ABS

Common thermoplastic, impact resistant, easy to machine. ABS is a common thermoplastic with all-around good mechanical properties, excellent impact strength, good heat resistance and good machinability.

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Contents

1.Advantages of ABS Injection Molding

2.Applications of ABS Molded Parts

3.Tips for Better Surface Finish

4.Optimal Molding Parameters

5.Case Study

1.Advantages of ABS Injection Molding

• Excellent mechanical properties
• Cost-effective material
• Easy to mold with stable processing
• ABS injection molding is widely used across electronics, home appliances, office equipment, instruments, machinery, and automotive parts.

We have produced ABS molded components for:

• Lighting products: lamp housings, diffusers, and reflectors
• Refrigeration and appliances: portable car refrigerators, knobs, and covers
• Mechanical parts: gears, protective panels, and enclosures
• Daily-use and lifestyle products: suitcase wheels and pet bowls
• And many other custom plastic components across various industries.

2.Application Fields of ABS Injection Molding

• Instrumentation & Light Industry: instrument panels, cases, brackets, cabinets, and musical instruments
• Construction: drainage ducts, pipe fittings, window and door frames, safety caps
• Automotive: interior and exterior parts, grilles, lamp covers, dashboards, control panels

3.How to Achieve a Good Surface Finish for ABS Injection Molded Parts

The appearance of ABS molded parts mainly depends on mold quality, processing parameters, and raw materials.

3.1 Mold Quality

• Cavity finish: Poor polishing or surface defects (scratches, pores, roughness) will directly affect the part's appearance. We ensure a mirror finish and use chrome plating if needed.
• Cleanliness: Oil, water stains, or excessive release agent can dull the surface. Molds are regularly cleaned and maintained.
• Draft angle: Insufficient draft makes demolding difficult and can cause surface drag marks. We optimize draft angles during DFM review.
• Venting system: Poor venting causes gas marks or dull surfaces. Each mold design is carefully checked for proper venting.
• Gate and runner design: Too small or abrupt changes increase shear and turbulence, resulting in poor gloss. We conduct mold flow analysis to optimize runner and gate sizes.

3.2 Molding Parameters

• Injection speed: Too slow or too fast can both cause surface defects. Proper balance ensures smooth filling and gloss.
• Cooling system: Inadequate cooling for thick parts leads to rough or matte surfaces. We optimize cooling channels for even temperature control.
• Holding pressure & time: Insufficient pressure or short holding time causes low density and poor surface finish.
• Melt temperature: Low melt temperature reduces flowability and gloss. Adjusting melt temperature improves surface quality.

3.3 Raw Materials

• Granule uniformity: Uneven particle size leads to poor melting and bad appearance-materials are screened before molding.
• Recycled content: Excessive recycled material affects quality and appearance; we control its proportion strictly.
• Moisture content: Moisture causes bubbles and surface defects; materials are pre-dried before production.
• Additive dispersion: Poorly mixed additives affect gloss; we use high-quality, well-dispersed materials.
• Impurities: Foreign materials cause spots or roughness; we ensure raw materials are clean and pure.

4.Best Parameters for ABS Injection Molding

4.1Key Properties

Moisture Sensitivity: ABS easily absorbs moisture; raw materials must be dried until moisture is below 0.3% to ensure gloss and strength.

Flow Behavior: The melt is non-Newtonian - higher injection pressure reduces viscosity and improves filling.

Shrinkage Rate: 0.3–0.8%, allowing precise dimension control.

Machine Type: Screw-type injection machines offer better quality and stability; all our production lines use screw-type machines.

Injection Volume: Recommended to use up to 50% of the machine's maximum shot size for better dimensional stability and surface gloss.

Runner Design:

-Main runner ≤100 mm (ideally ~50 mm)

-Sub-runner 5–10 mm for smooth filling

Ejection Force: Should be moderate to avoid whitening on part surfaces.

Post-Treatment: To release internal stress, parts are heat-treated at 70 °C for 2–4 hours.

4.2Typical Molding Parameters

Barrel Temperature:

-General ABS: 180–230℃

-Heat-resistant ABS: 190–240℃

-Flame-retardant ABS: 170–220℃

Nozzle: 20–30℃ lower than front barrel

Mold Temperature: 50–70℃ - crucial for surface quality and dimensional accuracy.

Injection Pressure:

-General ABS: 50–70 MPa

-Heat-resistant ABS: 60–85 MPa

-Flame-retardant ABS: 60–100 MPa

Adjust based on wall thickness and flow resistance.

5.ABS Injection Molding Case Study

5.1Product Basic information

Product Name: Switch Cover

Product Color: Light Gray

Product Size: 23.6 x 114.6 x 43.6 mm

Average thickness：1.76 mm

Cavity：2 Cavity

Product Material: ABS V0

Product appearance Requirements: No welding line, No any appearance defects

Switch Cover Design Drawing

5.2Preliminary Analysis

During the early stage of development, the following aspects were analyzed to ensure manufacturability:

Wall Thickness: 1.76 mm average, uniformity checked to prevent sink marks or warpage

Draft Angles: Assessed to facilitate ejection without surface scratches

Ribs and Reinforcements: Evaluated for mechanical strength while maintaining minimal material usage

Filling Simulation: Initial MoldFlow analysis predicts flow patterns, weld line formation, air traps, and potential short shots

Cooling Consideration: Front and rear mold cooling preliminary layout analyzed for cycle time optimization

5.3 Optimized Design

Based on preliminary analysis, the switch cover design was optimized as follows:

• Wall thickness slightly adjusted for uniform flow
• Ribs repositioned and dimensioned for strength without affecting appearance
• Gate location adjusted to avoid visible weld lines
• Cooling channels repositioned for balanced temperature distribution

Final Summary

The ABS V0 switch cover has been successfully optimized to meet both functional and aesthetic requirements. Key improvements include uniform wall thickness, reinforced ribs, strategic gate positioning, and efficient cooling channels. The final design ensures high-quality production with minimal defects, stable mechanical performance, and excellent appearance, ready for reliable mass manufacturing.