摘要:
A screw nose for a rubber extruder screw has an upstream portion of increasing diameter providing working engagement of the rubber flowing from the screw with the extruder barrel and a downstream portion of decreasing diameter providing working engagement of the rubber with a converging tapered wall of a flow channel block for reducing the shrinkage and pressure drop at the discharge end of the screw and thereby prevent porosity and blisters in an extruded rubber component.
摘要:
An extruder for extruding an associated material includes an extruder housing that has a feed section, a center section that includes a throttle section, and an outlet section with an extruder screw disposed in the extruder housing. The extruder also includes a throttle at the throttle section. The throttle has a plurality of pins that extend radially into the housing. The pins are adjusted by a cam extending around the extruder housing. The cam has an inner wall that has a plurality of cam surfaces engageable by pins. The radius of each of the cam surfaces gradually decreases from a maximum radius to a minimum radius distance. The pins have springs that urge the pins radially outward to contact the inner wall of the cam. The cam is rotated by a piston and cylinder assembly. The extruder further includes sensors for temperature, gauge, weight, and other properties of the material. The extruder also has a control apparatus for controlling the speed of the extruder and the throttle based upon any combination of temperature, gauge, weight, and production requirements while the extruder is in operation.
摘要:
A gear pump and method for pumping elastomeric material having two gears with meshing herringbone gear teeth. Each of the gear teeth has helical side portions and a curved central portion which extends circumferentially of the gear a distance equal to at least one half the pitch of the gear teeth to provide a continuous squeezing contact between the teeth of the two gears for pumping a uniform strip of elastomeric material from the gear pump.
摘要:
Apparatus for directing the flow of material from a supply source to one or more shaping dies has a flow channel therein. A flow directing insert (34A) located in the downstream region of the flow channel spreads the material toward the outer walls and improves uniformity of flow in an exit zone (40). In the downstream region (11), the channel height is gradually decreased and levels off near the exit. The flow channel may be split into two or mom flow branches (15A, 15B), each flow branch having a flow directing insert (34A) therein.