The Power of Polypropylene

The History and Uniqueness of Polypropylene

Polypropylene is a thermoplastic polymer and the second most frequently used plastic, following polyethylene. Due to its particular makeup, polypropylene has preferential use in specific industries such as the automotive and outdoor living industries. Like polyethylene polypropylene rose to prominence in the plastic revolution of the 50s, following the dominance and invention of Bakelite, the original plastic and a product of the very early 20th century.

Chemists first demonstrated the feasibility of synthesizing polypropylene in 1951, and was carried out in a commercially viable form only three years later. The Italian company Montecatini was the first to produce polypropylene, and this was surely a contributing factor to their monopolistic control of the European chemical industry throughout much of the 20th century.

While polypropylene has been superseded by other synthetics in certain use cases – like polyester in the instance of clothing manufacture – it retains ubiquity. This is interesting (and surprising) given polypropylene is not quite as permutable as polyethylene, a plastic which has many distinct structural variants. Perhaps an instance of the "if it isn't broken – don't fix it" mentality, polypropylene is so comparatively easy and inexpensive to produce that there has yet been reason to abandon it for another polymer.

Aside from being inexpensive, polypropylene is also very resilient – a key reason for its popularity. Polyethylene – a plastic typically seen used in standard plastic bags, is more ‘sturdy' that polypropylene, but this is primarily because it is far less rigid. While a polyethylene product may withstand more abuse, it will also deform much more quickly. Therefore, polypropylene is preferable in instances where a plastic product must not release its given form.

Resilient in the sense of its rigidity, polypropylene is also highly resistant to chemical and organic corruption. In other words, this plastic is not going to change its makeup in instances where it is momentarily or extensively confronted with an alien substance. Acids and other organic compounds do not threaten the integrity of polypropylene nearly as much as polyethylene. In more common terms, this makes the polymer a good candidate for outdoor use and makes it viable as a container for consumable goods or medical materials that cannot be contaminated by their vessel.

Car Cover

This history and description of polypropylene might suggest some immediate reasons for the use of that plastic in the production of car covers. Immediately advantageous to both consumers and manufacturers is its cost – car covers, often made up of multiple layers and considerable in size, could quickly become problematically precious if an expensive textile is used. While a good car cover is never cheap, these tools need to be reasonably priced, as part of their purpose is to suffer abuse that would otherwise impact your vehicle underneath. As such, car covers must be considerably more affordable than the repairs that would otherwise need to be carried out on your vehicle. A good car cover should be affordable enough to replace if it is ruined for the sake of the car.

While some covers are only intended for indoor use, the chemical incorruptibility of polypropylene is essential for outdoor car covers and the elements they must endure. Even in the case of indoor covers, this aspect is highly valuable. A crowded garage – the typical environment for an indoor car cover – is host to all kinds of home and yard-care chemicals that are prone to spillage. Any kind of car cover material that might be reactive in the case of a spill could result in damage to the vehicle that would have been lesser had the vehicle not been covered.

It is essential for any good car cover to be breathable, and breathability is in fact another benefit of polypropylene's particular makeup. The polypropylene used in car covers is almost always a fabric made up of threads of the polymer. Using the right knits and layering, you can make fabric sheets (that become car covers) which are unidirectionally permeable. This permeability is essential for car covers, as it ensures that the moisture which evaporates up into the car cover from underneath the car does not remain there. The accumulation of moisture, beside defeating part of the purpose of a car cover, also invites the development of molds, bacteria, and fungi. If the wrong plastic was used and (unlike polypropylene) it was susceptible to organic compounds, the likelihood of these undesirable residents would increase. Similarly, a plastic which is too labile could move further than the impermeability of the knit permits, and exterior fluids might pass through. A plastic that might leech substances would be defeated similarly. While polypropylene is obviously not entirely impervious to degradation, the manner in which it degrades – by forming a bark-like exterior – only minimally effects its utility in these applications, especially relative to other plastics.

UV vulnerability is one point of weakness for polypropylene which is nevertheless easily overcome, and the plastic has other related advantages which make this weakness worth negotiating with. Most polypropylene car covers will be UV treated, and this obviates UV vulnerability. UV vulnerability is shared by most plastics, and as such cannot be fixed by simply choosing another common plastic. The way polypropylene makes up for this vulnerability is by having an incredibly high melting point. If polyethylene was used and similarly treated, the polymer would become volatile at ~120 instead of ~160 degrees Celsius – which might make the difference when a car owner accidentally installs their cover atop a hood that has been overheating or left out in the direct sun.

When all is said and done, polypropylene car covers can be expected to have a considerable lifespan. Due to its lack of significant vulnerabilities, a well-kept cover – one that isn't mistreated or never cleaned – could go on indefinitely. The one major physical weakness of polypropylene car covers is tearing, though when you consider what might make a tear in any car cover, there isn't an affordable textile which wouldn't tear when, for instance, struck with a sharp branch or garage tool. Polypropylene is also technically vulnerable to the cold, but this is more of an issue for pure polypropylene solids, and not fabrics, the flexibility of which prevents direct stress to the polymer.

Outdoor Furniture

Polypropylene is a popular medium for resilient and stylish outdoor furniture. The same technical qualities which make the plastic so viable as a car cover fundament persist in this use case, with the exception that, in most cases, the polymer isn't used in a fabric form. On the occasion that it is, it will be to serve as umbrella cloth or the seat and back of a folding chair. The most recognizable form that polypropylene outdoor furniture takes is the plastic chair. Being light and durable, it is the perfect plastic to use for movable yet rigid seating. The most common image, perhaps, the white plastic Adirondack chair, does no justice to polypropylene, which takes color exceptionally well. Treated properly, colored polypropylene chairs will remain bright and vibrant summer after summer.

Polypropylene is also a popular medium for garden decoration. Due to its chemical and organic resistance, it won't rot and break left amongst the dirt and moisture of the garden. From pelicans to gnomes, there is a good chance that your favorite garden-deco is made from polypropylene. Polypropylene is especially likely in these cases because it is very mold friendly – due to its specific makeup it will not look cheap and poorly adhere to the shape of the mold like other materials do, nor will be likely to form air pockets or other sources of structural dis-integrity.


Polypropylene is a rather miraculous plastic which has seen persistent use since its invention during the plastics boom. It is a robust and reliable plastic, and for this reason sees use in demanding and precarious circumstances. Polypropylene is an excellent material for car covers, and the industry would likely be much less successful if the plastic was never employed. It is safe for consumables and is stable enough even for sensitive laboratory use. You will most likely find polypropylene everywhere in your home, should you know its trademark features, and where to look!

If you are interested in purchasing a polypropylene car cover after reading about this powerful plastic, consider exploring the options given here at Selected here or elsewhere, car covers are a wise purchase. For a minimal investment, it is possible to save magnitudes more in the maintenance of your vehicle and extend both its aesthetic and functional heyday. Visit the page for your model's cover and learn all the details about how polypropylene is effectively employed there!