Injection Molding with PCR & PIR Recyclates - Tederic 2025

Introduction

Processing post-consumer recyclates (PCR) and post-industrial recyclates (PIR) on injection molding machines has become not only a matter of environmental responsibility, but a legal requirement. Since February 11, 2025, the EU Packaging and Packaging Waste Regulation (PPWR) has been in force, mandating the use of recyclates in plastic packaging – from 10-35% in 2030 to 25-65% in 2040.

For injection molded part manufacturers, this means adapting production processes to work with materials of variable quality, higher abrasiveness, and unpredictable rheological properties. Tederic injection molding machines, thanks to special screw configurations, precise temperature and pressure control, and filtration systems, are prepared for processing recyclates while maintaining process stability and part quality.

PPWR 2030 Regulations: Mandatory Recyclate Content

The PPWR (Packaging and Packaging Waste Regulation) entered into force on February 11, 2025, introducing the most restrictive requirements in EU history regarding recyclates in packaging.

Required minimum post-consumer recyclate (PCR):

From 2030:

• 10% PCR – in food-contact packaging (PET bottles, HDPE containers)
• 35% PCR – in other plastic packaging (transport, technical, cosmetic packaging)
• Exceptions: packaging for transport of dangerous goods

From 2040:

• 25% PCR – in food-contact packaging
• 65% PCR – in other plastic packaging

Current status in Poland and EU:

• Average PCR share in plastic products in EU: 7.2% (2023 data)
• Plastic packaging recycling in Poland: 43% (2022)
• Required increase in recycling by 12 percentage points by 2030
• Premium packaging industry declares increase to 20% PCR by 2025

Consequences for manufacturers:

• PPWR non-compliant products will not be allowed on the EU market
• Financial penalties for non-compliance
• Required documentation and certification of recyclate sources
• Reporting obligation under extended producer responsibility (EPR)

Technological Challenges of PCR and PIR Processing

Processing recyclates on injection molding machines involves a series of technical challenges absent when working with virgin material.

1. Variable Viscosity and MFI

The Melt Flow Index (MFI) of PCR recyclates can vary from 30 to 70 within a single batch, while virgin material maintains MFI within ±5. This means:

• Unpredictable mold filling – the same material can fill the mold slower or faster
• Variable injection pressure – constant parameter correction required
• Differences between cycles – difficulty maintaining repeatability

Degradation mechanism:

• HDPE and LLDPE – polymer chain crosslinking increases viscosity, causes gels and contaminants
• PP (polypropylene) – oxidative degradation causes chain breakage, decreases viscosity

2. Contaminants and Inhomogeneities

Post-consumer recyclates have contamination levels up to 20 times higher than virgin materials:

• Microscopic metal particles – from optical sorters, screeners
• Paper, cardboard fragments – label residues
• Silica and dust – from grinding and washing processes
• Polymer foreign substances – mixtures of different plastics
• Carbon and char – from previous processing cycles

Consequences: spots, discolorations, risk of mold damage, reduced mechanical strength.

3. Thermal Degradation

Each processing cycle (granulation → extrusion → injection) shortens polymer chains:

• Reduced tensile strength – up to 15-25%
• Lower impact resistance – Izod test shows drops of 20-40%
• Increased brittleness – especially at low temperatures

4. Color Variability

PCR has an unpredictable base shade (yellowish, gray, brown), making it difficult to achieve consistent color, especially in light shades.

Tederic Injection Molding Machine Configuration for Recyclates

Tederic injection molding machines can be equipped with special configurations optimizing PCR and PIR processing while maintaining quality and process stability.

Special Screws for Recyclates

Screws for abrasive materials differ from standard ones in construction and material:

Design features:

• Barrier screw – separate zone separates solid phase from liquid phase, improving homogenization
• Additional mixing elements – dispersive mixing section (Maddock) or rhomboid mixing section
• Increased L/D ratio – 22:1 or 24:1 instead of standard 20:1 for better mixing
• Modified feed geometry – prevents blockage by irregular granules

Wear-resistant materials:

• PC-100 (nickel-boron alloy) – Rockwell hardness C 60-65, for medium-abrasive materials
• PC-700 (bimetallic tungsten carbide) – Rockwell hardness C70, >80% tungsten carbides
• HVOF coatings (tungsten carbide) – applied to screw flights, extend life 5-10x

Proper screw selection can extend its life from days to months with highly abrasive materials.

Barrel and Filtration Systems

Bimetallic barrel with wear-resistant inner layer (similar materials as screw) is necessary for long-term PCR processing.

Filtration systems in Tederic injection molding machines:

• Double venting – removes moisture and volatile contaminants
• Dual-piston filtration units – continuous filtration without production stoppage
• 80-120 mesh filter screens – retain particles >125-180 µm
• Filter change every 2-8h – depending on contamination level

Precise Temperature Control

Tederic offers advanced heating zones with ±1°C accuracy, crucial for recyclates:

• Temperature profile in 5-8 zones – precise melting control
• Lower plastification temperature – 10-20°C lower than for virgin material (minimizing degradation)
• Feed zone cooling – prevents premature melting and blockage

Example temperature profile for PP PCR (vs virgin material):

• Zone 1 (feed): 40°C (vs 50°C)
• Zone 2-3 (compression): 180-190°C (vs 200°C)
• Zone 4-5 (metering): 200-210°C (vs 220°C)
• Nozzle: 205°C (vs 220°C)

Hot Runner Systems

For PCR/PIR, particularly important are hot runners with easy cleaning access:

• Nozzles with replaceable inserts – quick replacement when blocked
• Easy-clean systems – cleaning possible without mold disassembly
• Pressure sensors in nozzles – real-time blockage detection

Injection Process Parametrization with Recyclates

Injection parameters for PCR and PIR require optimization compared to virgin material.

Temperature and Pressure

Reduced processing temperature (10-20°C):

• Minimizes further degradation of polymer chains
• Reduces formation of char and outgassing
• Requires cycle time extension of 5-15%

Higher injection pressure (10-25%):

• Compensates for reduced flow of degraded material
• Ensures complete mold filling with variable MFI
• Requires cavity pressure monitoring (in-cavity pressure sensors)

Times and Process Phases

Time adjustments for PCR/PIR:

• Injection time: +10-20% (slower filling reduces shear stresses)
• Packing time: +15-25% (compensation for unpredictable shrinkage)
• Cooling time: +5-10% (inhomogeneous crystallization requires longer time)

Automatic Variability Compensation

Advanced Tederic controllers offer material variability compensation features:

• Auto Viscosity Adjust (AVA) – automatic pressure adjustment to current MFI
• In-cavity pressure control – closed-loop control based on cavity sensors
• Adaptive injection – pressure and speed profiles adjusted in real-time

These systems can reduce scrap by 30-50% when working with PCR batches of variable MFI.

Quality Control in Recyclate Processing

Stable part quality from recyclates requires intensified control at every stage.

Input Material Control

Tests before production start:

1. MFI (Melt Flow Index):

• Test: 190°C / 2.16 kg (PP) or 190°C / 21.6 kg (HDPE)
• Acceptable deviation: ±15% from declared value
• Frequency: every new batch

2. DSC (Differential Scanning Calorimetry):

• Melting temperature, crystallinity, presence of polymer contaminants
• Detection of mixtures of different plastics (PP + PE + PS)
• Frequency: with changing suppliers

3. Mechanical tests:

• Izod test (impact resistance) – min. 80% of virgin material value
• Tensile strength – min. 85% of virgin value
• Elastic modulus – deviation max. 10%

Process Monitoring

Real-time monitoring parameters:

• Injection pressure – deviation >10% = correction signal
• Melt temperature – pyrometer measurement in nozzle
• Screw torque – detects viscosity increase/blockages
• Cycle time – increase >5% = possible material problems
• Specific energy – kWh/kg part (increase = process degradation)

Finished Part Control

100% visual or automatic control:

• Vision systems – detection of spots, discolorations, contaminants
• Dimensional control – increased frequency (every 50 parts instead of every 200)
• Functional tests – sealing, assembly strength

Case Study: Cosmetic Packaging with 50% PCR

Project profile:

• Client: Premium cosmetic packaging manufacturer (Poland)
• Part: Cylindrical container 100 ml, wall 2.5 mm
• Material: PP PCR 50% + PP virgin 50%, requirements: transparency, chemical resistance
• Machine: Tederic DE550 (electric injection molding machine, clamping force 550 kN)
• Mold: 8-cavity, hot runners with game-changer nozzles

Challenges:

• Recyclate MFI fluctuated 28-55 between batches
• Client required consistent color (milky shade)
• Container sealing >99.5% (2 bar pressure test)
• Contact-safe certification for cosmetics

Technical solution:

1. Machine configuration:

• Bimetallic screw 22:1 L/D with Maddock mixing section
• HVOF coating on screw flights (hardness RC70)
• Dual filtration system 100 mesh
• Pressure sensors in 4 cavities (50% monitoring)

2. Process parameters (optimized):

• Temperature: 190-205°C (vs 210°C for virgin PP)
• Injection pressure: 850-950 bar (vs 700 bar for virgin)
• Injection speed: 45 mm/s (reduced from 60 mm/s)
• Packing time: 18 s (vs 12 s for virgin)
• Cycle time: 38 s

3. Quality control:

• MFI test every 4h (with each material bag change)
• Vision system 100% discoloration control
• Sealing test co-injected samples (1 in 500 pcs)

Results after 6 months of production:

• Process stability: <2% scrap (vs 8% in test phase)
• Sealing: 99.7% parts passed pressure test
• Color consistency: ΔE <1.5 (acceptable to client)
• CO₂ savings: 1.2 tons/month vs virgin material production
• Material costs: 15% lower (PCR 30% cheaper than virgin PP)
• Screw life: No measurable wear after 6 months (2.5 million cycles)

Key success factors:

• Close cooperation with recyclate supplier (quality control at source)
• Adaptive pressure control (AVA) compensating MFI variability
• Regular filter replacement (every 6h)
• Operator training on PCR specifics

Best Practices for PCR and PIR Processing

DO – Recommendations:

• Audit recyclate suppliers – visit facility, check sorting and washing process
• Demand certificates – origin documentation, specifications, contact-safe certificates
• Test every batch – MFI, DSC, mechanical tests before production start
• Lower temperature – 10-20°C below virgin material recommendations
• Invest in special screws – ROI in 6-12 months through extended life
• Use in-cavity sensors – only way to stabilize process with variable MFI
• Regularly clean system – purging compounds every 24-48h PCR work
• Document everything – PPWR requires full traceability of recyclate sources

DON'T – Mistakes to avoid:

• Don't mix different PCR batches – even from same supplier may have different MFI
• Don't use standard screw – will wear out in 1-3 months with micro-metal PCR
• Don't overheat material – every +10°C means additional degradation
• Don't ignore torque increase – signals blockage or contamination increase
• Don't save on filters – cheap 40 mesh screen passes contaminants >400 µm
• Don't assume constant parameters – every PCR batch requires correction

Summary

Processing PCR and PIR recyclates has become a business necessity in light of PPWR 2030 requirements. Injection molded part manufacturers must prepare their processes for working with variable quality materials requiring special machine configurations and precise parametrization.

Key takeaways from the guide:

• PPWR 2030 mandates 10-35% PCR in packaging from 2030, 25-65% from 2040
• MFI variability 30-70 in single PCR batch – biggest technical challenge
• Contamination up to 20x higher than virgin material – filtration necessary
• Special screws extend life 5-10x – HVOF coatings, PC-700 steel
• Reduced temperature by 10-20°C minimizes thermal degradation
• AVA and in-cavity sensor systems stabilize process with variable material
• Case study shows 99.7% quality with 50% PCR in premium cosmetic packaging
• Material costs 15% lower vs virgin material production

Tederic injection molding machines, thanks to flexible configuration, precise control, and ability to mount specialized screws and filtration systems, are prepared for recyclate production challenges. The key to success is conscious machine configuration selection, process parameter optimization, and strict input material quality control.

Transitioning to recyclates is not just a regulatory requirement, but an opportunity to reduce material costs and improve the company's ecological image. With the right technical approach, the quality of PCR/PIR parts can match virgin material products.

If you are planning to implement production with PCR or PIR recyclates and need technical support, contact TEDESolutions experts. As an authorized partner of Tederic, we offer comprehensive consulting on machine configuration selection, process optimization, material testing in the application center, and training for production teams.

See also our articles on sustainable production, Tederic injection molding machines, and production cycle optimization.