Shenzhen Alu Rapid Prototype Precision Co., Ltd.

Plastic "hair" in injection molding usually refers to one of two things in manufacturing (especially for toys, dolls, action figures, or custom collectibles):

1.Molded plastic hair pieces — separate, sculpted hair components that are injection molded as rigid or semi-flexible plastic parts (often with detailed strands, waves, or styles).

2.Rooted hair — where synthetic hair fibers (like nylon or saran) are implanted into a pre-molded plastic head (not truly "injection molded" hair, but a post-molding process).

True injection-molded hair (where the hair strands themselves are formed directly during the injection process) is rare for realistic, flowing hair because plastic injection excels at solid, defined shapes rather than thousands of ultra-fine, flexible filaments. However, it is done for stylized, sculpted hair on figures and toys.

1. How Injection-Molded Plastic Hair Pieces Work (Common in Action Figures, Collectibles, Custom Minifigs)

This is the most direct form of "injection molding hair."

1.Process Steps:

          Mold Design — A precision steel or aluminum mold is created with detailed cavities shaped like individual hair strands, locks, bangs, ponytails, etc. These molds often have very fine details (sometimes with multi-slide actions or lifters for undercuts/complex shapes).

         Material Selection — Soft/flexible plastics like PVC, TPE, or PP are used for a slight "hair-like" flexibility, or harder ABS/PC for rigid, sculpted styles. Multi-shot or overmolding can create gradient colors or layered effects.

         Injection — Molten plastic is injected under high pressure into the hair-shaped cavities (often as a separate part from the head).

Cooling & Ejection — The part solidifies quickly, then ejects. Thin strands or fine details require excellent venting, cooling channels, and precise control to avoid defects like short shots or flash.

        Assembly — The molded hair piece is attached to the figure's head (snap-fit, glue, or insert-molded directly in some advanced setups)

2.Examples — Many modern collectible figures (e.g., custom LEGO-style minifig hairpieces, anime figures, or premium dolls) use injection-molded plastic hair for sharp, consistent details that painted or rooted methods can't match easily.

3.Advantages — Fast production, repeatable detail, no secondary assembly for the hair itself if overmolded.

4.Limitations — Strands can't be as fine/flexible as real synthetic hair fibers; best for stylized/cartoonish looks.

We at Shenzhen Alu Rapid Prototype Precision Co., Ltd. can design and produce such custom injection molds for plastic hair pieces — whether single-cavity prototypes or multi-cavity production tools — often in aluminum for faster turnaround on toy/figure projects.

2. Rooted Hair on Dolls/Toys (Most Common "Hair" in Mass-Produced Dolls)

This is what people usually mean when asking about doll hair manufacturing — it's not injection molded, but a separate process after the head is molded.

1.Process:

       The doll head (usually vinyl, soft PVC, or TPE) is injection molded first — hollow or solid, with small pre-punched or laser-drilled holes in the scalp.

       Hair Rooting/Implantation — Machines (or hand-rooting for high-end) use special needles to push looped bundles of synthetic hair fibers (nylon, kanekalon, or saran) through the holes from inside the head.

       The loops are secured (tied, glued, or heat-sealed) inside the head.

       Hair is styled, trimmed, and sometimes heat-set for curls/waves.

2.Why not injection molded? — True fine, flowing hair requires individual filaments that move independently — injection molding can't economically produce millions of ultra-thin, loose strands in one shot without them fusing or breaking.

Visual Examples of Injection-Molded Plastic Hair

Here are some illustrative examples of what injection-molded hair pieces look like on toys/figures:(These show typical molded plastic hair on collectible figures — detailed, sculpted strands in various styles and colors.)