Plastic Injection Molding vs. 3D Printing, manufacturing techniques have evolved significantly over the past few decades with new technologies that offer flexibility, cost savings and efficiency. Along with all the advantages and disadvantages, 3D printing and injection molding have played a very effective role and have also become popular in a wide range, their methods are very good in production. Both methods serve various purposes and operate on creating objects using difficult principles. They also have different advantages and limitations.

After understanding Plastic Injection Molding vs. 3D Printing of all these things, the difference between the two helps the business to go ahead and helps the engineer to decide which one will be better for the project. They have different factors like production volume, complexity, Cost, Material requirement and lead times.

Plastic Injection Moulding

Plastic injection molding requires long turnaround times to prepare for part creation (5-7 weeks even for simple parts), making it unsuitable for frequent design changes. However, despite the long turnaround times this process is ideal for producing parts in high volumes (1,000+ parts per run). The mold tool is also fine for producing large or small components of any complexity.

Advantages

• Able to mass produce a high volume of parts: Injection moulding can use a high number of molds at once, meaning that it is more cost-effective for producing a large number of objects  
• Enhanced strength of objects: The injection molding process uses a single layer of poured material to create parts, eliminating fissures or weak points. This method also suits dense materials like concrete, which would otherwise require dilution or modification for 3D printing.
• Minimal wastage: Because injection moulding involves pouring material into a mold, it uses exactly the amount of material required for the design. This means this manufacturing method is ideal for mass producing objects cost-effectively

Disadvantages of Plastic Injection Molding vs. 3D Printing

• Limited design capabilities: The use of a mold means there are design limitations placed upon this production method. Right angles in the design can make it difficult to remove an object from the mod without it breaking. Injection molding does not work well for creating precise and delicate designs that need to stand on their own.
• Difficult to correct mistakes or change designs: Because of the long set-up times associated with injection moulding it is difficult and expensive to rectify any mistakes in the design. To change designs or fix problems, you must completely remake the mold and scrap any produced objects.
• Expensive entry costs: Injection moulding machines are expensive, often costing upwards of six figures. Designed for industry, these systems are not really for hobby use as there is the cost of making molds, materials and design prototyping to take account of in addition to the original machine cost

Applications

Injection moulding is best suited to:

• Large batch production as you can create multiple identical objects simultaneously
• Strong, solid designs that are based on one continuous form
• Smooth finishes for parts that move against other objects. Creating smooth parts reduces friction compared to the rougher finish typically found in 3D printed parts.

How Plastic Injection Moulding Works?

1. Mold is made up of metals like steel or aluminum, and designed is made as per the requirements then the final product will be produced.
2. As I have said in above that molten plastic is injected in the mold at the high pressure.
3. Then, plastic fills the mold cavity and get the right shape.
4. Let the plastic cools and solidifies, then we will open the mold and get the final product.

3D Plastic Injection Molding

3D printing is an additive manufacturing process that involves building parts layer by layer using digital 3D models. It utilizes many materials such as plastics, metals, ceramics and biological substances to create complex structures. This technology has revolutionized what photo type and customization and even production do in a certain industry. Let us explain things in brief:

Advantages of Plastic Injection Molding vs. 3D Printing

• 3D printing has a low entry cost: A desktop 3D printer and supply of materials is cheaper than injection moulding equipment. The proliferation of open-source software and hardware can also provide ongoing support at little or no cost
• Easy to make design changes: Since it is an additive process, 3D printing allows you to make design changes even during production, saving time and money on a run of components that may have a flaw. Being able to pause mid process and make design changes means that you do not need to start the entire production run from the start. 3D printing is also good for quick prototypes as there is little set-up required ahead of production
• Good for intricate designs: Because it produces parts layer-by-layer, 3D printing is perfect for producing complex or intricate designs with detailed infrastructures

Disadvantages

• Despite the set-up being relatively fast, 3D printing is a slow production method. The CAD-based, detail-oriented process limits how many parts can be produced at once, with most printers only capable of building one or two items at a time
• 3D printing is unable to produce larger items as the process is limited by the size of the printing area. The design becomes increasingly unstable if parts hang off the edge of the printing area, so while large scale 3D printing is possible, it is not the best use of this process
• Rough finish: The finish of 3D printed parts is often rough because the layers are built additively, even with fine details. Therefore, post-build smoothing is necessary when a smooth finish is desired.

Key Differences Between Plastic Injection Molding and 3D Printing

Production Volume

• Injection Molding: Injection Molding excels for identical parts in mass productions. Once the mold is created it can produce thousands or millions of its parts in a cost effectively manner.

• 3D Printing: 3D printing is very efficient in running small productions. This approach isn’t cost-effective for high-volume production due to the longer times required for printing each item individually.

Cost Considerations

• Injection Molding: Front cost is for designing and producing, it is quite high but the cost involved is significantly higher in the product when we do it in the bulk. When we do high volume production, injection molding becomes much more economical.
• 3D Printing: 3D printing does not require any requirements, it has an initial investment which is quite low. However, the cost per part remains relatively constant, regardless of quantity, making it less competitive for large-scale production.

Part Quality and Durability

• Injection Molding: Injection molding produces highly durable parts that are in high demand for their mechanical, thermal, and chemical properties. The process allows for parts with tight tolerances and high strength.
• 3D Printing: 3D printing parts do not have much strength and durability compared to injection molding parts which is especially in plastic filaments. The layer-by-layer nature of 3D printing can result in parts that are more prone to breakage or wear.

Conclusion

Plastic Injection Molding vs. 3D Printing, processes have their benefits and drawbacks and so they should be considered as complementary rather than competing technologies. 3D printing is better for small batch, complex parts that may require frequent design changes or customization. Injection moulding, on the other hand, is better for large volume production of less complex parts that have successfully completed the design stage.