Build Consistent Compounds From Variable Recyclate
Reliable compounding starts with the right process route.
Polymer variability, contamination, moisture, additives and target properties all influence compounding performance and final material quality.
MAS compares regranulation, compounding, re-compounding and two-stage processing options to define the right route for your material and formulation.
Compounding Vs. Re-Compounding: What Changes?
Compounding combines a polymer or polymer blend with additives, fillers, fibres, colourants or modifiers to reach defined processing or end-use properties. Feedstock may be virgin, recycled or a controlled blend.
Re-compounding applies the same formulation discipline to recyclate whose composition, contamination, moisture, degradation and batch variability may require additional preparation, filtration, degassing, stabilisation or compatibilisation.
Decision rule: If the material only needs size reduction, melting and pelletising, simple regranulation may be sufficient. If properties must be deliberately changed or restored, evaluate compounding or re-compounding. Filtration and degassing are selected from measured material condition and output requirements—not automatically.
Revised comparison labels: Input consistency—characterised range; contamination—measured type and load; volatiles—measured moisture/volatile duty; primary task—add, restore or stabilise properties; filtration—conditional; degassing—conditional; quality control—recipe, input, process and output criteria.
| Comparison Criterion | Compounding (virgin) | Re-Compounding (Recyclate) |
|---|---|---|
| Input consistency | Known and stable | Fluctuating between batches and deliveries |
| Contamination | Effectively none | Wood, paper, rubber, non-melting foreign polymers |
| Volatiles | Low | High — inks, adhesives, moisture, residues |
| Primary task | Add properties | Restore properties, then add properties |
| Melt filtration | Usually not required | Essential |
| Degassing demand | Moderate | High, sometimes multi-stage |
| Quality control | Recipe compliance | Recipe compliance plus input compensation |
MAS refers to the result as upcycling rather than recycling: material does not simply return to circulation at the same grade, it re-enters at a specified, higher-value grade because the formulation was engineered into it during re-granulation.
The MAS Approach: Seven Process Stages, One Line
The route begins with the customer problem and compares feasible choices before equipment is selected.
Material Preparation and Cleaning
Wet or contaminated input is cleaned and dried before extrusion. DRD dry cleaning, the PreDensifier and SC pyrolysis oven are integrated where required by the material condition.
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Feeding and Dosing
Recyclate, additives, fillers and fibres enter through the large main feed opening. TMS silo scales and the TW throughput weigher support accurate gravimetric dosing.
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Plastification, Mixing and Homogenisation
The conical co-rotating twin screws plastify and blend the material with low shear, controlled melt temperature and short residence time.
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Melt Filtration
The CDF continuous melt filter removes wood, paper, rubber and other non-melting contaminants without interrupting production.
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Degassing
Vacuum degassing removes moisture, air and volatile substances from inks, adhesives and laminate residues before pelletising.
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Property Modification
Stabilisers, compatibilisers, modifiers, colourants, fillers and reinforcing fibres are incorporated at the appropriate position in the line.
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Pressure Build-Up, Pelletising and Handling
The melt is pressurised and processed through strand, water-ring or underwater pelletising before transfer to silo or big-bag filling.
Four MAS Compounding Routes — Which One Fits Your Material?
MAS offers four line concepts for compounding and re-compounding. The Twin-Compound line is the flagship and the most capable, but it is not the right answer to every brief — a clean post-industrial stream with a simple additive package does not need two extrusion stages. The table compares all four on the criteria that actually decide the choice.
| Line Concept | Architecture | Additive Entry Points | Best Suited To | Less Suitable For |
|---|---|---|---|---|
| Twin-Compound flagship | Two conical twin-screw extruders in series, CDF melt filtration between them | Two — before and after filtration | Fibre-reinforced compounds, highly filled granulates, high-value or non-filterable additives, incompatible formulation components, difficult-to-degas recyclate | Simple re-granulation of clean, consistent material — capability would go unused |
| Re-Compound Line | Conical twin-screw extruder → CDF melt filter → single-screw cascade extruder with patented melt distribution segment | One — before filtration | Re-granulating materials that are difficult to degas, correcting fluctuating input quality with filter-tolerant additives, colourants and UV filters | Long-fibre reinforcement, additives that cannot pass a melt filter |
| iQonicTwin Regrind | Modular single-stage system, recycling and compounding combined in one step | One — integrated | Post-consumer and post-industrial polyolefins and technical polymers where compact footprint, low energy use and fast recipe changeover matter most | Very high filler loadings, multi-stage additive strategies |
| Upgrade Line | MAS process modules retrofitted into an existing extrusion installation | Depends on existing line | Adding compounding, filtration or degassing capability to installed plant without replacing it; staged capital investment | Greenfield projects, where a purpose-built line is more efficient |
Route selection is confirmed by material testing. Scope of the Upgrade Line depends on the existing installation.
A Short Decision Path
- Does the compound need long fibres or very high filler loading? → Twin-Compound.
- Does any additive need to bypass the melt filter, or must two components stay separated until late in the process? → Twin-Compound.
- Is the main challenge degassing a difficult fraction, with a conventional additive package? → Re-Compound Line.
- Is the priority compact footprint, low energy consumption and frequent recipe changes? → iQonicTwin Regrind.
- Is there already an extrusion line on the floor that needs new capability? → Upgrade Line.
Related Technologies
Twin-Screw Extruder
The conical co-rotating twin-screw extruder used twice in the twin-compound line.
CDF Melt Filtration
The continuous melt filter that removes contaminants between the two extrusion steps.
iQonicTwin Regrind
Efficient regranulating and re-compounding line for recycled plastics.
MAS 110
The compact high-capacity extruder for larger recycling and compounding lines.
DRD Dry Cleaning
Water-free cleaning and drying for material preparation before compounding.
Materials and Input Streams
MAS compounding and re-compounding lines process the standard recyclable thermoplastics — PE, PP, PS, ABS, PA and PET. In practice there are few material limits: anything that can be melted can be re-granulated, and quality losses in the input can be corrected with the appropriate additives. Colourants and UV filters are used systematically to compensate for varying input quality.
Final suitability for any given project depends on polymer compatibility, contamination level, moisture content, additive requirements and the target compound specification — which is why MAS validates every formulation by test before a line is configured.
Define The Input Before Selecting The Line
- Post-Consumer Recyclate — Assess composition, contamination, moisture, odour and variability before formulation.
- Post-Industrial Recyclate — Confirm segregation, process history and additives; a simpler route may be adequate.
- Film And Low-Bulk Material — Compare densification, cutter compaction and direct controlled feeding.
- Regrind And Mill Materials — Confirm particle/bulk behaviour and consistency.
- Fibres, Fillers And Reinforcing Materials — Confirm feeding, dispersion, breakage, wear, filtration compatibility and maximum validated loading.
Compounding Applications
Supporting Technologies Across Every Compounding Line
Whichever line concept is selected, the same MAS component technologies are available to configure around it. Each has its own technical page.
| Technology | Process Stage | Contribution To Compounding |
|---|---|---|
| Conical co-rotating twin-screw extruder | Plastification, mixing | The core platform. Large feed opening, low shear, gentle plastification, compounding without side feeders |
| MAS 110 | Plastification, mixing | Higher throughput and productivity for larger recycling and compounding lines |
| CDF continuous melt filtration | Filtration | Removes non-melting contamination continuously, before the degassing zone |
| Patented degassing extruder | Degassing | Melt distribution segment for high-performance venting and pressure build-up |
| CC vacuum system | Degassing | Vacuum capacity matched to the volatile load of the input fraction |
| DRD dry cleaning machine | Preparation | Waterless cleaning and drying in one step, upstream of the extruder |
| PreDensifier | Preparation | Densifies very low bulk density material for stable feeding |
| SC pyrolysis oven | Preparation, maintenance | Removes stubborn organic contamination from components |
| TMS silo scales | Dosing, handling | Gravimetric accuracy for recipe compliance and inventory control |
| TW throughput weigher | Quality control | Continuous throughput verification against the recipe |
| Digitalisation in extrusion | All stages | Process monitoring, trend analysis and recipe management |
| HyperPET | Specialist | PET-specific processing where food-grade rPET is the target |
From Material Test to Commissioning
No MAS compounding line is specified from a datasheet alone. Because re-compounding depends on the behaviour of a specific input stream with a specific formulation, MAS validates both before the configuration is fixed — which is also why the company can commit to achievable compound quality rather than indicative figures.
1. Material Assessment
Input analysis, contamination profile, moisture, polymer mix and target specification are reviewed against the four line concepts to shortlist a route.
2. Trials In The Technical Test Center
The MAS Technical Test Center runs the customer’s own material and additives, with the MAS 24 and 55 laboratory extruders available for small-quantity formulation work.
3. Engineering And Financing
Line layout, dosing design, filtration sizing and pelletising integration are fixed, supported by project management and machinery financing where required.
4. Commissioning And Service
Installation, operator training, machine optimisation and long-term aftersales support, with individually replaceable wear parts keeping downtime short.
What Our Customers Say
We always have to try to buy as good as possible to produce top-quality regranulate. And we do that with the technology we bought from MAS.
Peter Daalder, CEO — Daly Plastics, Netherlands
Fatra was satisfied with the MAS cooperation, the possibility of tests before ordering, MAS innovative solutions and the final production performance achieved.
Ing. Jan Jedovnický — Fatra
