The process of paper recycling is essential for the environment, as it helps to conserve natural resources and reduce waste. However, the production of recycled paper requires a careful balance of old and new materials, and this is where clay comes in.

Clay is a vital component in the paper recycling process, as it helps to stabilize the fibres in recycled paper. When paper is recycled, the fibres degrade, and stabilizers like kaolin are used to help strengthen them. As a result, the addition of clay improves the quality and durability of the recycled paper [1].

The use of kaolin clay helps to mask the undesirable colours of raw pulp, thereby reducing the amount of bleaching agents required. This results in two benefits: firstly, it reduces the amount of whitening compounds added, and secondly, it reduces the amount of water purification needed as a result of the process. Clay is a natural material that has minimal environmental impact. [2]

In the paper recycling process, a mix of recycled paper fibres, kaolin, and new (virgin) pulp is used to produce fresh paper. The ratio of recycled to virgin pulp used in paper production varies based on the qualities and nature of the paper. Some virgin pulp or lignin source, such as wood, hops, grass, or seaweed, is needed to produce paper with the desired properties [3].

Although, historically, there have been concerns about the sourcing of wood for paper making, the fact that the paper industry requires a reliable and sustainable source of wood or alternative lignin sources, has driven better forestry research and stewardship. This has led to improved forest management practices and the development of new technologies that reduce waste and environmental impact [4].


In conclusion, the role of clay in paper recycling is critical. It helps to stabilize the fibre in recycled paper, leading to improved quality and durability. By using a mix of recycled and new fibre sources, the paper industry can reduce waste and conserve natural resources. With continued research and development, we can hope to see even more sustainable practices in the paper industry in the future.


  1. “Kaolin Clay: Functional Optical Additives,” BASF Corporation
    Kaolin In Paper Filling And Coating,  ZMS,
  2. Pulp and Paper (5) Bleaching – Aalto University Wood Science
  3. “Recycling Basics: How Does It Work?” EPA.
  4. “Sustainability in the Pulp and Paper Industry,” Ecolab.