Associated problems with using waste paper

• Recycled paper can and often does contain foreign substances that must be removed at an additional cost.

• Waste paper is of varying quality.

• The quality of the finished paper made with waste paper can be inferior to virgin paper.

• The water systems used during the paper making process become more polluted if waste paper is used, increasing treatment requirements and therefore increasing cost.

• Maintaining cleanliness of the mill itself is made more difficult with waste paper stocks on the premises.

Trade bodies regarding pulp production in Europe

There are trade bodies for most countries in Europe that produce pulp. The banner European organisation is known as the Confederation of European Paper Industry (CEPI). This gives useful information as well as links to other individual European country trade bodies such as the Paper Federation in the United Kingdom.

CEPI web site :: www.paperonline.org

Paper Federation of Great Britain - pfgb

An example of the sort of information available from the trade bodies with regard to regulations is;mills that make pulp designed for food contact uses, including both packaging and non-packaging, should comply with the Paper Federation's good manufacturing practice code. To protect the consumer, any product made from pulp must comply with certain standards so no illness is caused. For example, the cardboard container for a chicken kiev must not have any chemicals in it that could harm the food and in turn harm the consumer when they eat the chicken kiev.

For more information regarding the UK visit the Paper Federation address below.

Paper and Board Manufacturing Overview

As papermaking is quite a complicated technical process, computer controls monitor it from start to finish. The computers make adjustments to ensure such things as evenness, appropriate moisture content, proper mixing and proportioning of pulp and chemicals, sheet (of paper) formation, thickness and grammage, are controlled.

Manufacturers use mixtures of chemical wood pulp, mechanical wood pulp and other additives to make paper with very specific characteristics. Paper can vary in thickness as well as in strength and printability, i.e. how well the paper performs in a printing machine. Manufacturers may also apply a coating to the paper to improve its colour and brightness as well its printability.

World paper demand is projected to grow by about three percent a year through the next decade. That means global consumption will rise by almost 50 percent by 2010!

[Source: www.cppa.org]

The Processes

Wet processes

Stock preparation

The material to be used for making paper is first converted into pulp (a concentrated mixture of fibres held in liquid). As many of these fibres come from natural sources, e.g. plants, this process often requires many stages of separation and washing. Once the fibres have been taken out, they may also be bleached or dyed to alter the appearance of the final product.

Layering/Bonding

The pulp mixture is diluted with water resulting in a very thin slurry (gooey liquid). This dilute slurry is drained of water through a fine mesh/moving screen. Water is also removed through gravity, vacuum action, pressure and heat. A watermark may be impressed into the paper at this stage of the process (a distinguishing mark pressed onto the paper during manufacture; visible when paper is held up to the light.). As water is removed, cellulose fibres bond to form a web of paper (cellulose fibres are fibres that come from plant cell walls and contain glucose, which is a polymer).