PETG or PET-G is a thermoplastic polysterer. This material delivers a very strong chemical resistance as well as durability and formability for manufacturing purposes. PETG is popular for the ease at which it can be vacuumed and pressure-formed. It can also be bent into different shapes using heat due to its low forming temperature properties.
Because PETG is so easily manipulated, it is extremely popular and widely used for commercial and consumer purposes, especially those that use 3D printing and heat-forming manufacturing processes. PETG is not only popular in 3D printing, though. It is frequently used in fabrication techniques such as routing, bending, and die-cutting.
Okay. we can hear you shouting at the screen – “What does PETG stand for?” PETG is an acronym for Polyethylene Terephthalate Glycol. As you can see, you may want to stick to PETG!
PETG is actually an adaptation of PET (Polyethylene Terephthalate) with the only difference being Glycol. This is added at a molecular level to provide different chemical properties to certain creations.
Although PET uses the same monomers (small atoms or molecules that bond together to help form more complex structures) as PETG, it isn’t as strong and durable. Moreover, PETG boasts more impact resistance and is better suited to high temperatures.
Continue reading to find out more about PETG such as how it is made, what it is used for, and much more.
How is PETG Made?
Before we delve into the method of making polyethylene terephthalate glycol, we need to understand how PET is created. As with many technologies, the mid-twentieth century saw a huge advancement in polymer chemistry. Scientists discovered new materials that could be used in the place of standard, traditional organic products.
At the time, phthalic acid polymers were already being used in paints and varnishes and glycol-based synthetic fibers were in use for textiles. Nonetheless, the phthalic acid polymers were deemed to be too soft to work properly as fibers. Moreover, glycol-based materials had very low melting points so were not usable in textiles.
In 1941, two British scientists, John Whinfield and James Dickson managed to combine phthalic acid polymers with glycol-based synthetic fibers. In turn, they created polyethylene terephthalate (PET). Whinfield and Dickson used the process of esterification to heat glycols with terephthalic acid. This allowed them to create long-chain molecules of PET and these could be transformed into fibers that boasted very high melting points with low dissolvability.
It wasn’t until 1946 that PET became popular and widely used in textiles. Within just 6 years, PET was being used as a film for all kinds of food packaging. PET went on to be used in the manufacturing of solid bottles that held carbonated soft drinks, mineral waters, and beer.
Although PET continues to be widely used today, it does have some drawbacks. For instance, it can easily become crystallized when under high temperatures which weakens its structure and makes it opaque.
Then came the creation of PETG. This replaced the ethylene glycol within the molecular chain. Instead, a larger monomer took its place known as cyclohexane dimethanol. This stopped the crystallization of PET and allowed for improved heat resistance. Because of this, PETG molecules stopped collecting together as easily which lowered the melting point and completely stopped any crystallization. From occurring.
Therefore, PETG can be used for 3D printing, thermoforming, and many other forms of high-temperature applications without losing any of its properties.
What is PETG Used For?
Since its discovery, PETG has been adopted in many applications and in a range of industries. This is mainly down to its impressive heat, impact, and solvent resistance. You have undoubtedly handled PETG products before (maybe even today) as it is used in both retail and medical packaging, electronic insulators, and many advertising displays.
PETG has become widely used in 3D printing. This is because glycol limits and even prevents the common issues associated with PET such as its fragility, potential cloudiness, and risk of overheating.
PETG items can also be sterilized. Due to having excellent adhesion between its layers, resistance in low temperatures, minimal risk of deformation during the printing process, chemical resistance to acids and bases, and no odor when being printed, PETG has quickly become one of the most favored materials for 3D printing.
If you want to produce parts that are flexible but need to have good resistance to impacts and shocks, then polyethylene terephthalate glycol is an excellent material to use. This is why PETG is frequently used in the construction of protective components in different industries, food containers, and pressure-clad objects.
Compared to other substances such as polycarbonate and acrylic, PETG holds a range of advantages. Here are a few:
- Can be formed into different shapes easily – Being both vacuum and thermoformable, PETG can withstand high amounts of pressure without cracking or deforming. Injection molding is possible with PETG to make it into various shapes. It can also be shaped into sheets when required.
- Very strong as well as cost-effective – Because of its sheer strength and impact resistance qualities, PETG is perfect for high-strength display units. It is also ideal for 3D printing tasks, signage, and different displays.
- Recyclable and food-safe – PETG is used in the production of food containers and bottles for all kinds of beverages. Furthermore, it can be fully recycled which helps reduce waste and helps the environment.
- Non-toxic and odorless – Non-toxic with odorless emissions during the 3D printing process, PETG is suitable for home and office use.
- Can be colored easily – Because PETG is naturally transparent, you can create unique effects with it. However, it can also be colored with ease and blended to produce distinctive designs.
As well as advantages, there are a few disadvantages when using PETG. Here are a few:
- Prone to excessive oozing – Compared to PLA or ABS, PETG is more prone to oozing. Therefore, you will need to figure out the precise bridging and retraction settings as you 3D print. This may result in more post-processing to remove any unsightly blemishes in your 3D work.
- Can become brittle – If PETG is not stored in a dry space, it can absorb water, making it more brittle.
- Must follow all parameters – During the 3D printing process, the correct temperature parameters should always be followed when using PETG. It is recommended that you follow the parameters set out by the manufacturer. Also, a low printing speed of around 30-35 mm/s is advised while the 3D printing process takes place.
- Negative environmental issues – PETG is plastic. As with all plastics, it can have a negative environmental impact if it is not disposed of properly. It can take many decades for PETG to decompose which can lead to microplastics finding their way into the oceans. Although recyclable, PETG can still pose a threat to our ecosystem.
PETG, short for polyethylene terephthalate glycol, is a versatile and widely used plastic that has properties that are best suited for certain applications such as 3D printing.
Although used in other industries such as food production and for medical purposes, PTEG’s use in 3D printing has considerably increased over recent years and continues to be one of the best materials for molding into different shapes.