When you are looking for a mold, you should think of the quality of its plastic parts. Besides being compact, these parts should be durable and easy to operate. They should be easy to repair and have higher hardness and strength than the original ones. Also, the scope of disassembly and assembly must be minimized.
The use of standard parts is a great way to reduce the costs of injection mold repair. Unlike custom parts, standard components can be easily replaced if they are damaged.
A toolroom manager can simply call the component supplier for help and place an order for a new one. In contrast, if a moldmaker uses a custom part, the injection mold maker must replace the mold, incurring additional costs.
It is very important to properly maintain molds at all times. During the production process, molds are often connected to water.
Therefore, there are chances that water may spill on them during installation or disassembly. To prevent this from happening, injection molds should always be kept dry and protected with oil.
Flow lines in a mold result from variations in the rate at which the molten plastic cools down during the injection molding process. These variations can occur due to varying wall thicknesses or uneven cooling speeds during the injection process.
In either case, these defects reduce the part’s overall strength. A common example of this defect is a weld line, which appears as a wavy line on the surface of the finished part. The problem is often fixable by raising the temperature of the injection mold or by adjusting the flow pattern.
While flow lines can affect the functionality of a molded piece, they can also reduce its reliability. These imperfections are caused by differences in the cooling speed of the plastic during the molding process. This means that thinner parts of the piece can cool down before thicker areas are filled.
This is because the molten plastic cools down rapidly. To avoid this, molten plastic should be injected at higher temperatures and/or at higher pressures. However, this is not a perfect fix and often a redesign will be necessary.