Polypropylene (PP) is one of the most widely used thermoplastic materials in industry due to its combination of low weight, chemical resistance, durability and ease of processing.

It is commonly used in the form of polypropylene sheets, rods and machined parts to manufacture components tailored to the needs of sectors such as food processing, chemicals, automotive, construction, water treatment and urban furniture.

What is polypropylene? Properties and structure

Polypropylene, also known as PP, is a thermoplastic polymer belonging to the polyolefin family.

One of its main characteristics is that it can be moulded, welded and machined through the application of heat, allowing parts to be manufactured in different thicknesses, dimensions and geometries.

Its low density and minimal moisture absorption make it a suitable solution for industrial applications requiring resistance, hygiene and ease of maintenance.

Advantages and characteristics of polypropylene

Chemical resistance

Polypropylene provides good resistance to many acids, bases, salts and chemicals.

For this reason, it is frequently used in tanks, trays, linings, piping and components intended for chemical facilities or water treatment plants.

Compatibility must always be assessed according to the substance, concentration and operating temperature.

Low moisture absorption

PP absorbs very little water and maintains stable performance in humid environments or applications subject to frequent washing.

This property is particularly useful in the food industry, water treatment and other applications where hygiene and moisture resistance are key factors.

Ease of machining and welding

Polypropylene sheets and rods can be cut, milled, drilled and welded to manufacture custom parts. This plastics machining process facilitates their integration into machinery, production lines, tanks, linings and a wide range of industrial installations.

Good performance-to-cost ratio

Polypropylene offers a competitive balance between resistance, durability and cost.

In many applications, it can replace heavier materials or those requiring more maintenance, provided that the operating conditions are compatible with its properties.

Recyclable material

As a thermoplastic, polypropylene can be recycled and reintroduced into new production processes when managed correctly.

Its recyclability supports the development of solutions that are more closely aligned with the circular economy and the efficient use of resources.

Industrial applications of polypropylene

The excellent properties of polypropylene make it a widely used material across a broad range of industrial sectors. In the food industry, it is used for work surfaces, guides, separators, tanks and machinery components, provided that grades suitable for food contact are used in accordance with current regulations. In the chemical sector, it is a common solution for manufacturing tanks, ducts, linings and other equipment exposed to corrosive products, thanks to its high chemical resistance.

In water treatment, polypropylene is used in separators, piping, grilles and other components exposed to permanent moisture and aggressive environments. It is also one of the reference materials for the construction of welded swimming pools, spas and water tanks, where its excellent weldability, chemical resistance and durability ensure high performance and a long service life.

In the automotive and transport sectors, polypropylene is used to manufacture linings, supports, protective elements and technical parts that help reduce vehicle weight. In construction and civil engineering, it is used in piping, tanks, protection systems and linings resistant to moisture and various chemical agents. Polypropylene is also used in agriculture, the marine industry, urban furniture and technical equipment, where its low weight, durability, ease of machining and excellent corrosion resistance are especially valued.

When should polypropylene be selected?

Before selecting this material, it is important to analyse the actual operating conditions.

The factors to be considered include:

• The operating temperature.


• Mechanical loads.


• Contact with chemicals.


• Exposure to ultraviolet radiation.


• Hygiene or food-contact requirements.


• The dimensions and tolerances of the part.


• Whether the installation is indoors or outdoors.

Polypropylene generally offers greater rigidity than polyethylene and performs well at moderately high temperatures. However, it may provide lower impact resistance at low temperatures.

The selection should therefore always be based on the technical requirements of each project.

Differences between PP-C and PP-H

PP-H (polypropylene homopolymer) is characterised by greater rigidity, hardness and dimensional stability, making it ideal for industrial applications such as tanks, ducts and machined parts. PP-C (polypropylene copolymer), on the other hand, offers greater impact resistance, particularly at low temperatures, as well as excellent weldability, making it the preferred option for manufacturing swimming pools, water tanks, water treatment equipment and other welded structures. Both provide excellent chemical resistance, but the choice between them depends on the mechanical requirements and the final application.