(Source: littlewolf1989 / stock.adobe.com)
Workers in modern factories or production facilities have a lot to think about. Not only do they work alongside large and often dangerous industrial equipment, but they’re also likely to be in the same environment as automated guided vehicles and mobile robots. All these moving parts create more potential safety hazards in factories than ever before. In this blog, we’ll discuss how light curtains offer manufacturers a safety solution that meets the complex needs of the modern factory floor.
Automating safety-related control systems and procedures can prevent workplace injuries, reduce costly downtime, and keep production running smoothly. Some mobile machines or robots utilize proximity sensors to tell them when an obstacle or a person is in their path. Larger, more stationary equipment often utilizes light curtains—beams of light that are only broken when someone (or something) enters an area it shouldn’t—to alert them of a dangerous or potentially damaging situation.
Light curtains are a much less obtrusive—and less costly—alternative to physical barriers and gates that restrict movement on the factory floor and take valuable time for people, mobile robots, and machines to navigate around.
Safety levels for industrial machines and equipment are defined in two ways: safety integrity level (SIL) and performance level (PL). PL is a catch-all rating that applies to any kind of mechanical or electrical solution, while SIL is chiefly used to evaluate electronic or programmable systems. PL is usually cited when evaluating individual machines while SIL is more commonly applied to a group of machines or an entire facility.
Applications are subdivided into categories based on the level of safety they require. They range from Category B (or baselines) to Categories 1 through 4, with higher categories meaning applications requiring the highest level of worker protection. Meanwhile, light curtains are divided into two safety-related subcategories: Type 2 and Type 4. The required performance level (PLr) of the equipment and processes involved determine whether a Type 2 or Type 4 light curtain is called for. This requirement is defined by the potential severity of the damage, the possible frequency of the damage, and the potential for mitigating the effects of the damage. Higher-risk applications with a higher Plr need a Type 4 solution, while Type 2 light curtains are more appropriate for less dangerous implementations.
TE Connectivity’s new Safety Light Curtains (SLCs) offer industrial applications a compact, durable, and cost-effective solution for enhancing workplace safety in modern manufacturing facilities (Figure 1). TE’s SLC2 and SLC4 work by implementing an emitter to transmit multiple parallel beams of light to a receiver (Figure 2). If those beams remain unbroken, the machine or equipment will continue operating safely. If an object or human body part passes between the devices and breaks the beam(s), the receiver will send a signal and the equipment will immediately shut down.
SLC2 light curtains support various resolutions, enabling detection types such as hand, body, and access control. With resolutions between 30–40mm and 50–90mm, SLC2 light curtains are ideal for perimeter and access control in areas where larger objects need to be detected. Additionally, SLC2 light curtains are an optimal fit for the point of access or perimeter access since they can detect when someone has ventured into a dangerous area. SLC4 light curtains are more appropriate for the point of operation as they provide greater resolution (6mm–14mm) for finger detection in tiny spaces on or inside equipment. For Category 4 applications that require automated safety solutions with almost immediate response times, as an operator can be seriously injured in just a fraction of a second, the SLC4 light curtains deliver the highest level of safety.
Figure 1: TE Connectivity’s Safety Light Curtains use a combination of an emitter and a receiver, along with multiple parallel beams emitted with various resolutions. (Source: Mouser Electronics)
Figure 2: When any part of an SLC light beam is blocked, the machine is stopped.(Source: TE Connectivity)
Workplace incidents and injuries are hazardous for employees and often lead to costly downtime while equipment is inspected and safety procedures are reviewed. Reducing the potential risk for harm to employees leads to longer periods of uninterrupted operation and greater production. Enhancing workplace safety isn’t the only way light curtains and automated safety control systems can improve workplace efficiency. The invisible barriers that light curtains create can replace physical fencing and protective walls around equipment, making the workplace more navigable for people, automated mobile robots, and vehicles. Light curtains at the point of operation can prevent tampering or malfunction if a foreign object—or a human extremity—is in danger of damaging the equipment, potentially eliminating repair and replacement time and costs. Light curtains can also eliminate the need for gates or safety guards on the equipment itself, saving time for a mechanism to open and close the gates with each cycle.
TE’s SLC2 and SLC4 light curtains are an optimal safety solution for modern manufacturing facilities, offering one of the most compact form factors on the market with a minimal cross-section of 28mm × 30mm. They also provide robust protection against particulates (e.g., dust, sand, metal shavings) and liquid and boast high ingress protection ratings (IP67 and IP65). Powder-coated aluminum casings provide the SLC range with robust mechanical reliability and help deliver high performance in harsh or demanding environments. Their operational temperature range of -30°C to 55°C makes them an optimal solution for cold storage facilities. The positioning of the beams on the emitter eliminates any blind spots or problem areas in the curtain itself, and the integrated M12 connectors and plug-and-play cables make the SLC range simple to install and easy to reposition or reconfigure.
As automation continues to transform manufacturing, industrial safety systems and processes will also have to adapt. Factory floors and production spaces require more open space than ever for mobile robots and guided vehicles to pass by each other and employees safely without creating costly gridlock. Replacing physical walls and fences with “invisible” barriers can help expedite that freedom of movement and improve efficiency by reducing operational functions that add time to different procedures.
Safety light curtains at the point of operation aren’t just critical for saving distracted or fatigued operators from harm; they also eliminate the downtime a workplace incident can create, prevent potential equipment damage, and maintain uninterrupted operation. TE’s SLC range of light curtains provides this kind of multifaceted protection in a compact, robust package that is easy to implement and adaptable to changing manufacturing requirements. If enhancing workplace safety and improving efficiency are top of mind, TE’s SLC range of light curtains might just be the light at the end of the tunnel.
Alex Pluemer is a senior technical writer for Wavefront Marketing specializing in advanced electronics, emerging technologies and responsible technology development.
TE Connectivity is a global industrial technology leader creating a safer, sustainable, productive and connected future. Our broad range of connectivity and sensor solutions, proven in the harshest environments, enable advancements in transportation, industrial applications, medical technology, energy, data communications and the home. With approximately 80,000 employees, including more than 7,500 engineers, working alongside customers in approximately 140 countries, TE ensures that EVERY CONNECTION COUNTS.