Precision 3C Product Injection Mold | Built-to-Print Tooling

Product Overview

We specialize in the design and manufacturing of custom injection molds for Bluetooth earbuds plastic housing shells, widely used in 3C consumer electronic products.

Bluetooth earbuds housings are compact, appearance-sensitive components that require:

• High-dimensional accuracy for internal assembly

• Clean cosmetic surfaces for visible exterior areas

• Stable wall thickness for balanced molding

• Reliable performance under high-volume production

This type of 3C product injection mold is developed strictly according to customer 3D data and technical specifications, covering mold design, precision machining, assembly, and trial validation.

Our goal is to deliver molds that not only pass sampling but also run stably in mass production.

Application Scenarios

This custom injection mold is typically used for:

• Bluetooth earbuds with plastic housing shells

• TWS earphone enclosures

• Charging case components

• Small precision consumer electronic housings

• Appearance-sensitive 3C plastic parts

These products demand strict tolerance control and consistent surface quality.

Key Mold Engineering Focus

Injection molds for Bluetooth earbuds housings are different from general industrial molds.
The primary challenges lie in appearance control, precision fit, and deformation management.

1) Cosmetic Surface Control

Earbuds housings are visible exterior parts. Even minor surface defects are unacceptable.

• Optimized gate position to reduce weld lines

• Controlled flow balance to minimize sink marks

• Precision cavity polishing or texture finishing

• Accurate parting line alignment to prevent flash

Surface stability is critical for consumer electronics.

2) Precision Fit & Structural Accuracy

The housing must be assembled precisely with PCB boards, speakers, batteries, and internal components.

• Tight dimensional control of internal features

• Proper shut-off structure design

• Shrinkage compensation during mold design

• Stable mold alignment to maintain assembly tolerance

Assembly yield directly depends on mold accuracy.

3) Thin-Wall & Warpage Control

Bluetooth earbud housings often feature thin-wall structures.

• Balanced runner and gate system

• Optimized cooling layout

• Stress control during filling

• Moldflow analysis when required

The objective is to maintain dimensional stability after molding.

Mold Specifications

• Mold Type: Custom Injection Mold for 3C Products

• Product Material: Plastic (as specified by customer)

• Gate Type: Side gate / Sub gate / Pin point gate / Fan gate / Direct gate

• Runner System: Hot runner or Cold runner

• Mold Material: 1.2343 ESR / NAK80 / S136 or equivalent

• Mold Base: LKM / HASCO / DME / FUTABA

• Mold Life: Up to 1,000,000 shots (depending on material and design)

• Supported Drawing Format: STP / STEP / IGS / PRT / X_T

• MOQ: 1 set

Manufacturing Capabilities

Our tooling facility supports single-cavity and multi-cavity 3C molds.

• Maximum mold size: 2500 × 2000 × 1500 mm

• Machining precision: ±0.005 mm

• Injection precision: ±0.03 mm

• Lead time: 25–45 days, depending on mold complexity

In-house equipment includes:

• High-precision CNC machining centers

• EDM and mirror EDM

• Wire cutting machines

• Coordinate Measuring Machine (CMM)

Each mold undergoes dimensional inspection and trial molding before delivery.

Project Workflow

1. 3D data review and DFM analysis

2. Mold structure design confirmation

3. Steel preparation and rough machining

4. Precision machining and EDM

5. Mold assembly and fitting

6. Mold trial and parameter optimization

7. Final inspection and shipment

This structured workflow reduces trial iterations and improves first-shot quality.

Why Work With Us

• Experience in precision molds for 3C consumer electronics

• Familiar with compact structural and appearance-sensitive parts

• Stable machining supported by in-house precision equipment

• Clear technical communication throughout the project

• One-year after-sales support

We focus on molds that perform reliably in production, not only on initial approval.

Technical FAQ

Q1: How many mold trials are usually required before mass production?
The number of trials depends on product complexity and appearance requirements. With proper DFM review and structural evaluation, the first-trial success rate can be significantly improved.

Q2: Can you control cosmetic defects such as weld lines and sink marks?
Yes. Gate design, flow balance, and cavity finishing are optimized during mold design to reduce visible defects. Surface polishing or texture control is performed according to appearance standards.

Q3: Do you support high-gloss or textured surface finishes?
Yes. Cavity surfaces can be mirror-polished or textured based on customer specifications.

Q4: Can this mold be designed as a multi-cavity mold?
Yes. Depending on production volume and part size, both single and multi-cavity configurations are supported.

Q5: Is after-sales technical support available?
Yes. We provide technical assistance for parameter optimization and necessary mold adjustments after delivery.

Request a Quotation

To receive a quotation for a Custom Injection Mold for Bluetooth Earbuds Plastic Housing Shell, please provide:

• 3D product files (STP / STEP / IGS, etc.)

• Material specification

• Surface finish requirements

• Expected production volume

• Target lead time

Our engineering team will review your data and provide a detailed mold proposal.