The Production Process
Cartiera Cama and Cartiera Marchigiana are Italian paper mills producing recycled unlined cardboard, in various thickness and different weights, mainly intended for the industrial packaging sector (box factory).
Still inside the paper mill, the unlined cardboard produced can then be transformed into die – cut cardboard, of course for the box factory.
The main stages of the cardboard production process within the paper mill are:
The production process steps are:
Waste paper is the raw material used by the paper mill for the production of its unlined cardboard. It consists of the recycled paper that comes from the city collection and from industrial processing waste. This is the reason why the unlined cardboard produced by our paper mill can be actually considered recycled cardboard. The paper mill buys waste paper from specialized suppliers who, through a selection and cleaning process, transform waste into a secondary raw material.
The first phase of processing in the paper mill consists of the introduction of the waste paper into a tank of about 100 cubic meters, closed with a pneumatic opening, which is called “pulper”. In the pulping tank the paper is mixed with water to create the pulp from waste paper: this mixture is made up of 70% paper and 30% water and is continuously stirred by means of a mechanical system, to then be transferred to a second tank of 110 cubic meters. Subsequently, the mixture of paper and water is conveyed, through a system of pipes, to a first filtering system of the paper mill, in order to eliminate foreign bodies and water-insoluble materials such as plastic, glass, metals, etc.
The paper / water mixture (pulp) is then further diluted, until it is composed of 3% paper and 97% water. At this point, the waste paper pulp is ready to be sent, again through a piping system, to the continuous cycle machine, which constitutes the “heart” of the paper mill.
The initial part of the paper machine is made up of grilled cylinders, called formers as it is on them that, through the passage of the mixture of paper and water, the various layers of the unlined cardboard are formed, until a cardboard belt is formed. The cardboard belt is then conveyed through three presses. At the end of this passage, the percentage of paper present in the cardboard belt reaches a concentration of 45%. The cardboard belt at this point is ready to continue its transit towards the “drying room” area.
The dryer is a section of the continuous cycle machine, composed of 40 rotating cylinders heated directly by steam. Inside the dryer, with a temperature ranging between 70 and 80 °, the 40 rotating cylinders push the cardboard forward and, during the passage, the percentage of water present in the cardboard belt is reduced to 6 – 7%. Both the percentage of humidity and the thickness of the cardboard are continuously regulated and monitored by electronic equipment.
The cardboard belt, after passing through the dryer (therefore still hot), passes through a series of cylinders that press it to improve the surface appearance of the cardboard.
After pressing, the cardboard tape is passed through a cutting unit, where it is cut into sheets of the dimensions (sizes) ordered by the various customers. The cut sheets are automatically stacked on pallets, packed and labelled to be then stored waiting to be shipped to the customer or further processed.
Upon customer (box factory)’s request, the paper mill can die – cut the cardboard sheets. This processing phase requires that the introduction of the cardboard sheets into the die-cutting machines that are specific for the cut of the cardboard into the shapes requested by the customer (box factory). The die – cut cardboard is automatically stacked on pallets, packed and labelled to be stored and sent to the box factory.
