PLA may be one of the most widely used and popular filament materials used in 3D printing. However, it’s not exactly known for being particularly strong or heat-stable. While most people use PLA because of how easy it is to handle, what if there was a way to enhance the properties of your PLA print? The trick is annealing, Annealing could improve the strength and reduce inner force.

In this guide, we will explain the definition of annealing PLA and how to anneal PLA part for high strength.

What is annealing?

In annealing, the material is exposed to temperatures between its glass transition temperature and its melting temperature. To reach that temperature, heat must be applied very gradually to avoid the buildup of thermal stress. Once the target temperature has been reached, it is maintained for a period based on the prescribed annealing program.

In this high-temperature state, the material undergoes alteration at the molecular level. The molecular structure of the material reorganizes, achieving a more “crystalline” state. This merely means that its atoms and molecules become more orderly and take on repeating patterns across all three dimensions. This shift from being amorphous or non-ordered to crystalline enhances the rigidity and strength of the material.

Once the prescribed holding time at the annealing temperature has been completed, it is equally important for the temperature to be reduced gradually. This is the phase of crystal growth, and higher crystal grain sizes can be achieved with slow cooling. Larger crystal grains are associated with better mechanical properties. A slow cooling rate also prevents the buildup of additional thermal stress in the solid.

Not all materials are capable of attaining a more crystalline state. For truly amorphous solids, annealing is still beneficial as it eases the thermal stress resulting from the rapid heating and cooling of 3D printing. In such cases, the benefits of annealing are not as pronounced as those in solids that achieve a more crystalline state.

Why PLA needs annealing

As a 3D printing filament, the main strengths of PLA are that it prints at low temperature, is not prone to warping, and is produced from sustainable sources. However, there’s also a reason why 3D printed PLA products are typically only used for display items – they are not particularly strong or durable.

Compared to other 3D printing materials like ABS, PLA has very low tensile strength. It also has a glass transition temperature of only about 65 °C. For this reason, it is not recommended to use PLA for any outdoor applications. Left inside a car on a hot day, an object made of PLA would almost certainly become deformed.

Annealing is a way to address these limitations. A fairly standard manufacturing technique, annealing a material improves its strength, rigidity, toughness, and heat resistance. Luckily for you, you don’t need any fancy equipment to anneal PLA.

Advantages and disadvantages of annealing

1. Creates stronger parts

Whether it’s PLA or other 3D printing materials, annealing is a process that can make your finished part stronger. This is ideal if you want your 3D printed parts to be able to withstand greater amounts of mechanical stress. Specifically for PLA, annealing addresses the lack of strength and rigidity that the material is well-known for. It also does not alter the 3D printing process, which means that PLA is just as easy to handle as always.

2. Improves heat stability

Another noteworthy benefit of reconfiguring PLA (or any material) at a molecular level through annealing is that it improves the material’s heat stability. This pertains to the materials’ ability to maintain their shape when exposed to higher temperatures. Again, enhanced heat stability addresses one of the common flaws of PLA as a manufacturing material.

Heat stability enhancements typically become better at higher annealing temperatures. However, as we shall see later, keeping a thermoplastic at elevated temperatures for a long period also has undesirable consequences.

Disadvantages

1. Lengthens the manufacturing process

No matter the settings for your annealing procedure, it will always be an extra step to an existing manufacturing process. If you’re doing 3D printing for any commercial purpose, annealing will significantly lengthen the turnaround time for any completed part. It also requires a bit of work. If you have limited resources, adding an extra annealing step becomes a question of higher throughput versus better product quality.

2. Consumes additional energy

Heat is a central element to the annealing process. Whether you’re delivering heat via gas or electricity, this means consuming more energy for post-processing a finished 3D print. This likely isn’t a big deal for one-off products but can get quite expensive for commercial-scale manufacturing. If you’re planning to sell annealed PLA products or parts, then the extra cost of heating is something you cannot ignore.

3. Dimensional accuracy may suffer

In annealing, the target temperature can lie anywhere between a material’s glass transition temperature and its melting temperature. This is a very wide range. The benefits of annealing are typically magnified at higher temperatures, producing stronger and more heat-resistant materials.

The problem with heating any material well past its glass transition temperature is that it also starts to deform. This balance is critical to a successful annealing process for PLA. When annealed at very high temperatures, PLA starts to warp. If you’re working with a model with lots of intricate details, dimensional accuracy may suffer because of annealing.

In summary, annealing is not a perfect method. It may provide benefits in improving the mechanical strength of a material but seriously compromises its dimensional accuracy. With this in mind, annealing may not be a suitable post-processing step in all situations. 

How annealing PLA works

PLA loses the benefits of its semi-crystalline structure when it goes through the 3D printing process. This is because of how quickly the material is heated and then cooled, thereby preventing the growth of crystals in the structure. At this state, PLA takes on a more amorphous form. This form of PLA is more chemically reactive, less heat-resistant, and less resilient against mechanical stress.

When PLA is heated beyond its glass transition temperature, it undergoes a restructuring at the molecular level. Internal stresses are relieved spontaneously via the laws of thermodynamics. This is achieved by the removal of “dislocations” or linear defects in the material’s molecular structure.

After the period of annealing, PLA is cooled down very gradually. During this phase, recrystallization happens. Polymer chains start orienting in semi-regular patterns. Again, this happens spontaneously towards the material’s natural equilibrium state. 

How to anneal PLA

It’s fairly easy to try annealing your PLA print with some basic equipment. You will need three things – a stopwatch, a digital thermometer, and an electric oven with temperature controls. Once you have finished 3D printing your project with PLA, these are the steps to take in coming up with your very own annealed PLA:

1. Pre-heat the oven to the desired annealing temperature.

For PLA, this is typically between 65 to 70 °C. The specific value is up to you – benefits are more pronounced at higher temperatures, but there is also a higher chance of warping. 

2. Wait for the oven to reach a stable target temperature.

This is important as it common for electric ovens to overshoot the target temperature before settling down on a stable reading.

3. Place the PLA print inside the oven along with the digital thermometer.

Make sure that the thermometer is as close to the print as possible. It is best to put the object on top of a non-stick surface such as a silicone tray. This will save you the hassle of having to pry it off after.

4. Leave the PLA print inside the oven for the prescribed annealing time, all the while making sure that the target temperature is being maintained. The proper annealing time will vary depending on the dimensions of the print. A good rule of thumb to start at is 30 minutes for every 1/4-inch thickness.

5. Turn down the oven without opening its door. This will slow down the cooling process sufficiently to allow for recrystallization of the PLA structural grains. Let the print cool down until it naturally reaches room temperature.

Take note that you may not get the best results on your first shot at annealing. You may have to try different combinations of annealing temperature and time depending on the dimensions and level of detail of your 3D printed object. As long as you hit the prescribed annealing temperature, there should some profound improvements in the properties of the PLA material of your project.

Other tips you need to know

1. Use an electric oven

When using an oven for annealing, choosing an electric oven over a gas-fired one is advantageous for two reasons.

Most electric ovens use convection as the primary heat delivery system. This provides much more consistent, which should help ensure that no parts of your piece are significantly heated more than the others.

An electric oven also provides better temperature control. This is highly critical when doing annealing of PLA. It’s not enough that the oven is set to about 70 °C – it has to be at exactly that temperature. PLA can be easily ruined with improper temperature settings.

2. Scale up your piece

Warping is virtually unavoidable when annealing a PLA piece, even at the lowest temperatures. The effect of warping is more pronounced if you’re working with small pieces or those that are heavily detailed. An easy way to make warped features less glaring is to simply scale up your model. Of course, this isn’t always an option. However, if there is some leeway to the size of your final piece, you should always try and make it larger.

Printing at 100% infill may seem counter-intuitive for most users of 3D printers, but these settings deliver the best annealing performance. The added PLA material on the piece makes it much stronger after annealing.

More importantly, printing at 100% infill goes a long way towards preserving dimensional accuracy. This is simply because having additional material inside the piece helps resist the natural tendency of PLA to shrink during annealing.

3. Keep your eye on the piece

If it’s your first time to try annealing PLA, there will be a healthy dose of trial and error before you can get it right. Given this, it’s extremely important to not walk away from your oven once you have placed the PLA piece in. Look at it every now and then and watch out for signs of warping.

What you’re trying to avoid is the worst-case scenario where you end up with a puddle of molten PLA on the bottom of your oven. More than just the wasted hours spent on 3D printing, this would be a nightmare to clean up.

Summary

Aside from polishing and painting, there aren’t many post-processing options for PLA. If you want your PLA prints to become stronger or more resilient than standard PLA, then we suggest trying your hand at annealing. It’s not terribly difficult once you get the hang of it.

Annealing PLA is an excellent way to improve your PLA prints, especially if you’re selling them or using them as tools or replacement parts around the house.

Sometimes we need to print a big dimension part, that exceeds the 3d printer size. we need to print in separated objects, then connect them together with different angles. Gluing is the easiest way for this problem.

In this guide, you’ll learn how to glue PLA 3d prints in easy steps and the commonly used plastic glue for PLA material.

What is plastic glue?

Plastic glues are best known for their bond strength and durability. It also has better resistance to temperature, chemical, and moisture exposure than common adhesives. When working with plastic, it is important to use plastic glue.

There are many different kinds of plastic glue. However, only a handful of them works well with PLA plastic.

How to choose the right PLA glue

First, make sure the plastic glue you intend to use is compatible with PLA. Otherwise, you might deform your project or burn a hole through it. You can check the product box or ask your local hardware store if it is compatible with PLA before buying it. 

Second, weigh your priorities. Do you prefer a quick turnaround time? Then a fast-curing plastic glue may be best for you. If precision matters more, a slower curing time would be more beneficial. 

Third, consider where the final product will be used. Will it be used both indoors and outdoors? If yes, you might want to use a temperature resistant and waterproof adhesive. Will your project be subject to frequent vibrations–like in a vehicle? If yes, choose an adhesive with a high bond strength and good impact and stress resistance.

We list all the pros and cons of PLA compatible glues below. It should help you choose the right fit for your project.

Common PLA glues we use

1. Cyanoacrylate Glue

Cyanoacrylate is a strong, fast-acting glue that works well with almost any material (including PLA). How fast is fast? Cyanoacrylate can bond two surfaces in as few as 10-20 seconds. If you are working on a rush project, this might be the right plastic glue for you. 

Cyanoacrylate is also very popular. In fact, you have probably already used this at least once in your life. You may know it as “crazy glue”, “instant glue”, or “super glue”. It is commonly used for general home repairs, industrial needs, and even medical emergencies. Regardless if you will choose this glue for your PLA project, it is a good idea to have this at home.

Cons

• Brittleness
• Poor peel strength
• Poor temperature resistance
• Poor solvent resistance
• Rapid bonding to skin

2. Two-Part Epoxy

There are two kinds of epoxy glues. Two-part epoxy, also called two-component epoxy, will require you to manually mix a resin and a hardener together. One-component epoxy comes pre-mixed but requires heat to activate the hardener. Since PLA has low heat resistance, using one-component epoxy with PLA is not ideal. Stick to two-part epoxy if you are gluing PLA.

Cons

• More expensive
• Requires accurate mixing
• Short pot-life when mixed
• Long curing time
• Hazardous to health

3. Urethanes

Urethane adhesives have unique characteristics that set them apart from other plastic glues. For one, PU adhesives are waterproof and UV resistant, making them perfect for outdoor projects.  Moreover, they can be sanded, painted, and stained. If aesthetics matter to your project, you may wish to work with urethanes.

Urethane adhesives may not be as strong as epoxy, but they have impressive impact resistance. If urethane adhesives are good enough to hold a car’s windshield in place, surely they can effectively glue your PLA project too.

Cons

• Lower bond strength compared to epoxies
• Maximum shelf life of 1 year
• Hazardous to health
• Hazardous to environment
• Subject to government regulation

4. Acetone

Moreover, the strength of the bond depends on how much ABS is in the PLA material as well as the amount of acetone applied. It can also distort or warp the plastic being bonded. You may choose to use acetone as a bonding agent as an experiment, but it may be smarter to just use the right adhesive for PLA plastics.

Cons

• Questionable bond strength
• Will not work with pure PLA
• May distort plastic
• No prescribed curing time

PLA Gluing Step-By-Step

Whether you are designing one from scratch or downloaded a pre-designed template, check which parts you need to print and bond. Prepare all components and supplies needed for the next steps.

2: Prepare the surface for bondling

Adhesives work best with rough surfaces. Use sandpaper or steel wool to roughen up the surface you’d like to bond. Brush off or wipe the dust from the surface once you are done.

3: Check if your model is ready for gluing

Remove excess or uneven parts or edges with the help of flush cutters and needle-nose pliers. Make sure parts fit well together. If not, you may need to sand them down.

Remove all dirt, dust, and debris by wiping the surface clean. Avoid touching parts with your bare hands after.

4: Hold components in place

The last thing you would want when you are putting on glue is for your project to fall apart. That is why it is absolutely crucial to secure all components before gluing. 

This is similarly true for the curing process. Most adhesives take time to cure. It is important that your project keep its shape while curing. Otherwise, the glue may harden incorrectly and your project may end up deformed.

Depending on your project, you may use rubber bands, clamps, straps to secure each part together. For larger projects, you may need to use a combination of these.

5: Start gluing

Apply glue evenly throughout your model. Spot glue by putting a small amount of adhesive at regular intervals around your model. Use just the right amount of glue to avoid having to clean up the excess.

Start from the middle and work your way towards the edges. Make sure you have put glue on all seams.

6: Check all seams to make sure they are properly glued.

If there are seams that do not seem fully bonded and secure, apply step 5 to those seams.

7: Fill seams if needed
This step is completely optional. You can use Bondo to seal and smoothen gaps for a better looking final product.

8: Use an accelerating agent

This step is completely optional. Use an accelerating agent if you want to speed up curing.

9: Wait for the curing process to finish

Check the glue’s box for the curing time of your adhesive. If you don’t follow the prescribed curing time, it may lead to a weakened bond. Do not move your project or remove fasteners while curing is not yet complete.

10: Inspect your final product

Once the curing process is complete, remove the fasteners and inspect your final product. Test the strength of the bond to see if it fits your quality standards. Look at the aesthetics: are there rough edges that need sanding or excess glue that needs cleaning up?

Improve what needs to be improved. Repeat steps 4 to 9 if needed. Don’t stop until you satisfy your own quality standards.

Finishing

Finishing is the process of polishing your work to make it look as good and professionally done as possible. For gluing PLA, this can mean any of the following:

Friction Welding

You can use a Dremel rotary tool to friction weld PLA. Spin the two surfaces fast enough to melt into each other, creating a strong bond without adhesives. This is very useful when two printed parts don’t fit well together. By the end of the process, it will be hard to tell where each individual surface ends and begins.

Filling and Sealing

You can also use a Dremel or similar rotary tool to close gaps. Gently drag a spinning piece of PLA onto the seams you wish to weld. The heat will dissolve the PLA onto the seams, filling the gaps in successfully. This process is called friction surfacing.

Sanding and Polishing

To smoothen out the edges and surfaces of your project, sand them down. You can use 100-150 grit sandpaper.

After sanding, you can smoothen its appearance with the help of superglue or a heat gun. Use a heat gun with caution as PLA is more sensitive to heat than other plastics.

Tips You Need To Know

1. Make sure your surface is clean and dry.

Remove all dust, dirt, oils, and residue with alcohol or a plastic cleaning agent. Once the plastic surface is clean, do not touch the surface with your bare hands to avoid the transfer of oils.

2. Roughen the surface.

Use sandpaper (120 to 200 grit) or steel wool. You can also use Loctite’s two-part plastic bonding system, as that comes with an activator that helps roughen up the surface. As with step 1, remove excess dust and debris by using a brush or gently wiping the surface clean.

3. Apply the right amount of glue.

To avoid putting too much glue, use a smaller squeeze bottle or applicator. You can even use a paintbrush or needlepoint as an applicator.

4. Prepare the glue as stated in the manual.

Read the instructions carefully. Some glues come with two parts and require manual mixing. Follow the exact mixing ratios stated in the box to maximize the effectiveness of the adhesive.

5. Follow the curing process.

It is important to secure components together with rubber bands, straps, or clamps while the curing process is ongoing. Read your instruction manuals to find out how long you have to wait for the glue to completely dry and cure. Do not touch or move your project before the curing process is complete.

6. Keep safe

Follow the safety precautions stated in the instruction manual. When in doubt, use gloves, eye protection, a mask, and protective clothing. It is also preferable to glue in a well-ventilated area.

7. Protect the surrounding area.

Wipe off any excess glue immediately before it hardens using isopropyl or denatured alcohol. Make sure your plastic glues are properly sealed and stored in a cool and dry location, preferably with a temperature between 75°F (24°C).

Summary

If you choose the right PLA glue and follow the steps. Gluing 3D printed PLA together will not be a hard task.  

Lastly, remember that finishing and post-processing PLA are equally important. 

3D printing is a process where you can make three-dimensional models from a digital file. The printing process makes layers one on top of the next to create these models, and there are many materials, also called filaments, that are used. You can make many items, such as prototypes, surgical tools, movie props, and more.

How Does 3D Printing Work

The first step is making the digital version of the model you want to print. You can use a 3D scanner, an app, code, or 3D modeling software. There are many software programs, and many are available for free. Once you choose the right model software, you can design your model. Meanwhile, You also could download the files from 3d model marketplaces. There are so many models resource in other sites, free and paid.

After confirm the model need to print, the next step is converting STL files to g code format, 3d printer only support this type of date. The last step is setting with printer, such as nozzle and heated bed temp, speed and infill.

Who Uses 3D Printing?

3D printing is widely used in many fields. There are plenty of materials that can be used to print 3D objects that it has become more and more widespread. One major use of 3D printing is in making prototypes and models. The process reduces the time and cost of building an expensive model, and the project can be ready in just a few days.

1. Automotive and Aviation

One common use for 3D printing is in the automotive industry. They print spare parts for cars and tools, and they can use 3D printing to help restore old car models. The Aviation industry also uses 3D printing for parts and it has made engine making and other aspects of aviation much simpler than before.

2. Construction and Architecture

 In the construction industry, 3D models are very useful to show a project in the form of a model before the project is undertaken. In addition, they are now actually building doors, floors, and other parts of a structure.

3. Consumer Goods

4. Healthcare

What Materials Are Used to Print 3D

Advantages of 3D Printing

1. Rapid Prototyping

Three-dimensional printing speeds up the process of creating prototypes significantly. It is a quick, cost effective, and simple way to develop a prototype in a matter of hours. Prototyping is used frequently to test designs because it is accurate and fast. This is beneficial to the manufacturing process because companies can make the design happen much more quickly, sometimes even the next day.

In addition, there is less waste when 3D printing is used because it only prints the model. In the past, molds had to be made which led to greater waste. In addition, the cost of the prototype is reduced because it can be made quickly and it has less wasted material.

Companies can test their designs much more quickly and make changes before they go into mass production. Once a rapid prototype has been shown to be successful, the company can go to production with a reliable design. Prototypes are fully functional models, so they can be tested and modified when they are made

2. Demand Printing

Another huge benefit is that companies can print their models on demand. They do not need to store a lot of excess inventory because items can be printed as they are needed. The models are stored as digital files, and when a model is needed, it can be printed for the order. Businesses do not need to overstock as they can print exactly what they need when they need it.

This is beneficial on many levels. Companies will not need to put money out to make parts or products that sit on the shelves until a sale. Because items can be printed on demand, the customer will order the part, and it can be printed within a few days and shipped out.

3. Design Flexibility

Three-dimensional printing has incredible design flexibility because it can produce complex items that former processes may not have been able to make. There are no molds in 3D printing, and the mold used to cause limitations on the shapes of certain parts. With 3D printing, the entire process is simplified and the result is the ability to easily create more complex items.

The 3D printing process is able to maintain the strength of items by providing support only where it is needed. This in turn allows for intricate designs without excess materials, and the resulting product is efficiently produced.

4. Reduction of Waste

Three-dimensional printing is an additive manufacturing process, meaning that the only material that is used is what is needed to produce the part being made. This is vastly different from processes that cut models out of non-recyclable materials with a tremendous amount of waste. Not only is 3D printing more efficient, but it significantly reduces the waste, which reduces the cost because companies are only using the material they need. This translates into better pricing for the consumer as well.

5. Environmentally Friendly

Three-dimensional printing is a newer technology, so there haven’t been any significant studies done on the long-term impact on the environment. However, the efficiency and the fact that it eliminates significant waste is definitely environmentally friendly. In addition, it only uses energy during the printing process, which is beneficial.

Some 3D printing products are biodegradable, and they are also environmentally friendly. The fact that printing can be done in such a way that manufacturers can produce products on demand also leads to a reduction in waste. This reduces the impact of making and transporting products that may never be used. Fewer outdated parts will end up in landfills as well.

Studies are being done by institutions such as Yale University, and one thing is agreed upon, which is that the reduced waste is beneficial to the environment. Three-dimensional printing seems to be a sustainable manufacturing process.

6. Custom Designs

Three-dimensional printing is designed with software most of the time, and the ability to create complex geometrical shapes leads to an ability to customize designs to create unique products. It is easy to take a prototype and make changes to customize each one for individual customers. This opens the door to much greater opportunities, especially in the dental and medical fields.

In the Healthcare Industry, 3D printing is used to create custom prosthetics, dental implants, and other dental aids. They also make many surgical tools with 3D printing. Three-dimensional printing is revolutionizing the healthcare industry.

Consumer goods also benefit from 3D printing. Companies make customized products including high-quality shorts wear to fashion accessories. Using the additive manufacturing process of 3D printing, companies can make one-time customized items for specialized athletes or accessories for movie sets.

7. Easy Access

Although additive manufacturing has been practiced for over 30 years, it has experienced extraordinary growth since 2010. As more materials are developed for the 3D printing process, 3D printing is set to explode even further, and it is readily available and competitive in pricing. It is used across a broad range of industries, and the number of companies offering 3D printing services is growing as well.

Three-dimensional printing is accessible to just about anyone who wants it today. As it becomes a mainstream staple for manufacturing, this will only continue to grow.

8. Risk Management

Three-dimensional printing allows companies to more effectively mitigate risk because they can create a rapid prototype and test the design. If there are any flaws or faults, or even if the customer wants to change it, it can be done effortlessly.

In the past, companies needed to create a mold before they could even begin to make a prototype. This step is eliminated, and the design goes right from a digital file to printing, and it can be changed and edited as necessary. This greatly reduces the risk to a company in trying out innovative new designs and products.

9. Lower Cost

Manufacturing cost is made up of three different categories, including material cost, labor cost, and machine operation costs. Three-dimensional printing reduces the costs in all three categories. The material cost is lower because additive printing has no waste. There is no excess material that needs to be cut out. The material that is used is only there to produce the model.

In addition, the labor is reduced because companies only need one person to operate the 3D printing machine. This is especially true when companies order a prototype to test. If multiple models are needed, there could be more labor involved, but never as much as older manufacturing techniques.

Finally, the cost of machine operation is lower. The largest expense is the filament, which is the material used. Different filaments will cost different amounts of money, but there is no waste, so every part of what you buy is used. Three-dimensional printing does use higher energy when it is in use, but even so, the overall cost is lower.

10. Manufacture on One Step

Often manufacturing is a multistep process, and 3D printing changes that. In the past, it was necessary to make molds, and then create products and remove them from the mold before moving on to the next part of the process.

With 3D printing, the design goes from the computer file to printing with no steps in between. The item is printed, and then it is ready to be sanded and painted, if necessary. It is a much faster process with only one step, which is beneficial all around.

11. Faster Production

A huge advantage is that items can be produced very quickly with 3D printing. Companies can create complex designs on a computer and upload them. These designs can be printed in a few hours.

In the past this process could take a significant amount of time, and the project was in a holding pattern until the product was available for inspection. In addition, when companies have an order, they can have it fulfilled much more quickly than in the past.

12. Better Quality Items

The way 3D printing works is to extrude the material through a nozzle once it is heated to its melting point. The 3D printing builds the model in a process of layering. This allows for step-by-step assembly of the item, so it is much easier to know when something needs to be changed or fixed.

Old processes would make products, but there was no way to know if there were air bubbles inside until a later time when the device failed. Now the entire process can be controlled from start to finish with the method of building products in layers.

13. Blended Raw Materials

Most manufacturing is unable to support the blending of materials, and even when they can, it can be very expensive. Three-dimensional printing can not only blend different raw materials, but it uses an incredibly diverse range of raw materials, including the following:

• Glass
• Metal
• Paper
• Wood
• Bamboo
• Ceramics
• Biomaterial
• Silver
• Precious metals
• Thermoplastics

The process is simplified in 3D printing, so it is possible to use the exact material that is best for each project, and it doesn’t slow the process down at all.

14. No Tools Needed

Manufacturing processes often require many expensive and specialized tools to produce the products. With 3D printing, this becomes unnecessary. The entire model is produced by the 3D printer without any other tools. You may need to sand or paint the product after production, but it will be built without any extra tools. This saves the manufacturer a lot of money.

15. Allows for Easy Proof of Concept

Proof of concept is evidence of an idea. It shows a model, and it differs from rapid prototyping because the model is not tested. This is very useful when a company needs proof of concept to patent the idea or generate support before it goes further into the design and production process.

Is 3D Printing the Wave of the Future

By all indications, 3D printing is growing rapidly and will be around for a long time. The speed of producing a prototype or proof of concept is the most widespread use today, but more and more industries are making use of this technology to create better designs and customizable products.

Studies are being done to determine the long-term impact on the environment, but there are some benefits, including reduced waste, that are beneficial. In the past, companies might order products that sat on the stockroom shelves for years before finally being left in a dump, and 3D printing changes that because orders can be printed on demand. The process is quick and efficient, so it isn’t necessary to order months ahead.

Conclusion

The rise in 3D printing along with its improved efficiency and diverse materials is changing the way manufacturers produce their items. Companies are using 3D printing to make parts for automobiles and jets, space shuttle parts, and more. Consumer goods manufacturers are making highly specialized fashion wear and athletic equipment, and other companies make packaging for food and other items.

Finally, the healthcare industry is making great use of this technology, as it allows the manufacture of customized prosthetics. Metal plates and screws used in surgery can also be made with materials that will degrade within six months, and there are many tools and devices made as well.

Many companies benefit from 3D printing because it is so much more efficient. It saves time, as shipping out designs is as simple as sending a digital file, and products are printed from this digital data. Items are printed in layers, which allows for close monitoring of the product for any flaws or revisions that might need to be made.

Three-dimensional printing is more popular all the time, and it is much more accessible than it was in the past. The growth of this industry has led to more creations, and it is easy to try out ideas at a fraction of the cost and time. There is no doubt that 3D printing is here to stay, and the process is continually being improved. It is beneficial across all industries, and the potential is significant.

It’s frustrating how your attempt to print a 3D prototype results in having the PLA filaments breaking off at the slightest touch. PLA filaments are commonly used in 3D printing, but its tendency to go brittle has frustrated many hobbyists and professionals alike. 

A roll of brittle PLA filament not only results in broken pieces but also reduces texture strength and causes uneven extrusion during the printing process.  

Various theories have been suggested on why the PLA filament keeps breaking apart during print. Users also seek ways to overcome the brittleness of the filament. Before we explore the available options, let’s dig deeper into the potential causes of such incidences. 

Why PLA Filaments Get Brittle?

Often, the complaints of PLA filaments getting brittle arise when they are left idle for a few months. But there are also instances when a spool of PLA broke easily after being used for just a few weeks. The obvious sign of such brittleness is the PLA filament breaking into pieces with the slightest contact. 

Both experts and regular users couldn’t agree on the causes of the brittleness with each holding on to their respective arguments. However, chances are, there is more than one contributing cause that makes the PLA filament brittle. 

For a start, PLA, which stands for poly-lactic acid, is known to be relatively brittle in nature. This means that it is inherently brittle to a certain extent, particularly when compared to materials like ABS. PLA is also known to degenerate rather rapidly, which explains why it eventually snaps off with during printing. 

The degeneration process of PLA filaments could take months, but there are conditions that could further aggravate the flexibility of the material. A commonly circulated theory is the moisture adsorption by the filament. When placed in a humid environment, the filament absorbs moisture from the air and alter its physical properties.

Usually, it is the outer part of the reel that starts getting brittle, as they are highly exposed to the moisture. To make things worse, the attempt to straighten a rolled filament applies mechanical stress beyond the tolerance of its altered flexibility. This explains why the filament keeps breaking off when you tried printing with it. 

In some cases, color additives that are added into the filament may change its mechanical properties. For example, you may have black filament snapping off easily while transparent PLA works fine in the same environment. Occasionally, it could be the quality of the filament itself that is the culprit.

Fixing PLA Filaments That Have Gone Brittle

Are there any fixes when the PLA filaments have gone bad? There is a slight chance of getting the filament into its original form by applying heat on it. The theory that supports this suggestion is that the heat would cause the moisture to evaporate, leaving the PLA in its original structure. 

Here are two ways of using heat to dry the PLA filament.

1. Heating The PLA Filament Roll

In certain cases, heating the entire filament roll may reverse its brittleness. This is assuming that the changes in its physical properties are still reversible. 

 Place it in an oven for 2 hours and check out if the flexibility has returned. You’ll want to ensure that the temperature does not exceed 50°C when you’re heating the entire roll of filament. It’s crucial that you don’t exceed the suggested heating temperature as the entire reel may turn soft and rubbery.

Repeat the process if you feel that the brittleness has decreased but yet to reach the ideal level. 

After heating the roll of filament, you could check if it’s still brittle by bending the filament and see if it breaks off.

If these attempts failed, you could try cutting 2-3 meters of the filament off the roll. In most cases, only a short length of the filament is affected while the remaining is in its original condition.

2. Increase The Nozzle Temperature

If you’re having issues with brittle 3D prints, you could increase the temperature of the nozzle. This ensures that sufficient heat is applied to both evaporate the moisture and soften the physical form of the PLA filament. You’ll want to try a few different temperatures to get the ideal value that works. 

However, it must be noted that these methods may not be effective if the physical properties of the PLA have been altered permanently. If the PLA material has gone through irreversible molecular changes, no amount of heat will fix its brittleness

You’ll have to replace the brittle PLA filament with a new one if the above suggestions don’t solve the issue. 

Prevention Measures In Handling PLA Filaments

When dealing with brittle PLA filaments, prevention is always better than cure. If you’re having regular issues with PLA filaments snapping into pieces, you’ll want to stop leaving the filament on the 3D printer after usage.

Instead, ensure that the filament is retracted into the reel after printing and store in a sealed pouch or container. If possible, place desiccant in the storage to ensure that excessive moisture is removed. This prevents moisture adsorption from weakening the structure of the filament.

Besides that, you could also cover the reel of PLA filament that you’re currently using with a plastic bag and puncturing a hole for the filament to be fed to the 3D printer. This method minimizes the chance of moisture being absorbed into the PLA material.

As mentioned, the physical properties of PLA are easily altered by temperature, moisture, and additives. You’ll want to be diligent when ordering supplies of PLA filaments because improper handling may result in brittleness of the material. Try bending a new roll of PLA filament to ensure that it’s in proper condition.

Final Thoughts

There’s no quick fix to brittle PLA filament. Heating and drying may not always be successful. It is better to have a habit of storing unused PLA rolls in a dry environment and ensure that you’re getting the material from a reputable supplier.

We come in contact with plastic products in our everyday activities. Interestingly, not all of these plastics are considered safe for use in health-conscious industries such as Food, Medicine, and Beverages.

It’s no surprise that regulatory bodies such as the FDA have placed a ban on the use of harmful plastics in these industries. So, let’s take a look at the list of “safe” FDA approved plastic filaments to use for 3D printing.

PLA

PLA is one of the most common plastics used in 3D printing. Unlike most of the 3D plastic filaments, Polylactic acid (PLA) is produced from renewable sources such as starch.

Hence, it’s completely biodegradable, and can be used to produced from already existing plastic manufacturing equipment. Therefore, PLA is cost-effective in addition to its biodegradable nature.

It’s no surprise to see that this bioplastic is a used asset in health-conscious industries such as medicine, food, and beverages. For instance, PLA is utilized in producing biodegradable medical objects such as screws, plates, and rods. It’s also used in making plastic bottles, and food wraps, thanks to its ability to constrict under heat.

Besides, it’s application in these industries, PLA is majorly used in plastic injection molding, where it is printed in the shape of an interior cavity before being encased with other materials.

Mode of Production

Basically, this plastic filament is mad through two processes – polymerization and condensation. The former also referred to as an open ring polymerization, utilizes metal catalysts in conjunction with lactides to create PLA filaments with higher molecular density.

The latter, although similar in process, differs in the temperate range used during production. More so, the products(condensate) are different.

Properties of PLA Filament as an FDA-Approved Plastic

Moving on to the characteristics of PLA, let’s examine some of its crucial properties as an FDA-approved plastic filament;

• A sharp contrast to petroleum-based plastic products, PLA is completely produced from the polymerization of starch from carbohydrate-rich sources.
• PLA is considered as a carbon-neutral compound. Since it is produced from renewable and sustainable sources, and it’s zero-impact on carbon emissions.
• As a thermoplastic, PLA plastic becomes liquid at a temperature above 150 degrees without a significant change in structure. Therefore, users can easily recycle this material, as opposed to thermoset plastics which can only be heated once.
• Mind you, PLA in the liquid or vapor form is considered toxic if inhaled or absorbed into the skin.

Flexible Filaments

Due to the incompatibility of rubber in 3D printers, flexible filaments with the same level of elasticity have been developed for use in these printers.

Flexible filaments such as Thermoplastic elastomers (TPE) and thermoplastic urethane (TPU), made from a cross-link of rubber with plastic, are now utilized in the production of materials such as car tires and rubber bands. More so, these filaments are utilized in sporting goods, footwear, and even medical devices

Due to its inert nature, regulatory bodies such as FDA, have approved the use of these filaments in health-conscious industries. Mind you, the use of TPE in food packaging and beverages is still being closely monitored, as it’s regarded as a Legally Food-Safe Material.

TPE and other types of flexible filaments boast of an impressive resistance to weathering and chemicals. No doubt, this property makes it an excellent food packaging material. In fact, a recent conference on TPE showed the use of this material as a safe alternative to PVC materials in food packaging, medicine, and sportswear.

Mode of Production

Thermoplastic elastomers and other types of flexible filaments undergo a process similar to the vulcanization process used in rubber production. Via polymerization technique which requires the copolymerization of two or more monomers, thermoplastic is able to exhibit more than one characteristic.

In this material, one monomer provides an amorphous or soft segment while the other provides the crystalline solid segment, which also acts as the thermal stable component. Unlike the vulcanization process which is reversible, flexible filaments transition from a liquid (melt) state to a solid flexible material that’s reversible.

Properties of Flexible Filaments as an FDA-Approved Plastic

• Fungus resistance is a prized asset in the food packaging industry. Due to the clamp-down on the use of most preservatives, flexible filaments are the ideal candidate for sealing medical devices, food, and beverages from fungal attacks in the form of molds and decay.
• Flexible Filaments such as TPE and TPU, have an impressive UV resistance ratio, high heat resistance, and solvent resistance. Therefore, you can use these materials in handling food and other health-sensitive materials.
• Let’s not forget it’s high tensile strength, high versatility, and abrasion resistance in various applications.

Nylon

No doubt, this is one of the most popular and versatile filaments in 3D printing. No doubt, it’s versatility lies in its ability to mix with different additives to form a variety of materials with different structures.

Nylon materials, known for their tough and flexible nature, offer a high abrasive and impact resistant. Thanks to its diverse physical properties and price affordability, this material can easily replace and mimic the tensile strength of brass, steel, and even rubber at a lesser price.

Besides these properties, nylon materials such as the FDA-Approved Ertalon 6 PLA nylon, are chemical and corrosion-resistant. In addition to this, nylon resins are an important component of food packaging materials where an oxygen barrier is crucial for maintaining the freshness of food products.

Since nylons are high temperature-resistant, they are used for sausage sheaths and meat wrappings. With this material, you can easily machine it and fabricate it to precision via 3D printers and CNC machines. So, let’s take a look at how nylon filaments are produced.

Mode of Production

Polymerization reaction also comes into play in the production of this organic compound. Nylon is manufactured when the appropriate chemical building blocks (monomers) are combined through a rigorous condition to produce long-chain polymers via polymerization or condensation. Sometimes, nylon polymer chains can contain as much as 20,000 monomer units connected via an amide group.

For example, the monomers for the popular FDA-Approved nylon 6-6, are hexamethylene diamine and adipic acid. These monomers are specifically chosen for their high-chemical resistivity and heat resistance. What’s more? Water is released as a by-product and instantly removed since it hinders the continued formation of polymer chains.

Properties of Nylon Filaments as an FDA-Approved Plastic.

There’s a bid for more efficient machines without compromising on the strict hygiene standard prevalent in many industries. In fact, this has spurred the need for materials with both tribological and mechanical properties.

• Nylon-metal composite, for instance, is valued for its high tensile strength, durability, elasticity, and resistance to chemical attacks. This material is also drawn into filaments and utilized for the use of yarns, cordage, and fabric.
• In the fabric and textile industry, resilience and longevity are important in the manufacture of fabrics
• Nylon materials such as polyester are known for the ability to maintain their smooth appearance, and the wrinkles are easily removed.
• In addition to this, nylon materials with open construction can help radiate heat from the wearer, while those with closed construction helps to trap-in heat.
• Let’s not omit the low absorbency rate of nylon materials in textiles, food packaging materials.

PETG

Here’s an extra-tough 3D filament that’s not only recyclable, but it’s considered safe by the FDA. It has an extremely high tensile strength that’s ideal for creating sturdy prints.

More so, it’s considered a better alternative to PLA and ABS, due to a smoother finish and lower shrinkage during printing. As a variation of Polyethylene Terephthalate (PET), PETG has the ability to withstand moisture, act as thermal insulation material, hence, making it conducive for food packaging.

More so, the glycol addition to PET results in a plastic filament that’s more durable, less brittle, and stronger. In fact, PETG inability to become brittle when overheated makes it an excellent material for medical devices.

Mode of Production

As mentioned earlier, this composite plastic filament is a variation of PETG. Thanks to the addition of glycol in the manufacturing process, this material has a lot of advantages over its predecessor, PET.

As an oil-based polymer, this material constitutes of 3 main components – terephthalic acid, glycol, and cyclohexane dimethanol. No doubt, this is considered a relatively simple process that involves the combination of two or more monomers in varying concentrations.

Properties of PETG (T-glass) as an FDA-Approved Plastic

Properties such as high thermal conductivity, chemical resistance, and moisture resistance, are important criteria for selecting materials in health-sensitive institutions and industries.

PETG meets these criteria, and it’s no surprise to see industries such as Food and beverage packaging industries utilizing this material.

In addition to this, some Red Cross Chapters also utilizing this material for their Vial of Life Program; a container where you can store your medical history in the case of an emergency. As a thermoplastic, it’s recyclable without any form of degradation in structure or properties.

PCL

The PCL or Polycaprolactone, is a popular flexible plastic filament utilized in the production of Thermoplastics such as TPU, and other types of plastics like Polyvinyl chloride (PVC). This polymer helps to improve the end-use properties and processing characteristics of most thermoplastics.

Polycaprolactone’s popularity, no doubt, stems from its biodegradable nature which is considered a positive property in the approval of materials for everyday use. Unlike other types of biodegradable plastic, this material is also bio-absorbable, i.e; the body can easily degrade this material without incurring any harm or hindrance to normal bodily functions.

These characteristics make it an indispensable asset in controlled drug release mechanisms and medical implants. Sadly, this filament is not an ideal candidate for tissue engineering due tt its low mechanical strength and cell adhesion.

Mode of Production

This filament is produced via a ring-opening polymerization reaction. Through the help of a set of catalysts, the ring-opening polymerization reaction yields a semi-crystalline, water-resistant polymer with a low melting point of 63 degrees. Furthermore, PCL has a -60 degrees glass transitional phase.

Properties of PCL Filaments as an FDA-Approved Plastic.

PCL is a homopolymer that has infiltrated into the field of a medical implant and drug release mechanisms.

For instance, it is used as a component of dental lplints and can also act as a root canal filler in lieu of the gutta-percha, a less effective alternative.

With its respect to its biodegrade and bio-absorbable nature, the  FDA recently approved the use of this filament as a suture under the brand name; Maxon. More so, researchers recently discovered the collagen-mimicking effect of PCL in removing wrinkles and other signs of aging in seniors.

PEEK

Obtained through step-growth polymerization, this filament is a semi-crystalline thermoplastic known for its high heat and chemical resistance.

It’s no surprise that this is regarded as the highest performing thermoplastic, and it is commonly used in demanding applications such as oil, automobile, aerospace, and most importantly, medicine.

From piston parts to high-performance chromatography columns to electrical cable insulation to bearings, PEEK materials are specifically built to withstand and bear demanding applications.

Also, PEEK or Polyether ether Ketone is considered as an advanced biomedical material. Its application in this field extends beyond its use as a partial replacement skull in different neuro-related applications. Interestingly, this material is also utilized in spinal fusion devices in the treatment of spine-related injuries.

Mode of Production

These polymers are obtained via a step-growth polymerization by the dialkylation of bisphenolate salts. Another way to achieve a similar result is a reaction between disodium salt of hydroquinone and 4,4′-difluorobenzophenone at a high temperature of 300 degrees in diphenyl sulphone.

Properties of PEEK Filaments as an FDA-Approved Plastic

As a semi-crystalline thermoplastic, PEEK boasts of excellent chemical and mechanical properties that are even retained at high temperatures.

Conclusion

There’s a need for an increased awareness of the use of harmful plastics in our everyday activities. More so, the presence of carcinogens in plastics such as Poly Vinyl Chloride (PVC), has driven manufacturers to search for safe plastics. By utilizing these FDA-approved plastics for your 3D printing, you will be able to avoid health hazards.

PLA:

One major benefit of PLA as a material is that it is Biodegradable, other oil based plastics can take over 400 years to biodegrade also leave behind toxins in the ground, in the right conditions PLA only takes 60 and leaves no toxins behind.

So you may be asking, is it a good material to print with? Well generally yes. PLA is now the most common material people print with. The main reason for this is that is is really easy to print with. When printing other plastics such as ABS, the plastic warps massively when cooled, this is not an issue with PLA and it can even be printed with no heated bed. Due to this almost every FDM Printer can print this material which is why it is so widely used. As the material is so easy to print, it can often be printed faster than other types of materials.

PLA also has other benefits such as it having little to no smell when being printed, the only smell released is a sweet scent. The material also offers a resistance to the environment around it, the filament does not soak up moisture and can be left open for large amounts of time however, it is recommended to keep it sealed in a bag.One other benefit to PLA is its high hardness, a feature that is useful when you want no flex in your prints.
Finally PLA just looks good. Prints come out crisp and well formed which is a massive pro for anyone looking to make beautiful models without any artefacts.
There is also a wider range of filaments in PLA such as Flame retardant filament or Conductive filament.
So let’s get onto some of the downsides to this magical material! We know that PLA is very hard but unfortunately it is also very brittle. This causes prints under strain to snap relatively easily.

Another common problem with PLA is the temperature resistance. Prints that are made from PLA will deform if left in the heat. I have personally had this happen when leaving a print in direct sunlight on a hot summers day.

Apart from that there really are no other downsides to PLA as a filament.

PETG:

Pros:

So what are the pros of PETG, Well thanks to the added glycol, this material is a reasonably durable. This material is capable of withstanding quite a bit of damage due to the added flexibility. Though not too flexible this material does have a bit of give. Along with the extra durability these materials are also are quite scratch resistant. This would be perfect if you are using it a situation where your part is being used in a rough situation and you do not want damage to show.
Another great feature when using PETG is its heat resistance. The glass transition temperature (the temperature where a material softens) is around 80 degrees Celsius. This is an enormous benefit if you are planning to store your printed part somewhere warm like a car or an attic. And that is about it for the positives for PETG.

Cons:

Now let’s get onto some of the cons about the material. Unfortunately there are quite a few but all of these issues I am about to explain are not major, just slightly irritating.

Firstly PETG is hygroscopic – a fancy word for it being absorbent. This means that it can easily get damaged in damp situations. This causes the materials to pop when the water goes through the hotend and leaves prints with an unwanted texture. Luckily this is easy to prevent and fix.  To dry your filament just stick your filament in the oven at 60 degrees Celsius for 4 hours. To store you Filament correctly it is always good practice to keep it in a sealable bag.

Another issue with PETG is stringing. Stringing is when small residues parts of plastic are left on your prints. These look like little hairs. This is also not a massive issue as it is entirely possible to remove them with heat and some snippers. Unfortunately this does effect the quality of the print though. Surfaces are also not usually very good looking, this is due the PETG naturally being very translucent. This sometimes makes prints appear to have scars from the light being reflected on the print.

Finally, the last issue I would like to talk about is post processing with this material. Unfortunately PETG is a very slippery filament, this means that it is very hard to post process. When painting PETG, the paint will not stick very well to the material. As we talked about earlier, PETG does not scratch very easily, this is also a negative when you would like to sand your prints. Lastly, many glues and epoxy resins will not adhere to this materials which makes it hard to stick parts together. The only way that I have managed to get parts to stick is by friction welding them, this used heat to merge two parts together to form one.

PLA vs PETG: Which is better for your project?

If you want a material that is just easy to use I recommend you use PLA, you don’t really need to store it in a special way and it prints at relatively low temperatures and has little to no stringing. If you are looking to print some tough models that need to take a bit of wear and tear I recommend that you use PETG due to its slight flexibility and scratch resistance. If you are concerned about the waste of 3D printing, don’t be! Both of these materials will not harm the environment if disposed of safely.

So to conclude, it really depends on what you print. I generally use PLA more than PETG just because it is easy to print and it doesn’t require me to do any cleanup after the print is done. My prints don’t normally get beaten around or over heated so for my prints I use PLA.