PVC properties & PVC-U properties | density, resistance & rigid PVC

PVC is one of the most important engineering plastics. The decisive factor is the balanced combination of rigidity, dimensional accuracy, chemical resistance, good electrical insulation capability and problem-free machining. For construction, plant engineering, enclosures, environmental technology and numerous technical applications, rigid PVC offers a stable, economical and reliably calculable solution.

The following chapters present the properties in a structured way, place them in a practical context and make the material decision easier.

Key values of rigid PVC in direct practical relevance

Property	Typical value / range	Significance in technical application
Density	approx. 1.38 g/cm³	dimensionally stable, robust, higher weight than PE/PP
Temperature range (continuous)	–10 °C to +60 °C	reliable for technical and indoor applications
Vicat softening	74–80 °C	limit for heat-exposed components
Tensile strength	approx. 45–55 MPa	stable for sheets, covers, enclosures
E-modulus	approx. 2,500–3,000 MPa	high rigidity, low deflection
Chemical resistance	very good	ideal for plant, environmental and chemical engineering
Electrical properties	very good insulation	suitable for electrical covers and divider sheets
Water absorption	< 0.5 %	dimensionally stable even in moisture
Machinability	very good	sawing, milling, drilling, bonding, thermoforming

Further variants and sheet thicknesses: PVC sheets

Material characteristics of rigid PVC

Rigid PVC is an amorphous thermoplastic with high dimensional stability and very good dimensional accuracy. The low moisture absorption ensures that the material behaves reliably even under changing climatic conditions. The structure of the material makes it self-extinguishing, which is a relevant safety aspect in technical areas.

The impact strength is lower than ABS or PE-HD, but is sufficient for typical technical applications. High rigidity and good chemical stability make rigid PVC particularly versatile.

PVC properties at a glance

PVC (polyvinyl chloride) is one of the most frequently used plastics in industry, construction and technical applications. Rigid PVC or PVC-U in particular stands out due to a balanced combination of strength, chemical resistance and good machinability.

Among the most important PVC properties is the high resistance to many chemicals. PVC is resistant to numerous acids, alkalis and salt solutions and is therefore suitable for tank construction, plant engineering and technical applications with chemical exposure.

The mechanical properties also make PVC versatile. Rigid PVC has good rigidity and dimensional stability. At the same time, the material can be sawn, milled, drilled and bonded. This produces precise components, covers, cladding or technical cut pieces.

Another important characteristic value is the PVC density. Rigid PVC or PVC-U typically has a density of about 1.35 to 1.45 g/cm³. This makes the material heavier than many other standard plastics such as polyethylene or polypropylene, but it offers high stability and load-bearing capacity.

PVC also shows low water absorption and good electrical insulation properties. As a result, the material is frequently used in apparatus engineering, in electrical engineering and in technical plastic sheets.

The temperature resistance of PVC in continuous operation is usually around 60 °C. For applications with higher temperatures, alternative engineering plastics are often used. Through the combination of chemical resistance, stable mechanical properties and good processability, PVC sheets and rigid PVC products are among the established materials for industrial and technical applications.

PVC-U properties – differences and advantages

PVC-U stands for unplasticised polyvinyl chloride and is often also referred to as rigid PVC. In contrast to flexible PVC, PVC-U contains no plasticisers. This produces a firm, rigid and dimensionally stable plastic that is used particularly in technical and industrial applications.

The PVC-U properties differ significantly from plasticiser-containing PVC. While flexible PVC is flexible and elastic, PVC-U offers high mechanical strength and excellent dimensional accuracy. The material is therefore suitable for technical plastic sheets, pipe systems, tanks, machine cladding and chemically exposed components.

A key advantage of PVC-U is its high chemical resistance. The material withstands many acids, alkalis and salt solutions and is therefore frequently used in plant engineering, tank construction or water technology. At the same time, PVC-U absorbs only little moisture and remains dimensionally stable even under continuous load.

PVC-U also stands out due to its good processability. Rigid PVC can be precisely sawn, milled, drilled and bonded. This produces dimensionally accurate cut pieces and technical components with high fit accuracy.

PVC-U also offers economic advantages. Compared with many high-performance plastics, the material is cost-efficient and at the same time durable. The combination of stability, chemical resistance and easy machining makes PVC-U a versatile standard material for numerous industrial applications.

Temperature resistance – behaviour under heat and cold

The continuous operating range is between –10 °C and +60 °C. Within this range, the material remains dimensionally stable and mechanically reliable.

Important points for practice:

• From above 60 °C, PVC noticeably loses rigidity.
• The Vicat softening at 74–80 °C marks the limit for dimensional stability.
• Below 0 °C, brittleness increases – avoid impact loads.

For continuously high temperatures, PET, PC or PEEK are better suited. Machining under thermal load: Plastic machining

Mechanical properties – rigid, stable, dimensionally accurate

Rigid PVC combines good tensile strength, high compressive strength and a pronounced E-modulus. As a result, the material is particularly suitable for covers, structural components, mounting plates and enclosure parts.

Advantages at a glance

• high rigidity → low deflection
• good compressive strength → stable under surface loads
• low creep tendency → dimensionally accurate in the long term
• sufficient impact strength for indoor and technical areas

Comparative classification:

• more rigid than PP, PE-HD, PETG
• ABS is more impact-resistant – but less chemically resistant
• PC offers higher toughness, but is more cost-intensive

Precise milled parts made of rigid PVC: Milled parts

Chemical resistance – one of the strongest advantages of PVC

Rigid PVC is particularly resistant to a wide range of technical media. This makes it the preferred material in apparatus, plant and ventilation engineering.

Resistant to

• acids (e.g. hydrochloric acid, sulphuric acid)
• alkalis
• many salts
• alcohols
• oils and greases
• aqueous solutions

Limited or no resistance to

• aromatic hydrocarbons (e.g. toluene)
• chlorinated hydrocarbons (e.g. chloroform)
• ketones (e.g. acetone)

Material data: PVC material data

Electrical properties – reliable insulator

Due to the very low water absorption and constant electrical strength, rigid PVC is excellently suited for:

• switch box covers
• divider sheets
• electrical enclosures
• mounting plates

Even in damp environments, PVC remains electrically stable – a decisive advantage over other plastics.

Density of PVC – how high is it?

The density of PVC is one of the important material characteristics when selecting engineering plastics. It influences, among other things, weight, stability and the behaviour of the material in practical use.

Rigid PVC or PVC-U typically has a density of about 1.35 to 1.45 g/cm³. This places PVC above many other standard plastics such as polyethylene or polypropylene, which have significantly lower densities.

The comparatively high PVC density ensures good dimensional stability and solid mechanical properties. At the same time, the material remains easy to machine and is suitable for numerous technical applications where stability and chemical resistance are required.

The exact density of PVC can vary slightly depending on formulation, additives and manufacturing process. For plasticiser-containing PVC, the value is sometimes somewhat different from that of rigid PVC or PVC-U.

In industrial use, PVC density plays a role particularly in the design of tanks, technical sheets, machine cladding and chemically exposed components. The material combines a comparatively high dead weight with good load-bearing capacity and a long service life.

Processing – versatile and precise

Rigid PVC can be easily milled, sawn, drilled, thermoformed and bonded. Solvent adhesives create a firm, homogeneous bond by briefly softening the surface.

Tips for optimum results

• execute cut edges cleanly → fewer stress peaks
• avoid heat build-up → material remains dimensionally stable
• when welding → observe the temperature window exactly

Details on processing: Plastic machining

Typical areas of application – where PVC plays to its strengths

• apparatus and tank construction
• ventilation and environmental technology
• machine cladding
• enclosures and covers
• electrical installation (mounting plates, divider sheets)
• cover and support sheets

Related materials:

• flexible PVC – flexible, damping
• PVC rigid foam sheets – lightweight, decorative

Comparison with alternative plastics – decision by requirement

PVC vs. PP

• more rigid
• better media resistance
• easier to machine

PVC vs. PE-HD

• more dimensionally stable
• lower impact strength

PVC vs. ABS

• more chemically resistant
• less impact-resistant

PVC vs. PC

• more cost-effective
• significantly lower fracture and impact resistance Chemical resistance of PVC The chemical resistance of PVC is one of the most important reasons for the broad use of this material in industry and engineering. Rigid PVC or PVC-U in particular shows high resistance to many aggressive media and is therefore suitable for demanding environments. PVC is resistant to numerous acids, alkalis and salt solutions.

As a result, the material is frequently used in tank construction, plant engineering, water treatment and chemically exposed components. Pipe systems, cladding and technical plastic sheets also benefit from these properties. PVC remains dimensionally stable against many aqueous chemicals and moisture and shows low water absorption. These properties contribute to a long service life and reliable function. However, the chemical resistance of PVC has limits.

Certain organic solvents, aromatic hydrocarbons or strongly oxidising media can attack the material or alter its properties. The material selection should therefore always be matched to the respective application and the medium used. For industrial applications, PVC overall offers a balanced ratio of chemical resistance, cost-effectiveness and good machinability. Particularly for technical plastic sheets and chemically stressed constructions, PVC-U is therefore one of the established standard materials.

Selection guide – when rigid PVC is the right choice

PVC is particularly suitable when:

• high rigidity and dimensional stability are required
• components come into contact with chemicals or moisture
• low water absorption is decisive
• precise milling or cutting work is planned

For high impact strength or extreme temperatures, alternatives such as ABS, PE-HD or PC should be considered.

Full sheet range: Plastic sheets

FAQ

What temperatures can PVC withstand continuously? Up to about 60 °C, PVC remains dimensionally stable; above this, rigidity decreases.

How strong is rigid PVC? High tensile and compressive strength combined with pronounced rigidity – ideal for technical components.

How chemically resistant is PVC? Very resistant to acids and alkalis; sensitive to solvents such as acetone.

When is flexible PVC useful? When flexibility, damping or a sealing function is required.