Self-Cleaning Continuous Flow Screenchanger
Cofit presents the renewed series of AP screenchangers - a perfect synthesis between simple use and technological innovation.
This series was born to meet the demand of plants where it is important to keep the extruders running and where superior material filtration is an asset.
The originality of this solution by Cofit makes it possible to clean the filter cartridges without the need to remove them from the screenchanger and without interrupting the extrusion process.
The AP incorporates two filter cartridges
The cleaning is done in one filter cartridge at a time. When one filter cartridge is being automatically cleaned, the melt continues to flow through the second filter cartridge.
Self-cleaning of the filter
- When one of the two filters requires cleaning, the operator shuts one of the two inlet valves, so that the entire flow of material is channeled towards the second filter cartridge.
- At the same time, an outlet valve is opened to divert part of the flow of material towards the dirty filter. The pressure exerted by this flow pushes all the impurities through the opened purge valve, until the filter cartridge is completely clean.
Replacement of filtering screens during the production
The replacement of the screens is also an easy procedure, which does not interrupt the production process.
The two valves which control the flow to the filter cartridges are simply shut one after the other, until the screen replacement has taken place.
The material is then allowed to flow as far as the filtering unit, where the entrapped air residue is eliminated.
The flow valves are then moved to their normal operating position where the material again flows through both clean filter cartridges.
Advantages
AP is CONTINUOUS
The filtering cartridges are cleaned or replaced without having to interrupt production
- Guarantees uninterrupted, continuous extrusion production
- Enables the attainment of extreme uniformity of the plastic material
AP is SELF-CLEANING: minimum wear of the screens
Thanks to an exclusive Cofit patent, the filter cartridges are cleaned without being taken out of the screen changer
- Being able to clean the screens means that their replacement is required only periodically, when they have become completely obstructed. Screen replacement is done without interruption of the extrusion process
AP is SOLID: reliable and durable
AP is made from a steel body for a low maintenance, trouble free life.
- There are no moving parts to be driven by hydraulic or pneumatic power units
- Chrome plating provides high protection against wear
AP is ECONOMICAL
No hydraulic or pneumatic units are involved
- No hydraulic unit is required
- No control panel is required
- The self cleaning feature, when combined with the large filtering surface of the two cylindrical filter cartridges, makes the operation of the AP the most economical of all screenchangers
The applications
The AP series is perfect for installations which deal with thermoplastic materials such as: PE, PP, ABS, PS, etc. It was developed to meet the requirements of extrusion installations for film, sheet, mono-filaments, bioriented film, pipe, tubing, fibers, compounding, natural and synthetic rubbers, soft PVC
| Technical data | |
|---|---|
| Processing | Manually operated, continuous, self-cleaning |
| Type of material | Steel |
| Filtering unit area | Up to 600 cm² |
| Heaters | Hardened |
| Material status | Very suitable for processing moderately contaminated materials. The AP guarantees a melt with distinctive purity and uniformity |
| Operating temperature | Up to 300° |
| Pressure | Up to 800 bar |
| Hourly capacity | Up to 3000 kg/h |
| Machined product | ABS, PE, PP, PET, PS, natural and synthetic rubbers, and flexible PVC |
| Resulting product | Film, sheet, mono-filaments, bioriented films, pipe, tubing, fibers and compounding, etc. |
