The Complexity of Polyurethane Products and Sustainability
Sustainability has become a crucial focus for industries across the globe– but for a manufacturer of synthetic products, what does sustainability truly mean? The perception of the general public is that man-made materials, especially those that are petroleum-based, can only do harm to the environment. While this may be the case in situations where there are viable, natural alternatives, there are also situations where the durability of a man-made, engineered product can be a more sustainable choice.
At PSI Urethanes, we believe that polyurethane products play a pivotal role in advancing sustainable practices across various sectors, especially in manufacturing. However, achieving sustainability with polyurethane products is not without its complex challenges. As a leading custom polyurethane manufacturer, we understand the importance of creating durable, versatile, and eco-friendly solutions that demonstrate longevity and minimize waste. In today’s blog post, we delve into the complex relationship between polyurethane products and sustainable practices.
Cast Polyurethane Products vs. Die Cut Parts
The inception of an item is a key factor to consider in its overall sustainability, so let’s start by discussing how polyurethane products are made. At PSI Urethanes we commonly use a few different manufacturing methods: casting, water jet cutting, compression molding, and injection molding.
Manufacturing Cast Urethanes
Manufacturing cast polyurethane items is a process that involves pouring liquid urethane into a mold, then curing the polyurethane so that it holds its shape once it is removed from the mold. While this may sound straightforward, there are many resources that go into producing cast parts.
The majority of manufacturing resources are spent on tooling, which is the process of creating a custom tool or mold. This uses energy-intensive CAD design and CNC machining of the mold. As a subtractive manufacturing process, CNC machining a metal mold can produce waste. However, excess material can be recovered and used to form new cast metal blocks to create new molds for polyurethane parts.
As a petrochemical-based substance, reducing the amount of urethane wasted is critical to driving sustainability in manufacturing. While there is a calculated waste which is unavoidable in urethane casting, this process generally produces less waste material compared to the others.
Manufacturing Molded Urethanes
Next we have our molded urethanes, which is really an umbrella term for parts made with two manufacturing methods: compression molding and injection molding.
Like cast urethanes, molded urethanes use a metal mold that is created using complex CNC machining devices. From that point on, compression molding is similar to casting in that the molds are filled by hand. Rather than curing on their own, however, compression molded parts are placed under heat and pressure to influence the curing process. This allows for greater control over the final dimensions, so parts can be made to closer tolerances using this method. Injection molding essentially wraps all of those steps into one by injecting liquid polyurethane into a pre-heated mold at high force to create pressure within.
It’s worth noting that these processes also produce a planned amount of waste as a result of mold design. In order for material to fill an entire mold cavity, there must be channels, often known as runners, that allow material to fill the mold entirely. Once the molding process is complete, this excess material is discarded. Even so, these machines create parts much more efficiently compared to casting processes performed by hand, so for high volume orders compression molding and injection molding can save time and energy per unit overall.
Manufacturing Water Jet Cut Urethanes
Another polyurethane manufacturing process that we often use is water jet cutting. In most cases water jet cut urethanes require no tooling at all, using a CNC-driven pressurized water jet rather than custom tools. This gives the process a distinct advantage over urethane casting in terms of energy savings. Conversely, water jet cutting produces more polyurethane waste than casting does. When a part is die cut from a urethane sheet, the excess material is usually too small to be used for other projects and must be discarded. You might imagine that the water usage of this machine would pose a threat to sustainability, but the reality is quite the opposite. Process water can be reused again and again, which can help keep the water consumption of our manufacturing facility as low as possible.
Now that we’ve covered our most common manufacturing methods, let’s get into how polyurethane material itself contributes to sustainability and environmental protection.
We minimize waste to save costs in more ways than one.
Speak with an expert about your polyurethane manufacturing needs today.
The Longevity of Polyurethane Products
One of the key advantages of thermoset polyurethane products is their exceptional longevity. Polyurethane products generally outlast their rubber, metal, and plastic counterparts, reducing the need for frequent replacements. This durability translates into fewer resources consumed and less waste generated over time, which contributes significantly to sustainable practices across all industries.
Polyurethanes in The Automotive Industry
As an example, polyurethane parts are used extensively in the automotive industry due to their resilience and ability to withstand harsh conditions. From bushings and seals to gaskets and motor mounts, polyurethane products help ensure that vehicles operate efficiently to reduce emissions while also reducing the environmental impact of frequent part replacements. This sustainability boost is further amplified in electric vehicles, where polyurethane parts can perform the same functions and support robust battery cell configurations that eliminate fuel emissions altogether. Our static dissipative urethane formulation is designed just for applications like this, where it can provide parts with even greater performance and further longevity.
Recovering Cores with Polyurethane
Polyurethane isn’t always a standalone product. In fact, we have the ability to bond polyurethane to cores of all kinds, like metal, nylon, PVC, and other materials. This bonding process allows the original core to remain intact after repeated or sustained wear. When the bonded polyurethane reaches the end of its life cycle, it is simply stripped from the original core and replaced. This drastically extends the life cycle of the core and uses less resources than manufacturing an entirely new part.
Specialty Polyurethane Products for Environmental Protection
Polyurethane drain protectors are instrumental tools for supporting environmentally friendly practices in the chemical industry. At PSI Urethanes, we specialize in creating innovative polyurethane solutions designed to address specific environmental challenges such as those faced when dealing with hazardous chemicals. One such example is our patented DrainProtector™, a specialty product that provides an effective shield for drains against liquid contaminants including solvents and harsh chemicals. By preventing these harmful substances from entering the water system, polyurethane products like the DrainProtector™ and DrainProtector™ II play a direct role in safeguarding our natural resources from contamination.
Does your facility struggle with harsh chemical handling and eco-friendliness?
Contact us today to ask about DrainProtector™ and our other spill protection products.
Recycling Thermoset and Thermoplastic Polyurethane
When polyurethane products reach the end of their life cycle, are they able to be recycled? The answer is yes and no. It depends on the formulation, namely whether it is thermoplastic or thermoset.
Thermoplastic Polyurethane
Thermoplastic polyurethane (TPU) is a remarkable material known for its elasticity, transparency, and resistance to oil, grease, and abrasion. One of the most significant advantages of TPU is its recyclability. Unlike thermoset polyurethane, thermoplastic polyurethane can be melted down and reformed without losing its essential properties.
This characteristic makes TPU an excellent choice for industries committed to reducing their environmental footprint.
By incorporating recycled TPU into new products, manufacturers can decrease their reliance on virgin materials and minimize waste. This recycling process supports sustainability initiatives and aligns with the growing demand for eco-friendly products in the market.
Thermoset Polyurethane
Recycling thermoset polyurethane has proven to be much more challenging, with best practices still yet to be discovered. Unlike thermoplastic urethanes which can be melted and reformed into new items, thermoset polyurethanes cannot return to their liquid state when heated. While thermoplastics can retain their properties after going through a change of physical state, thermosets will simply burn and lose their desirable properties when heated, rendering them unusable (although our flame retardant urethane formulation may have something to say about that).
In recent decades there have been numerous studies which explore different possibilities of thermoset urethane recycling methods. Some of these proposed ideas include mechanical recycling- in which the material is ground into small chunks where it can be used in applications like playground floor padding- and chemical recycling- a much more complex process in which the individual polymer elements are chemically separated from one another for reuse. While there is no one ‘right’ way to recycle thermoset urethanes as of yet, these options and more are being evaluated every year.
Despite the challenges, polyurethane products are a viable avenue for companies to explore in the quest for sustainability. Their durability, versatility, and recyclability make them superior to traditional materials in demanding applications. At PSI Urethanes, we are dedicated to manufacturing high-quality polyurethane solutions that deliver the highest value to our customers- and often that coincides with promoting sustainability. We look forward to seeing how the complex relationship between sustainability and polyurethane continues to grow in the coming years.
