What is Expanding Polyurethane
Polyurethane is an extremely versatile polymer that makes it possible to obtain a wide range of products for the most diverse applications. A number of objects which are indispensable in our daily life, are made of polyurethane. For example, car seats, sofas, bumpers, chairs and more. It is durable, functional, multipurpose, insulating, can be painted over and integrates perfectly with all materials. Rigid polyurethane is a material with high technical and aesthetic properties.
It can be used to make small items such as large and bulky objects.
Polyurethane moulds are excellent for the production of technical items due to characteristics such as strength and longevity. Furthermore, thanks to its use in moulding processes, the material lends itself well to the production of products with complex, customised shapes.
This material does not peel, age or discolour; it withstands all environmental conditions and can therefore also be used in environments with high salt and humidity. It is an inert material, will not perish and is waterproof.
Our company is involved in the processing and moulding of polyurethane foam on behalf of third parties, for the manufacture of moulds or plastic articles for various sectors. To request a quote and find out the prices of our services, get in touch!
The advantages of polyurethane foam
Why is polyurethane so widely used? For a number of intrinsic features and advantages:
- Long service life (over 50 years)
- Production cost-effectiveness
- Versatile, allows for simple and complex shapes
- Can be painted, allowing an infinite number of surface finishes
- Can be combined with other materials
- High mechanical characteristics
- Variable thicknesses
- Aesthetic and tactile appeal
- Weather resistance and impermeability
- Resistance to UV radiation
- Resistance to chemicals
- Environmental sustainability
- Health safety: does not contain or release hazardous components
Positioning of structural rigid polyurethane
The choice of which material to use in a project depends on many factors, including:
- The feasibility of the design (or freedom of design)
- Equipment costs
- Production costs
- The tactile/aesthetic quality
- Minimum and recommended annual batches
Polyurethane can be used as a substitute for other materials with similar characteristics, the main ones being: wood, fibreglass, thermoformed parts and plastic. Each has its own strengths and weaknesses, both from a technical and economic point of view.
The above diagram aims to compare the distinctive and relevant factors of each material in a comparative context so that you can easily identify which material is best suited to your needs.
For instance, it can be concluded that the main characteristics of polyurethane can be summarised as follows:
- Low mould investment
- Average production costs (depends a lot on the chosen finish)
- Maximum design freedom (shapes, thicknesses, dimensions, undercuts)
- High perceived quality of the material
- Annual batches ranging from a few pieces to a few thousand
Moulding Technologies
Even within the same polyurethane system, such as rigid polyurethane, there are various production technologies and processes, each with its own special features.
As illustrated in the diagram above, Linea ar offers its clients two mould-making technologies: epoxy resin moulds and aluminium moulds. In both cases, the moulds are loaded.
The other technology available on the market is aluminium press moulds.
The resin moulds:
- They are the cheapest to make, especially as the size increases
- They have a limited lifespan (about 5,000 prints)
- They present greater technical limitations in technical shapes such as edges, shutters, corners, dowels, etc.
Aluminium moulds:
- They cost more than resin moulds but are still low compared to other plastics.
- They have an almost infinite mould life
- The quality of the moulded part is higher due to the greater precision and wear-free aluminium
- They allow more complex moulds to be made
The main difference between wheeled moulds and press moulds can be summarised as follows:
- Press moulds require a long set-up time and therefore the minimum batch sizes required are typically larger than for wheeled moulds (at least a hundred pieces per order in the case of press moulds and a few dozen in the case of wheeled moulds). It is also the most flexible approach as moulds can be inserted and removed from production without the need for complex planning.
- In contrast, press tools allow a higher moulding speed (albeit with less flexibility) and therefore the possibility of moulding quantities per day of the same article that are up to two/three times greater than those of wheeled moulds.
In summary, wheeled for flexibility and small/medium batches, press for large production runs.
To learn more about the potential of polyurethane, please get in touch.
