Friday, 6 November 2015


A Fourdrinier is a huge papermaking machine which takes input as waste paper Or wood fibres and produces output as a finished paper roll.
Many modern paper making machines are based on the principles of the Fourdrinier Machine.

This Machine was invented in the early 1800's and is accredited to Henry Fourdrinier , a London based Stationer , although it was actually invented by a Frenchmen called Louise - Nicholas Robert.

The Fourdrinier Machine consists of four main sections :-

(1.) Forming section Or Wet end
(2.) Wet Press section
(3.) Dryer section
(4.) Calender section

Although , so many other small things are also present in between these sections like :- Size press , M.G roll , Coaters , Pope reel e.t.c.

(1.) Forming Section :-

Because woodpulp fibres Or waste paper fibres ( in case of recycling ) has a strong tendency to clump, it needs to start off with a very high percentage of water content, allowing the pulp to have an even distribution, the slurry (or furnish) held in the Headbox contains around 99% water.

The furnish travels down the Slice onto the revolving Wire ( woven plastic fabric meshed conveyor belt ) at the Breast Roller point of contact.

As the furnish travels along the wire, so water is removed and the pulp fibres are aligned in a uniform direction.

It is this process that allows perfect distribution of the pulp fibre across the sheet as well as giving the paper strength and stability by aligning the fibres. Suction rollers hold the furnish to the meshed wire and help remove the water content.

By the time the paper or web has reached the Wet Press Section , at that point the consistency has gone from 1% pulp content to 25%.

(2.) Wet Press Section

The Wet Press Section carries the wet web between a series of rollers under high pressure to squeeze more water from the paper, much like a mangle.

The Felts ( woven plastic fabric conveyor belts ) support the web and also aid water removal by absorption. As the web enters the third section the paper web consistency can be as high as 40%.

(3.) Dryer Section

In this section , Steam heated rollers cause further water removal by making direct contact with paper through evaporation as well as further use of felts , bringing the water level down to as low as 30%.

(4.) Calender Section

The final Calendar Section allows the web to pass between Calendar Rollers that smooth out the surface of the paper.
If the paper has a coating then the degree of calendering will change the characteristics of the coating.

For example, gloss artpapers have a higher degree of calendering than a velvet sheet.

The main purpose of Calender section is to make the paper smooth , brighter and glossy.

Now one thing that is not shown in the diagram and is the first thing that strikes anyone who visits a paper mill for the first time is the absolute vastness of Fourdrinier machines.

Each roller in the Dryer Section can have a diameter of several metres, the width of the reel of paper can vary from 5 to 10 metres long and weigh several tonnes.

The Machine from the Top Box to the Dry End could cover the distance of a football field.

The machines are so large that operatives have to use three wheel scooters to move from one end to the other.

No comments:

Post a Comment