Different production processes are chosen based on the material properties and desired characteristics of the final product.
The typical mass‑production workflow for collectible toys includes the following stages: Design → Prototype → Tooling (Mold Making) → Injection Molding → Decoration → Assembly → Packing.
Among these, injection molding is one of the most widely used processes for manufacturing everyday plastic items – from computers, telephones, fax machines, keyboards, cups, to stereo equipment. In the toy industry, it is primarily employed for high‑precision assembled toys, such as Gundam models and Lego bricks. Blind box figures are also mainly produced via this method.
A general outline of the injection molding process is as follows:
Solid plastic raw materials (e.g., PVC, ABS) are heated to their specific melting points until they become molten. The molten plastic is then injected into the mold (tooling) at a controlled speed and under high pressure from the injection molding machine. Once the cavity is filled, the mold is cooled through built‑in water channels, causing the liquid plastic to solidify into a finished part that exactly matches the shape of the cavity. The entire cycle – from raw material feeding to finished product ejection – can be fully automated. This makes injection molding highly suitable for mass production, as it is fast, efficient, and capable of producing parts with complex geometries, tight tolerances, and consistent quality regardless of size.
The tooling (mold) is the core component of the injection process.
It must be both precise and durable, as it operates under high temperatures and repeated use. Injection molds are typically made of metal – most commonly steel and copper. Molds with simple structures and standard materials are relatively inexpensive, but if the parts require very high precision, the mold cost increases significantly.
A completed collectible figure is usually assembled from multiple plastic components – such as the head, torso, limbs, and accessories. Producing all these parts via injection molding requires a separate mold for each component. Consequently, the total cost of manufacturing and maintaining these molds is high, and the overall production cycle is longer. To balance tooling investment, production efficiency, and the complexity of steel molds, manufacturers typically run batches of 3,000 to 5,000 units per production run.
Apart from the high mold cost, the Achilles' heel of injection molding lies in two inevitable defects: parting lines and gate marks.
The mold is composed of two halves – the injection side and the ejection side (also referred to as the A‑side and B‑side, or front and back halves). At the interface where these two halves meet, there is always a tiny gap. When the molten plastic is injected, a thin raised line forms on the finished part along this seam – this is known as the parting line. Gate marks, on the other hand, are small residual blemishes left at the point where the runner (the channel that delivers the molten plastic) connects to the part cavity.
Both parting lines and gate marks are unavoidable in the injection molding process. The perceived quality and premium feel of a collectible toy often depend on how well these imperfections are handled. On higher‑end, more finely crafted collectibles, these marks are made barely noticeable – either by placing them along inconspicuous edges or by post‑molding treatments such as polishing and manual repair after demolding.