Traditional rear seat closing screw tips are prone to leakage and excessive wear on equipment which naturally leads to cushion variation, part weight variation, and unnecessary maintenance costs. The APV (pat. 6203311 & 6464488) was created to have a self cleaning screw tip design that provides shot-to-shot repeatability and accuracy, regardless of initial velocity, without excessive barrel wear.
The screw tip shouldn't be treated as "just a replacement component." The feedscrew and non-return valve are responsible for both quality and efficiency as well as the repeatability of your process. Each APV is designed to be optimized for the material(s) being processed. Compared to traditional "free flow" OEM style screw tips, the APV typically has 1/4 the distance to closure. This means that you will have fast, consistent closure with no leakage.
Unlike traditional rear seat closure, the APV utilizes sliding closure. A positive seal is obtained when the ring slides past a circumferential groove on the valve body. This method of closure allows for consistent sealing without the reliance of decompression. Sliding closure enables the valve to close positively while withstanding pack and hold pressures of 20,000 PSI without creeping into the cushion.
Unlike traditional screw tips, the APV does not requre excessive ring thickness and friction to obtain positive clousre. This allows for a minimal land length which translates to minimum pressure drop during crecovery. Consequently, the APV uses far less distance to close as compared to other valves, typically .030" vs .120" distance to close.
As a result, the APV closes much faster, eliminating leakage and reducing cushion variation. This less restrictive design enables faster recovery times, less erratic temperature changes, and an increased ring to barrel clearance - eliminating excessive wear on the barrel and valve components. Perhaps more importantly, the APV was designed on the basis of customization. Rather than an off-the-shelf, one-size-fits-all solution, each screw tip is custom designed to ensure optimal performance for your machine-to-material relationship. The groove geometry and distance to close can be tailored to best suit the resin(s) being processed so that you can achieve a consistent cushion, regardless of viscosity.
Unlike traditional interlocking (castellated) screw tip designs, the interlocking APV does not cause excessive barrel wear. The increased ring to barrel clearance of the APV design allows for increased wear-life of the valve and barrel. Many interlocking APV's have lasted 12 years in major 24/7 manufacturing facilities and are still in use today.
APV Non-Return Valve Features
The APV was designed with flexibility in mind, each APV is custom designed to best suit your molding operation. The APV can accommodate any molding challenge on any OEM press. Our full range of APV design options all give you the same world class repeatability.
Standard APV
The standard APV utilizes the superior sliding closure to give you world class repeatability. Groove geometry and distance to close are tailored to best suit the resin(s) being processed for your application. The standard APV can greatly improve cushion variation without the use of excessive decompression. The APV has outperformed all competing screw tips in extensive independent trials performed at various OEM laboratories.
APV Mixing Valve
The APV Mixing valve provides the same sliding closure and repeatability as the standard APV while incorporating a spiral mixing chamber in the valve body. The APV mixing valve helps improve dispersion and melt quality from general purpose screws and other poor feedscrew designs. By incorporating the mixing chamber in the valve body, the L/D of the feedscrew is effectively lengthened. The APV mixing valve is a quick economical fix for poor color dispersion and other melt quality issues.
APV Interlocking Valve "castellated"
The APV interlocking valve still provides the same sliding closure and repeatability as the standard APV while incorporating an interlocking ring. This design improves the valve wear life by causing the ring to rotate with the feedscrew. In high RPM molding operations the interlocking APV greatly reduces wear. The interlocking or "castellated" style ring can be incorporated in both standard and mixing APV variations. Unlike traditional castellated screw tips that cause excessive barrel wear, the APV interlocking valve has an increased ring OD to barrel ID clearance. This reduces wear on the barrel ID while greatly improving the wear life of the valve. We have customers using the same Interlocking APV and Injection Barrel for 12 years and counting!
Ask us about our price breaks when ordering multiple valves!