Recycling of Flexible Plastic Packaging

Michael Niaounakis

• Publisher: William Andrew
• Year: 2019
• Print ISBN: 9780128163351
• eBook ISBN: 9780128166031
• Topic: Technology & Engineering
• Subtopic: Materials Science
• Index: Technology & Engineering

Recycling of Flexible Plastic Packaging presents thorough and detailed information on the management and recycling of flexible plastic packaging, focusing on the latest actual/potential methods and techniques and offering actionable solutions that minimize waste and increase product efficiency and sustainability. Sections cover flexible plastic packaging and its benefits, applications and challenges. This is followed by in-depth coverage of the materials, types and forms of flexible packaging. Other key discussions cover collection and pre-treatment, volume reduction, separation from other materials, chemical recycling, post-processing and reuse, current regulations and policies, economic aspects and immediate trends.This information will be highly valuable to engineers, scientists and R&D professionals across industry. In addition, it will also be of great interest to researchers in academia, those in government, or anyone with an interest in recycling who is looking to further advance and implement recycling methods for flexible plastic packaging.- Presents state-of-the-art methods and technologies regarding the processing of flexible plastic packaging waste- Addresses the challenges currently associated with both waste management and available recycling methods- Opens the door to innovation, supporting improved recycling methods, manufacturing efficiency and industrial sustainability

1

Flexible Plastic Packaging and Recycling

Abstract

This chapter gives a general overview of flexible plastic packaging. It also presents the benefits and limitations of flexible plastic packaging as they are reflected in life cycle assessment studies. Flexible packaging is also compared with rigid packaging. Emphasis is given to the recycling problem of flexible multilayer plastic packaging. Further, it describes the various options of recycling and the waste management hierarchies used by EU and US Environmental Protection Agency.

Keywords

Benefits; Flexible plastic packaging; LCA; Limitations; Multilayers; Recycling; Rigid packaging; Waste management hierarchy

1.1. Definition of Flexible Packaging

The expression “flexible packaging” refers to packaging structures that are capable of being flexed or bent, such that they are pliant and yieldable in response to externally applied forces. Accordingly, the term “flexible” is substantially opposite in meaning to the terms inflexible, rigid, or unyielding. A packaging structure that is flexible, therefore, may be altered in shape to accommodate external forces and to conform to the shape of objects brought into contact with them without losing their integrity. As one of the fastest growing segments of the packaging industry, flexible packaging delivers a broad range of protective properties while employing a minimum amount of material. It typically takes the shape of a bag, pouch, liner, or overwrap.

1.2. Flexible Packaging Categories

Flexible packaging is typically described in relation to the type of product being packaged, for example, retail food, medical devices, pharmaceuticals, etc. It can also be categorized by layer/function. It is convenient to categorize packaging by layer or function:

1. • primary packaging—the material that first envelops the product and is in direct contact with the contents;
2. • secondary packaging—the material that is outside the primary packaging, often used to group primary packages together. Film wrappers around the primary packaging are examples of secondary packaging; and
3. • tertiary packaging—the material that is used for bulk handling, warehouse storage, and transport shipping. The most common form is a palletized unit that packs into containers.

These broad categories are arbitrary. For example, depending on the use, a shrink wrap can be primary packaging when applied directly to the product, secondary packaging when bundling smaller packages, and tertiary packaging on some palletized distribution packs.

1.3. Selection Criteria of Flexible Packaging

The main selection criteria for an optimum flexible packaging could be summarized as follows:

1. • product protection (performance)
2. • packaging cost
3. • usage benefits and
4. • environmental impact

Flexible packaging protects the enclosed product from damages (breakages, spoilages, contamination), extends shelf/usage life, safeguards hygiene, and provides an attractive appearance. Most flexible packaging has been optimized for minimum material usage for a given functionality. Flexible packaging reduces overall package size and weight, reduces shipping costs, and promotes fitting more products on a delivery truck. In most cases, flexible packaging materials are intended for single use.

Flexible packaging can be monolayer, coated monolayer, or multilayer. The layers are different material with specific functions in the structure and can include outer bulk layers, barrier layers, tie layers, and seal layers.

Polyethylene, including low density polyethylene (LDPE), linear low density polyethylene (LLDPE), and high density polyethylene (HDPE), is by far the most used polymer in the flexible packaging industry. Other polymers are polypropylene, including cast polypropylene and biaxially oriented polypropylene (BOPP), poly(ethylene terephthalate) (PET), and poly(vinyl chloride) (PVC).

Polyethylene gives the packaging its bulk and structural integrity. For tougher packaging, a packaging company might opt for PET. Polyethylene can also be used to seal the package. But often lower melting point ethylene-vinyl acetate (EVA) is the better choice for that. And if the food inside the packaging is greasy, a food company might opt for a higher-end sealant ionomer, such as Surlyn® (DuPont, ex-Dow). Most food packaging needs a barrier layer to protect against oxygen. Ethylene-vinyl alcohol (EVOH) and poly(vinylidene chloride) (PVDC) are effective in blocking oxygen. If even more barrier is needed, a package might incorporate a metallized film [1]. Metalized films provide optimal protection for high oxygen, gas and water vapor barrier levels, aroma, and flavor retention. Metalized films can also provide special optical properties or a metal look for decorative applications.

There is demand to replace part of these films, especially those used for packaging goods with a short shelf life (e.g., food packaging, waste bags) with films made of biodegradable polymers. The most commonly used polymers in plastic packaging are made of fossil fuel–based resources and degrade very slowly in the environment. Packaging materials made of bio-based polymers address the concerns about depletion of natural resources and greenhouse gas (GHG) generation effects. Bio-based polymers are expected—once fully scaled-up—to help reduce reliance on fossil fuels, reduce production of GHGs, and be biodegradable or compostable as well. Packaging is the biggest application for bio-based and biodegradable polymers nowadays [2].

1.4. Benefits of Flexible Plastic Packaging

The food and beverage market is flexible packaging's largest end user segment, although healthcare has become the fastest growing. Flexible packaging is used in almost every consumer goods section. The benefits of flexible plastic packaging can be summarized as follows [3]:

1. • Less material needed for production.
2. • Uses less energy to produce and less plastic than rigid containers.
3. • Lighter weight allowing transport of higher volumes of product.
4. • Generates less CO₂ during transportation.
5. • Creates less waste and takes up less space in the landfill.
6. • Extends the shelf life of many products, especially food.
7. • Maintains freshness.
8. • Provides efficient product-to-package ratios.
9. • Reduces food waste.
10. • Creates self-appeal.
11. • Enables visibility of the contents.
12. • Easy to open, carry, store, and reseal (convenience).
13. • Extensible into diverse product categories.

1.5. Flexible Packaging versus Rigid Packaging

Consumer, retail, and technology trends have contributed to a gradual replacement of rigid formats by ...

Table of contents

• Cover image
• Title page
• Table of Contents
• PLASTICS DESIGN LIBRARY (PDL) PDL HANDBOOK SERIES
• Copyright
• Preface
• 1. Flexible Plastic Packaging and Recycling
• 2. Environmental and Socio-Economic Effects
• 3. Polymers Used in Flexible Packaging
• 4. Types, Forms, and Uses of Flexible Plastic Packaging
• 5. Collection and Feedback
• 6. Separation/Sorting and Volume Reduction
• 7. Solvent- and/or Chemical Agent-Based Separation
• 8. Post-processing and Reuse
• 9. Chemical Recycling
• 10. Legislation and Regulatory Framework
• 11. Economic Evaluation and Trends
• Index