--- title: "Sandwich Injection Molding to Increase Post-Consumer Recycled Content" id: "2119" type: "post" slug: "sandwich-injection-molding-to-increase-your-pcr" published_at: "2023-10-20T19:25:36+00:00" modified_at: "2024-08-01T19:28:15+00:00" url: "https://www.plasticsengineering.org/2023/10/sandwich-injection-molding-to-increase-your-pcr-002119/" markdown_url: "https://www.plasticsengineering.org/2023/10/sandwich-injection-molding-to-increase-your-pcr-002119.md" excerpt: "Engel developed a technology that allows the production of parts with recycled plastic (PCR) at their core and virgin plastic at the skin." taxonomy_category: - "Automotive & Transportation" - "Building & Construction" - "Business" - "Durables" - "Industry" - "Injection Molding" - "Materials" - "Process" - "Recyclate" - "Recycling" - "Regulation" - "Resins" - "Strategy" - "Sustainability" taxonomy_post_tag: - "Business" - "Circular Economy" - "Injection Molding" - "Plastics Waste" - "Polyolefins" - "Recycling" - "Resins" - "Sustainability" --- [Home](https://www.plasticsengineering.org/) » [News](https://www.plasticsengineering.org/news/) » [Industry](https://www.plasticsengineering.org/c/industry/) » Sandwich Injection Molding to Increase Post-Consumer Recycled Content # Sandwich Injection Molding to Increase Post-Consumer Recycled Content Sandwich injection molding process. Courtesy of Engel### Engel developed a technology that allows the production of parts with recycled plastic (PCR) at their core and virgin plastic at the skin. Brands and retailers have made ambitious commitments and goals to include Post-Consumer Recycled content (PCR) in their products despite the technical challenges that come with it. This is why [injection molding machine manufacturer Engel](https://www.plasticsengineering.org/2023/05/no-pelletizing-needed-for-injection-molding-000046/) has developed a technology that allows the production of parts with PCR at their core and virgin plastic at the shell. **You can also** [read Industry 4.0 in Injection Molding.](https://www.plasticsengineering.org/2024/07/industry-4-0-in-injection-molding-005727/) ## Increasing Post Consumer Recycled (PCR) Content In contrast to conventional coinjection, ENGEL’s skin melt process brings the two melts together even before injection. The secret is a second plasticizing unit responsible for the skin material. It is located at an acute angle above the horizontal injection unit where the reyclate is melted. The virgin material (the skin material) reaches the cavity first, then the recycled plastic (PCR) flows in and displaces it. This results in a recycled material core while the virgin material is at the wall. The amount of recycled material depends on the geometry of the molded part and the filling pattern of the cavity. The injection position plays a major role, as does the viscosity ratio of the skin and core material. Processing of plastics with the sandwich injection molding method can help manufacturers add up to 50 % recycled material to their products with: - High surface quality. - No switch-over marks on the part. ## Example From the Logistics Industry [Transport boxes produced with sandwich injection molding. Courtesy of Engel.](https://blog.engelglobal.com/en/at/blog/processing-of-plastic-recyclates-with-the-dosing-method.html) Transport boxes from the logistics industry tested this technology. Interestingly, the skin melt boxes’ force-displacement curves and compression values were similar to the boxes consisting of virgin material. Finally, this opens new opportunities for manufacturers to play with the recycled content and processing parameters to get quality products. Definitely, sandwich injection molding can make an important contribution to the circular economy. By **[Juliana Montoya](https://www.plasticsengineering.org/author/jmontoyaplasticsengineering-org/)** | October 20, 2023 [https://www.plasticsengineering.org](https://www.plasticsengineering.org) ##### [Juliana Montoya](https://www.plasticsengineering.org/author/jmontoyaplasticsengineering-org/) [Website](https://www.plasticsengineering.org) | [+ postsBio ⮌](#) ### Other posts you could read [May 14, 2026Carbon Fiber Production from End-of-Life Automotive Polymers](https://www.plasticsengineering.org/2026/05/carbon-fiber-production-from-end-of-life-automotive-polymers-011254/) [April 27, 2026Nanocomposite Films from Car Bumper Waste](https://www.plasticsengineering.org/2026/04/nanocomposite-films-from-car-bumper-waste-011041/) [May 11, 2026Global Polymer Feedstock Supply Chains Face Rising Disruptions](https://www.plasticsengineering.org/2026/05/global-polymer-feedstock-supply-chains-face-rising-disruptions-011233/) [May 1, 2026High-Viscosity Photopolymers Transform Additive Manufacturing](https://www.plasticsengineering.org/2026/05/high-viscosity-photopolymers-transform-additive-manufacturing-011153/) [May 7, 2026PCR Plastics Are Redefining Aesthetic Standards](https://www.plasticsengineering.org/2026/05/pcr-plastics-are-redefining-aesthetic-standards-011186/) [April 20, 2026Real-Time Melt Monitoring in Extrusion and Injection Molding](https://www.plasticsengineering.org/2026/04/real-time-melt-monitoring-in-extrusion-and-injection-molding-011167/) [May 12, 2026Why Recycled Polymers Still Cost More Than Virgin Resin](https://www.plasticsengineering.org/2026/05/why-recycled-polymers-still-cost-more-than-virgin-resin-011239/) [April 29, 2026Renewable Functional Coatings for Advanced Applications](https://www.plasticsengineering.org/2026/04/renewable-functional-coatings-for-advanced-applications-011134/) ## Share Your Thoughts [Cancel reply](/2023/10/sandwich-injection-molding-to-increase-your-pcr-002119/#respond) - [https://twitter.com/share?url=https://www.plasticsengineering.org/?p=2119&text=Sandwich+Injection+Molding+to+Increase+Post-Consumer+Recycled+Content&via=Plastics_Mag](https://twitter.com/share?url=https://www.plasticsengineering.org/?p=2119&text=Sandwich+Injection+Molding+to+Increase+Post-Consumer+Recycled+Content&via=Plastics_Mag) - [https://www.facebook.com/sharer.php?u=https://www.plasticsengineering.org/?p=2119&t=Sandwich+Injection+Molding+to+Increase+Post-Consumer+Recycled+Content](https://www.facebook.com/sharer.php?u=https://www.plasticsengineering.org/?p=2119&t=Sandwich+Injection+Molding+to+Increase+Post-Consumer+Recycled+Content) - [https://www.linkedin.com/shareArticle?mini=true&url=https://www.plasticsengineering.org/?p=2119&title=Sandwich%20Injection%20Molding%20to%20Increase%20Post-Consumer%20Recycled%20Content&summary=Engel+developed+a+technology+that+allows+the+production+of+parts+with+recycled+plastic+%28PCR%29+at+their+core+and+virgin+plastic+at+the+skin.&source=Plastics+Engineering](https://www.linkedin.com/shareArticle?mini=true&url=https://www.plasticsengineering.org/?p=2119&title=Sandwich%20Injection%20Molding%20to%20Increase%20Post-Consumer%20Recycled%20Content&summary=Engel+developed+a+technology+that+allows+the+production+of+parts+with+recycled+plastic+%28PCR%29+at+their+core+and+virgin+plastic+at+the+skin.&source=Plastics+Engineering) - [https://www.reddit.com/submit?url=https://www.plasticsengineering.org/?p=2119&title=Sandwich+Injection+Molding+to+Increase+Post-Consumer+Recycled+Content](https://www.reddit.com/submit?url=https://www.plasticsengineering.org/?p=2119&title=Sandwich+Injection+Molding+to+Increase+Post-Consumer+Recycled+Content) - [/cdn-cgi/l/email-protection#407f3335222a2523347d102c21333429233360052e27292e252532292e27606d6013212e243729232860092e2a252334292f2e600d2f2c24292e2760342f60092e23322521332560102f33346d032f2e33352d25326012252339232c252460032f2e34252e3466222f24397d28343430337a6f6f3737376e302c213334292333252e27292e252532292e276e2f32276f7f307d72717179](/cdn-cgi/l/email-protection#407f3335222a2523347d102c21333429233360052e27292e252532292e27606d6013212e243729232860092e2a252334292f2e600d2f2c24292e2760342f60092e23322521332560102f33346d032f2e33352d25326012252339232c252460032f2e34252e3466222f24397d28343430337a6f6f3737376e302c213334292333252e27292e252532292e276e2f32276f7f307d72717179) - [#comments](#comments)