Nordson Screen Changer Alternatives: How to Choose
Process engineers look for an alternative to a Nordson BKG screen changer for a few recurring reasons: total cost of ownership, spare parts and engineering support, and application fit when the feedstock changes. Cofit’s alternative for clean and semi-clean polymer is the AP Series, a continuous and self-cleaning double cartridge screen changer that works without hydraulic systems. For high-contamination recycling, Cofit’s GorillaBelt is an automatic melt filtration system. For recycled PET, Cofit’s solution is ScrapeAway, an automatic, continuous and self-cleaning laser melt filter.
Why Process Engineers Look for a Nordson Screen Changer Alternative
Nordson Corporation, through its BKG brand, is a major supplier of screen changers and melt filtration equipment, with both continuous and discontinuous designs. The question is not whether these screen changers work — they do. The question is which solution fits a specific application best.
Process engineers typically evaluate alternatives for one of four reasons: total cost of ownership, including auxiliary systems such as hydraulic units and their maintenance; spare parts lead time and direct access to engineering support; application fit when the feedstock changes, for example when recycled content rises; and competitive specification of a new line, where several suppliers are compared on technical and commercial parameters.
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When Nordson BKG and When Cofit: An Objective Framework
Both suppliers produce capable continuous screen changers. The question is not which is better, but which fits the application better.
- Your organisation already has established Nordson service agreements and parts inventory
- The line is already equipped with a hydraulic power unit that can serve the screen changer
- You prefer to buy the complete melt delivery package from a single supplier
- Your OEM has a Nordson-qualified installation standard and you prefer to stay within it
- You are retrofitting an existing line and want to avoid hydraulic infrastructure installation
- Floor space or utility connections make an external hydraulic unit impractical
- You require filtration fineness down to 3 μm with continuous operation and no hydraulic unit
- Total cost of ownership, including auxiliary systems, is a primary evaluation criterion
- You want direct access to the engineering team that designs and builds the screen changer
When the Feedstock Is Contaminated Recyclate
If your polymer stream contains a significant share of post-consumer recyclate or hard contaminants, the AP Series is not the right choice: it is designed for clean and semi-clean polymer. For these applications, Cofit’s GorillaBelt, an automatic melt filtration system, is built for high-contamination recycling, up to 10% by weight. For recycled PET, Cofit’s solution is ScrapeAway, an automatic, continuous and self-cleaning laser melt filter. To define the right filtration setup for your recycling line, Request a Technical Alignment.
Practical Considerations When Switching Screen Changer Suppliers
Replacing a screen changer — whether from Nordson or any other supplier — involves three engineering checkpoints that determine whether a direct substitution is feasible or whether additional modifications are required.
1. Melt channel geometry and flange connections
The screen changer mounts between the extruder barrel outlet and the die adapter. The inlet and outlet flange dimensions, bolt pattern, and melt channel bore diameter must match the existing line geometry — or adapter flanges must be machined. In most cases, a process engineer from the replacement supplier reviews the existing line drawings before any equipment is specified, confirming fit or identifying the required adapter work.
2. Filtration area and throughput capacity
The replacement screen changer must provide equivalent or greater filtration area at the line’s throughput rate. Undersizing the filtration area relative to throughput raises baseline ΔP above operational limits and accelerates screen saturation. The replacement supplier should confirm filtration area specification against the line’s throughput, polymer viscosity, and required filtration fineness.
For a complete guide to diagnosing and solving melt pressure instability after a screen changer replacement, see melt pressure instability: causes and solutions →
3. Control system integration
Screen changers with automatic cycles need control signals, typically a ΔP trigger and optional integration with the line’s PLC or SCADA. The Cofit AP Series does not need them: the cleaning is activated by the operator with a key, which simplifies installation on lines where control system access is restricted.
Cofit Screen Changers: Technical Specifications
Three Cofit product families for the full melt filtration spectrum — from fine-filtration film and fiber applications to high-contamination post-consumer recycling.
- Filtration fineness: down to 3 μm
- Melt pressure: stable during cleaning cycle
- No external hydraulic control unit required
- Max operating pressure: above 500 bar
- Cleaning: backflush activated by the operator with a key
- Applications: film, fiber, sheet, coating
Fresh belt advances automatically through the melt zone — no cleaning cycle and no screen pack to replace. Designed for high-contamination recycling: metal fragments, aluminium foil, paper fibres, cross-linked polymer.
- Automatic belt advance — no cleaning cycle
- Designed for post-consumer and post-industrial recycling
- Handles metal fragments, aluminium foil, paper fibres, cross-linked polymer
Two laser-drilled filter discs, fixed scrapers and an automatic discharge system remove contaminants without stopping the line. For contaminated recycled melts; effective also on elastomers.
- Filtration 100–1,000 µm
- Up to 5,000 kg/h per unit
- Up to 250 bar and 300 °C
- Melt loss below 1%
For the complete technical guide to screen changer types: Screen Changers for Plastic Extrusion → · Continuous vs Discontinuous →
Frequently Asked Questions
In most cases, yes — with a flange adaptation review. The AP Series installs in the same position in the extrusion line (between extruder barrel outlet and die adapter) and performs the same function as a Nordson BKG continuous screen changer. The key mechanical checkpoint is the inlet and outlet flange geometry: bolt pattern, flange diameter, and melt channel bore must match or be adapted to the existing line. A Cofit process engineer reviews the existing line drawings before specifying any replacement equipment to confirm fit or identify required adapter work. Because the AP Series works without hydraulic systems, installation is usually simpler. Note that the AP Series is designed for clean and semi-clean polymer: for high-contamination recycling, see GorillaBelt; for recycled PET, see ScrapeAway.
The AP Series is a continuous and self-cleaning double cartridge screen changer that works without hydraulic systems: while one cartridge filters, the operator activates the cleaning of the other with a key, and a backflush of melt cleans the screen without stopping the line. Melt pressure stays stable during the cleaning cycle, and filtration fineness reaches down to 3 μm.
Yes. For contaminated post-consumer and post-industrial recyclate, Cofit’s GorillaBelt is an automatic melt filtration system in which fresh belt advances through the melt zone without any cleaning cycle. For recycled PET, Cofit’s solution is ScrapeAway, an automatic, continuous and self-cleaning laser melt filter with filtration from 100 to 1,000 µm. To define the right filtration setup for your line, Request a Technical Alignment.
A like-for-like screen changer replacement on an existing line — where flange geometry is confirmed and no additional civil or utility work is required — usually requires only a short planned stop. The AP Series does not require hydraulic line routing or commissioning of a hydraulic unit. The full installation sequence is: flange adapter confirmation (pre-installation), mechanical installation, function test, and production startup. Cofit engineers provide direct technical support throughout the installation process.
Cofit manufactures its screen changers at its facility in Cerro Maggiore (Milan), Italy, and holds standard spare parts in stock for its current product range. Parts requests go directly to the engineering team. For customers in specific regions, lead times should be confirmed with the Cofit sales team.
Evaluating a Screen Changer Replacement? Start with the Engineering.
Cofit engineers work directly with OEMs and converters to assess application fit, confirm line geometry, and specify the right continuous filtration solution — without commercial pressure. Request a technical alignment or calculate your current lost production first.
Cofit deals with research, engineering, manufacture and distribution of screen changers that keep the line running, including for post-consumer and post-industrial recycled materials.
Contact us to upgrade your extrusion system or ask us for more information about any product or service.