How to Recycle Household Cardboard

How to Recycle Cardboard at Home
If you are a green minded person, trying to save the planet or just fed up of being surrounded by unwanted cardboard you have come to the right place. This article is for anyone that might be interested in recycling cardboard on a domestic level. Most information about cardboard recycling is aimed at the industrial sector and large businesses. There is little point adding cardboard directly to a compost bin because it will not break down at the same rate as the other materials in the bin or heap. This is why I have developed a technique that works to produce perfect compost for growing organic vegetables in the garden. You do not need any specialist tools or equipment to follow this simple 3 step guide.

Cardboard comes in many different grades and will often contain inks, adhesives, security tags (magnetic strips), metal staples (heavy duty cardboard often used for furniture and other large items), plastic handles, wire ties, packing tape and laminates. This makes the process of recycling on a large scale a complicated process. However on a domestic scale (that means at home) all these unwanted materials can be easily removed. Almost every type of cardboard can be turned back into a pulp. There are a few types of very heavily laminated cardboard that are not suitable for recycling and these must be left out of the process. My rule of thumb is that if it will not tear by hand it is too heavily laminated to be included. Everything else goes in and usually comes out as “pulp”. I do sometimes wonder what happens to all the adhesives, inks and chemicals embedded in the cardboard. It would be interesting to have the pulp analysed in a laboratory to see exactly what it contains.

The type of household cardboard in this load was made up of cereal packets, brown cardboard, frozen food packaging, tea boxes etc.

Figure 1. Ripped-up Cardboard

This is how to recycle cardboard on a domestic scale.

Step 1 – Tear, Rip, Cut or Shred the cardboard into small pieces. The smaller the better as this will make the process quicker and easier in the later stages. The main aim being to get the cardboard to absorb as much water as possible. Place the shredded cardboard in a large bucket or suitable water tight container.

Step 2 – Add boiling (or very hot water) to the shredded cardboard until it is all suitably submerged. A few kettles (2 or 3) of water should be enough for a standard size bucket of cardboard. I recommend making use of this opportunity to have a break and make a cup of tea whilst the kettle is on. Now add a surfactant of some sort to make the water softer. Washing up liquid is a suitable product to use for this part of the process. Agitate (stir) the mixture with a spade, a wooden stick or any other suitable object that you have to hand. Leave the cardboard for a couple of hours (at least ) to soak in the hot, soapy water. I would recommend moving the bucket to an outbuilding, shed or garage ready for the mixing process as soon as it begins to cool.

Figure 2: Cardboard soaking in hot water with surfactant

Step 3 (a few hours later...) The mixture will now be cool enough to handle and a few of the fibres of the cardboard should now be beginning to break down into a pulp. There will be some loose fibres in the water but other than that it will not look much different to when you added the hot water. This is perfectly normal at this stage and everything is going to plan. The final stage is of this process is to agitate the mixture very thoroughly. This is difficult (but not impossible) to do by hand. I use an electric drill with a paint/plaster stirring attachment. At the moment I am building a frame to house the drill and mixing attachment as a more permanent arrangement. This is not finished yet but will make the job much easier and hopefully less messy.
Figure 3: The cardboard pulp after the mixing process

The mixing has to be done carefully and only with a drill that has variable speeds. Using any other type of drill may lead to personal injury, damage, chaos, profanity, sloppy cardboard pulp splattered over everything (but mainly your trousers) and perhaps a severe telling off from the missus! I suggest wearing old or protective clothing when stirring the mixture although the pulp simply rubs off when dry. Do not use a cordless drill as this will most likely damage the internal gears or clutch mechanism within the drill because the load will be too heavy. When stirring the mixture it will become thicker and additional water may need to be added at certain intervals. A watering can is probably the most suitable method to add cold water to the mixture. The final product will be a dull grey (or brown) fibrous pulp. It is now ready to be added directly to your compost bin or heap. The best way to do this is to mix it with grass cuttings and/or other finely chopped compost material derived from household or garden waste.

Figure 4: A much closer view of the cardboard pulp (what? Well maybe this was a step too far! but it does show how well this technique works.

It really is that simple to achieve. A large pile of unwanted cardboard can be reduced to half a bucket of pulp within a few hours and most of that time is spent waiting (or drinking cups of tea) for the water to be absorbed into the cardboard. This saves time, money and fuel (by not taking cardboard to the waste recycling centre or council “tip” as we still call it in our house!). This cardboard pulp which is high in carbon will provide a valuable amount of wood fibre to the compost as it degrades. Cardboard is notoriously difficult to compost and will only break down when mixed with the correct amount of nitrogonous materials. The materials need to be kept damp (not too wet) and aerated to allow a natural build up of heat. Accelerators can be added to speed up the composting process. The droppings of herbivores (these are vegetarians of the animal kingdom!) contain no harmful pathogens and are ideal for this purpose. This will assist the waste in the compost helping it to break down. Just ensure that you do not compact the mixture or add too much of one material at a time in general. I will discuss the process of making compost again in a subsequent post. Add only finely chopped materials and ensure that all materials are thoroughly mixed together.

I hope that you have found this article insightful or at least enjoyed looking at some of the pictures. Thank You for visiting my Wholefruit website. I have lot of ideas and information about growing organic fruit and vegetables with the home made compost from this and other sources around the home and garden. In my next post I be writing about one of the ways to utilise the compost when I describe my technique for growing organic carrots and how anyone can easily grow a bumper crop of their own.

Marvin Africa