The calendering industry, like most others, is competitive, and calendering companies strive to keep up with, if not go beyond, the conventional technologies used in it to gain an edge. At JiangYin QinLi Rubber Machinery Co. Ltd. in China, management and engineers decided to upgrade their hydraulic actuators and controls to boost productivity and efficiency.
Calendering is the process by which textiles, plastics, metals and rubber are sent between a pair of hard rollers to smooth or finish them. The process was invented by Charles Goodyear, who used it on rubber in the 1800s. The Goodyear Tire & Rubber Co. remains a dominant player in the field of calendering to this day.
Across its rubber, plastic, metal and fiber film operations, JiangYin QinLi needs to deliver consistent quality while being the most economical supplier on the market. In calendering, quality generally stems from maintaining minimal thicknesses while preserving material tolerances. Doing so, however, makes mechanical calendering machines cumbersome. And machines that rely on electric motors to move rollers require manually adjusting the gap between rollers, as different materials require different roller spacing.
It is difficult to calibrate this gap on mechanical equipment, and making adjustments can take considerable time. Even under the best conditions, it is difficult to maintain a precise gap due to changing environmental conditions and constant wear on parts experience wear.
The arrival of hydraulic calendering over the last several years has opened the door to new ways to improve on mechanical calendering. With hydraulic calendering, rollers are moved by hydraulic cylinders, giving the cylinders a virtually infinite range of positionings to meet more demanding production needs.
For example, customers for calendered rubber sheets now expect available thicknesses to include those from 0.05 to 0.1 mm with tolerances of ±0.01 to 0.005 mm. In some extreme cases, they need tolerances of ±0.0025. These tolerances are difficult to execute, but holding such tight tolerances saves on raw materials and reduces manufacturing costs while improving sales due to higher-quality product—at least for the few manufacturers able to manage it.
JiangYin QinLi took its technical specifications and reached out to Wuxi Forever in search of an end-to-end, best-in-class calendering solution. The integrator assisted in everything from schematic design to post-deployment support and supplied everything from transducers and motion controllers to cylinders and hydraulic power units. Wuxi Forever even crafted an HMI terminal in which velocity, cylinder distance and required margin are all controlled by technician using a touchscreen.