Dry-Flat continuous conditioning machine from Thema16 April 2007
The Dry-Flat continuous conditioning machine is the result of Thema System's long experience in the field of drying and natural conditioning of leather. The Dry-Flat line meets market requirements for a machine to dry or simply condition skins or hides which have varying moisture content at delivery and which, after conditioning, will have precisely controlled, uniform humidity and perfect flatness. This has been achieved by removing the moisture in a natural, unforced manner, with temperature and relative humidity parameters under constant control and management by PLC. The leather is spread out flat on a permeable conveyor at the conditioning machine in-feed. The conveyor belt is then joined by a second permeable belt so that the leather is held flat between them. Throughout the subsequent conditioning process, the leather is stretched flat between the conveyor belts until they separate at the out-feed of the machine. The tension and perfect synchronisation of the two belts as they grip and transport the leather is maintained by specially designed and patented chain drive mechanisms for the conveyor rollers. As the leather is firmly constrained, forced ventilation can be used to give a much higher rate of air movement than with other machines on the market. Higher airflow rates allow drying at temperatures only a few degrees above ambient and at higher relative humidity allowing conditioning without over-drying those areas that would normally dry more quickly. The machine is fitted with exhaust and inlet vents for the circulating air. The ambient air conditions are measured with a thermo-hygrometer and the relative humidity inside the machine is controlled via the PLC which automatically operates the vents. If ambient air conditions are likely to be unsuitable for the optimum operation of the conditioning machine, the machine can be supplied with chilled water batteries or a rotary chemical-type dehumidifier to reduce the relative humidity of the incoming air. The working width is 3,100mm and the number of modules comprising the conditioning chamber is specifically tailored to suit the types of leather and throughput speeds required by the customer. The Dry-Flat conditioning line can be supplied with infeed and outfeed at the same end of the machine, or with outfeed at the opposite end to allow incorporation into throughfeed process lines. Using the Thema Dry Control device it is possible to monitor the actual temperature of the leather throughout the conditioning process. All operating parameters of the conditioning machine are continuously displayed and easily controlled by the operator through a touch screen. Further advantages include conditioning at temperatures close to ambient; uniformity of conditioning with variable thickness of leather; flat leather without curling or deformation caused by the drying process; increased cleanliness of leather surface compared to other technologies; increased productivity; reduced maintenance and operating costs; and low energy consumption.