Injection molding is a production method for creating s […]
Injection molding is a production method for creating simple parts by slowly injecting melted material into a specially designed mold, or mold. The basic principle of injection molding is that the material to be injected is placed into the mold at elevated temperatures and pressures. The material will harden in the mold while inside the mold until the injection time is complete. When the injection time is complete, the mold is removed and the product, which may be metal, plastic, rubber, or other thermo-plastic fluid such as polyethylene, comes out of the mold.
Mold cavities are used in injection molding to manufacture internal parts. There are two types of cavities available in injection molding; solid-state and hybrid. With hybrid, the cavities are filled with liquid nitrogen, which hardens the metal as it is being poured in the mold, while the solid-state variety contains inert gas or iron that hardens as the metal passes through the mold cavity. In the case of solid-state injection molding, the two cavities are one; therefore, there is only one set of internal parts that are being manufactured.
There are two different methods in which injection molding is done, either direct and indirect. With direct injection molding, the material to be molded comes straight out of the mold, while with indirect injection molding, the material is placed in the mold, and the mold cavity is then opened to allow the material to flow out through the hole that was drilled into the part. Indirect injection molding takes a large volume of material and forces it through a small hole. When this type of molding is used, it requires that the part must be made with as few parts as possible, because if the mold is accidentally stopped, there would be a large loss of production.
The other main consideration for injection molded manufacturing is the initial costs, which can vary greatly. Initial costs generally include the cost of parts, labor and materials to create the product. On the average, the costs are around $5 per unit. This number is based on the number of pieces that are being created, and not necessarily the cost of each individual piece. One thing that should be noted is that depending on the kind of material that you will be using in your creation, there could be a variation on initial costs. For example, if you will be using steel for the product, your costs will be much higher than those for plastics because of the additional material that is needed to create the parts.
The other major consideration is the uniform wall thickness that is created during injection molding. During the cooling process, the walls in the cavities are open, which allows for any liquid or gasses to escape to the outside of the product. For this reason, the injection molding process must ensure that the walls remain uniform throughout the entire creation process. If not, the cavities will be filled with varying amounts of melted plastic, which will then leak into the other parts during the cooling process.
In general, injection molding is one of the easiest ways of producing large numbers of identical products. However, you still have to be aware of the unique characteristics of the material that you will be using in your creation. This includes identifying the right temperature to heat the material up, as well as the right pressure and flow rate that is necessary to prevent the walls from closing in on the individual parts. This process typically calls for large quantities of equipment, which is why most factories that use this method of product manufacturing usually employ several production lines. This helps to increase the speed at which the injection molding manufacturing process can take place, but it also means that the price of these large machines can become quite expensive.