Herzog Needle Type A(S) Shut Off Nozzle – Spring Operated
- Prevents: Stringing, drooling
- Melt flow separation at nozzle orifice
- Easy to install
- Economic solution
- Compact, space saving design
Description
Herzog Needle Type A(S) Shut Off Nozzle – Spring Operated
The spring actuated machine needle shut-off nozzle s type A(S) are used in processing of thermoplastics , principally with low viscosity materials such as: PA, PPS, PE, POM, PP.
Download (PDF) : Type A(S) Brochure
Download (PDF): Type A(S) Installations & Service Manual
Finds application in: Packaging, automobile and leisure industries, medicinal and electronic equipment.
Prevents:
- Stringing, drooling
- Air pockets during screw retraction
- Material leakage when dosing with a withdrawn injection unit
- Material leakage while vertically injecting
Operation:
The nozzle is opened directly from the injection pressure and closed again with spring power. A needle which moves axially in the needle shut-off nozzle is held in the closed position by the force of the spring. The nozzle orifice is normally closed. With the increasing melt pressure exerted against the spring through a ring of exposed surface area on the needle, the nozzle opens at 200 bar . If the melt pressure drops (below 80bar), the nozzle closes.
– If the standard opening pressure is not appropriate, the needle must be modified to the requirements (modification of the spring is not possible).
– A temperature resistant material (max. 520°C) is used for the spring construction.
– The nozzle size required depends on the injection rate per second (cm3/s).
Productivity factors:
- Controlled, clean shut-off of the melt stream
- Shorter cycle times – increase in productivity
- Increased process reliability and repeatability
- Usability with increased back pressure – improved homogenization
- Quick machine installation
- Add-on capability (on tool side)
Option:
- Filter module