The intricate and complex design of different material products leaves us amazed. For example, you see plastic toys, glass products, and metal equipment. Have you wondered how they are manufactured? Injection molding is the science behind it. However, it is not always a perfect process. There are several advantages and disadvantages of injection molding.

 

Knowing both sides of the procedure is crucial. It helps you manage the manufacturing process more efficiently and prevents mishaps. Are you unfamiliar with the pros and cons of injection molding? Fret not! This guide will provide you with a detailed insight into the merits and drawbacks of this process. So, let’s get started! 

 

What is Injection Molding?

 

In this previous article, I discussed the basics of injection molding in detail. However, let’s have a bird’ s-eye view of this process before discussing its pros and cons.

 

Injection molding is a process for producing complex-shaped products. It uses molten raw material filled into cavities of molds with various shapes. The molten material cools, adopts the shape of cavities, and creates products with specific. This process offers both precision and repeatability for easy bulk production.

 

It is not a single-step process but involves a series of steps. The first step is the preparation of raw materials. For example, grind the raw material first and then melt it. Each material has a specific melting point. So, you must provide the temperature according to material requirements.

 

After melting, the raw material is poured into the specifically designed cavities. Those cavities are known as molds. After pouring the molten material into molds, it is left to cool for hours. Several cooling channels perform this task. After cooling, a product of a specific shape is produced.

 

Injection molding stands out due to its versatility and flexibility. It has become a necessity in several manufacturing industries. For example, in the automotive industry, it is used to produce frames and panels. Moreover, medical devices, electronics, and consumer goods are also made using this procedure. 

 

Advantages of Injection Molding

 

Why is injection molding the backbone of modern manufacturing? The answer lies in its advantages. Let’s dive in and explore the key benefits it offers.

 

1- High Efficiency and Speed

 

It is one of the prominent advantages of injection molding. Injection molding is highly efficient in cost, energy, and time. HOW? This process only takes time to prepare the molds. Once molds are ready, injecting the melted raw material takes a few minutes. As you know, this is an advanced manufacturing procedure.

 

Therefore, it uses effective cooling channels. These channels solidify the material in no time. Moreover, the machinery’s simple design makes the final product’s ejection easy. In this way, you can create thousands of products in no time. As it takes less time, it is also beneficial regarding energy efficiency. Overall, this is a fast and highly efficient procedure. 

 

2- Precision and Consistency

 

Injection molding stands out in precision and consistency. WHY? The reason lies in the design and automatic system used in injection molding. This process uses an automated control system. From filling molten material to ejection, every step is pre-defined and automated. So, you can create the products with narrow detail and tight tolerance.

 

By injection molding, you can also maintain consistency. For example, you want to create thousands of the same products in different batches. So, each product must have the same strength, flexibility, and shape. All these are possible with injection molding. The precise and dedicated design of molds ensures consistency in each batch. 

 

3- Design Flexibility

 

Injection molding benefits you in terms of design flexibility. HOW? Let me explain it in simple words. First of all, injection molding offers design flexibility for different materials. You can create complex geometric designs on various materials, from soft to hard. Moreover, it also provides a lightweight design with thin walls without compromising durability.

 

What I like about injection molding is its flexibility for multi-material parts. Actually, this process has over-molding capabilities. It means you can create a product with different material properties. For example, it produces a product with rigid corners and a soft core. Moreover, injection molding provides flexibility in design customization and finishes. 

 

4- Reduced Material Waste

 

Reducing material waste is another significant benefit of injection molding. It not only saves money but also helps sustain the environment. As I said above, injection molding is an automated system that uses CAD software. So, an exact amount of material is injected. However, some debris, such as runners or excess flash, is left behind during molding.

 

You can reuse them after melting, which reduces waste. Secondary processes such as cutting and finishing cause material waste. However, injecting molding is so efficient that it eliminates the need for post-processing. Lastly, this process supports recyclable materials, which further reduces material waste. 

 

5- Low Long-Term Cost

 

Injection molding is an advanced procedure that uses the latest technology and machinery. So, no doubt, all those tools cost more initially. But it is a cost-effective option for long-term use. HOW? This process uses an automated control system, which reduces labor costs. The molds used are durable and do not require maintenance, reducing costs.

 

Moreover, injection molding is an energy-efficient process. You can create thousands of products using less energy, which saves electricity bills. This process also reduces the chances of rejection by producing defectless products. In this way, it reduces the cost of remanufacturing. So, invest once in injection molding and save forever. 

 

6- Ability to Incorporate Multiple Features

 

Injection molding is an all-in-one process. You can incorporate several features into one product. The advanced mold design features hinges, snaps, and threads. They are used to create pockets, notches, and grooves for the same product. So, there is no need for secondary processes such as machining and milling.

 

This reduces material waste and saves money and time. Moreover, incorporating multiple features helps you customize. For example, you can create logos and branding elements on the products. It eliminates the need for extra printing machines and helps increase production volume. 

 

Disadvantages of Injection Molding 

 

No process is perfect, so injection molding is no exception. With so many advantages, this process still has some shortcomings. So, before you decide, let’s discuss the other side of the picture! 

 

1- High Initial Cost

 

Injection molding requires a high initial cost. First, the cost of molds is higher. It mainly depends on the design of the mold. If you choose an intricate design mold, it will cost you more. On average, the prices of the molds range from hundreds to thousands of dollars. Moreover, if you buy them from other countries, then the cost further increases.

 

The second reason is that it uses complex machines. Those machines require proper setup for efficient working. So their setup takes time and needs money. Moreover, you must hire skillful staff if you cannot operate the injection molding. It increases labor costs. So, injection molding is unsuitable for small-scale production due to its high cost. 

 

2- Lengthy Lead Time for Mold Development

 

Before starting injection molding, molds are created. This is called lead time for mold developments. As I said above, injection molding uses highly precise and complex molds that take time to develop. The design and precision of the mold decide the precision of the final products.

 

First, you have to create a model for the mold design. It should be precise and accurate to ensure efficiency. After preparing the model, it is sent to the manufacturers. Developing the final mold takes about weeks to a month. After production, several tests are performed to ensure its final results, which also takes time. 

 

3- Limited Material Options

 

Although injection molding is versatile, it handles only a few materials. For example, it is the most suitable option for thermosetting plastics and thermoplastics. The reason is that they match the requirements of injection molding. For instance, the proper flow of the material after melting is crucial. This flow helps inject more efficiently.

 

However, some materials, such as ceramic and glass, can not flow and become thick quickly. Moreover, injection molding machines impart significant pressure on the materials. So, brittle materials are not suitable for this procedure. They can break during the process and affect the final precision level. 

 

4- Energy Consumption

 

Injection molding is energy-efficient in many ways. But still, some reasons make it less energy efficient. For example, melting the raw material is the first step in this process. All the materials possess different melting points. So, machines that melt those materials require significant gas or electricity.

 

Furthermore, some machines exert pressure on the melted material. Those machines also require a power supply. Moreover, the last step of cooling requires specific cooling channels. Those channels work with electricity sources. So, overall, injection molding is less beneficial in terms of energy consumption.

 

5- Cooling and Cycle Time Issues

 

Cycle time is the period in which molding machines complete one cycle of production. It is mainly related to cooling systems. Among all the steps, the cooling process takes time in injection molding. The reason lies in materials, cooling channels, and parts’ thickness. For example, some materials, such as thermoplastic, cool down more quickly.

 

On the flip side, thermosetting plastic takes time to solidify. Moreover, if you create thick parts, the cooling takes time, and vice versa. Lastly, cooling channels also affect the cooling period. If they are not appropriately installed, solidification takes time. As a result, overall cycle time increases.

 

6- Environmental Concerns

 

Injection molding is risky in terms of environmental sustainability. The reason is the use of plastic material. Injection molding is well-known for producing plastic products. Msot of them are non bio degradebale. So, after use, when they are thrown in the open areas, they cause pollution and harm living things. 

 

Moreover, injection molding involves the melting of plastics. When plastic is melted, it produces volatile organic compounds(VOC). VOCs are emitted into the air, which is risky for human health. Lastly, energy used to drive the molding machines comes from non-renewable sources. The constant use of this energy can cause depletion of natural resources. 

 

How to Decide If Injection Molding Fits Your Project

 

Are you not sure if injection molding is the right fit for your project? Fret not! In the section below, I will discuss some key aspects to consider. They will help you make the final decision about its selection. Let’s jump right in!

 

• As you know, injection molding has a large production volume. It is a suitable option if you want to produce thousands of identical products. Conversely, you should not consider injection molding if your project involves prototypes.
• Injection molding can handle various materials. However, thermoplastic and thermosetting plastic are most suitable for this procedure. So, if you want to produce plastic products, you should choose this process.
• While choosing injection molding, keep your budget in mind. This process initially cost more due to higher prices of tools and setup. But in the long run, it is a cost-effective option. If you want to run a large-scale business, consider injection molding.
• Injection molding requires time for mold development, so its overall lead time is extended. If you are initiating a project and are not concerned with lead time, go for it. But if you cannot afford a long wait, consider other manufacturing options.

 

Sıkça Sorulan Sorular 

 

What are the four steps of injection molding?

Injection molding involves a series of steps. They include

 

• Clamping of the molding plates
• Injection of molten material
• Solidification or cooling 
• Ejection of the  final product

 

What is the strongest material for injection molding?

Injection molding is a versatile procedure that can handle several materials. Polycarbonate (PC) is the strongest material. It is transparent thermosetting plastic. With this material, you can obtain durable and hard plastic products. 

 

How many types of injection molding are there?

Injection molding can be classified in various ways. However, based on motor or driver, it is classified into three types. Those include;

 

• Hybrid injection molding
• Hydraulic injection molding 
• Electrical injection molding 

 

Çözüm

 

Injection molding is a practical manufacturing procedure. In this article, I have discussed the pros and cons of this process. For example, it is an energy-efficient procedure. It can save you money for long-run use. Moreover, it can handle several materials and produce more products.

 

Besides the pros, injection molding also has some cons. For example, it has a long lead time. 

 

Moreover, it can handle a few materials and has a higher initial cost. All these pros and cons help you decide whether it is a reliable process for your project. However, I recommend using this process if you are initiating a large-scale business.