Injection molding is a very common and widespread means of production used especially in the plastic industry. A whole range of plastic products are made through this means, from buckets to bottle tops to flowerpots, plastic helmets, tool handles, toys, to machine parts. Indeed injection molding produces much of the plastic products we use daily. Products made from injection molding vary in size, shape, and functionality and that might give us an idea as to why it is always readily employed.
The reason for its prevalent use is due to its cost-effectiveness; especially when the product has to be produced in vast quantity, speed of production, and repeatability, in that the process can be repeated over and over again.
How Does Injection Molding Work?
From the name, one can infer that it has to do with ‘injecting’ a substance for ‘molding’. In simple terms, what Injection Molding involves is injecting plastic into a mold, and as the plastic sets, it retains the exact shape of the mold.
Technically, plastic, either in granular form or pellets, is fed into the machine through a hooper. From the Hooper, the raw plastic now travels through a section where they would be led by a screw to the point of injection. What this screw does is to apply pressure on the raw plastic, slowly turning it and leading it to the point it gets injected into the mold. While in this section, friction and heat, from heaters around the base of the machine, heat it and turn the plastic into liquid or molten form. It is this form of plastic that when injected into the mold, takes the shape of the space around it, and retains it, slowly cooling, until it is ejected.
Both thermoset and thermoplastic plastics can be used for injection molding, but most companies prefer thermoplastic because it can be used again and again, and some of the pellets used can be from recycled thermoplastic plastic, unlike thermoset which can only be used once.
Why Is Injection Molding A More Preferred Means Of Production?
There are various reasons as to why companies readily employ injection molding in production, and some of these reasons include:
Injection molding is the most preferable option when a company needs to cut back on cost, especially when the items are to be produced in bulk. Once the machine is available, production can start, and in time, production would begin to pay for itself.
This helps manufacturers save some money, especially for labor.
Scale Production and Repeatability
Similar to the previous point, this mode of production is used in a situation where a particular product has to be produced in great numbers, from a thousand, up to hundreds of thousands. The beauty of injection molding is that you can produce the exact type of a product over and over again, with great precision and accuracy, so that all are identical, as long as you have the type of mold used from the start. The method can be repeated over and over again.
This process is very favored because it can be used to produce any form of an object, in whatever shape or size. Injection molding is not limited unlike other forms of production. The only thing important is to get the appropriate mold.
It Allows For Correct Detailing
For example, when producing the handle of a tool, or other products that may need screws or a complex interior, injection molding is the best option because it allows for proper detailing since the plastic takes the exact form of the mold.
Factors to Consider Before Going Into Injection Molding
Perhaps the key factor to consider is cost. Getting started, that is acquiring and setting up the machine can be quite pricey, but as time goes on, it would pay for itself, and sooner than you think, if you start work right away. Another way it could prove costly is with the molds. Ordinarily, you cannot use the same mold for every product as the mold for a bottle is different from that of a bucket. Molds see made from various materials, but the most common are aluminum and steel. Aluminum is used for being cheap, but it cannot be used for multiple productions, unlike steel that can be used up to a million times, although getting a steel mold can be more expensive. But like the machine, it would pay for itself.
Also, you have to keep in mind that every product you make has to be made by this process. This is something you do not want to forget especially when designing the product as you have to remember that it would be made by injection molding.
You also have to take into note the number of products you would be making. Anything from a thousand above would appropriately require the process of injection molding. Doing about a hundred or so may not be a very good idea, economically speaking.
Injection molding presents a lot of advantages, and perks, making it a widely used option in a range of production, especially when taking into account factors like cost, and scale of production, making it almost the industry standard, and for its extensive use.