Plastic Injection Molding: Top 10 Advantages

From toddler toys to zooming race cars, plastic injection molding technology is all around us. The popularity of injection molding as a manufacturing process is backed up by the multiple advantages that it offers. 

Plastic injection molding, as the term states, is a process that involves injecting molten plastic into a mold to create different shapes/plastic parts. It is one of the most widely utilized manufacturing processes in the modern world when it comes to mass production of plastic parts. 

While the technology appears to be fairly recent, it really all began in 1872, when John Wesley Hyatt patented the first plastic molding machine. The plastic injection molding machine (and its modern versions), since then has revolutionized the world of plastic injection mold making. 

Irrespective of whether the part is an essential automobile unit, a piece of medical equipment or a fancy button, the process works with precision!

So what makes it so good, especially when compared to conventional molding techniques?

The range of products that can be produced using the process with a variation on size, design, intricacy and finish makes the process invaluable in the modern world of growing technology. 

Following are the top 10 advantages of plastic injection molding:

1. Flexibility of design

One of the key reasons behind the invention of plastic injection molding is the ability to be flexible in designs. The flexibility of the technique is one of the most remarkable features that attracts clients in need of plastic parts. 

The ability to choose multiple plastics (material selection), create precise designs, be flexible in terms of color choices, the process covers it all. 

This allows the users to create designs of their choice which is a significant change when compared to the traditional molding processes. 

2. Precision with complex designs

The techniques used within plastic injection molding make it possible to create complex designs and add a large number of details to the parts. Since the injection molds are subjected to high pressure, the plastics get pressed harder which makes it possible to create complex designs. 

This makes it possible to create intricate design features within plastic parts to a complete precision level which is completely impossible with conventional molding machines. 

The fabrication of any type of plastic parts can be created to a precision level within 0.001 inches. 

Additionally, since the process is completely automated, even the most complex of designs are comparatively inexpensive to manufacture. 

3. Faster mass production (efficiency)

Injection molds are designed using Computer-aided designs (CAD) and Computer-aided manufacturing (CAM) processes. The designs are created as per customer specifications and are used to create the desired parts. 

The actual production process, after the molds are prepared is extremely fast. Compared to conventional methods of molding, injection molding is extremely quick even when mass production levels are required. 

The process of plastic injecting is in itself not time consuming. The swiftness of the process allows for mass production of parts from a single mold creating a high production output rate. 

4. High Strength

Plastics have changed over the years. 

Increased strength, durability and precision is an essential requirement of all industries. Lightweight but sturdy plastic parts are now being used even in the most rugged environments. 

Unlike conventional machines, plastic injection molding makes it possible to add fillers inside the injection molds. 

The fillers include different strength imparting materials like silica, calcium carbonate, mica, alumina trihydrate, glass, clay, etc. 

The fillers are specially selected to add strength/stiffness to the material. These fillers work by reducing the overall density of the plastic during the molding process. This results in greater strength of parts that are being molded. Additionally, some fillers also add to the heat resistance properties of the plastics. 

Various industries like the automobile industry require small plastic parts that need to be extremely strong and durable. Traditional molding machines had their limitations in this aspect. However, with plastic injection molding, high strength plastic parts can now be mass-produced. 

5. Flexibility to change material, color, and finishes

The need to have the right colors, material and finish are the most essential factors in the plastic industry. And let’s be honest, the choices are endless. With the advancement of modern technology as well as in the world of polymers, a wide variety of plastic resins have been identified. There is hence a large selection to choose from.


Leading injection molding companies are hence experienced working with a large variety of resins along with complete knowledge of resin selection for a particular project. The selection of resins for a project depends on the following factors:

  • Tensile strength
  • Impact strength
  • Heat deflection
  • Water absorption
  • Flexural modulus of elasticity

Multiple coloring techniques are available for adding shades the plastics. 

Additionally, multiple finish appearances like smooth surface finish, matte or even unique textures are possible with plastic injection molding processes. 

6. Simultaneous use of different plastics

This is one of the major advantages of plastic injection molding. Different types of plastics have different properties suitable for different industrial processes. The ability to use different types of plastics simultaneously is a superior property that is possible with plastic injection molding. 

This is needed in cases where it is required to alter basic plastic properties like density, elasticity, color, texture as well as other mechanical properties of the material. 

Co-injection molding makes it possible to use different resins to create a material of choice. Further, the use of different polymers together helps in reduction of the total material cost. 

7. Low labor cost

The ability to produce plastic parts in bulk with minimal time input and high output ratio makes it a highly efficient process in terms of cost. This is one of the biggest reasons for the plastic injection molding process to have reduced labor costs associated with it. 

Additionally, the molding equipment is designed to require minimal supervision. The self gating tool streamlines the operations as well as the production with minimal human intervention.

3D computerized design units, automized fabrication as well as completely computerized plastic injection molding machines work to produce high quality while using minimal labor. And that’s not all. The inclusion of automation reduces the chances of human error, adding to the long list of benefits. 

8. Waste reduction

Environmental considerations must go hand in hand with industrial manufacturing processes. This is especially true for the plastic industry which is one of the greatest nonbiodegradable solid waste generating sector. Plastic waste accumulation or plastic pollution around the world has gone up to a very serious level. The destruction of ecology and natural habitats is evident. 

Unlike the conventional machines that cut plastic pieces from larger blocks and leave out substantial waste behind, plastic injection molding uses only the required amounts. Plastic injection molding is hence not just more efficient (especially when making smaller, lighter parts), but also produces much less waste in comparison to traditional techniques. 

Various leading plastic injection molding manufacturers are committed to sustainable, green initiatives. The excess plastic generated during the molding process is recycled using state of the art machinery, thereby minimizing the waste produced. 

9. Cost efficiency

The entire process of plastic injection molding is automated and performed by minimal human intervention. The introduction of computerized machines, robotics as the main operators/ managers of the process has revolutionized the sector. The reduced labor costs are one reason for the process to be more cost-efficient. Reduced labor costs create a significant cut in the overall costs for manufacturing the products.

However, that is not the only factor. 

Other significant reasons include the ability to create precise and accurate parts in one go. Computer-aided designs (CAD) along with computer-aided manufacturing (CAM) help in creating accurate parts without the need to recreate. This helps in reducing the overall manufacturing time and hence the associated costs. 

Automation not just helps eliminate manual labor but also reduces the chances of inaccuracies, therefore making the process more cost-efficient. 

Additionally, high mass production output makes the process extremely cost-efficient. 

While the creation of molds can initially be expensive, the costs get significantly reduced in the long term. This is because multiple volumes of plastic parts can be created within the same cost (one mold). 

Conventional plastic machines can cost about 25 times more in the long run when compared to plastic injection molding machines!

10. Wide Acceptance

In a world where plastic technology is growing by leaps and bounds, plastic injection molding is possibly the most popular manufacturing process. Almost all industries in the present world have been changing their manufacturing process and are considering substituting metal parts with plastics, considering the possibility of getting similar strength levels with high durability and precise designs. 

Final thoughts: Needless to say, plastic injection molding has received huge popularity and wide acceptance for a good reason. The aforementioned points point out to the multiple benefits that the technology offers. 

It is hence one of the best alternatives to produce plastic parts that are precise, produced at a fast pace, offer design and material flexibility and is cost-efficient too! Plastic injection molding is one of the most versatile techniques that is available within the modern plastic manufacturing processes. 

The world of plastics is growing. While the possibilities of using this versatile material are endless, the environmental concerns too are significant. The issues of plastic waste accumulation and destruction of various land and marine habitats have raised some important questions in the global ecological communities.

The need to shift towards more environmentally friendly technology is hence evident. 

The process of plastic injection molding is not just superior in terms of efficiency, simplicity, and reliability but is significantly environment-friendly. Since the overall scrap plastic produced during the manufacturing process is highly reduced, the overall waste production is less. Additionally, the possibility of re-using the minimal scraps produced is a great advantage to the environment.