Much has been made of the negative effects of plastics on the environment in recent years, and with good reason. However, what may seem obvious to specialists in the industry is not obvious to everyone. What many people don’t know are the basic properties in the different types of plastics, some of which are more environmentally friendly than others. Plastics can be categorized as Thermoplastics of Thermosets.
A thermoplastic is a class of polymer that can be softened through heating and then processed using methods such as extrusion, injection molding, thermoforming and blow molding.
Thermoplastics harden once cooled and do not show any changes in chemical properties after being heated and cooled multiple times, making them easily recyclable.
Thermoplastic resins are substances that soften at high temperatures and then solidify once again at low temperatures. These characteristics allow thermoplastic materials to be molded into a wide range of forms and structures, making plastic resins useful across numerous sectors.
What are Thermoplastic Polymers?
Thermoplastic polymers are materials made up of linear molecular chains. These polymer chains can be melted and reformed. This makes them ideal for applications where they need to be molded or shaped, such as injection molding. Thermoplastics are also easier to recycle than other types of plastic, making them better for the environment. Thermoplastic polymers are a suitable substitute material used in a wide range of products, from secondary packaging to car parts.
The curing process for thermoplastics involves the pellets softening and becoming more fluid as additional heat is applied and the high heat distortion temperature increases. The curing process is completely reversible, as no chemical bonding takes place. This characteristic allows thermoplastics to be recycled without affecting the materials’ physical properties, due to their chemical resistance.
What Types of Thermoplastics are there?
There are two main structures of thermoplastic polymers: Crystalline and Amorphous.
This type of thermoplastic has a definite and repeating 3D pattern or shape. The best examples of crystalline thermoplastics are polyethylene (PE) and polypropylene (PP).
Amorphous thermoplastics have no definite 3D shape or pattern. The best examples of amorphous thermoplastics are polystyrene (PS) and polyvinyl chloride (PVC).
What are the Most Popular Types of Thermoplastics?
The most popular types of thermoplastic polymers are:
- Polyethylene (PE)
- Polypropylene (PP)
- Polystyrene (PS)
- Polyvinyl chloride (PVC)
What is the Process Behind Thermoplastics?
A thermoplastic is any plastic material with a low melting point that softens when heated, solidifies when cooled, and can be re-melted or molded after cooling. The molten plastic is then injected into a mold where it cools and solidifies, a process also known as injection molding. This process can be repeated multiple times, making thermoplastics ideal for applications where large quantities of the same item need to be produced, such as in mass production.
Structured polymer composites gave rise to thermoplastic composites. These materials feature a thermoplastic matrix, which prevents chemical instability. Thermoplastic composites soften and can be remolded without degrading when heated. They harden into the final shape when they cool.
What is the Purpose of Thermoplastic Materials?
Thermoplastic materials are used in a variety of applications, both industrial and consumer. Common examples include:
- Secondary packaging, such as crates
- Car parts, such as dashboards and bumpers
- Appliances, such as washing machine tubs
- Furniture, such as chairs and tables
Thermoplastics are also used in 3D printing. In this process, the thermoplastic filament is extruded from a nozzle and deposited layer by layer to create a three-dimensional object.
Why are Thermoplastics Important?
Thermoplastics are important because they can be recycled repeatedly without losing quality. This makes them much more sustainable than other types of plastics, which can only be recycled a few times or not at all before they need to be disposed of. Thermoplastics are also generally less harmful to the environment and offer many benefits such as:
Thermoplastics offer several benefits over other materials, both in terms of their environmental friendliness and their practicality. Some of the main benefits of thermoplastics include:
- They can be reused numerous times
- They’re less harmful to the environment
- They’re easy to mold and shape
- They’re lightweight and strong
- They are low cost
Thermoplastics are largely resistant to chemical attack, which makes them suitable for many process applications as well as working as a good electrical insulator. This can be beneficial for the chemical industry too.
Thermoplastics handle corrosive materials and corrosive environments well, meaning that they provide corrosion protection.
Thermoplastic materials have exceptional thermal stability and good dimensional stability, they are suitable for practically every form of fluid transport application since they can convey materials at extreme temperatures (hot or cold).
UBQ™ – The Most Climate-Positive Thermoplastic in the Market
One of the best ways to reduce the impact we have on the environment is by choosing materials that are made from sustainable and renewable resources, like UBQ™ – a biobased thermoplastic.
UBQ™ is a sustainable plastic alternative, made from 100% unsorted household waste, including all organics and non recyclables. With UBQ™, manufacturers are finally able to create products that positively impact our world without compromising on profitability.
UBQ™ serves as a powerful material swap for the manufacturing industry, helping businesses meet their sustainability goals. Integrating this thermoplastic into conventional processes enables manufacturers to reduce the carbon footprint throughout the supply chain and of final products.
By diverting landfill-destined waste and converting it into a valuable thermoplastic, UBQ prevents methane emissions, groundwater leaching and protects finite resources for future generations. Every ton of UBQ™ produced prevents up to 11.7 tons of CO2eq; life cycle assessment auditors ‘Quantis’ have designated UBQ™ as “The Most Climate-Positive Thermoplastic Material on the Market”.
Are Thermoplastics Recyclable?
Thermoplastics are easily recyclable as the polymer chain does not degrade when heated. Because the chemical bonds within the chain remain intact while the weaker bonds between polymer chains break down, thermoplastics can be melted and reused repeatedly.
Are Thermoplastics Safe?
Most types of thermoplastic are safe to use as intended. However, there have been concerns raised over PVC because of the vinyl chloride monomer (VCM) that is used in production. However, modern manufacturing methods mean that the release of VCM is very low while the residual VCM left in the polymer is so low that it can’t be detected.
Are Thermoplastics Biodegradable?
Most thermoplastics are not biodegradable. However, some thermoplastics, such as poly(lactic acid) (PLA), poly (vinyl alcohol) (PVAL, PVOH) and polyhydroxyalkanoates (PHAs) are.
Are Thermoplastics Brittle?
Below their glass transition temperature (Tg), thermoplastics are brittle and deform by elastic deformation. However, when above their Tg, thermoplastics are ductile and deform mainly through plastic deformation. So, in short, thermoplastics go from brittle to ductile as they are heated through their Tg.
Can Thermoplastic be Remolded?
Thermoplastics can be remolded repeatedly by heating and then reforming them into new shapes.
Can Thermoplastic Melt?
Semi-crystalline thermoplastics melt at a particular temperature when their crystalline regions transition to a random arrangement. This melting point is different for different thermoplastics. Amorphous thermoplastics do not have an ordered structure and therefore do not melt; they have a glass transition temperature, below which the material is brittle and, as the temperature increases, the material softens and becomes more rubbery.
Can Thermoplastic be Painted?
Thermoplastics can be painted to provide a different surface finish. However, you will need to use the correct type of paint so that it doesn’t react with any polymer coating and cause discoloration and lower weather resistance. Acrylic-based paints, including spray paints, are a good option for painting thermoplastics.
Can Thermoplastics be Welded?
Thermoplastics can be welded using a variety of different techniques. You can find out more about welding thermoplastics here.