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...

  Jetting, also known as jet, worm track, or snake-like pattern, refers to the snake-like curves on a plastic injection molded part along the flow direction from the gate, as shown in Figure    1. Under normal circumstances, the molten plastic fills the mold cavity in a “fountain flow” manner, as shown in Figure  2, which depicts the “fountain flow” in detail. However, when the molten plastic flows at a high speed through narrow areas, such as the nozzle, the runner and the gate, and then suddenly enters an open and relatively wider area, the plastic melt will be injected from one end to the other of the cavity in the form of jet streams, creating folded strips. The melt that enters the cavity later fills the remaining space in the mold cavity with a normal fountain flow and is welded to the jetted streams. Since the melt is immediately cooled the moment it makes contact with the cavity wall (mold surface) which has a relatively low temperatu...

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 (...

1, filling defect It always show uncomplete filling or edge collapse,it will dective product,waste material,labor and time.ther are many possible reason, such as nozzle temperature is too low,not enough supply,flowablity not good,injection pressure is low,the gate is too small or not right position,the mold surface is not smooth enough,nozzle is blocked,venting problem     2,flash or burr It always happen in parting line,it will increase the difficulty of machining or dishape,even defective.the possible reason such as:nozzle temperature too high,injection too much material,flowbility is very good,injection pressure too high,clamping force too small     3,sink mark It always caused by material shrink after injection molding,possible reason such as:nozzle temperature too high,resin supply not enough,shrinkage is too big,injection molding pressure too low,holding time too short,injection speed too slow,mold teperature too high,cooling time too short,the thickness of pr...