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Plastic recycling process to reduce CO2 emissions and save costs
Injection molding processes for recycled materials
The use of recyclates improves the CO2 balance. At the same time, contamination causes odor pollution and fluctuations in quality.
With our innovative recycling processes for plastics, we are responding specifically to these challenges. ENGEL enables its customers to build a Circular Economy.
Advantages of plastic recycling processes
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30% CO2 savings through direct processing of flakes
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Solutions to increase the recycled content in the component by up to 100%
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No odors, streaks or moisture residues in the component thanks to degassing
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More safety thanks to filtration of the melt
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Realization of “design for recycling” with ENGEL technologies
Regranulation of used plastics requires a large amount of energy in recycling. With our two-stage plastic recycling process, this step can be skipped. Depending on the recyclate used, you save more than 400 Wh of energy per kilogram of plastic. This is a CO2 reduction of 30%.
With our injection molding processes for a circular economy, you can increase the recyclate content in the component. A recycling rate of 50% is reached with the skinmelt process. The foilmelt process achieves an even higher percentage. In the two-stage process, no virgin material is used at all. Therefore, the part consists of 100% recyclate.
Volatile components of the material, such as gases or moisture, are eliminated with our integrated degassing process. Degassing enables a wider range of recyclate applications, delivers component quality without streaks, and decreases residue buildup in the mold. Odor is reduced enormously. Especially with painted components, beautiful surfaces are achieved thanks to degassing.
Filter systems reliably remove contaminants from the recyclate. Depending on the design, they protect the plasticizing unit, hot runner and mold. Suitable filter systems are offered for different degrees of contamination. This prevents clogging of the mold, hot runner and sprue channels by unwanted particles. In addition, the component quality increases.
“Design for recycling” can be implemented with a visible high-quality skin and recyclate in the core. Our plastic recycling processes in multi-component injection molding are particularly suitable, if the molded part has the same polymer base. Manufactured components can simply be recycled again.
Advantages of plastic recycling processes
30% CO2 savings through direct processing of flakes
Regranulation of used plastics requires a large amount of energy in recycling. With our two-stage plastic recycling process, this step can be skipped. Depending on the recyclate used, you save more than 400 Wh of energy per kilogram of plastic. This is a CO2 reduction of 30%.
Solutions to increase the recycled content in the component by up to 100%
With our injection molding processes for a circular economy, you can increase the recyclate content in the component. A recycling rate of 50% is reached with the skinmelt process. The foilmelt process achieves an even higher percentage. In the two-stage process, no virgin material is used at all. Therefore, the part consists of 100% recyclate.
No odors, streaks or moisture residues in the component thanks to degassing
Volatile components of the material, such as gases or moisture, are eliminated with our integrated degassing process. Degassing enables a wider range of recyclate applications, delivers component quality without streaks, and decreases residue buildup in the mold. Odor is reduced enormously. Especially with painted components, beautiful surfaces are achieved thanks to degassing.
More safety thanks to filtration of the melt
Filter systems reliably remove contaminants from the recyclate. Depending on the design, they protect the plasticizing unit, hot runner and mold. Suitable filter systems are offered for different degrees of contamination. This prevents clogging of the mold, hot runner and sprue channels by unwanted particles. In addition, the component quality increases.
Realization of “design for recycling” with ENGEL technologies
“Design for recycling” can be implemented with a visible high-quality skin and recyclate in the core. Our plastic recycling processes in multi-component injection molding are particularly suitable, if the molded part has the same polymer base. Manufactured components can simply be recycled again.
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Take advantage of our expertise, plant engineering and technologies for processing plastic flakes or regranulate. We will support you in finding the right plastic recycling process.
Overview of our plastic recycling processes
| Procedure | Product name | Industry | Applications | Process |
|---|---|---|---|---|
| Two-stage process | Automotive & Mobility, Technical Injection Molding, Packaging, Electronics | Bumpers, engine covers, logistics, pails, flower pots, drainage pipe fittings | Direct processing of recyclates with degassing and filtration of the melt | |
| Sandwich injection moulding | skinmelt, co-injection | Automotive & Mobility, Technical Injection Molding, Packaging, Electronics | Furniture/furnishing, logistics (boxes), pails | Multi-component injection molding with high-quality material on the surface and recyclate in the core |
| Foil/film back molding | foilmelt | Automotive & Mobility, Technical Injection Molding, Packaging, Electronics | Interior/exterior trims, trims for white goods, electronic products | Create functional, haptic and decorative surfaces with films - the film is back-injected with recycled material |
| PET / rPET processing | Packaging | Thin-wall packaging | PET processing with powerful machines |
Details about our plastic recycling processes
Two-stage process
The two-stage injection molding process enables a circular economy with minimal use of resources. Contaminated regrind is processed directly in the injection molding machine. The material gets degassed and filtered. This eliminates an entire work step: regranulation. This significantly reduces costs and energy consumption.
Your advantages with the two-stage process
Consistently high product quality despite recycled material
Consistently high product quality despite recycled material
Integrating degassing, filtration and additives into the injection molding process makes it reliable - even with contaminated recyclates.
Reducing CO2, saving energy and costs
Reducing CO2, saving energy and costs
Direct processing of regrind in injection molding requires more than 30% less energy for processing the recyclate, as regranulation is no longer necessary.
No odors, streaks or residual moisture in the component
No odors, streaks or residual moisture in the component
Thanks to the integrated degassing process, volatile accompanying substances are eliminated and better component quality is achieved. Less fogging forms in the mold, and the mold service life is increased.
Gentle fiber additives and cleaning of the recyclate
Gentle fiber additives and cleaning of the recyclate
In addition to filtration of the material, the process enables gentle fiber processing. With the help of high fiber lengths, you can manufacture components that meet high mechanical requirements.
Result
Wide range of applications for recycled materials
Component meets high quality requirements
Part of the manufacturing process (regranulation) is skipped - you save valuable energy
Plastic recycling processes in practice
ENGEL wins Austrian State Innovation Award for two-stage process
On 7 October 2024, Austrian Federal Minister for Labour and Economy, Martin Kocher, presented the award in Vienna. The State Award honours Austria’s most innovative companies, and the jury recognised ENGEL’s contribution as a groundbreaking transformation in the recycling process.
Increased efficiency through ENGEL's two-stage process
Post-consumer recycled (PCR) plastic flakes are processed directly with ENGEL's two-stage process. The company AVK Plastics BV uses this technology to produce new pallets from shredded polyolefins. The customer saves costs and valuable energy with the plastic recycling process.
Direct processing of contaminated regrind
Thanks to the two-stage plastic recycling process, the material cycle can be closed with very little use of resources.
Sandwich injection molding
Sandwich components are a great solution in a circular economy. Recycled plastic such as post-consumer waste can be hidden inside the product. The recyclate is not visible on the surface.
Your advantages with sandwich injection molding
Reduce CO2 footprint
Reduce CO2 footprint
By using recycled material, valuable resources such as raw materials can be saved
Cost savings due to recycled material in the core
Cost savings due to recycled material in the core
With high-quality material on the skin, you inject a lower-cost material into the component’s core.
Weight reduction due to foamed core
Weight reduction due to foamed core
Reduce the shot weight of the component with foamed core material. There are no sink marks on the surface
Increase mechanical properties
Increase mechanical properties
The fiber reinforcement in the core increases the strength of the component.
Result
Sandwich components have a visibly high-quality surface
Components with up to 50% recycled core possible
Plastic recycling process with different types of sandwich injection molding
The animation shows the sequential flow of the co-injection process:
Injection of skin material (green)
Injection of core material (gray)
Sealing with skin material (green)
This animation shows the sequence of the dosing process:
The upper unit contains the virgin (skin) material (green). The main unit contains the core material.
Before injection, the skin material is transferred to the main unit.
The filling process is identical to the conventional injection molding process.
The skin material forms the outer layer. The core material remains inside.
Plastic recycling process with different types of sandwich injection molding
co-injection
The animation shows the sequential flow of the co-injection process:
Injection of skin material (green)
Injection of core material (gray)
Sealing with skin material (green)
skinmelt
This animation shows the sequence of the dosing process:
The upper unit contains the virgin (skin) material (green). The main unit contains the core material.
Before injection, the skin material is transferred to the main unit.
The filling process is identical to the conventional injection molding process.
The skin material forms the outer layer. The core material remains inside.
Types of Sandwich Injection Molding - Functionalities & Applications
What are the types, functionalities and applications of sandwich injection molding? Find out in the blog post.
Sandwich injection molding as an ideal application for recyclates in practice
Foil/film back molding
In film back injection molding, the recycled material is attached to a film. This happens directly in the mold during the injection molding process. Only the film is visible on the surface. The product is significantly upgraded.
Your advantages with the foilmelt process
Facilitated “Design for Recycling”
Facilitated “Design for Recycling”
With the outer film, you achieve an improved component surface. The recycled material remains hidden in the core.
Flexible Designs
Flexible Designs
You can implement different designs. Switching to a new design is quick and easy.
One-shot Process
One-shot Process
Injection molding production of the surface design in a fully automated production cell. No reworking necessary.
Cost-efficient Production on a Large Scale
Cost-efficient Production on a Large Scale
Reducing manufacturing and assembly tasks by producing a fully functional component in one production cell. Result: savings in weight, time, and costs.
Result
The recyclate is hidden behind the film layer
Your plastic part is provided with a film layer through surface finishes and functionalizing
The component is visually upgraded
Plastic Surface Finishes with Different Types of Film Back Injection Molding
Preforming the film
Positioning of the insert by a robot
Hot substrate is injected by standard back injection molding and merges with the film
After cooling, the material and film are ejected as one piece
Film is inserted into the mold
Film is positioned in X and Y direction and clamped by a sealing frame
Hot substrate is injected using the standard film back injection molding process and merges with the PUR coating layer
After the material has cooled, the film is ejected as one piece
Film is inserted into the mold
Infrared heating and vacuum preforming pull the film into the mold
Hot base material is injected in a standard film back injection molding process and merges with the film
When closing the mold, the film is trimmed with cutting edges
After cooling, the material and film are ejected as one piece
Plastic Surface Finishes with Different Types of Film Back Injection Molding
Film insert molding
Preforming the film
Positioning of the insert by a robot
Hot substrate is injected by standard back injection molding and merges with the film
After cooling, the material and film are ejected as one piece
In-mold decoration
Film is inserted into the mold
Film is positioned in X and Y direction and clamped by a sealing frame
Hot substrate is injected using the standard film back injection molding process and merges with the PUR coating layer
After the material has cooled, the film is ejected as one piece
Roll-to-roll in-mold labeling
Film is inserted into the mold
Infrared heating and vacuum preforming pull the film into the mold
Hot base material is injected in a standard film back injection molding process and merges with the film
When closing the mold, the film is trimmed with cutting edges
After cooling, the material and film are ejected as one piece
Film Back Injection Molding: Best-practices of Surface Finishes and Functionalizing Plastic Parts
PET / rPET processing
Produce thin-wall containers made of PET in just one process step. The powerful injection unit of our e-speed injection molding machine makes it possible. This significantly expands the range of applications for PET and rPET.
Your advantages with rPET in thin-wall injection molding
Use the closed recycling loop
Use the closed recycling loop
PET can be recycled an infinite number of times and PET parts can contain up to 100% recycled content.
Direct processing of PET flakes
Direct processing of PET flakes
ENGEL is the first supplier to enable thin-wall injection molding for PET. Reach high recycling rates directly with the injection molding machine.
Compliance with the law
Compliance with the law
From 2025, all plastic packaging must have a recycled content of at least 30% and be 100% recyclable. With our plastic recycling process, you meet these requirements.
Upcycling PET bottles
Upcycling PET bottles
With the plastic recycling process, PET bottles or other packaging products can be re- or upcycled.
Result
Thin-walled containers made of PET or rPET
Bottle-to-cup recycling is possible
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