The purpose of the non-return valve
is to ensure molten plastic flows in only one direction.
The injector is mounted on the melt cylinder directly in front of the rear non-return valve
. After the supercritical fluid has entered the mixing zone of the screw, it is finely dispersed by shearing and mixing processes, and by diffusion in the melt.
Most processors recognize that the non-return valve
is a problem in molding.
Along with the innovative screw, Nordson supplies a custom-designed, poppet-style non-return valve
, whose free-flowing channels prevent polymer degradation and whose rapid shut-off ensures shot-to-shot consistency.
The screw, heater bands, and barrel have the job of melting and injecting hot plastic into the part cavities, but everything depends on the non-return valve
or check ring to function properly.
One of the most important details in injection molding is the non-return valve
or check ring.
It consists of a special screw and barrel combination plus a non-return valve
. Spirex says the system has outperformed four other commercial systems (including a GP and a barrier screw) in recovery time, percentage of maximum torque used, and plasticating rate in tests with five PP resins, two PEs, two nylons, ABS, and PET.
Unveiling QSO Quick Shut-off non-return valve
that delivers both high flow and rapid material shutoff for part weight consistency.
Glycon Corp., Tecumseh, Mich., has agreed to allow Spirex Corp., Youngstown, Ohio, to make and sell the Glycon QSO (quick-shutoff) non-return valve
. Glycon will also continue to sell the valve.