There are two templates on the injection molding machine, one is not moving, called the fixed template; the other can be moved, called the moving template. The molds are attached to the two templates by screws and pressure plates, respectively. When the mold is opened, the moving template of the injection molding machine moves, thereby driving the mold to open.
After the mold is finished, it is necessary to carry out injection molding, and the injection molding machine starts to hit the product. However, there are many models of injection molding machines, each of which has its own parameters. The design of the mold must be able to meet the customer's requirements for the injection molding machine model, otherwise it will not be able to produce.
There are many design parameters for the injection molding machine. The following focuses on several parameters related to the mold.
The injection quantity is the maximum mass value (or volume value) that the injection molding machine can shoot the melt at one time, which represents the maximum injection capacity of this type of injection molding machine. The amount of melt glue used in the mold of the design is smaller than that of the injection molding machine. Otherwise, the product is not full and cannot be produced.
2. Clamping force
The clamping force is the pressing force of the injection molding machine to the template when the mold is closed. The clamping force required for the molded article to be formed must be less than the rated clamping force of the selected injection molding machine. Otherwise, the glue is easy to run from the parting surface, creating a flash.
Clamping force = clamping force constant × product projection area: P = Kp × s
3. Pull rod spacing
There are four tie rods in the injection molding machine and the movable template dead angle. Their role is to ensure that the injection molding machine has sufficient strength and rigidity, and is responsible for sliding the template. However, it tends to limit the size of the mold because the mold is mounted from the middle of the tie rod.
The mold dimensions cannot be larger than their tie rod spacing at the same time. If the length dimension of the mold exceeds the distance between the rods, look at whether the mold is hoisted into the rod workshop by rotation. If the rotation cannot be carried out, only the mold size can be changed. Or replace the injection molding machine.
4. Nozzle size check
The nozzle head of the injection molding machine is generally spherical. When selecting the sprue bushing, the spherical radius of the sprue bushing should be matched with the radius of the nozzle spherical surface. In order to prevent the high pressure melt from overflowing from the contact gap between the nozzle and the sprue bushing, the radius of the ball of the sprue bushing should be smaller than the radius of the nozzle, and the size of the small end of the main channel should be slightly larger than the size of the nozzle hole, so that the nozzle can be poured It is easier to align the mouthpiece.
5. Checking the ejector
Classification of ejector
(1). Center ejector mechanical ejection
(2). Double ejector mechanical ejection on both sides
(3). The hydraulic jacking of the center ejector and the mechanical ejection of the double ejector on both sides
(4). The hydraulic jacking of the center jack is combined with other auxiliary cylinders.