Pineapple waste

Sustrato

Sustrato is a project that explores the application of ancestral techniques to transform the pineapple industry waste into four different biomaterials and sustainable products, which show the potential of organic agroindustrial waste to be used as raw material.

Unlike the production of some other fruits and vegetables, pineapple producers can only obtain one fruit from each harvested plant and are the only monetary product that maintains the whole industry. Moreover, the pineapple plant leaves, which represent 75% of the harvested product, are usually thrown away and are considered the main residue. Therefore, around one ton of daily pineapple leaves are discarded by each producing company.

In addition, pineapple producers do not have a current waste management system. They only pile up the waste in their production fields for degradation or throw it away through garbage trucks. This unregulated practice generates different issues, such as the production of greenhouse gas emissions, a change in the soil PH, an increase in pests that affect nearby crops and even promotes infectious diseases that can affect workers.

Sustrato takes up existing knowledge in ancestral material manufacturing techniques to revalue the commonly discarded pineapple leaves by using them to create four biomaterials (felt, agglomerated, bioplastic and ropes), as well as some sustainable products made out of these materials. The materials and products developed offer sustainable and compostable alternatives with competitive properties and prices, compared to similar products currently on the market. Also, it can represent an opportunity for producers to increase their income.

The field research and the collection of waste used as raw material for the development and prototyping of the project were carried out in Grupo Gasperín, a pineapple production company, in Ciudad Isla, Veracruz. That region represents one of the leading agricultural production areas in Mexico and has more than 3,000 pineapple producers.

Through a long experimentation and testing process, 4 biomaterials made out of pineapple leaf fibre and bagasse were developed: felt, bioplastic, an agglomerated material and rope.

The felt and agglomerated material are made from extracted pineapple leaf fibre. They have demonstrated great properties for sound reduction and rebound. Hence, some products for acoustic absorption were designed with each material. Those can reduce more than 10db, while similar products on the market (synthetic and natural) only reduce about 4db.

The rope is also made of pineapple leaf fibre and it has high strength. It is softer and lighter than similar natural ropes on the market.

The bioplastic is made out of pineapple leaf bagasse and natural binders. It is a permeable, translucent material with a degradation time that takes no longer than two years, which makes it an ideal material for solid product packaging. In addition, the material can be sealed with heat and humidity, so no extra additives are required.

This project changes the perception of organic waste by demonstrating its economic value and potential to be reused in developing sustainable materials and products.

Making process

The pineapple leaves are collected from the pineapple producer at Ciudad Isla. Then, they are boiled to facilitate fibre extraction, which is carried out through a decortication machine. The fibre is separated from the bagasse to be used in the fabrication process of different materials.

To make felt and the agglomerated material, the fibre is carded and manually organised on a net fabric to form a layer, which is felted on a rigid surface with an artisanal technique. To achieve a specific thickness several layers are added through humidification with natural binders diluted in water and the wet material layer is pressed until it dries.

To make the pineapple fibre rope it is only needed to separate the fibre and place it in Sustrato's DIY braiding machine. Then, when the fibre is braided and stretched out a small amount of the diluted natural binders is sprayed on it. Finally, the resulting rope is dried.

For the bioplastic, the bagasse is mixed and boiled with water and natural binders to get a paste. The paste is poured on a smooth mould and dried until the material separates itself from the mould surface. Then, the resulting layer is hung for a couple of hours to let it dry completely.

Text submitted by the maker and edited by the Future Materials Bank. For information about reproducing (a part of) this text, please contact the maker.