There are many types of gates for plastic injection molding parts, such as Direct sprue gate, Side gate, Fan gate, Pinpoint gate, Submarine gate, etc. Every type of gate that has its advantages, today we will explain each type of molding gate when you use your molding parts, according to each gate of advantages and disadvantages you could choose the gate you prefer,

Gate types and descriptions

  1. Direct sprue gate – used in the case of single-cavity or when putting the gate direct to the base of the injection-molded product. Residual strain tends to occur because the injection pressure will directly apply to the molded product, but its mold construction is most simple, this type of gate is normally for the none appearance part surface.
  2. Side gate – this type is the most generally adopted and used well in multi-cavity molds. Its shape is rectangle or semicircle and placed at the side of the molded product, this is normal gate which used for the molded parts,
  3. Fan gate – its structure is similar to the side gate, but the gate width is bigger and fan-shaped. Used in large size molded products, this type of gate is normally for the clear injection molding parts, such as PMMA injection molding parts, PC injection molding parts or any other transparent clear plastic molding parts, the reason this type of gate is easy to mold the good surface, but the disadvantages are this type gate is hard to trim off, must use some special tool or laser cutting process.
  4. Pinpoint gate – diameter of the pinpoint gate is between 0.5mm to 2mm, and as an advantage, it does not need any finishing. Gate allowance is fast and pressures that because balance strain will not join to the molded stock. If the gate cross-sectional areas are small, flow distance will decrease and flow marks tend to occur around the gate, this type of gate is normally for the multiple cavity small parts, like 16 cavity or 24 cavity molds, when you use this type of gate then we normally call this mold as 3 plate mold.
  5. Disk gate – this gate is used to prevent eccentricity and weld when molding disk or cylinder-shaped products, however, there is a disadvantage in that the finishing of the gate part is difficult.
  6. Film gate – this type will be applied to the plate-shaped molded product. This type is effective to prevent deformation by suppressing strain.
  7. Tap gate – this is a method that sets up a tab on the side of the molded product, and the gate is placed there. Commonly, the gate and the tab should be fixed at a proper angle. Gate allowance will allow on the gate separate, so overcome balance strain and movement marks under the tab are available, after molding this tap will be cut off by manual.
  8. Submarine gate – there is a runner part on the parting line shallow, but the gate reaches the side of the molded element through a fixed template or moving template from the runner part. When releasing the mold opening, the gate will automatically get cut, this is the most common gate we sue to product the part, fast and automatically, one of the best gate types in the plastic mold technology, the disadvantages is for some of the parts does not have enough space for the sub-gate.

Cold runner - side gate - fan gate

Advantages of plastic injection molding

  • Plastic injection molding allows manufacturers to produce large quantities of plastic parts in a fast efficient and cost-effective manner.
  • This process injects molten plastic into stiff molds or frames and then applies pressure as the plastic cools.
  • Using this technique, plastic part manufactures enjoy a high degree of design flexibility and can create parts of almost any size, shape, or function.
  • This process can also build complex designs with multiple intricate elements.
  • Beyond its versatility and efficiency plastic injection molding of manufacturers.
  • A number of important advantages by reducing cost as well as the environmental impact of production.
  • Once the molds are created equipment programmed, manufacturers can produce quantities of parts that fit the precise specification.
  • The molds used for plastic injection don’t need to be replaced or adjusted as often as those used for other manufacturing processes.
  • This ensures that more parts are produced in less time without sacrificing precision.
  • Plastic injection molding saves money and time while improving quality and output.