The manufacturing world is a diverse one that is filled with many firms, many consumers, and many products. Not forgetting, many materials. It is also a fast-paced world, constantly evolving. There is the creation of new products daily. The invention of new production processes and the discovery of new materials for production are really mind-blowing. It is a world full of many options.

However, some options remain constant. These are tested and trusted, to do the job. These options have been for many years. And continue to yield top results. One of such is the injection molding process. It remains one of the best production processes around. It is ideal for many products. And new tech continues to find new ways to make it ideal for other materials.

Whatever it may be, Injection molding is a good process and ideal for PA66. You do not agree? That is because you don’t know about PA66 injection molding. So, this article will tell you about PA66. So, don’t be in a rush to leave. Read on and learn more.

What is Nylon

First, let’s discuss what nylon is. Nylon is an artificial fiber. It is one of the most commonly used polyamides. It refers to a group of synthetic polymers made up of polyamides. It is a silk-like material made from petroleum and is often melted into films, shapes, or fibers. With nylon, you can make it into many variations by simply adding more properties or addictives.

Nylon is widely used in almost all industries. You can use it to create apparel. It is lightweight and very resilient. They are strong, with abrasion resistance. You can use it to make packaging for food, molded parts for cars, and so on.

What is Nylon PA66

Nylon has many variations and one is PA66 and also referred to as nylon PA66. It is one of the first examples of nylon. Wallace Hume Carothers invented it in 1935. At the DuPont research center. It has gone on to become the most used nylon. That is 2011, there were said to be. 2 million tons of PA66 used in production around the world.

Firms often use it when they require high rigidity or high strength or good heat and chemical resistance. In automobiles, firms create airbags from PA66. Firms use it due to its top balance of properties. And for its relatively cheap. Also, it has great stiffness and toughness. It has great tensile strength. Nylon PA66 is vital to clothing industries, rug firms. Even used in bicycle wheels and snowmobiles.

The Difference Between Nylon PA66 and PA6

But PA66 isn’t the only thermoplastic nylon. There is also the popular PA6 which competes with PA66 in the market. But how do they differ? This we will discuss here.

There is one key difference between PA6 and PA66 while PA6 comes from diamine. PA66 comes from both diamine and diacid. They are both polyamides. But PA66 came into being before PA6. Also, PA66 has high tensile strength while PA6 has low tensile strength. PA66 is not recyclable.

Whereas PA6 is recyclable, PA66 has around 80% impact strength while PA6 has about double of that. PA6 is monadic nylon while PA66 is dyadic. These are some key differences between PA66 and PA6.

What Is Injection Molding

Injection molding is the production process for creating items by injecting melted materials into a mold. It is a technical process used in many industries. It is also ideal for many materials. Such as thermoplastic, metals, glasses. But thermoplastic is its regular usage. You can use it for ABS, PA66, and much more.

It is the most modern means of creating plastic parts. Firms use it to make toys, auto parts. Dashboards, bottle caps, plastic food storage, and so on. The process involves the heating of materials, injection into a mold, and shaping and cooling to form a product.

How to Injection Mold PA66

Injection molding is a unique production technique that requires that you consider certain aspects of it. There is a special purpose machine for injection molding. But in terms of the material you’ve to assess some things. So, assess the parts of the material, the traits of the machine, and your desired product. Let’s look in detail at the injection process for PA66.

Details To Consider When Injection Molding PA66
  • Drying

Dryness refers to the moisture of the material and the process of drying it after molding. For PA66, drying isn’t vital if there is sealing. That is if you seal the material before molding. Drying is not required. But if you do not seal it, then, dry afterward in a hot air oven of 85°C. This would help extract the moisture in it.

But if the material has a moisture content of > 0.2, then you should vacuum dry for 12 hours at 105°C. This would yield top results for your product.

  • Mold Temperature

You should also assess the mold temperature. The mold heat level affects the look of the material. It alters its crystallinity. So, generally, go with a mold-heat level of 80°C.

Your product may have thin walls. Then, you might need annealing to retain dimensional stability. Due to its crystallinity changes in time especially, at less than 40°C mold-heat level. So, you have to assess the mold temperature with care based on the parts of the mold and material.

  • Injection Speed

Also, assess the injection speed of the process. This is very vital. It is the speed at which the material is injected. And this can ruin the process if done wrong. If the speed is too fast for the material, it can cause spilling and damage. If it is too slow, it can cause bubbles in the mixtures. That is an uneven mixture of the material. So, this aspect is vital.

For PA66, the injection speed should be high. But in cases, where the grade has been reinforced, it should be slightly lower.

  • Melt Temperature

Next is the melt temperature –it is another key aspect of the injection molding process. Remember, that we stated before that this process involves heating. That is heating of the material for molding. In this case, we are heating PA66 until it turns to liquid and can be molded.

Melt temperature refers to the level at which PA66 melts. If the heat level is too low, it will melt slowly and not even. But if it is too high, it can cause damage to the material. So, there are two suggested levels for melt. You can meet at 275-280°C or at 260-290°C.

But know that this depends on the properties of PA66. If you have altered these parts and they are glass-filled grades, then we recommend nothing above 300°C, but only below.

  • Injection Pressure

The injection pressure refers to the rate of pushback. It is the pressure by which the mold fills. The pressures are applied to the mold cavity as it fills. And it is very vital to the shape of products. It affects shrinking or deforming.

The key is to find a balance. Get the right pressure based on the material and mold. Use their traits to decide on the injection pressure. But there are still some basic standards you can adopt. In general, the pressure should be between 75-125 MPa.

  • Gate and Runner

These are also key aspects of the molding process. The gate location is vital in controlling cooling which helps during fast freeze-off periods. Simply, get an ideal gate. You can use any type. Just ensure the location is right.

But take care with the aperture. Ensure it is not below half of the part’s thickness. Once you do this, you are good to go.

When using cold runners, gates can be large. But when using hot runners, gates should be smaller. And for submarine gates, let the gate’s diameter be 0.75 mm.


In summary, PA66 is great nylon. Its usage can not be overstated. Clothes use it, rugs use it. Cars use it, electronics use it. Gears use it, industrial products use it. The list goes on and on. Not only is it the oldest nylon. But it is also the most used. Its parts are the key to its broad usage.

PA66 is high in water resistance. It has top chemical resistance too. It can withstand repeated impacts. PA66 is lightweight and has good chemical strength. Also, it is very cheap in relation to other options. So, it is one every firm wants to use. More so, even you want to create mass products. Using limited resources and reducing costs.

Nylon PA66 is your to-go material. So, once paired with injection molding, the results are top. But you can alter this quality with bad choices. If you choose the wrong heat level, you are calling for harm to your product. Or the injection speed is too high. All these are little details to note. So, thank you for reading our short intro to PA66.