The pursuit of the perfect solution
Nearly a decade ago, seeing that its current solution was not future-ready Windsor realized that, in order to achieve its vision of becoming a premium machine supplier, it would need an automation partner with world-class products. B&R quickly proved it was up to the task, with a prototype of an injection molding machine that exceeded Windsor’s expectations. It became clear that the two companies share not only a focus on customer satisfaction, but also a constant aspiration for perfect solutions based on cutting-edge technology. One might say they are two companies "from the same mold".
With 530 employees and two state-of-the-art production centers in the Indian state of Gujarat, Windsor Machines Limited has grown to become the country’s largest manufacturer of plastic processing machinery. The facility in Chhatral manufactures injection molding machines, whereas the facility in Vatva handles the manufacturing of pipe extrusion lines and blown film extrusion lines.
Leadership in injection molding machines
Since its founding in 1964, Windsor has worked hard to reinforce its leadership in injection molding. In 2010, Windsor obtained the technology for higher tonnage machines from Italtech, a well-known Italian injection molding machinery manufacturer.
Today, the Injection Molding division offers a complete portfolio of products ranging from 100 to 1,300 tons using hydro-mechanical and toggle clamping technology. Products using hydraulic and servo motor technology cater to a wide range of industries, including household items, furniture, packaging, automobiles, electrical/electronic components and RPVC/CPVC fittings, always with a focus on energy efficiency.
Advanced technologies for mold quality
Windsor relies solely on B&R technology for its automation tasks. Windsor’s ARMOUR, CASTLE and SPRINT injection molding machines are very successful in the market. Together with B&R, Windsor pinpointed the key factors for the success of their projects: a faster controller, a modular I/O system and an HMI unit that is perfectly tuned to how the machine operates.
A high-speed, full-featured B&R controller ensures consistent high quality, which results in a stable and precise mold every time. Temperature control with auto-tuning is easily implemented using B&R's Automation Studio software development environment. This allows faster responses to temperature fluctuations and environmental changes, thus improving molding stability and reducing the amount of electrical energy needed for barrel heating. In addition, the standby temperature is now standardized in order to prevent materials from burning and to save time when restarting with a new mold.
An extremely rapid, fast-response closed loop injection process ensures superior reproducibility and consistent molded product quality. Smooth velocity for pressure changeover effectively prevents flashing while ensuring stable and repeatable molding conditions. Automatic functions are provided for mold height adjustment, lubrication, purging and barrel heating.
The ability to efficiently set parameters on the visualization device is essential to efficient machine operation and, ultimately, to satisfied users. With this in mind, developers at Windsor selected B&R’s Power Panel, an HMI device with a built-in controller, which B&R customized to the exact requirements of the machine in terms of design and key layout. The Power Panel’s many features include the ability to display machine cycle time details on a single screen, edit process parameters online, store mold data (recipes) in internal memory or on external USB storage devices, automatically calibrate linear transducers and protect access using a four-tiered password system.
With B&R’s Automation Studio development environment, implementing temperature control was extraordinarily easy. The results speak for themselves: faster responses to temperature fluctuations and environmental changes, improved molding stability and reduced electrical energy needed for barrel heating.
B&R’s web server based diagnostic tool, System Diagnostics Manager (SDM), makes maintenance much easier. SDM can be enabled with a simple mouse click in B&R's Automation Studio development environment.
Customized parameter pages accessible via the web server can also be created for remote viewing and management tasks. Operators can maintain strict control of molding requirements by monitoring machine performance based on shot weight consistency and cycle time parameters such as refill and injection time. Maintenance functions such as hardware diagnostics, a scheduler, production data, event logs, trends and statistical process control data for various critical parameters are also available.
Extrusion lines also optimized
Third-generation pipe extruders form Windsor are now providing stiff competition to international brands in terms of reliability, aesthetics, power optimization and sturdiness. The most current installations include CPVC pipe manufacturing lines for both domestic as well as international markets. Windsor’s collaboration with KUHNE GmbH has also provided the company a significant technological edge in monolayer and multilayer blown film lines since 1992.
As Windsor’s automation partner, B&R took on the task of automating its high speed extrusion lines for pipe and blown film. APROL – B&R's process control system – is used as a centralized operator station for the complete extrusion line. Machine functions like reversing haul-off control, fully automatic thickness measurement and control, IBC system control and gravimetric dosing control are handled by a central B&R controller.
Additional distributed intelligence is provided by two-station full surface auto-winders equipped with HMI devices for local operations. All hydraulic components, pneumatic valves and sensors are wired using the highly modular X20 and X67 I/O systems, adding both design flexibility and cost effectiveness.
In any extrusion line, PVC processing is a challenge. As a heat-sensitive material, it demands extremely precise temperature control during processing. B&R’s closed loop control with auto-tuning ensures highly accurate temperature control for the extruder barrel and die heads. Melt pressure is also handled using closed loop PID control to achieve accurate pipe length cutting.
"Working with B&R over the past decade has been a great experience. Our customer now has a product that combines the advantages of Windsor’s experience in building injection molding and extrusion machinery with B&R's automation expertise. We realize that without such a partnership, it would be extremely difficult to meet the market’s growing challenges." T. S. Rajan, COO at Windsor Machines