(1) Single Parting Surface Injection Mold
When the mold opens, the moving mold and the fixed mold separate to remove the plastic part. This is called a single parting surface mold, also known as a two-plate mold. It is the simplest and most basic form of injection mold. It can be designed as a single-cavity injection mold or a multi-cavity injection mold as needed, and it is the most widely used type of injection mold.
(2) Double Parting Surface Injection Mold
A double parting surface injection mold has two parting surfaces. Compared with a single parting surface injection mold, a double parting surface injection mold adds a partially movable intermediate plate (also called a movable sprue plate, which has a sprue, runner, and other parts and components required by the fixed mold) to the fixed mold part. Therefore, it is also called a three-plate (moving plate, intermediate plate, fixed plate) injection mold. It is often used in single-cavity or multi-cavity injection molds with point gate injection. When the mold opens, the intermediate plate separates from the fixed platen at a certain distance on the guide pillars of the fixed mold to remove the solidified material of the gating system between the two plates. Double parting surface injection molds have complex structures, high manufacturing costs, and difficult component processing, and are generally not used for molding large or extra-large plastic products.
(3) Injection molds with side parting and core-pulling mechanisms
When the plastic part has side holes or side recesses, a side-moving core or slider is required for molding. After injection molding, the moving mold first moves downward a certain distance, and then the inclined section of the bent pin fixed to the fixed mold plate forces the slider to move outward. At the same time, the ejector rod of the demolding mechanism pushes the ejector plate to remove the plastic part from the core.
(4) Injection molds with movable molding components
Due to certain special structures of the plastic part, the injection mold is required to have movable molding components, such as movable punches, movable cavities, movable inserts, movable threaded cores or rings, etc., which can be removed from the mold along with the plastic part during demolding and then separated from the plastic part.
(5) Automatic Unscrewed Injection Mold
For threaded plastic parts, when automatic demolding is required, a rotatable threaded core or ring can be installed on the mold. The opening action, the rotation mechanism of the injection molding machine, or a dedicated transmission device can be used to rotate the threaded core or ring, thereby removing the plastic part.
(6) Runnerless Injection Mold
A runnerless injection mold uses a method of insulated heating of the runner to keep the plastic between the injection molding machine nozzle and the cavity in a molten state, so that no solidified material from the gating system is present when the plastic part is removed from the mold. The former is called an insulated runner injection mold, and the latter is called a hot runner injection mold.
(7) Right-Angle Injection Mold
Right-angle injection molds are only suitable for angle injection molding machines. Unlike other injection molds, the feeding direction of this type of mold is perpendicular to the mold opening and closing direction during molding. Its main runner is located on both sides of the parting surface between the moving and fixed molds, and its cross-sectional area is usually constant, which differs from molds used in other injection molding machines. To prevent wear and deformation of the injection molding machine nozzle and the inlet end of the main runner, replaceable runner inserts can be installed at the end of the main runner.
(8) Injection molds with demolding mechanisms on the fixed mold
In most injection molds, the demolding device is installed on the moving mold side, which facilitates the operation of the ejection device in the injection molding machine's mold opening and closing system. In actual production, due to the shape limitations of some plastic parts, it is better to leave the plastic part on the fixed mold side for molding. Therefore, to remove the plastic part from the mold, a demolding mechanism must be installed on the fixed mold side.
