PV Cable Protection: TPU vs. PVC vs. Rubber Compared
The material of a roof penetration determines its durability, flexibility, and weather resistance. For PV cable penetrations, three main materials are considered: TPU, PVC, and rubber (EPDM). This comparison highlights the differences and explains why NEXCAPE relies on TPU.
An Overview of the Three Materials
| Property | TPU | PVC | Rubber (EPDM) |
|---|---|---|---|
| UV Resistance | Very High | Medium (yellows) | High |
| Flexibility | Very High | Low to Medium | High |
| Temperature Range | -40 to +80 °C | -10 to +60 °C | -40 to +120 °C |
| Aging Resistance | Very High | Low | Medium |
| Mechanical Strength | High | Medium | Medium |
| Suitable for 3D Printing | Yes | No | No |
PVC: Inexpensive, but Not Durable
PVC is the most commonly used plastic material for construction accessories. It is inexpensive to manufacture and widely available. However, PVC has significant disadvantages for outdoor use: it becomes brittle under UV radiation, yellows over time, and can crack at low temperatures. For a roof penetration designed to last 25 years or more, PVC is not an optimal choice.
Rubber (EPDM): Proven, but Limited
EPDM rubber is known from flat roof waterproofing. It is UV-resistant and flexible, but it has limitations in terms of shaping. Complex geometries – as required for precisely fitting roof penetrations – are difficult to achieve with EPDM. Furthermore, its mechanical strength is lower than that of TPU.
TPU: The Best of Both Worlds
TPU (Thermoplastic Polyurethane) combines the advantages of both materials. It is highly flexible like rubber, yet mechanically more resilient and dimensionally stable. Its outstanding UV resistance ensures that the material does not become brittle even after years on the roof.
A crucial advantage: TPU is suitable for 3D printing. This allows NEXCAPE to produce penetrations with precise geometries that are perfectly matched to various tile profiles. Manufacturing takes place in Germany.
Why NEXCAPE Relies on TPU
- Durability: UV-resistant and age-resistant for the entire lifespan of the PV system
- Flexibility: Adapts to various tile profiles
- Precision: 3D printing enables exact cable routing for 2, 4, or 6 strings
- Tool-free installation: MC4 connectors do not need to be removed
For Solar Installers and Installation Companies
NEXCAPE roof penetrations are available in lengths of 105, 125, and 150 mm, each with and without PE cable opening. B2B volume discounts apply for orders of 20 pieces or more.
Discover NEXCAPE TPU roof penetrations in our shop: to the TPU roof penetrations for solar cables
