Let's take a look at the top six advantages of this process:. There are several good reasons that plastic injection molding is known as the most common and most efficient form of molding. The process itself is extremely fast compared to other methods, and the high production output rate makes it even more efficient and cost-effective.
Speed depends on the complexity and size of the mold but only about seconds pass between each cycle time. With the short period between cycles, a greater quantity of molds can be produced in a limited amount of time, thus increasing possible revenue and profit margins. Injection molding can handle extremely complex parts, and uniformity, as well as the ability to make millions of virtually identical parts. To optimize the effectiveness of high-volume injection molding and maximize the precision and quality of your parts, key design elements should be taken into account.
The part design must be developed to maximize the efficiency inherent in high-volume molding. With the right design , parts can be made consistently and with quality. Without a good design, costly processing mistakes can be made. Around the industry, most molding professionals agree that there are fundamental design elements that must occur during the injection process to work correctly. Injection moulding is also not ideal for producing large parts as a single piece.
This is because of the size limitations of injection mould machines and the mould tools. The final disadvantage is that large undercuts require experienced design to avoid and can add even more expense to your project. Injection moulding is used for a range of applications where a repeatable manufacturing process is required. This includes manufacturing items such as wire spools, packaging, bottle tops, toys, combs, musical instruments and components , chairs, small tables, storage containers, mechanical parts, and automotive parts and components.
Injection moulding is the most common method for manufacturing plastic parts, particularly in high volumes. Injection moulding is becoming more environmentally friendly as machinery becomes more efficient and materials such as thermosetting polymers are capable of withstanding extreme temperatures and conditions.
Although there is some material waste with injection moulding it is less than with many other manufacturing processes. Of course, the exact materials used also have a bearing on the environment in relation to how long they last, if they can come from recycled materials and how they are disposed of. There are also considerations around the carbon footprint of the lifetime of the products that are created, including during manufacture.
Moulding costs correlate with the number of cavities in a mould. Fewer cavities require less tooling work, which lowers the manufacturing costs to create an injection mould. Added details such as these will increase the cost, as they require more tooling.
The most cost-effective type of injection moulding is rubber injection moulding, which produces a high yield of durable products.
In addition, consistent vulcanisation processes with precise temperature controls can lower costs by reducing waste material. While the mould tools have a high cost, the actual injection moulding production has a relatively low cost. With over 85, commercial plastic material option available and 45 polymer families, there is a wealth of different plastics that can be used for injection moulding.
Of these, the polymers can be broadly placed into two groups; thermosets and thermoplastics. Polyethylene offers a number of advantages including high ductility levels, good tensile strength, strong impact resistance, resistance to moisture absorption, and recyclability. This tough, impact-resistant plastic is widely used across industry.
With good resistance to acids and bases, ABS also offers low shrinkage rates and high dimensional stability. This strong, impact resistant plastic has low shrinkage and good dimensional stability. A transparent plastic that is available in different optically clear grades, PC can provide a high cosmetic finish and good heat resistance.
There are many different types of PPA or nylons , each of which has its own advantages. Generally-speaking, nylons offer high strength and temperature resistance as well as being chemically resistant, apart from against strong acids and bases.
Some nylons are abrasion resistant and offer good hardness and stiffness with good impact strength. Commonly known as acetal, this plastic has high hardness, stiffness, strength and toughness. Oftentimes large parts cannot be produced via injection molding as a single piece.
This is due to the size limitations of injection mold machines and the mold tools themselves. For example of a large injection molded part consider the shopping carts at Target.
Although the machinery exists to mold very large pieces e. CNC machines have similar limitations regarding product size while 3D printing has even more limitations.
CNC is limited to the travel and size of the bed in the milling machine while large 3D printed parts often need to be printed in multiple pieces and then bonded together. Large undercuts require experienced design to avoid and can often add costs to the project.
What Are Some of The Considerations For Injection Molding: Before you endeavor to produce a part via injection molding consider a few of the following things: Financial Considerations Entry Cost: Preparing a product for injection molded manufacturing requires a large initial investment. Make sure you understand this crucial point up front. Production Quantity Determine the number of parts produced at which injection molding becomes the most cost effective method of manufacturing Determine the number of parts produced at which you expect to break even on your investment consider the costs of design, testing, production, assembly, marketing, and distribution as well as the expected price point for sales.
Build in a conservative margin. Design Considerations Part Design: You want to design the part from day one with injection molding in mind. Simplifying geometry and minimizing the number of parts early on will pay dividends down the road. Tool Design: Make sure to design the mold tool to prevent defects during production. For a list of 10 common injection molding defects and how to fix or prevent them read here.
Consider gate locations and run simulations using moldflow software like Solidworks Plastics. Production Considerations Cycle Time: Minimize cycle time in as much as it is possible.
Using machines with hot runner technology will help as will well-thought-out tooling. Assembly: Design your part to minimize assembly.
Much of the reason injection molding is done in southeast Asia is the cost of assembling simple parts during an injection molding run. To the extent that you can design assembly out of the process you will save significant money on the cost of labor. Consider the housing for an electric drill produced by Panasonic see below : Picture courtesy of Panasoni c One of the most obvious advantages to injection molding is that the housing serves multiple purposes. Conclusion Injection molding is a great technology for finished production on a massive scale.
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Contact Us. We look forward to hearing from you. Since obtaining only one product by one shot is very inefficient, a mold is usually designed to have multiple cavities connected with a runner so that many products can be made by one shot. If the length of the runner to each cavity is different in this case, the cavities may not be filled simultaneously, so that dimensions, appearances or properties of the moldings are often different cavity by cavity.
Therefore the runner is usually designed so as to have the same length from the sprue to each cavity. Use of reprocessed materials. Sprues and runners among moldings are not products. These portions are sometimes discarded, but in other cases they are finely reground and reused as materials for molding. These materials are called reprocessed materials. Reprocessed materials are not solely used as materials for molding but usually used after blending with virgin pellets, since there is possibility of deterioration in various characteristics of the plastics because of the initial molding process.
For the properties when reprocessed materials are used, please refer to "reprocessing capability" in the plastic data base. Molding condition means cylinder temperature, injection speed, mold temperature etc.
Depending on the conditions selected, the appearances, dimensions, and mechanical properties of the molded products change considerably. Therefore, well-tried technology and experience are required to select the most suitable molding conditions.
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