Enclosures & Machine Guards
Transparent thermoplastic products used as protective elements in industrial and sanitary environments. A complete guide to materials, thicknesses, and applications.
Table of contents
Quick selection
Orientation table for initial material selection based on the primary application requirement.
| Requirement | Recommended material |
|---|---|
| Debris/impact resistance | Polycarbonate 6–15 mm |
| Transparency + easy cleaning | PMMA |
| Alcohol disinfection | PMMA (PC cracks!) |
| Temperature >50 °C | Polycarbonate |
Important
Polycarbonate is susceptible to stress cracking on contact with isopropyl alcohol and other solvents. In environments requiring alcohol disinfection, use PMMA.
1. Machine guards
Industrial machine guards must comply with safety standards and provide visibility of the technological process. Material selection depends on the machine type and hazard.
| Machine | Material | Thickness |
|---|---|---|
| CNC machines | PC | 8–15 mm |
| Presses | PC | 10–15 mm |
| Welding stations | Tinted PMMA | 4–6 mm |
| Industrial robots | PC | 6–10 mm |
Guard mounting rules
Tip
Use load-spreading washers at mounting points to prevent material cracking from vibration and point stress.
2. Hygienic screens
Screens used in environments with elevated sanitary requirements: food processing, pharmaceuticals, laboratories.
Key parameters
- Surface smoothness: Ra < 0.8 μm
- PMMA: resistant to aldehydes, acids, peroxides
- PC: sensitive to alcohols — always verify compatibility!
Caution
Before using polycarbonate hygienic screens, verify compatibility with the disinfectants in use. Alcohols and some aldehydes can cause stress cracking in PC.
3. Device enclosures
Plastic enclosures must account for thermal expansion of the material and provide adequate sealing.
Thermal expansion — example
Enclosure types
- Folded: flat elements joined at edges
- Thermoformed: bent from a single sheet
- Multi-wall: multi-layer, insulating
4. Technical showcases
Material thickness selection for showcases depends on dimensions and required structural rigidity.
| Showcase type | PMMA thickness | PC thickness |
|---|---|---|
| Small (up to 400×400×400 mm) | 3–4 mm | 3–4 mm |
| Medium (up to 800×600×400 mm) | 4–6 mm | 4–5 mm |
| Large (up to 1200×800×500 mm) | 6–10 mm | 5–8 mm |
Tip
Polycarbonate has higher rigidity and impact resistance, so thinner gauges can be used compared to PMMA for the same showcase dimensions.
5. IP ratings
Enclosure protection ratings per IEC 60529. Determining the appropriate IP rating is critical when designing enclosures for electronic equipment.
| Rating | Protection |
|---|---|
| IP54 | Limited dust protection + splash-proof |
| IP65 | Dust-tight + water jet protection |
| IP67 | Dust-tight + immersion up to 1 m |
6. Processing techniques
Thermal bending
Bending temperatures
Bonding
- PMMA: solvent bonding (e.g. chloroform, dichloromethane)
- PC: reactive adhesives (not solvent-based!)
Critical
Do not use solvent cements on polycarbonate — they cause stress cracking. For PC, use only reactive adhesives (e.g. polyurethane, epoxy).
Related topics
- Glossary — material and technology definitions
- Material Comparison — how to choose the right material
Need an industrial guard or enclosure?
IP-rated production. PMMA and polycarbonate. Quote within 24h.
Request an enclosure quotePlexiSystem Encyclopedia — Enclosures & Guards
Last updated: January 2026