Injection molding is a field with very high technology content. In addition to years of experience accumulation, it also needs a heart to be good at discovering and be very proficient in the whole process of injection molding. Correct learning of all aspects of injection molding requires a lot of repeated experiments, trial and error and summary. But considering that we have many years of innovative experience in the field of injection molding, we can help all those who want to engage in injection molding to avoid detours. You don't have to spend time thinking. If you plan to produce injection molded parts, here are four main design options:
Mold design parameters: the design of injection mold is the most important part of the injection project, and it is also very time-consuming, because a lot of ideas have to be invested. It is very important for the success of injection molding enterprises to do a good job in the first time. In order to get the best injection products, there are many design parameters to be considered, the most important of which is draft and cavity bending.
Mold design parameters
More complex molds have many complex cavities through which the plastic must fill completely. These bending, especially when the bending is very severe, will lead to the in mode stress at the atomic structure level and the in mode stress of components with different cooling methods from the outside to the inside. Designing the mold to a smoother, softer turn will avoid sudden changes in the flow direction and prevent these stresses from accumulating in the part.
Draft (or, more accurately, draft angle) is the thinning of a part, the purpose of which is to make it easier to eject the part when the mold is opened. Drafts are sometimes incompatible with part design, either from an aesthetic or functional point of view, but the smallest draft is better than no draft. The draft required also varies with the surface finish of the tool or the texture requirements of the part. Smoother tools require fewer drafts than normal tools.
Part design parameters: the design of injection parts requires the combination of manufacturability, practicability and aesthetics. Compromise between repeatability, cost, intensity, functionality and aesthetics. A balance will be sought to ensure that all of these factors are not below the minimum requirements. From the point of view of injection molding, the design parameters such as part wall thickness uniformity and part wall thickness itself are the most critical factors. Uniform part thickness will ensure that the defects such as warpage, distortion or cracks caused by uneven wall thickness caused by parts cooling at different cooling rates are minimized. The thickness of parts is mainly determined by cost, part strength and production speed. Thicker parts are more expensive because they consume more plastic, while thinner parts cool faster and can be discharged earlier, saving critical time in the production process. However, despite the additional cost, thicker parts are usually stronger.
Part design parameters
Gate design and positioning: there are generally two kinds of gates in injection molding: manual edge adjusting gate and automatic trimming gate. As the name suggests, each type has a specific reason for its use, either manually or automatically, from a mold. If the gate is too bulky to use the automatic integrated gate shear, the gate can be sheared manually. Automatic gate dressing is used to reduce downtime for manual gate removal to achieve uniform production speed.
Gate design and location
The gate location is usually close to the thickest part and the melt flows from there to the thinner area of the mold. This ensures the minimization of part defects, such as dents, voids, and inadequate packaging of parts. In some cases, it may be necessary to include a secondary gate to ensure proper filling of the void. Reducing the wall thickness to the thickest at the gate and then thinning down the cavity will ensure good flow.
Molding conditions and parameters: These are easy to adjust variables, such as mold and melt temperature, cooling time, injection pressure, injection speed, holding pressure and time, which can affect the effect of finished products. All of these factors have an impact on this part, and sometimes they are negative and need to be minimized. However, adjusting one variable to limit a particular defect may make the component vulnerable to another defect; therefore, a balancing act is followed by the right trade-off to achieve the necessary requirements and partially perform its intended functional satisfaction.