Case Study: 2150mm Industrial Machine Guard

Project Summary: Large-Format Machine Guard for Heavy Equipment OEM

A heavy equipment manufacturer producing industrial production machinery for the packaging and converting industries engaged DitaiPlastic to produce large-format machine guards and safety enclosure panels for a new flagship production line. The parts are large — over 2 meters on the long axis — and carry functional safety requirements under OSHA 1910 and ANSI B11 machine guarding standards.

We produced the full guard set in HDPE (for chemical resistance in wash-down zones) and polycarbonate (for viewing windows in operator-access areas), replacing a welded sheet-steel and laminated-glass design that was heavy, expensive, and slow to manufacture.

The Challenge

Machine guards are boring — until they fail. A guard that cracks on a production floor exposes operators to rotating equipment, pinch points, and flying debris. The challenge on this program was delivering a guard set that was large (over 2 m), impact-resistant to a real specification, and compliant with machine guarding standards, at a unit cost that made sense for a capital equipment OEM building 60–80 machines per year.

Specific requirements:

• OSHA 1910.212 / ANSI B11.19 guarding requirements — guard must prevent access to hazard zone and withstand reasonably foreseeable impact.
• Impact resistance to a 6 kg steel projectile at 20 m/s without penetration (per client’s internal spec, exceeding ANSI B11.19).
• Chemical resistance in wash-down zones — must survive hot caustic cleaning chemistry used in food-adjacent converting applications.
• Viewing windows with optical clarity and the same impact performance as opaque panels.
• Size: largest panel 2150 x 1100 mm, 4 mm nominal wall.

Our Solution

We split the guard set into two material families: HDPE for opaque panels in wash-down zones, polycarbonate (PC) for viewing windows. Both are heavy gauge vacuum formed on our large-envelope line.

HDPE opaque panels

6 mm HDPE sheet, pre-colored safety yellow to match the client’s brand and machinery visual standard. HDPE was selected over ABS for its superior chemical resistance to the hot caustic wash chemistry, and for its cold-temperature impact performance in refrigerated converting lines.

Polycarbonate viewing windows

6 mm optically clear polycarbonate, vacuum formed with low-distortion tooling and a UV-stable hard coat applied post-form. PC delivers 250x the impact resistance of equivalent thickness acrylic and passes the 6 kg / 20 m/s projectile test with margin.

Tooling and process

CNC aluminum tooling on our large-envelope forming line (2500 x 1500 mm usable form area). Post-form CNC trim for mounting holes, cable passes, and edge finishing. All panels are edge-sealed and labeled with laser-etched guard ID tags for maintenance traceability.

Structural validation

We coordinated impact testing at an independent lab to the client’s 6 kg / 20 m/s projectile spec. Both HDPE and PC panels passed with no penetration and only cosmetic surface marking.

Technical Details

• Materials: HDPE 6 mm (opaque, safety yellow); polycarbonate 6 mm (clear, UV hard-coated).
• Largest panel: 2150 x 1100 mm, 4 mm wall post-form.
• Impact: 6 kg steel projectile at 20 m/s — no penetration on either material.
• Chemical resistance (HDPE): validated to 2% NaOH at 70 degrees Celsius for 24 hours, no visible attack.
• UV stability (PC): hard coat rated for 10,000 hours QUV-A with less than 5% haze increase.
• Compliance: guard design reviewed against OSHA 1910.212 and ANSI B11.19 by the client’s internal safety engineering team.
• Annual volume: 70 machine sets (approximately 840 panels total).

Results

• Weight reduced 62% versus the welded sheet-steel guard design — 48 kg saved per machine set, reducing installation labor and shipping cost.
• Unit cost reduced 38% versus the sheet-steel baseline at 70 machine sets per year.
• Lead time reduced from 10 weeks to 5 weeks — critical for the client’s made-to-order business model where capital equipment customers specify lead time down to the week.
• Zero field failures across the first 180 machines deployed globally.
• Safety acceptance: guard set approved by customer EHS teams in 14 countries on first review.

Client Testimonial

“The weight reduction alone changed our installation playbook — two technicians can handle the full guard set now instead of four plus a lift. DitaiPlastic’s engineering team understood that a guard is a safety component, not just a cover, and the impact test results gave our product safety team what they needed.”

— Director of Product Engineering, Heavy Equipment OEM

Related Capabilities Deployed

• Large-envelope heavy gauge vacuum forming (up to 2500 x 1500 mm)
• HDPE and polycarbonate heavy gauge forming
• UV-resistant hard coating on PC viewing windows
• 5-axis CNC trim for mounting and cable-pass features
• Impact and chemical resistance test coordination

Lessons Learned / Key Takeaways

1. HDPE is underused in machine guarding. Its chemical resistance, cold-temperature impact performance, and formability make it a better choice than ABS for wash-down and refrigerated environments.

2. Polycarbonate viewing windows outperform laminated glass on weight, impact, and cost — and they don’t shatter. For viewing panels over 600 mm on any axis, PC is almost always the right answer.

3. Large-format thermoforming is a structural win against sheet steel for guards over 1.5 m and production volumes of 50–500 sets per year. Below that volume fabricated steel may still be cheaper; above 500 sets injection molded segments start to compete.

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We produce large-format industrial guards, safety enclosures, and equipment covers for machine builders across packaging, converting, food processing, and heavy industry. contact us to request a DFM review and quote on your guard set.