Types of plastic in pipes
Pipes used in Switzerland are mainly made of the three plastics polyethylene, polypropylene and polyvinyl chloride. These types of plastic are all generally easy to recycle if they are sorted by type.
Occurrence of plastic types in pipes
In addition to the main plastics, there are also applications for polybutene in smaller quantities as well as specialties such as cross-linked polyethylene, filled polyethylene and aluminum-PE multilayer. There are hardly any areas of application for recycled polybutene, while there are only limited recycling options for the specialties.
Problematic additives or aggregates such as plasticizers or flame retardants, which make recycling impossible, are rarely used in pipe production. Their use is not permitted in drinking water supplies, for example, and is not technically necessary. Pipes for electrical installations (electrical protection and laying pipes) in building construction are an exception.
Variety of plastics in the pipe sector
The variety of materials is greater in building construction, which also makes recycling a greater challenge.
| Civil engineering | Building construction | |
|---|---|---|
| PE | Drinking water supply Gas supply Cable conduits | Waste water / drain |
| PP | Drainage | Waste water / drainage (historical) |
| PB | No application | Drinking water supply |
| PVC | Drainage | Waste water (historical) |
| more | Multi-layer in the district heating sector, otherwise rare (e.g. diffusion barrier layers for supply pipes in contaminated soils). Minor use of other plastics, e.g. in housings of fittings and pumps | Cross-linked PE (PE-X): Drinking water Multi-layer pipes: Heating construction, basement and storey supply, pre-insulated pipes Unknown types of plastic, some with flame retardants and plasticizers in electrical installations. |
types of plastic
Polyethylene (PE)
Polyethylene is characterized by its high chemical resistance and flexibility. PE is available in different types (LDPE, HDPE, PE-RT), which influences its mechanical properties. Due to its versatility, PE is one of the most frequently used and recycled plastics in the world. In addition to pipes, PE is also used for packaging, such as films, bags and bottles, as well as for cable sheathing.
Polypropylene (PP)
Polypropylene is characterized by its high resistance to heat and chemicals. PP is characterized in particular by its hardness and rigidity. In addition to pipes, PP is also used for packaging, household items and car parts (e.g. bumpers, nonwovens). Polypropylene is the second most widely used plastic in the world.
Polybutene (PB)
Polybutylene is a thermoplastic material that is primarily used for pipe systems in water supply, heating technology and industrial applications. It is very flexible, durable and resistant to high temperatures and chemicals. PB was popular in the past for drinking water pipes, but has lost importance in Switzerland, although it remains a relevant niche plastic in the pipe sector.
Polyvinyl chloride (PVC)
Polyvinyl chloride is a versatile plastic that is available in both soft (soft PVC) and hard (hard PVC) variants. In addition to pipes, it is also used for window frames, floor coverings and cable insulation. PVC is known for its durability and rigid PVC, as used for pipes, is easily recyclable. Soft PVC poses recycling challenges due to the additives it contains (e.g. plasticizers).
Other types of plastic and special applications
- Cross-linked polyethylene (PEX): Cross-linked polyethylene is a polyethylene in which the material is additionally reinforced with chemical compounds after the product has been manufactured. As a result, PEX is difficult to melt and can therefore hardly be mechanically recycled. Chemical recycling, in which the material is broken down into its components, may be an option for recycling in the future. PEX is used in particular in water distribution in building construction, and historically also in heating systems
- Filled polyethylene (PE Silent): Filled polyethylene is a polyethylene to which minerals are added during production. The minerals are harmless to health and improve sound insulation. Sound-insulated pipes are used exclusively in sanitary facilities in the waste water sector to prevent noise emissions.
- Multi-layer pipes (PE-ML): Multi-layer pipes consist of different layers of plastic and often also an aluminum layer. The plastics are usually PE and sometimes PP. For the recycling of multilayer pipes, it must be possible to separate the different materials in the recycling process. This means that both aluminum and plastics can be recovered.