Quality Assurance of Recycled HDPE in the Plastic Packaging Industry

Abstract

The recycling of plastic has the potential to support circular material use, thus decreasing the need for virgin plastics. However, there is an existing issue with assuring quality of recycled plastic materials, causing finished products to perform with poorer properties and unexpected deviations. Based on a thermoformed plastic packaging product, Product Y, made of recycled high density polyethylene (HDPE), this thesis is written in collaboration with Company X and researches how to assure quality of Product Y.
The purpose of the thesis is to research how Company X can achieve uniform quality on the finished products, regardless of when or where the recycled HDPE is manufactured. To fulfill the aim of the thesis, the research questions to be answered are:
1. What affects the quality of recycled post-industrial and post-consumer HDPE to be used for packaging?
2. What is most important regarding the recycling processes to achieve high- quality plastic?
3. What are the issues regarding plastic recycling processes globally?
The method is divided into three parts; a literature study to gain necessary background knowledge on the subject, conducted interviews with internal and external industry representatives to gain insights on how the industry works today, and material testing to compare if the results are corresponding to expected results. The material testing includes Shore D hardness test, measuring of material thickness, tensile test, melt flow index, differential scanning calorimetry, and thermoforming test with a following visual inspection of the finished products.
After analyzing interview findings and material testing, it was concluded that conducting polymer tests for different material properties is important for quality assurance. The customer and plastic processing company should agree on the testing procedure. Cooperation between the involved parties is crucial for successful quality assurance of the recycled material. Transparency, global standards, and a coordinated approach will help overcome quality assurance challenges in plastic recycling today.

Popular Abstract

Ensuring Quality in Recycled Plastic for Packaging: Challenges and Solutions BY TORA ABRAHAMSSON & JULIANA KALLING
Plastic packaging is widely used due to its affordability, and the increasing use of recycled plastics presents challenges in quality assurance. Unexpected issues can occur during the manufacturing process, impacting the final products. This article delves into what can be done to improve quality assurance, identifies responsible parties, and explores the complexity of the recycled plastics industry.
During this project it has been shown that there is a big challenge for plastic processing companies in the packaging industry to balance cost-, and quality trade-offs when handling recycled plastics. While there is a desire to embrace sustainable materials, recycled plastics can lack quality due to degradation from repeated heating and processing. This unpredictability makes it challenging to anticipate how recycled materials will behave, leading to unexpected deviations in the finished product's design. Moreover, the fact that it is often impossible to trace the recycled material’s history does not make the situation any easier.
It has been shown that it is clearly difficult for the involved parties in the plastic packaging supply chain to take concrete actions for quality assurance. The absence of global standards complicates matters, leaving each stakeholder accountable for their part in the process. This ambiguity allows plastic processors to shift blame onto other involved parties, hindering progress. To overcome this challenge, plastic processing companies must carefully select suppliers, maintain transparent relationships, and foster open dialogues to contribute to quality assurance.
Choosing appropriate testing procedures is essential for quality assurance throughout the recycled plastic manufacturing process. Various tests can be performed to investigate different material properties, depending on the product's purpose, where these testing procedures are highly individualized. An appropriate testing procedure should be conceived by the customer, in agreement with the plastic processing company and the suppliers, to fulfill the customer's demands for the product. Collaboration among these stakeholders is crucial to ensure the testing process fulfills the customer's requirements.
To verify the content and properties of recycled plastics, a combination of tests should be conducted. Relying on a single test is insufficient; comparing results from multiple tests provides a comprehensive understanding of the material behavior. The test results should then be compared with the supplier's provided technical data sheets (TDS) for verification. If deviations arise, a dialogue with the supplier is essential for clarification and resolving any issues.
The quality assurance of recycled plastics for packaging presents various challenges that demand collective action. Collaboration, transparency, and tailored testing procedures are vital to navigate this complex landscape successfully. The plastic packaging industry must embrace responsibility, foster strong relationships across the supply chain, and promote sustainable practices. By doing so, high-quality recycled plastics can be ensured, paving the way for a more environmentally conscious and efficient packaging industry.
Master thesis project by Tora Abrahamsson and Juliana Kalling
Faculty of Engineering | Lund University Department of Design Sciences
2023-06-02 Lund

• author: Abrahamsson, Tora and Kalling, Juliana
• supervisor: Katarina Elner-Haglund
• organization: Innovation
• course: MMKM05 20231
• year: 2023
• type: H2 - Master's Degree (Two Years)
• subject: Technology and Engineering
• keywords: Thermoforming, Plastics, Recycling, Packaging Industry, HDPE
• language: English
• id: 9121269
• date added to LUP: 2023-06-14 09:14:17
• date last changed: 2023-06-14 09:14:17