Plastic wall plug anchor mold-1

Manufacturing Process of Plastic Expansion Anchor Molds

1. Mold Design

   • Structural Analysis: Expansion anchors are typically hollow cylinders with barbs or expansion slots, requiring a draft angle of 1°–2° for demolding.

   • Parting Surface Design: Mostly uses two-plate or three-plate mold structures to ensure smooth demolding.

   • Cooling System: Uniformly arranged cooling channels to prevent product deformation (temperature variation controlled within ±3°C).

2. Material Selection

   • Core/Cavity: Pre-hardened steel (e.g., P20, 718) or quenched steel (e.g., H13) with hardness HRC 48-52.

   • Expansion Anchor Material: Commonly PP (polypropylene) or nylon (PA6), known for good toughness and low cost.

3. Machining Process

   • CNC Rough Machining: Milling the basic shape of the mold base, leaving a 0.2mm allowance for finish machining.

   • EDM Precision Machining: Electrical discharge machining for fine structures like barbs and expansion slots.

   • Polishing: Mirror polishing of the cavity surface (Ra ≤ 0.8μm) to reduce demolding resistance.

   • Assembly & Trial: Adjusting the ejection system (air or mechanical ejection) and optimizing injection parameters.

4. Injection Molding

   • Process Parameters:

     • Barrel Temperature: PP (180–220°C), PA6 (240–280°C).

     • Injection Pressure: 60–100MPa.

     • Holding Time: Adjusted based on wall thickness (typically 5–15 seconds).

   • Post-Processing:

     • Deburring: Automated trimming or manual inspection.

     • Quality Testing: Sampling to test expansion force (must comply with GB/T 3098 standard).

Pictures of wall plug mold:

Applications of Plastic Expansion Anchors

Plastic expansion anchors (also known as wall plugs or anchor sleeves) are common construction fasteners primarily used for securing screws or hooks in substrates such as concrete and brick walls.