With its incredible strength-to-weight ratio, polyurethane is an increasingly important material across diverse trade sectors. Answering three of the commonly asked questions about Polyurethane can further illustrate its value.
Summing up the capabilities and possibilities of polyurethane is not an easy task. Not least as the many applications of this highly durable and versatile substance are expanding all the time.
If you are deciding whether PU is the best option for creating a part or component, understanding its construction can be helpful. As can gaining insights into its tried and trusted uses to date. Exploring how many niche products are moulded from a PU mix can help to ‘cement’ decisions about whether to include it in your R&D projects.
You no doubt have a basic idea of how it is made. However, here are the answers to three commonly asked questions about polyurethane.
Is polyurethane a plastic?
The answer to this question is yes, but with a caveat. It is considered to be a unique form of plastic material, due to its composition and an incredible range of capabilities. Therefore, while some refer to it as plastic, others treat it as a separate entity.
Plastic is generally a term applied to many types of synthetic or semi-synthetic organic compounds – often containing carbon and hydrogen molecules such as PVC, nylon and polyethene. Plastics can be moulded into a solid form.
While sharing similar traits, thermoset polyurethanes have a distinctive chemical structure. A structure that means PU can become far more stable and rigid than other forms of hard plastic. Hence polyurethane is used for components that would break or crack under pressure or excessive friction if traditional plastics were used instead.
Also, there are PU applications that are often mistaken for rubber! That’s because it can be mixed and formed into an incredibly diverse range of structures, from a liquid or soft foam to a highly elasticated material.
Is Polyurethane a sealant?
It is typical for specifiers to see polyurethane as fitting into only‘one groove’. For example, they are aware of its potential as a hard, dense and highly durable material for wheels, rollers and stops. Or, it is their go-to solution for any foam requirements they have.
Many people are unaware of how multi-talented polyurethane is, which means its use as a sealant is sometimes overlooked. This is, in fact, one of the ways polyurethane comes into its own. As a sealant, it is both successful and durable.
Polyurethane has an elastomeric memory, which means it can spring back to its original shape even when considerable force is used to stretch, bend or deform it. The result is a sealant that creates an airtight stopper even in situations where movement and pressure are applied.
There are forms of polyurethane that are solidifying liquids too, creating the perfect adhesive, coating or binding agent, becoming incredibly hard when set. Making it a great substance to apply when you need your fixing agent to create an impervious seal.
Polyurethane is also highly resistant to heat and moisture, as well as energy. So, as a sealant, it can create an impenetrable barrier against everything from electric shocks to slow-growing fungi!
Is polyurethane recyclable?
This links to another often asked question, is polyurethane an environmentally sound alternative to plastic and rubber? To which the answer is yes, on many levels. Not least as its stability means it won’t leak toxic chemicals or fumes, and its longevity means it won’t need to be replaced for a long time.
Polyurethane can also be both repurposed and recycled.
Mechanical recycling of polyurethane can be used to grind and powder it. This substance can then be mixed with fresh ingredients to create new foam or reaction injection moulded (RIM) parts.
Polyurethane mechanical recycling can also involve granulating to create adhesives or binding agents, or PU foam can be shredded to bind as rebound underlay for example.
There are ways to chemically recycle polyurethane too, breaking it down into gas and oil, including formulating polyols for fuel.
What you need to know about polyurethane
With a broader understanding of what is polyurethane and what is PU capable of, the next question is usually ‘can it be moulded to the shape I need?’.
That’s a query that needs to be discussed with the team at Custom Moulded Polyurethane, a company with a long track record for making PU the right solution to a myriad of different industrial specs.