Exploring possibilities of alternative to raw materials for paper and pulp manufacturing, highly dependent upon trees.
Logging of trees has been a major problem in many countries due to rising environmental issues. Due to this the world is facing a crucial problem of raw material for paper and pulp manufacturing. This problem has been arising because of unavailability of any alternative raw material for paper and pulp manufacturing. The below article shows the possibility of using various materials like Sugarcane Bagasse, Bamboo stem, Karkadeh, Okra, Sesame, Jute in paper and pulp production.
Paper is said to be the most important part or aspect in the development of any nation. Paper helps in the economic, social and environmental development of any country/nation. It has been seen that the population is increasing at an alarming rate and this has affected the overall lifecycle of humans. Scarcity of goods and products has become a major problem. The increase in population has also affected the paper and pulp industry. It is estimated that the world population will be 12 billion by 2075. The restrictions on logging of trees from government and NGO’s and increase in population have made the paper and pulp industry shift from its traditional method to renewable and sustainable method for preparing paper. There has also been hike in prices of paper since last 2-3 years.
Pulp and paper is made by collecting fibrous raw material from tree logs or non-woods. Firstly wood is chipped and wood fibres are separated into cellulose fibres, lignin and other sugars. According to requirement Chemical or Mechanical pulping is performed. They are further mixed with water to prepare slurry. This slurry is then run through a variety of press rolls and heaters to remove the water content. Depending upon the paper colour required; additives are used in the bleaching process. Finally the pulp is poured in the head-box of Fourdrinier machine and passed through number of section in the machine to finally form a paper. This is how paper is prepared from pulp and finally delivered to the customer in industrial paper making. Similarly handmade papers are prepared by passing the pulp through a screen mesh.
India has a large amount of agricultural waste produced every year. This waste is either thrown away or burnt in open air which results in affecting the environment. Thus this agricultural raw material can be used in production of paper. This will help in reducing the waste and also be responsible to attain a sustainable cycle for paper and pulp industry. Agricultural raw material is generally called as non-wood fibres. Non-wood fibres are able to replace wood fibres to a great extent. These fibres contain lower lignin content which makes it easier to de-lignify during the pulping process. Non-wood fibres contain high cellulose, large fibre length and almost similar properties to that of hard wood fibres.
The above table shows the physical and chemical properties of some non-wood fibres and it is seen that bamboo has highest fibre length (mm) while sesame and okra seeds have lowest fibre length (mm). Bagasse has highest Hemicellulose content among all the Non-wood fibres. Large Fibre length results in providing greater strength to the paper whereas short fibres provide opacity and smooth surface. With these properties almost similar to that of hardwood pulp, the paper prepared still has some disadvantages like low tear resistance, low opacity etc. which can be further eliminated to some extent by using external additive while preparing pulp. In the year 2003 studies were carried out on various factors affecting dimensional stability of bagasse paper and it was concluded that the dimensional stability of non-wood fibres can be increased or improved by using various additives. Additives like Internal & External sizing can improve the stability of paper. The paper produced from non-wood fibres can be used in making paper bags, books, envelops, etc. A large amount of paper made from recycled or waste paper is being used today in e-commerce sector; this can be replaced by non-wood paper which gives the same properties. Most countries which do not have large forest area have already been using Annual plants and Agricultural waste as raw material for paper and pulp manufacturing. Similarly developed countries should also shift their traditional approach and implement this sustainable approach of paper making.
Article and pictures are contributed by – Omkar Kokatay (TE Printing, PVG COET & GKPWIM)