How to Choose the Right Safety Light Curtain for Your Hydraulic Press

The core of choosing the right safety light curtain for a hydraulic press is to build a reliable, invisible safety barrier—that is, to cut off power before a dangerous action occurs, rather than reacting passively after an accident. A safety light curtain forms a protective light barrier by emitting infrared rays. When any part of the operator's hand or body enters the danger zone and blocks the beam, the system will trigger a shutdown within milliseconds. Below are some suggestions from Jianlong Hydraulic Technology on purchasing a suitable safety light curtain for your reference!

1. Working Principle 

The safety light curtain forms an invisible infrared light wall in front of the danger zone. Once any part of the operator blocks the beam, the light curtain immediately sends a signal to the control system, triggering the slide to stop or return within milliseconds.

2. Three Key Selection Factors

Based on Chinese national standards and industry practice, the following three core parameters must be considered when selecting a beam type:

2.1 Selection Dimension: Beam Spacing (Resolution)

2.1.1 Technical Requirements and Recommendations

• Clamping Area: Select 14-30mm (Finger/Palm Protection)

• Moving Part Area: Select 30-50mm (Arm Protection)

2.1.2 Consequences of Incorrect Selection

• Excessive spacing will result in missed hand detection, causing serious injury; insufficient spacing will lead to frequent accidental shutdowns, impacting production efficiency.

2.2 Selection Dimension: Safety Level

2.2.1 Technical Requirements and Recommendations

• Type 4 or PLd/SIL2 and above must be selected, with dual-loop redundancy design to ensure reliable shutdown even in the event of a single fault.

2.2.2 Consequences of Incorrect Selection

• Low-level gratings may fail to issue a shutdown signal in the event of a circuit failure, resulting in complete protection failure.

2.3 Selection Dimensions: Installation Method

2.3.1 Technical Requirements and Recommendations

• Mold Closure Area: Use a through-beam installation, with the transmitter and receiver positioned on opposite sides to ensure complete beam alignment and an angle deviation of <1°.

• Moving Parts Area: Single-sided installation can be used to save space.

2.3.2 Consequences of Incorrect Selection

• Installation deviations can lead to blind spots in detection, preventing personnel from being detected when entering the danger zone.

3. Installation Distance Calculation (Critical Safety Step) 

The light curtain must be installed at a sufficient distance from the danger point to ensure a sufficient safety margin from when a hand is detected until the slider comes to a complete stop. Reference distance calculation formula (based on ISO 13855):

Safety distance S = K × (T1 + T2) + C

3.1 K: Approach speed (usually 1600 mm/s or 2000 mm/s)

3.2 T1: Light curtain response time (usually ≤15ms)

3.3 T2: Hydraulic press stop time (needs actual measurement)

3.4 C: Additional compensation value (related to light curtain resolution; for example, when resolution ≤30mm, C = 8 × (resolution - 14))

4. Environmental adaptability requirements

Hydraulic presses operate under harsh conditions such as high temperature, oil contamination, and vibration. The following must be confirmed during selection:

4.1 Protection rating: The light transmitter and receiver must meet IP65 or higher.

4.2 Anti-interference capability: Good anti-interference capability against electromagnetic signals, welding arc light, and ambient light sources.

4.3 Oil-resistant design: The lens surface should have a hydrophobic coating to prevent oil contamination from affecting the inspection.

If you can tell me the tonnage, opening height, operation method (manual/automatic), and workshop environment (presence of oil stains/high temperature) of the hydraulic press, I can help you narrow down the specific model range. For more information/advice on hydraulic press safety light curtains or to purchase high-quality hydraulic presses, please contact us (or scan the WhatsApp QR code below). Jianlong Hydraulic Technology will provide you with personalized and customized professional solutions and is dedicated to serving you.