Why do single-use takeaway coffee cups need an inner coating?

Jane Merchant
April 22, 2022
takeaway coffee cups

Just as retailers and consumers were making headway in the fight against plastic waste, the Covid-19 pandemic struck and fuelled demand for single-use items.

Governments around the world rolled back regulations on plastic bans as people increased their consumption of plastic masks, gloves, and takeout packaging due to health concerns. As a result, the accumulated litter from single-use food items and beverages increased by 11.3% in 2020.

As we settle into a post-pandemic lifestyle, single-use plastic items, such as disposable cups, are once again falling out of favour. A sustainable alternative is paper takeaway coffee cups, which are a more cost-effective, convenient, and reliable solution for many cafés and roasters.

However, one concern about paper cups is how effectively they can contain hot liquids while remaining sustainable. This is because they typically need an inner coating to not only strengthen the cup, but also prevent leakages and provide additional insulation.

Read on to find out more about the most sustainable inner coatings for paper cups.

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disposable cups

Why do we coat single-use takeaway coffee cups?

Traditionally, takeaway coffee cups were made from styrofoam and petroleum-based plastics, such as polypropylene (PP).

However, these materials have fallen out of favour as they can be difficult to recycle. This is because they require specialised recycling facilities, which some communities may not have. As a result, most plastic cups are never recycled and often end up in landfills.

This, in turn, has led to a rise in single-use paper takeaway cups, which are currently dominating the disposable cup market. That being said, paper is highly permeable and must be coated to prevent liquids from seeping out.

Paper cups are made using pulped wood chips that have been bleached and processed. Typically a thin polyethylene plastic layer is then heated and applied to the interior of the cup.

While this coating makes up less than 5% of the total cup, it would be enough to prevent it from being recycled.

During the recycling process, paper cups are de-pulped. When this happens, the plastic coating breaks down into flakes. These often clog up the screen that separates paper fibres from other contaminants.

Any plastic that passes through this process may pose issues by melting during the paper rolling process. This can cause the paper to break down, and the entire paper production process to grind to a halt.

As with plastic cups, paper takeaway coffee cups require a specialised facility to remove this coating and process each material separately.

Unfortunately, these facilities are not easily accessible, and therefore suitable coating alternatives were required. The material needed to be cost effective, durable, and able to provide thermal insulation. Furthermore, it needed to be economically competitive and capable of contributing to a circular economy.

While several alternative materials exist, bioplastics such as polylactic acid (PLA) quickly became a popular choice.

Why are bioplastics popular for coating takeaway coffee cups?

Over recent years, bio-based plastics have become a popular choice for coating takeaway coffee cups and packaging materials.

These bioplastics include materials such as PLA, which is produced by allowing bacteria to ferment natural starches like corn and sugar cane into hydroxy acids.

This coating has proved popular as it can be applied to cups using existing extrusion equipment. Depending on its additives, weight, and processing conditions, it can be recycled or biodegraded in residential or industrial facilities.

Consistent testing has shown PLA offers effective barrier properties in a range of papers, provided it is applied properly, and is free from pinholes and air bubbles.

A PLA coating has no odour or aftertaste as it is resistant to high temperatures, as well as the fatty acids found in drinks that contain milk.

While a cup’s specific qualities differ depending on the manufacturer, cup size, and material type, most PLA-coated cups can be broken down in the presence of bacteria and fungi. These metabolise the cup into water, carbon dioxide, and organic compost.

Depending on the cup, between 60% and 90% can disintegrate within 180 days at a minimum temperature of 25°C (77°F).

On the other hand, a PLA-coated takeaway coffee cup can decompose in under a month at an industrial composting facility where temperatures are between 50°C and 60°C (122°F and 140°F).

takeaway coffee cups

Things to consider before adopting PLA-coated takeaway coffee cups

Despite the obvious benefits of PLA-coated cups, there are a few things to consider before committing to them.

First, the PLA cups may come at a higher cost compared to traditional, plastic-coated cups.

To avoid losing loyal customers, it is essential for businesses to inform them of the higher costs before making the switch.

Notably, a 2021 survey shows 74% of consumers are willing to pay more for sustainable packaging.

The second thing to consider is that PLA-coated cups cannot be placed in traditional waste bins alongside plastic or paper. Doing so may contaminate the entire waste stream.

Recycling contamination occurs when materials are sorted into the wrong recycling bin, or when materials are not properly cleaned. For example, this is when food residue remains on a plastic yoghurt container.

As a result, PLA-coated cups must be processed by facilities that can compost biopolymers.

If consumers do not have access to the appropriate recycling infrastructure, roasters and cafe owners may need to collect the cups and arrange for them to be processed. This can be done by implementing a coffee packaging or takeaway cup recycling scheme.

takeaway cups

Essentially, the best way to manage any potential issues is to educate customers before, during, and after making the switch to PLA-coated takeaway coffee cups. This includes telling them about the impending switch and letting them know where and how they can dispose of their used cups.

Furthermore, roasters can educate consumers about the sustainability of PLA-coated cups, including whether the paper used to make it is Forest Stewardship Council (FSC) certified.

At MTPak Coffee, we provide specialty roasters around the world with sustainable packaging services. This includes a range of compostable takeaway coffee cups that are made from recycled kraft paper and lined with polylactic acid (PLA), a fully compostable bioplastic made from plant-based starches.

Our range includes double or single wall cups, as well as coffee cup sleeves. We can also help you brand your takeaway coffee cups with details of your business, allowing you to communicate the cup’s recycling qualities to customers.

Furthermore, we offer a range of low minimum order quantity (MOQ) options. This means you can order as little as 500 fully customised units in just five working days.

For more information on our takeaway coffee cups, contact our team.

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