When you see a few defective parts released from the Pet Preform Mould, you realize that you will have to stop production and find out what the problem is. This is a terrible feeling. Injection molding defects are certainly not uncommon, but they have not made them easier to handle – especially when QA waits, order queues, and delivery deadlines are imminent.
Injection defect
It may not be surprising that defects in finished molded parts are prone to occur when you think of the injection molding process. Molds need to be properly designed to benefit the actual process and serve it. Due to melting and curing temperatures, viscosity, hardness and many other factors, the right material must be chosen. This process requires proper calibration, the specific hold time and pressure depend on all of the above factors, and so on.
In summary, injection molding defects can be attributed to three root causes: product/mold design, material selection, and process calibration. There is some overlap between these issues depending on the specific problem and your solution. For example, sometimes time or money considerations mean that creating a completely new mold is not feasible, so the choice of materials and processes must be considered more strongly. At other times, it is more beneficial to build an absolutely correct model in the long run.
Let's take a look at what defects you might encounter from these root causes and how to fix them:
1) mold or product design defects
Due to sub-optimal mold or product design, you may encounter two of the most common injection molding defects (meaning suitable for injection molding, not aesthetic or functional issues):
Cavity: Also known as a void or vacuum cavity. A hole sounds like: an unfilled empty gap in your part or product (sometimes even invisible). Cavities or voids pose a serious threat to the structural integrity of the finished part.
Streamline: These are color-changing stripes, indicating that molten plastic is difficult to flow through the mold at a uniform rate, resulting in irregularities.
product design
If you have been working in the injection molding field for a long time, you may hear such a spell: "Uniform wall thickness, uniform wall thickness, uniform wall thickness." Wall thickness difference is the main reason for the design of injection molding defects. However, uniform wall thickness is not always absolutely critical.
If the part requires a different wall thickness, you can do this as long as you can gradually incorporate the thickness variation into the part design. Subtle changes in wall thickness help to ensure that the flow rate does not change drastically as the molten plastic material enters the mold. A uniform or gentle wall thickness also ensures a more uniform cooling time, which means that the cooling time in thicker areas is not much longer than in thin areas - this is the root cause of voids or voids.
The last design tip: Rounded corners also help to ensure uniform filling and flow of the cavity, helping to alleviate these problems. In addition to "even wall thickness", be sure to remember "no sharp angles".
Finally, choose a reliable China Pet Bottle manufacturer, such as Jilian Mold, we have a wealth of experience in the production of molds, no matter what problems we encounter during the entire production process, we are able to be the fastest Find the solution within the time to deliver quality products on time.