Silk Screen ABS Keycap Print

Screen Printing on Injection Molded Plastic Parts: Complete Process Guide for ABS and Engineering Plastics

Screen printing (silk screen printing) is a surface decoration process where ink is transferred through a stencil mesh onto the surface of a plastic part. The ink passes only through the open areas of the mesh to form precise patterns, symbols, or text on injection molded products.
Unlike UV printing, screen printing uses thicker ink layers, delivering:

• Excellent opacity
• Strong adhesion
• Long-term abrasion resistance
• High chemical and solvent resistance

For ABS keycaps, screen printing is widely used for:

• Letter marking
• Functional symbols
• Backlit legends
• Industrial control labels

Screen printing can be applied to most thermoplastic injection molded materials, but surface energy and ink compatibility must be optimized. At Benma Electric, we routinely screen print on the following plastics:
1. ABS (Acrylonitrile Butadiene Styrene)

• Most common material for keycaps and control panels
• Excellent ink adhesion
• Stable color performance
• Ideal for consumer electronics

2. PP (Polypropylene)

• Requires surface treatment due to low surface energy
• Used in automotive, home appliances, packaging
• Flame or plasma pretreatment recommended

3. PC (Polycarbonate)

• High transparency and impact resistance
• Frequently used in backlit products and light guides

4. PA (Nylon)

• Engineering plastic with strong mechanical strength
• Requires special solvent-based inks

5. PMMA (Acrylic)

• High gloss decorative parts
• Precision lettering with fine line thickness

6. TPU, TPE, Silicone (With Special Inks)

• Flexible plastics require elastic ink systems
• Used for buttons, wearables, medical devices

At Benma Electric, screen printing is integrated into our injection molding production flow to ensure maximum efficiency and consistency.

Step 1: Injection Molding of Plastic Parts

• Precision mold design
• Strict dimensional tolerance
• Clean, uniform surface finish
• Material controlled per customer specification (ABS, PP, PC, etc.)

Step 2: Surface Cleaning and Pretreatment

• Dust removal
• Oil and mold release agent elimination
• Plasma, flame, or corona treatment (especially for PP and low-energy plastics)
• Improves ink surface tension and adhesion

Step 3: Screen Plate Making

• Stainless steel or polyester mesh
• Mesh count selected by pattern resolution
• Emulsion coating and UV exposure
• Precision artwork alignment

Step 4: Ink Selection and Color Matching

• Solvent-based or UV-curable inks
• Color matched to Pantone or RAL standards
• Wear-resistant and chemical-resistant additive selection

Step 5: Screen Printing Operation

• Semi-automatic or automatic printing machines
• Controlled squeegee pressure and angle
• Multiple passes for layered colors if required

Step 6: Curing and Drying

• Infrared baking or UV curing
• Ink cross-linking for long-term durability
• Adhesion tested after full cure

Step 7: Quality Inspection

• Color consistency
• Registration accuracy
• Scratch resistance
• Adhesion cross-cut tests
• Abrasion and alcohol rub testing

Proper design is critical for high-yield printing. At Benma Electric, we provide design optimization support before tooling and printing.

1. Minimum Line Width

Recommended ≥ 0.15–0.2 mm

Thicker lines improve durability

2. Font Selection

Avoid ultra-thin fonts

Use industrial sans-serif fonts for clarity

Avoid overly small characters

3. Edge Distance

Keep printed area ≥ 1.5 mm from sharp edges

Prevent ink distortion during squeegee movement

4. Surface Flatness

Screen printing is best for flat or slightly curved surfaces

Deep curved or complex 3D shapes may require transfer printing or UV printing

5. Multicolor Registration

Limit to 2–4 colors for high-precision alignment

Each color requires independent screen plate

Benma Electric supports both processes, and we help customers choose the best solution based on:

• Part geometry
• Required durability
• Production volume
• Color performance
• Cost target

Even if you do not have drawings, Benma Electric can provide a full engineering solution from concept to mass production.

Step 1: Send Us Your Requirement

• Physical sample, photo, or concept idea
• Material preference (ABS, PP, PC, etc.)
• Printing effect requirement
• Quantity forecast

Step 2: Engineering Evaluation

• Mold feasibility
• Surface decoration analysis
• Printing position optimization
• Process quotation

Step 3: Tooling & Sample Approval

• Mold manufacturing
• Injection molded samples
• Screen printing trial samples
• Customer confirmation

Step 4: Mass Production & Quality Control

• Stable production scheduling
• Batch-based inspection
• Packaging and export logistics support

BMA

Benma Electric is a professional manufacturer specializing in custom plastic and metal products, including:

• Injection mold design & production
• Precision plastic injection molding
• CNC machining
• UV printing, spray painting, electroplating

Assembly and packaging services
Certified with ISO9001 and SMETA, we serve customers across North America, Europe, Asia, and Australia, offering consistent quality, competitive pricing, and dependable delivery.

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Workshop

Processing Workshop

Material

Warehouse

Hardware

Workshop

Assembly

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Benma Electric is not just a printing workshop - we are a full-service precision manufacturing partner offering:

1. Integrated Manufacturing

Plastic injection molding

Screen printing

UV printing

Laser engraving

Spray painting

Ultrasonic welding

Full product assembly

2. Strong Engineering Support

DFM analysis for printing feasibility

Mold design optimized for surface decoration

Ink compatibility testing

Print position simulation

3. Certified Quality System

ISO 9001 certified quality control system

SMETA sIncoming, in-process, and final QC inspection

4. Global Export Experience

Serving customers in North America, Europe, and Asia

OEM and ODM projects supported

Multilingual engineering and sales communication

5. Stable Mass Production Capacity

Automatic screen printing lines

Multi-cavity molds for high output

Batch traceability and SPC control

Allocating distinct areas for different injection molding processes helps streamline operations and speed up production.

We utilize modern industrial equipment to achieve precise manufacturing and efficient workflow.