Short Run and Bridge Manufacturing Services
05 July, 2023
Both 3D printing and injection molding are manufacturing processes commonly used for producing plastic parts and components. Let’s take a look at the pricing and benefits of each method in detail.
3D printing is also known as additive manufacturing. A 3D object is constructed using a CAD (computer-aided design) model or digital 3D model. 3D printing has numerous applications in product design, aviation, the medical industry and more. In medical settings for instance, 3D printing is used to make valves and stents used in surgical procedures and even prosthetics.
This method is most suited for small or medium-sized projects that have a one to two week turnaround time. It’s most commonly employed when the project involves intricate designs that can’t be produced in a custom mold, or for designs that are subject to last-minute changes.
3D printing is also very useful in prototyping applications. It is used in the creation of prototypes before final production, as it is much more time and cost effective than other methods available in the market.
It is also very affordable compared to traditional injection molding or manufacturing. For this reason people pursuing hobbies involving the creation of 3D objects also commonly use this method.
3D printing has a number of different benefits including:
To start 3D printing at home, all you need is a desktop 3D printer and a supply of materials so the initial investment is low. If you are not expecting to use the printer regularly, it’s even cheaper just to outsource your printing to a specialist like us as there are no upfront costs, and you only pay for each 3D printed part that is produced. The more parts that are printed the cheaper they are, until you get to the point where the economies of scale make injection molding significantly cheaper.
Since 3D printing is an additive process the design can be changed easily, even in the worst case scenario during production (although this is uncommon). Usually you would change the CAD file in between prints to iterate on your design if you’ve noticed any design flaws in the original print.
Since the product is manufactured layer by layer in 3D printing, you can create very intricate designs and parts that are not possible to make with regular manufacturing techniques, like creating internal spaces that are not accessible from the outside for instance.
There are also some disadvantages to 3D printing however, including:
Most printers can only produce one or two units at a time, so it takes a lot of time especially if you want to mass produce something. For this reason it’s better to outsource your printing to a 3D printing company like us that has access to multiple machines. If you want to produce something en masse on a very large scale however, it’s cheaper and quicker to use traditional manufacturing methods like injection molding.
3D printers are pretty innovative folk. There are for example 3D printers which can be used to print houses out of concrete in a matter of hours. In most cases though, the size of the products that can be created is limited by the size of the printing area and capacity of the printer. Hobbyist printers tend to be quite small, professional printers can be much larger. In some cases for large products, the print must be split into component parts which are later reconstructed.
Since 3D prints are built layer by layer the end product will have a rough finish (although you can choose how fine you want the finish to be by choosing a higher resolution print. A finer finish is more expensive). Because the finish is not perfect, time and energy needs to be spent to machine the product after completion if you want a smooth finish.
3D printing technology is coming ahead in leaps and bounds but at this point in time printing in very dense materials is not very practical.
Injection molding is a manufacturing process that produces parts by injecting material that has been heated to the point of melting into a mold. Parts can be made using materials ranging from metals and glass to different types of plastic polymers.
It is most suited for high volume production and designs that require a strong and smooth finish. It is most commonly used after the final design has been approved after going through a prototyping stage, as the molds used in injection molding are pricey, and it’s best not to make a mold until any issues in your prototype have been ironed out.
When using injection molding to mass produce a product, a large number of molds can be used at the same time, which drastically cuts down production time. Injection molding is much quicker than 3D printing, which is why it’s used to manufacture products at scale.
A single layer of poured material is used to create products made via injection molding. This means that there will be no fissures or weak spots. Injection molding can also be used to create products using dense materials like concrete.
Since each mold uses the exact amount required for one design there is very little to no wastage of materials or resources and little required machining once the part is created.
If your design is very intricate or involves a lot of angles or internal spaces, the product can break when being taken out of the mold, or be impossible to create through this process.
Injection molding can only be done with an expensive metal mold that will hold up to repeated use. It is difficult, therefore, to make last-minute changes or rework the mold. In most cases if you are not happy with a product you will need to make a new mold from an updated CAD file, which is expensive.
The equipment used in the injection molding process is expensive. It is mostly used in commercial manufacturing facilities. Moreover, making molds is a costly affair. That’s why it’s best to use a manufacturing company like us. We already have all the required machines, that means you only need to pay for the mold/s you need. We can even store them for you in between production runs if you’d like.
The pricing and profitability of each method above vary based on a number of factors. The main determinants of cost are the size of your run and the complexity of your design. You can find out specifically how much does 3D printing services cost here.
The initial design and molding costs will be higher in the case of injection molding. Comparatively, 3D printing can be set up at a lower investment.
However, if the volume of your project is very high and you require more than 2,000 units, you can easily cover the initial investment costs by manufacturing en masse.
Injection molding is much faster and cheaper when the volume of output required is high. The per-piece cost becomes significantly cheaper than 3D printing if you want to produce very large volumes of parts or products, even with the initial cost of the mold factored in.
If you have a small or medium product run in mind, or are looking for bridge manufacturing services, then 3D printing or vacuum casting may be more cost effective. Even though the price per unit when taken by itself can seem higher than injection molding, since there is no large upfront investment in mold making the final cost will be lower in the case of a small run.
If you only need one or two items you’re definitely better to stick with 3D printing.
If you want to update and change your design throughout the production process or if your design is very intricate and complicated then 3D printing is the way to go.
Injection molds cannot be altered easily and any sort of change means that you have to start over from scratch with a new mold. Each time you start over you will end up spending more money.
Moreover, intricate designs involving angles and spaces in the middle of the products cannot be effectively manufactured using injection molding. This type of product can easily break when being removed from the mold. Damaged products will lead to wasted materials and resources.
Therefore, 3D printing is more economical in the product development stage or prototyping stage when you will have to revise and rework your design multiple times, or in the case of complex items.
The truth is, both have their place in the manufacturing process, and both serve different needs. It’s not an either-or scenario. Depending on your requirements and budget you can choose either one or a combination of the two, eg. 3D printing for initial prototyping before mass production using injection molding. This is usually what we recommend for clients wanting to mass manufacture, as it is the cheapest approach overall.
If you are on the lookout for affordable, fast and high quality 3D printing or injection molding give us a call on 1.888.202.2052 or fill out our quote form. If you’re not sure which of these methods are best for your project we can suggest the one most suited for your needs based on your budget and requirements.
If you’ve enjoyed this article, you might also like this article on DIY injection molding.
Looking for applications of 3D printing? How about custom 3D printed chess sets!