{"id":14751,"date":"2026-09-15T09:49:13","date_gmt":"2026-09-15T09:49:13","guid":{"rendered":"https:\/\/elitemoldtech.com\/2-plate-vs-3-plate-mold\/"},"modified":"2026-10-01T09:58:17","modified_gmt":"2026-10-01T09:58:17","slug":"2-plate-vs-3-plate-mold","status":"publish","type":"post","link":"https:\/\/elitemoldtech.com\/ko\/2-plate-vs-3-plate-mold\/","title":{"rendered":"2-Plate vs 3-Plate Injection Molds: Differences, Cost and Part Design Impact"},"content":{"rendered":"

A two-plate mold has one parting line, so the runner and parts eject together and the gate usually sits on the part’s edge. A three-plate mold adds a second parting line that strips the runner away automatically and lets small pin-point gates sit anywhere on the part. In the 2-plate vs 3-plate choice, two-plate is cheaper and simpler.<\/p>\n

Three-plate earns its extra cost when the gate has to be on the face or center of the part.<\/p>\n

How a Two-Plate Mold Works<\/h2>\n

A two-plate mold splits into two halves: the cavity side on the fixed platen and the core side on the moving platen. Plastic flows from the sprue through runners on the parting line and enters the part through a gate, usually an edge gate or a submarine gate.<\/p>\n

When the mold opens, the part and runner eject together, and the runner is then cut off by hand or removed by a robot. A submarine gate shears itself off.<\/p>\n

Two-plate tools are the default for most parts. Fewer components. A short stroke, quick cycles, and the lowest cost to build and maintain.<\/p>\n

How a Three-Plate Mold Works<\/h2>\n

A three-plate mold adds a runner plate between the fixed half and the cavity plate, creating two parting lines. The runner system therefore sits on its own plane, above the parts, and feeds each cavity through a tiny gate.<\/p>\n

The mold opens in sequence, controlled by latch locks and puller bolts:<\/p>\n

    \n
  1. The first opening breaks the pin-point gates and frees the runner.<\/li>\n
  2. A stripper plate pushes the runner off its pullers.<\/li>\n
  3. The main parting line opens and the parts eject.<\/li>\n<\/ol>\n

    Parts and runner drop separately, so no one has to degate by hand, which is the main operational advantage. The price is complexity: more plates, more wear parts and a longer opening stroke.<\/p>\n

    2-Plate vs 3-Plate: Side by Side<\/h2>\n

    The table compares 2-plate and 3-plate molds on the factors that drive cost and design.<\/p>\n\n\n\n\n\n\n\n\n\n\n\n\n
    \uc694\uc778<\/td>\nTwo-plate mold<\/td>\nThree-plate mold<\/td>\n<\/tr>\n
    Parting lines<\/td>\nOne<\/td>\nTwo<\/td>\n<\/tr>\n
    Typical gates<\/td>\nEdge, submarine, direct sprue<\/td>\nPin-point, anywhere on the part<\/td>\n<\/tr>\n
    Runner separation<\/td>\nManual, robot or sub gate<\/td>\nAutomatic in the mold<\/td>\n<\/tr>\n
    Tool price<\/td>\nLower<\/td>\n\ub354 \ub192\uc74c<\/td>\n<\/tr>\n
    Cycle time<\/td>\n\ub354 \uc9e7\uac8c<\/td>\nSlightly longer<\/td>\n<\/tr>\n
    Runner waste<\/td>\nShorter runners<\/td>\nLonger runners<\/td>\n<\/tr>\n
    Mold opening<\/td>\nShort<\/td>\nLonger, needs more press daylight<\/td>\n<\/tr>\n
    \uc720\uc9c0 \uad00\ub9ac<\/td>\nSimple<\/td>\nMore wear parts<\/td>\n<\/tr>\n
    \ucd5c\uc0c1\uc758 \ub300\uc0c1<\/td>\nMost parts, edge-gated designs<\/td>\nCenter gating, multi-cavity round or cosmetic parts<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

    Where the Gate Goes Decides the Mold<\/h2>\n

    For many parts, the two-plate or three-plate question comes down to one thing: where the gate is allowed.<\/p>\n

    Edge gating works for flat, rectangular and side-accessible parts. It leaves a small mark on the edge that can be trimmed or hidden.<\/p>\n

    Center gating suits round parts, caps, cups and deep housings, because filling from the center gives balanced flow, even shrinkage and fewer weld lines. That helps roundness and flatness a great deal. On a two-plate tool, center gating is only possible with a single cavity fed straight from the sprue. For several cavities gated at the center, you need three plates or a hot runner.<\/p>\n

    Long, thin parts may also need several gates along their length to fill before the plastic freezes, which again points to pin-point gating.<\/p>\n

    Typical Parts for Each Mold Type<\/h2>\n\n\n\n\n\n\n\n\n\n
    Part<\/td>\nUsual choice<\/td>\n\uc774\uc720<\/td>\n<\/tr>\n
    Flat covers and brackets<\/td>\nTwo-plate<\/td>\nEdge gate is acceptable<\/td>\n<\/tr>\n
    Clips and small technical parts<\/td>\nTwo-plate with sub gates<\/td>\nAutomatic degating at the edge<\/td>\n<\/tr>\n
    Bottle caps and closures<\/td>\nThree-plate or hot runner<\/td>\nCenter gate for roundness<\/td>\n<\/tr>\n
    Cups and deep containers<\/td>\nThree-plate or hot runner<\/td>\nBalanced fill from the center<\/td>\n<\/tr>\n
    Cosmetic housings with hidden gate spots<\/td>\nThree-plate<\/td>\nGate inside a recess on the face<\/td>\n<\/tr>\n
    Single large round part<\/td>\nTwo-plate with sprue gate<\/td>\nOne cavity, center fill<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

    These are typical 2-plate and 3-plate applications, not rules. Resin, cavity count and volume can change the answer.<\/p>\n

    Marking Gate Locations on Your Drawing<\/h2>\n

    Designers often leave gate location to the toolmaker, then reject samples because of a gate mark on a visible surface. A few drawing notes prevent that:<\/p>\n