Welding is a process of joining two or more pieces of metal together. Traditionally, welding is done using various types of metal electrodes and filler materials. However, with the advent of new technologies and materials, welding has expanded beyond metals. One such material that has gained popularity in recent years is PLA or polylactic acid. PLA is a biodegradable and renewable thermoplastic that is commonly used in 3D printing. In this article, we will discuss the process of welding PLA and some techniques to help you get the best results.
What is PLA?
PLA, or polylactic acid, is a biodegradable and renewable thermoplastic that has gained popularity in recent years due to its environmentally friendly properties and ease of use. In this article, we will discuss the history of PLA, its properties, its applications, and its future.
History of PLA
PLA was first discovered in 1932 by Wallace Carothers and his team at DuPont. However, it was not until the 1990s that PLA became commercially available. In 1997, Cargill Dow LLC (now known as NatureWorks LLC) introduced the first commercially available PLA, called NatureWorks PLA.
Properties of PLA
PLA is biodegradable and breaks down into the water, carbon dioxide, and organic compounds under certain conditions.
PLA is derived from natural resources and is therefore renewable.
Low melting point:
PLA has a low melting point, making it easy to work with and process.
PLA is transparent and can be made into clear packaging materials.
PLA has good strength and can be used in various applications.
PLA is approved by the FDA for use in food packaging and other applications.
Applications of Welding PLA
PLA has a wide range of applications in various industries due to its properties. Some of the common applications of PLA are:
PLA is used in packaging materials such as trays, cups, and containers. It is a popular alternative to traditional petroleum-based plastics as it is biodegradable and renewable.
PLA is a popular material in 3D printing due to its low melting point and ease of use. It is commonly used in the production of prototypes and small parts.
PLA can be used to make various textile products such as clothing, upholstery, and bedding. It is a popular alternative to traditional synthetic fibers as it is biodegradable and renewable.
PLA is used in medical devices such as sutures, drug delivery systems, and tissue engineering scaffolds. It is a popular alternative to traditional materials as it is biocompatible and biodegradable.
PLA is used in various agricultural applications such as mulch films, plant pots, and seed trays. It is a popular alternative to traditional petroleum-based plastics as it is biodegradable and renewable.
Future of Welding PLA
PLA has gained popularity in recent years due to its environmentally friendly properties and ease of use. As consumers and businesses become more conscious of their environmental impact, the demand for sustainable materials such as PLA is expected to grow. The global market for PLA is projected to grow from $1.7 billion in 2020 to $3.8 billion by 2025, according to MarketsandMarkets. However, there are still some challenges that need to be addressed, such as the cost of production and the limited availability of raw materials.
Welding PLA, or polylactic acid, can be a challenging task due to its unique properties. PLA is a thermoplastic polymer that is derived from natural resources and has gained popularity in recent years due to its environmentally friendly properties and ease of use. In this article, we will discuss the properties of PLA that make it challenging to weld, the methods of welding PLA, and the best practices for welding PLA.
Properties of PLA that Affect Welding
PLA has several properties that make it a challenging material to weld:
Low melting point:
PLA has a low melting point, which can make it difficult to weld as it can easily deform and burn.
Poor thermal conductivity:
PLA has poor thermal conductivity, which means that it does not conduct heat well. This can result in uneven heating and poor weld quality.
PLA is a brittle material that can crack and break easily, making it challenging to create strong and durable welds.
Methods of Welding PLA
There are several methods of welding PLA, each with its advantages and disadvantages. The most common methods of welding PLA are:
Hot air welding:
Hot air welding is a process that uses a hot air gun to heat the PLA and melt it together. This method is commonly used in welding thermoplastics and can be used to weld PLA. The main advantage of hot air welding is that it can produce strong and durable welds. However, it requires skill and experience to achieve good results.
Ultrasonic welding is a process that uses high-frequency vibrations to melt and fuse the PLA together. This method is commonly used in welding thermoplastics and can be used to weld PLA. The main advantage of ultrasonic welding is that it can produce strong and durable welds without the need for additional materials such as adhesives or filler rods. However, it requires specialized equipment and can be expensive.
Solvent welding is a process that uses a solvent to dissolve the PLA and fuse it together. This method is commonly used in welding thermoplastics and can be used to weld PLA. The main advantage of solvent welding is that it can produce strong and durable welds without the need for additional materials such as adhesives or filler rods. However, it requires specialized equipment and can be hazardous due to the use of solvents.
Best Practices for Welding PLA
To achieve good results when welding PLA, it is important to follow the best practices:
Clean the surface:
Before welding PLA, it is important to clean the surface thoroughly to remove any dirt, grease, or other contaminants. This will ensure good adhesion and a strong weld.
Preheat the material:
Preheating the PLA can help to reduce the risk of deformation and improve the quality of the weld. The temperature and duration of preheating will depend on the thickness of the material and the welding method.
Use the correct welding method:
Choosing the right welding method for the application is critical to achieving a strong and durable weld. Each welding method has its advantages and disadvantages, and it is important to choose the method that is best suited to the material and application.
Use the correct welding parameters:
When welding PLA, it is important to use the correct welding parameters such as temperature, speed, and pressure. This will ensure good weld quality and reduce the risk of deformation and cracking.
Test the weld: After welding, it is important to test the weld for strength and durability. This can be done by applying force to the weld or by using non-destructive testing methods such as ultrasonic testing.
Hot Air Gun Welding PLA
Hot air gun welding is a popular method for welding PLA. To weld PLA using a hot air gun, you will need a hot air gun, a pair of pliers, and a scrap piece of PLA.
- First, clean the surfaces that you want to weld together using a piece of sandpaper or a file.
- Cut a small piece of scrap PLA and hold it with a pair of pliers.
- Hold the hot air gun about 2-3 cm away from the PLA and heat it until it melts.
- Once the PLA is melted, remove the hot air gun and press the two surfaces that you want to weld together. Hold them in place until the PLA has cooled and solidified.
Soldering Iron Welding PLA
Soldering iron welding is another popular method for welding PLA. To weld PLA using a soldering iron, you will need a soldering iron, a pair of pliers, and a scrap piece of PLA.
- Clean the surfaces that you want to weld together using a piece of sandpaper or a file.
- Cut a small piece of scrap PLA and hold it with a pair of pliers.
- Hold the soldering iron about 2-3 cm away from the PLA and heat it until it melts.
- Once the PLA is melted, remove the soldering iron and press the two surfaces that you want to weld together. Hold them in place until the PLA has cooled and solidified.
Tips for Welding PLA
Use a low temperature:
PLA has a low melting point and can easily burn if heated too much. Make sure to use a low temperature when welding PLA to avoid burning the material.
Clean the surfaces:
Make sure to clean the surfaces that you want to weld together using a piece of sandpaper or a file. This will ensure that the surfaces are free from any debris or contaminants.
Use a scrap piece of PLA:
It is always a good idea to use a scrap piece of PLA to practice your welding technique before welding your final project.
Welding PLA can be a slow process, so make sure to take your time and be patient. Rushing the process can result in a poor weld.
Future Tips Welding PLA
In addition to the tips mentioned above, there are a few more things to keep in mind when welding PLA:
1. PLA available
There are different types of PLA available on the market, and each type may have different properties and requirements when it comes to welding. Some types of PLA may require higher temperatures or longer preheating times, while others may be more sensitive to moisture or UV radiation. It is important to read the manufacturer’s instructions and recommendations for the specific type of PLA you are working with.
2. Use a Welding Jig or Fixture
Welding jigs or fixtures can help to ensure accurate and consistent welds, especially when working with complex shapes or large parts. A jig or fixture can hold the parts in place during welding, reducing the risk of warping or distortion. You can either purchase a pre-made jig or fixture or make your own using materials such as wood, plastic, or metal.
3. Avoid Overheating
PLA can be sensitive to heat, and overheating can cause the material to degrade, discolor, or deform. It is important to monitor the temperature during welding and avoid exceeding the recommended temperature range. You may also want to use a temperature sensor or thermal imaging camera to monitor the temperature of the material and prevent overheating.
4. Use a Backing Material
Using a backing material can help to support the weld and prevent the material from sagging or deforming. The backing material can be made from a heat-resistant material such as aluminum, copper, or steel, and can be placed behind the weld during welding. The backing material should be shaped to match the contour of the weld and should be secured in place using clamps or magnets.
5. Clean the Weld
After welding, it is important to clean the weld to remove any residue or excess material. This will ensure a smooth and consistent finish and improve the appearance of the weld. You can use a file, sandpaper, or a scraper to remove any excess material, and then clean the weld using mild detergent and water.
6. Consider Post-Weld Treatment
Depending on the application, you may want to consider post-weld treatment to improve the properties of the weld. Post-weld treatment can include annealing, stress relieving, or surface treatment. Annealing can help to improve the strength and ductility of the material, while stress relieving can reduce the risk of cracking or deformation. Surface treatment can improve the adhesion and compatibility of the material with other materials or coatings.
7. Use Safety Precautions
Welding can be a hazardous task, and it is important to use proper safety precautions to protect yourself and others from harm. This includes wearing protective gear such as gloves, safety glasses, and a respirator, and working in a well-ventilated area. You should also follow the manufacturer’s instructions for the equipment and materials used in the welding process.
welding PLA can be a challenging task, but with the right tools, techniques, and precautions, you can achieve strong and durable welds. It is important to choose the right welding method and parameters, clean the surface, preheat the material, use filler rods, test the weld, and practice. You should also consider the type of PLA, use a welding jig or fixture, avoid overheating, use a backing material, clean the weld, consider post-weld treatment, and use safety precautions. With these tips, you can successfully weld PLA and create high-quality and reliable products.
Conclusion Welding PLA
Welding PLA can be a challenging process due to its low melting point and tendency to break. However, with the right tools and techniques, it is possible to weld PLA effectively. Hot air gun welding and soldering iron welding are the two most common Welding PLA.