Kraft paper is one of the most popular materials for coffee packaging.
Lightweight, affordable, and versatile, it is the go-to choice for many roasters, both for bags and takeaway cups. The global kraft paper market is valued at more than $17 billion, with predictions it will grow a further $5 billion by 2028.
A key driver behind this growth is its perceived sustainability: natural (or unbleached) kraft paper is both recyclable and compostable. For roasters, using kraft paper helps lower their environmental impact and showcase a commitment to a circular economy.
However, when left untreated, kraft paper’s barrier properties are relatively low. This means oxygen and light can enter, causing the coffee to lose its distinct characteristics and become stale.
As such, many decide to add layers and laminates, including PET and aluminium foil. And while this improves its barrier properties, it can change the way it needs to be handled once empty.
Read on to find out more about kraft paper coffee bags and its impact on the environment.
What is kraft paper?
Kraft paper packaging has been around since the late 19th century. Invented by Carl F. Dahl, it takes its name from the German word kraft meaning “strength”.
The process of making kraft paper involves boiling wood chips in sodium sulfide and sodium hydroxide to chemically convert them into wood pulp.
This removes a polymer called lignin from the pulp, as lignin binds cellulose fibres together at a microscopic level. As a result, the pulp is high in cellulose, which is the main component of paper and is naturally structurally resistant.
Once the pulp is formed, it is then screened to remove larger pieces, before being washed to remove any residual fluids. The resulting pulp can then be made into a variety of paper products, including kraft paper.
Today, kraft paper has become a widely used packaging material for a range of goods. In its natural form, its light brown colour and rough texture is favoured for its earthy, natural associations.
However, the qualities that make it eco-friendly also means it will weaken when it makes contact with water and will eventually degrade in the presence of heat, sunlight, and humidity.
Is kraft paper environmentally sustainable?
Kraft paper is derived predominantly from wood chips, a renewable resource. However, in order to determine whether it is sustainable or not, it is important to make the distinction between its manufacture and its after-use.
In recent years, the manufacture of kraft paper has become considerably more eco-friendly.
To make kraft paper, the lignin and cellulose in the wood must be separated by cooking it in chemicals such as sodium sulfide.
Although there are various malodorous emissions as a result of this process, control of these odours is achieved through their collection and burning in a recovery boiler. This means that hardly any sulfur dioxide (an indirect greenhouse gas) enters the atmosphere.
In the past, chlorine was widely used in the bleaching of wood pulp, especially chemical pulps produced by the kraft process, which produced significant quantities of toxic dioxins.
However, since the 1990s, the use of elemental chlorine in the delignification process was substantially reduced and replaced with ECF (Elemental Chlorine Free) and TCF (Totally Chlorine Free) bleaching processes. As a result, dioxin production has reduced significantly.
The wastewater involved in kraft paper production was also historically an environmental issue, releasing considerable amounts of organic material into rivers and lakes.
Today, thanks to advancements in treating industrial wastewater, the toxicity of this organic matter has been substantially reduced.
According to the Forest Fibre Industry’s 2050 Roadmap, there are continuous plans to reduce the environmental impact of paper production.
For example, work is underway to convert wood-based biorefinery complexes into chemical and mechanical pulp mills and repurposing recycled fibre-based biorefinery waste water into moulded products or insulation materials.
There are also plans for waste to undergo biomass and waste/residue gasification to become a fuel source — allowing paper mills to eventually power themselves.
When left untreated, kraft paper is one of the easiest materials in the world to recycle. In most places, it can be disposed of at home along with corrugated cardboard, where it will be collected and taken to a recycling facility.
Here, it is sorted, to ensure all impurities and toxins are properly removed, before being taken to a mill, where the recycling process begins.
Recycling kraft paper packaging involves a number of steps, including pulping, cleaning, screening, deinking, dispersion, kneading, bleaching, water treatment, and waste handling. At the end of the recycling process, new paper items are produced.
For most kraft paper products, this can be done up to seven times.
According to the European Paper Recycling Council Monitoring Report 2020, the EU committed to reach a 74% paper recycling rate by 2020. In spite of Covid-19 increasing the need for disposable paper packaging for hygiene purposes, they managed to reach 73.9%.
Problems with recycling kraft paper only tend to occur when it has more than one layer or if the kraft paper packaging is contaminated with food, dirt, or grease.
For example, if it has an aluminium interior, this must be separated before it can be recycled, which is a process that not all facilities have the equipment to handle.
An alternative to recycling kraft paper is to send it to a composting facility. Because it is made of long virgin maritime pine fibers, it is completely organic when left unbleached (or when laminated with other compostable materials, such as PLA).
This means it will break down within a few weeks when placed in a commercial composting environment, leaving no pollutants.
Green packaging might have been an optional extra in packaging a few years ago – but times have changed. Sustainability is no longer just a plus, it’s a must. Modern coffee drinkers have shown that they are more aware than ever of the impact that coffee consumption has on the planet.
At MTPak Coffee, our unbleached kraft paper coffee bags for roasted coffee are 100% natural, biodegradable, and compostable. Their strength and flexibility help protect the coffee beans without affecting their quality, ensuring that every bag of coffee arrives with customers exactly as it should.
They can also be reinforced with polylactic acid (PLA), helping to improve their barrier properties while maintaining their compostability.