Biochar as an additive and filler for cardboard and paper
Adding our biochar powder to cardboard box and paper pulp can substantially increase strength and durability as well as resistance to heat, while making the product carbon negative.
Paper and packaging are made from fiber and filler. The fiber binds the sheet; fillers lower cost and tune bulk, printability, stability and drying. Biochar can take the place of the filler. A blend of biochar and paper pulp has been called "chardboard".
Packaging made this way has a useful life above the soil first. When it is composted afterwards, the carbon goes back into the ground instead of the atmosphere.
The benefits for this industry
- Longer shelf life for produce. Biochar can sorb ethylene, the plant hormone that drives ripening, so packaging for fruit such as bananas or kiwis could keep it fresh for longer.
- Low thermal conductivity. Early tests of chardboard show reduced heat transmission, which suits sleeves for hot or cold drinks and boxes that keep food warm.
- Anti-static protection. Biochar produced at higher temperatures is conductive, so the packaging could dissipate static and protect electronics in transit.
- Moisture and odor absorption. The porous structure takes up moisture and vapors, which helps keep products fresher and resists mold. Charcoal tissue made in Japan from plum pits, known as umezumi, is already used for its deodorizing properties.
- Compatible with beneficial bacteria. Food waste containers could be inoculated with efficient degraders to reduce odor and prevent nutrient loss on the way to composting.
- Cradle to cradle. At the end of its first use the material can go into a compost bin or garden. Even in landfill it may help reduce odors and leaching. Recycling chardboard needs more research.
Possible products
The original list of ideas ran past 55, a number that has become shorthand for the many uses of biochar. By category:
- Food and beverage packaging: coasters, coffee packaging, cup sleeves and holders, food trays, egg cartons, fruit packaging, napkins, place mats, take-away containers, sandwich wrappers, disposable plates.
- Yard and garden: seedling starter pots, seed tape, sheet mulch, seed blockers, leaf litter bags, plant wrap, weed barrier cloth.
- Home: book covers and bookmarks, ceiling tiles, furniture, drop cloths, picture matting, wall covering, hangers, kitchen waste compost bags.
- Medical: biodegradable bedpans, urinals and kidney dishes, surgical masks and caps, patient gowns and slippers, underpads and exam table paper, band aids and skin wrap.
- Office and shipping supplies: bags, boxes, cubicle dividers, folders, notebook covers, envelopes, edge protectors, fiber drums, shipping tubes.
- Personal use: diapers, toilet liners, sanitary napkins, biodegradable urns, gift wrap.
- Pets: pet caskets, waste bags, litter liners, training pads.
- Miscellaneous: car insulation, gaskets.
Source. This page summarizes "Biochar Paper: elevating biochar from novelty to ubiquity" by Kathleen Draper and Hans-Peter Schmidt, Ithaka Journal, 2015. Read the original article. See also 55 uses of biochar.
