Did you know? Regular preventative maintenance of injection molding tools like mold cavities is important to effectively fulfill plastic injection molding demands. Hence, manufacturing plastic products using the mold cavity isn’t the end of your tasks as a machine operator. Instead, once you complete production work, maintaining the mold cavity is just as crucial as the manufacturing process. Besides, poorly maintained molds may produce parts that do not meet standards, resulting in increased downtime, waste of raw materials, and a negative impact on the bottom line.   Mold Cavity Maintenance Checklist: Below are the eight key practices to consider when upkeep molding cavities that you use for plastic injection manufacturing tasks:   Frequently Analyze Mold Cavity Condition: It is imperative to comprehensively inspect the injection molds before beginning a fresh manufacturing cycle. It is important to thoroughly inspect the surfaces of the injection molding die to ensur...

Manufacturers’ task is to produce products that serve a wide range of functional and aesthetic purposes, often turning to multi-material injection molding solutions-more specifically, insert injection molding and overmolding. Because these two processes have some similarities, they are generally considered interchangeable, but there are also some key differences. Understanding the basic differences between insert molding and overmolding will allow you to choose the most appropriate type of multi-material molding for your application.     1. Insert Injection Molding Insert injection molding is a process that requires an insert, usually metal, to be pre-placed in the tool to inject the plastic flow.   Plastic packaging inserts can create a molded plastic sheet, which is generally stronger than a plastic sheet created using secondary assembly.   Insert injection molding can be done by manual insert loading-for very small batch applications or extremely complex pa...

As the connecting area between the runner and the cavity, the gate plays a vital role in the injection molding process. Gates-their style and where they are placed can affect the overall cycle time, the cost of the mold, and the appearance of a molded part. Therefore, it is important to know how to use the gate before starting an injection molding project.     This Blog looks at the six most common gate types used in plastic injection molding: side gates, tab gates, direct gates, hot gates, pin gates, and sub-gates. It looks at the properties of these unique gate styles and provides suggestions when to best use them. 1. What is a Gate? Molten plastic material is injected into a mold cavity, causing the material to solidify and form a product. This process involves passing molten plastic through gates and runners until it is able to reach the gate, which opens up an opening that allows the molten plastic to enter the mold cavity. Not all gates are the same. Gates can be locate...

How the Hot Runner Systems Works The cold runner of a plastic injection mold refers to the section between the mold inlet and the gate. The molten plastic maintains its fluidity inside the runner by virtue of the injection pressure and its own heat. However, as a part of the molding material, the runner is not a product. As a result, when designing a mold, we need to consider not only the filling effects, but also the material-saving effect produced by shortening or downsizing the runner; but in actuality, it is not easy for us to have the best of both worlds. Types & Application of Hot Runners When applying the hot runner technology, the proper selection of gate type is of critical importance, because gate type directly determines the selection of hot runner components as well as manufacturing and application of molds. Therefore, the hot runner system can be classified into 3 types based on the gate type, i.e. (1) hot tip hot runner system, (2) sprue gating hot runner system and (...

The Runner Design Concept The runner refers to the melt flow passageway between the end of the main runner and the gate, which is used to change melt flow direction and allocate it to each cavity in a stable and balanced way. The basic design principle of the branch runner is little pressure/heat loss, with the minimum quantity of plastic retained in the runner. Sectional Shapes of the Branch Runner:   –Circular, with the minimum specific surface area (runner surface area/runner volume), but during production, both sides of the mold plate need to be aligned. –The commonly applied forms, trapezoid and U-shape are easy to process. –Semicircle. –Rectangle, larger specific surface area and high resistance to flow, thus seldom applied.   The Principle of the Runner Design The runner is usually designed on either half of the plastic injection mold. When considering the layout of the cavity and the branch runner, it is better to ensure that when projected on ...

Mold inserts are the terms relative to the integrated core – when the mold core is made of a single piece of steel, it is called an integrated core, while an insert is a part that’s inserted into the mold core made primarily of the steel material. As a matter of fact, the biggest weakness of an insert is that it weakens the rigidity of the mold as a whole. However, the application of different insert materials is able to independently enhance the rigidity of the weak parts.   Now, let’s see what the circumstances for mold inserts applications are: Material Saving. The dimensioning of a mold core is defined by its highest point. If there is only one single point rising up regularly, this part can be inserted, so as to make the core shorter during dimensioning. Easy Processing for mold making. During processing, EDM is the slowest equipment with the poorest precision. As a result, an insert is selected to avoid EDM processing. Facilitate Ventilation. Inserts are us...