive adhesive.

A gear pump extruding machine for extruding a rubber material includes a screw feeder, a gear pump provided on an outlet side of the screw feeder, and a die disposed on an outlet side of the gear pump. The gear pump extruding machine further includes protrusive members that are movable forward and rearward to protrude into a fluid communication channel that keeps the screw feeder and the gear pump in fluid communication with each other, to thereby change the volume of the fluid communication channel. An actuator is provided for moving the protrusive members to protrude into the fluid communication channel, and is controlled by a controller. When the volume of the fluid communication channel is changed, the rate at which the rubber material is extruded is adjusted to prevent the rubber material from being warmed excessively at all times.

A method of forming a tread comprising two or more layers of rubber is described. The method includes the steps of: extruding a rubber compound through an extruder and a gear pump and mixing with an accelerant and then applying a continuous strip of rubber directly onto a tire building machine to form a first layer of rubber having a first cure rate; adjusting the amount of accelerant to obtain a second cure rate different than said first cure rate, and then applying a strip of rubber having a second cure rate onto the tire building machine, wherein one of the cure rates is faster than the other cure rate.

Provided is a thickness variation adjustment-type air ring capable of accurately and optimally controlling the volume of cooling air at all positions in the circumferential direction, and stably manufacturing a synthetic resin film having an exceptionally low thickness variation. A thickness variation adjustment-type air ring is provided on a die of an inflation film manufacturing apparatus which locally controls the volume of cooling air discharged from a cooling air passage in a circumferential direction to adjust the thickness variation of a synthetic resin film when blowing the cooling air around a molten synthetic resin tube extruded in a longitudinal direction to cool and solidify the molten synthetic resin tube to form the synthetic resin film, the thickness variation adjustment-type air ring. The thickness variation adjustment-type air ring includes: a ring-shaped passage adjustment portion arranged sequentially in the circumferential direction inside of the cooling air passage; and a plurality of moving portions connected at a predetermined position in the circumferential direction of the passage adjustment portion so as to move a connecting portion of the passage adjustment portion in a predetermined direction independently from other portions, wherein a space in which cooling air can circulate inside the cooling air passage is locally adjusted in the circumferential direction and the volume of cooling air is locally controlled in the circumferential direction.