Case Study

Efficient Production of Plastic Products

Designed and built by Orex, the SHUTTLE-5700 HYBRID rotomoulding machine enables the use of renewable energy sources in the plastic moulding process while delivering material savings and higher productivity.

Orex manufactures specialized rotomoulding machines used in the production of plastic products through the rotational moulding process. These machines are used to produce water storage tanks, toys, housings, and other items with complex shapes. For a customer in Germany, Orex designed and built a custom machine: the SHUTTLE-5700 HYBRID. It is the first machine of this size and technological sophistication developed by the Polish company. Compared to other solutions available on the market, it stands out for its flexibility in the use of energy sources and its high efficiency, delivering significant savings. The solution is based on Siemens technology and control cabinets supplied by Rittal.

How Does Rotomoulding Work?

Rotational moulding, also known as rotomoulding, is a manufacturing process used to produce three-dimensional plastic products.

"Rotomoulding offers significant advantages over alternative plastic forming methods. It minimizes material waste, contributes to higher product quality, and reduces the cost of producing short production runs. It also enables the manufacture of products with complex shapes and intricate geometries,"
explains Sławomir Kocur, Procurement and Logistics Specialist in the Automation Department at Orex.

The central component of Orex rotomoulding machines is the oven. Inside the oven, the plastic material is deposited onto the walls of the mould under high temperatures while the mould rotates on two axes. A key role in this process is played by the heating system, which includes components such as gas burners and other heating technologies. Product formation is made possible by the rotation system, which ensures the even distribution of molten plastic over the inner surfaces of the mould, resulting in a uniform wall thickness. An additional function of rotomoulding machines is provided by the cooling system. It cools the product after moulding, helping to retain its final shape.

Achieving high product quality requires precise process control. Orex rotomoulding machines, including the SHUTTLE-5700 HYBRID, are equipped with advanced automation and control systems that not only ensure accurate moulding process control, but also enable parameter monitoring and the programming of various production cycles and mould configurations.

The rotomoulding process requires strict adherence to technological parameters and close monitoring at every stage of production.

The moulding process can be controlled either manually or automatically. At the heart of the control system is a SIMATIC S7-1500 PLC, while process management and monitoring are provided through a SIMATIC Comfort HMI touch interface.

Hybrid Solutions

The SHUTTLE-5700 HYBRID combines different mould-heating technologies, increasing energy efficiency, reducing greenhouse gas emissions, and improving process productivity. A key advantage of hybrid machines is the ability to alternatively use gas burners or electric heaters powered by renewable energy sources, such as solar panels and wind generators, to heat the moulding chamber.

"The hybrid solutions implemented by Orex are extremely important in the context of climate protection. Replacing conventional energy sources with renewable ones helps reduce greenhouse gas emissions and lower the overall carbon footprint,"
emphasizes Marcin Koter, Sales Manager at Siemens Poland.

The SHUTTLE-5700 HYBRID is one of the most important hybrid machine models manufactured by Orex for the thermal processing of powdered polyethylene (PE) materials using the rotational moulding process. These machines are equipped with advanced monitoring and diagnostic systems that enable continuous analysis of machine parameters and help prevent potential operational issues. In addition, Orex solutions based on Siemens technology provide precise process control, resulting in higher product quality and more efficient production management.

Siemens Technology for Rotomoulding Solutions

The rotational moulding process requires strict adherence to technological procedures and close monitoring of parameters at every stage of production. During manufacturing, a properly prepared mould containing powdered polyethylene is rotated inside the oven chamber for a specified period, at appropriate speeds and with programmed changes in rotational direction. A key factor in ensuring the correctness of the process is achieving and maintaining the proper moulding temperature.The OREX SHUTTLE-5700 HYBRID machine has been adapted to operate with electric heating elements consisting of 24 heating panels rated at 40 kW each, as well as a gas-oil heating system comprising two burners with an output of 1,250 kW each. As the burners are installed within a heat exchanger, this solution enables clean air circulation within the oven chamber while providing improved combustion conditions for both natural gas and heating oil.

"The SHUTTLE machine has been equipped with modern motion and position control systems, PID heating controllers, fast SSR contactors, and temperature, pressure, and position sensors. This makes it possible to precisely tailor the technological process, ensuring extensive production and technological capabilities,"
says Sławomir Kocur.

The machine built by Orex incorporates a range of Siemens solutions from the SIMATIC, SIMATIC NET, and SINAMICS product families, as well as SIRIUS/SENTRON low-voltage switching and protection equipment.

The Siemens-based solutions employed by Orex enable precise process control, which in turn translates into higher product quality and more efficient production management.

The moulding process can be controlled either manually or automatically. At the heart of the control system is a SIMATIC S7-1500 PLC, which manages the actuating components, collects measurement data, and processes the acquired information to execute the process algorithms. Process management, monitoring, and data acquisition are provided through a SIMATIC Comfort HMI touchscreen interface. Another important aspect is the use of reliable switching and protection devices from the SIRIUS/SENTRON product family.

“The control system incorporates the latest Siemens technologies, ensuring precise control over the process. Key components responsible for machine control include SINAMICS servo drives equipped with advanced safety functions. Their implementation enables smooth speed regulation for both the major and minor rotational axes, within a range of 0.5 to 7 rpm,” says Krzysztof Staszek, Industrial Automation Programming Expert at Orex Rotomoulding.

The use of absolute encoders on the drive axes enables precise control of the rotational movement of the machine arms. Thanks to this advanced technology, the mould can be positioned accurately, ensuring both operational safety and fast handling during loading, unloading, and maintenance activities.

As standard, the Orex machine is equipped with an electricity consumption meter, a power quality analyzer, and a gas consumption meter.

Safety First

A key aspect of any production line is the protection of personnel from injury and equipment from damage. In the Orex solution, these requirements are strictly observed and supervised by dedicated safety systems supported, among others, by Siemens technology.

“The safety of the SHUTTLE machine throughout its entire service life is ensured by a comprehensive set of devices and safety systems, supported by modern active gas detection systems, flame detectors, interlocking locks, and motion interlocks. Combined with specially designated and protected work zones, as well as trained and safety-conscious operating personnel, the machine provides a safe and modern working environment,” says Krzysztof Staszek.

To further enhance operational safety, the oven chamber is equipped with an emergency exhaust gas extraction system and an additional heat-exchange fan. In addition, access to the machine is secured by a safety fence with dedicated process and maintenance access gates. The machine includes designated zones that may only be accessed by authorized personnel performing operational or maintenance tasks.

Operation of the SHUTTLE-5700 HYBRID and monitoring of the production process are carried out via a touchscreen control panel.

The safety of the SHUTTLE machine throughout its entire operational life is ensured by a comprehensive system of devices and safeguards, supported by modern active gas detection systems, flame sensors, interlocking safety locks, and motion interlocks.

Each workstation has been equipped with an independent manual control panel. The safety and quality of the technological process are overseen by a SAFETY system implemented through a Siemens Fail-Safe PLC, as well as our top-of-the-line SINAMICS servo drives equipped with integrated SAFETY functions

Marcin Koter, Sales Manager, Siemens Poland

Control Cabinet Equipment

An important part of the machine’s equipment is the range of solutions supplied by Rittal, including VX25 control and distribution cabinets with integrated climate control, as well as VX25 Ri4Power and RiLine60 power distribution systems.

In addition to Siemens solutions, the SHUTTLE-5700 HYBRID machine incorporates equipment supplied by Rittal, including VX25 control and power distribution cabinets with integrated climate control, as well as VX25 Ri4Power and RiLine60 power distribution systems. In total, the machine is equipped with 12 Rittal cabinets housing low-voltage electrical equipment.

“The two main supply cabinets are equipped with a Siemens 2500 A main circuit breaker and Rittal NH3 630 A fuse-switch disconnectors. In the outgoing feeder cabinets supplying the individual heating elements, RiLine60 busbar systems with 30 × 10 mm copper busbars have been installed, together with fuse-switch disconnectors and connection adapters,” explains Bartosz Kaźmierczyk, Product Manager responsible for the Power Distribution segment at Rittal.

The cabinet and busbar system forms a comprehensive solution for the construction of certified low-voltage switchgear assemblies with internal compartmentalization. The VX25 Ri4Power system has been tested with Siemens electrical equipment in accordance with the EN 61439 standard, including the 3WL1225 2500 A air circuit breaker (ACB) used in this project.

“This solution is designed for applications with current ratings of up to 6,300 A. VX25 Ri4Power combines power distribution and control technology within a single enclosure. The comprehensive modular system enables fast and flexible implementation of any switchgear section with forms of separation from 1 to 4b. It also allows the creation of individually configured busbar compartments, functional units, and connection areas,”
says Bartosz Kaźmierczyk of Rittal.

The project also incorporates four Blue e+ air conditioning units, each with a 2 kW cooling capacity. Each unit is mounted directly on the door of a switchgear cabinet. To improve energy efficiency, Rittal uses innovative hybrid technology in its air conditioning systems. This technology combines a conventional compressor-based cooling system with a heat pipe system that provides passive cooling. The compressor operates only when passive cooling alone is insufficient. As a result, the solution delivers both lower energy consumption and reduced CO₂ emissions.

To ensure optimal thermal conditions for the equipment installed inside the cabinets, Blue e+ air conditioning units with a cooling capacity of 2 kW have been deployed.”

High Quality, Cost Savings, and Environmental Benefits

The use of environmentally friendly solutions and materials, including power systems based on renewable and low-emission energy sources, is one of the distinguishing features of machines developed by Orex. Other advantages of the company’s hybrid solutions include reduced material waste and lower production costs, particularly for small production runs.

Compared with other moulding technologies such as injection moulding or press forming, the rotational moulding process does not require the high pressures needed to force material into a mould. This characteristic makes it an ideal method for manufacturing large, one-piece products such as tanks, containers, and external housings.In addition, rotational moulding significantly minimizes material waste. Unlike competing production methods, where excess material is often trimmed off and discarded, nearly all of the plastic used in the rotational moulding process becomes part of the final product. This results in more efficient material utilization and contributes to lower overall production costs.

“The tooling used in rotational moulding is generally simpler and less expensive than the tooling required for other moulding technologies. As a result, the process is more accessible to manufacturers, especially those producing short-run batches. In addition, products manufactured using this process are characterized by higher quality. They are seamless and free of welds and joints, making them more resistant to wear, damage, and mechanical stress. All of these advantages make rotational moulding an attractive choice for products that must perform in demanding environmental conditions,”
concludes Przemysław Orlik, CEO of Orex Rotomoulding.