Professional Zinc Alloy Surface Finishing Solutions

Hand Polishing

Hand-Polishing

Definition

Hand-polishing refers to a pretreatment process that uses manual operation of polishing tools combined with abrasive media or polishing paste to perform physical grinding on the surface of zinc alloy zipper sliders and luggage accessories. Its core purpose is to remove surface defects of workpieces, improve surface finish, and provide a uniform and clean substrate for subsequent barrel plating

1. Core Overview

Key Characteristics of Hand Polishing

High flexibility

Can accurately adapt to complex structures such as gaps of zipper sliders and corners of luggage accessories, making up for the insufficient dead angle processing of mechanical polishing.

High controllability

Operators can adjust polishing pressure, speed and angle in real time according to the surface condition of workpieces, avoiding batch processing defects.

Suitable for soft substrates

Aiming at the soft texture of zinc alloy, hand-polishing can reduce substrate loss through refined operations and ensure the dimensional accuracy of workpieces.

Controllable cost

No need for complex automated equipment, suitable for small and medium batch, multi-category zinc alloy accessory production scenarios.

2. Equipment Selection

2.1 Automatic Hardware Polishing/Buffing Machine

Applicable Polishing Stage: Rough Polishing, Medium Polishing Supporting Tool Parameters: Grinding Wheel: Diameter 125mm, Grit 40-80 Mesh; Cloth Wheel: Diameter 125mm, Medium Hardness

2.2 Polishing Machine with Dust Cover

Supporting Tools: Dual Cloth Wheels (Diameter 200mm), Can Install Rough/Finish Polishing Wheels Simultaneously Applicable Scenarios: This machine used for products such as puller and sliders.

3. Key Materials

3.1 Polishing Wax

① Rough Polishing: Yellow Wax Wax Type: Coarse-grained wax Recommended Proportion:40%–50% ② Fine Polishing:Purple Wax Wax Type: Medium-grained wax Recommended Proportion:30%–35% ③ Refined Polishing:Green Wax Wax Type: Fine-grained wax Recommended Proportion:20%–25%

3.2 Polishing Wheel

① Rough Polishing: Linen Polishing Wheel ② Fine Polishing: Linen Polishing Wheel ③ Refined Polishing: Fabric Polishing Wheel / Cotton Polishing Wheel / Bleached Fabric Polishing Wheel

4. Standard Operation Process

5-Step

1.Batch-thread products into fixtures, then transfer to splints 2.Apply yellow wax to the polishing wheel 3.Start polishing 4.Finish polishing 5.Conduct product comparison Note: Do not pick up the polished product immediately; it will be very hot.

5. Key Notes

Workpiece deformation

Zinc alloy has a soft texture (hardness about HB60-80), and the polishing pressure should be controlled at 0.3-0.5MPa to avoid workpiece deformation and excessive polishing loss of the substrate

Dust-proof environment

The polishing environment should be dust-proof, avoid stacking friction during workpiece turnover, and use special material frames for separation

Cannot be mixed

Abrasive media/polishing paste of different polishing stages cannot be mixed to prevent cross-contamination from affecting gloss

Overheating

Avoid overheating of workpieces during polishing (temperature ≤60℃), overheating is likely to cause oxidation and discoloration of zinc alloy, and intermittent polishing can be used for cooling

Dead corner treatment

Dead corners such as gaps of zipper sliders and corners of luggage accessories need to be focused on to avoid residual polishing paste affecting the uniformity of subsequent barrel plating

6. Expert Tips

Prioritize the combination of "dry polishing + semi-dry polishing"

dry polishing for rough polishing improves efficiency, and semi-dry polishing (wet with a small amount of polishing liquid) for medium/fine polishing improves gloss

Select equipment according to workpiece size

small handheld polishing tools are preferred for zipper sliders (small size), and bench-top polishing machines can be matched for large luggage accessories

Test polishing verification is required before mass production

determine polishing pressure, speed and time parameters to ensure that the workpiece dimensional tolerance (±0.02mm) meets the requirements

7. Why Choose QLQ?

1. We have a complete quotation sheet. If you need it, feel free to contact us! 2. We not only supply machines and raw materials, but also show you how to use them after you purchase them, so as to ensure that you can polish products to a glossy finish. We will guide you through every step of the process with hands-on instructions for all the key details. If you buy the machines from us, we will provide you with a complete solution, teach you all the operational specifics, and make sure you can produce high-quality polished products.

Get a Free Quote Today

Send us your samples or drawings — our engineers reply within 24 hours with pricing and technical advice.

Workshop Planning Data

Hand Polishing — Data Zinc Alloy Finishing Managers Need

Hand polishing and buffing delivers the mirror finish required for zipper sliders, luggage hardware and jewelry-grade zinc alloy parts, and is the bridge between die-casting quality and plating brilliance.

260 m²Workshop Area

14 peopleTeam Size

74 kWInstalled Power

200-400k pcs/dayDaily Output (10 h)

Quality Inspection & Control

Check item	Method	Acceptance standard
Mirror finish grade	Gloss meter 60°	Gloss ≥ 800 GU on visible surfaces
Wheel marks / streaks	Angle-light inspection	No visible buffing streaks after waxing
Edge & corner integrity	10× magnifier	No rounded-off sharp edges; geometry preserved
Wax residue	Wipe + solvent test	No buffing compound left in grooves or holes
Surface roughness	Ra tester	Ra ≤ 0.2 μm before bright plating
Consistency	Master sample comparison	Operator output matches approved master within ΔE < 1

Workshop Layout & Floor Area

Zone	Area
Hand bench area (16 benches)	120 m²
Buffing / finishing area	60 m²
QA & master samples	30 m²
Wax & consumable store	20 m²
Utility & lockers	30 m²
Total workshop	260 m²

Manpower & Shift Plan

Role	Headcount
Hand polishers / buffers	10
QC inspectors	2
Line supervisor	1
Maintenance / utility	1
Total (2 shifts × 10 h)	14

Power & Utility Demand

Equipment	Demand
16 × bench spindles (2.2 kW each)	35 kW
Buffing motors (4 × 3 kW)	12 kW
Dust extraction	9 kW
Air compressor	11 kW
Lighting & auxiliary	7 kW
Installed total	74 kW
Typical running load	≈ 60 kW

Production Flow Chart

Receive & SortGroup parts by size and finish class

Rough PolishRemove die-cast seams and parting lines

Fine BuffWax + cloth wheel to mirror finish

Clean & DegreaseRemove buffing compound residue

QC InspectGloss, streaks, geometry check

Protect & TransferWrap in trays, transfer to plating

Daily Capacity — 10-Hour Operating Day

Parameter	Value
Cycle per batch	20-35 min
Operator output	15,000-25,000 pcs / 10 h
Daily line output	200,000-400,000 pcs
Monthly output (26 days)	5-10 million pcs
Reject target	≤ 1.5%

Output Value Estimate

Parameter	Value
Processing fee per piece	USD 0.004-0.010
Daily output value (10 h)	USD 1,200-2,800
Monthly output value	USD 31,000-72,000
Annual output value	USD 375,000-870,000