The Evolution of Double Color Molding Machines: Witness to Technological Innovation and Industrial Transformation

author: mia

2025-05-16

The double color molding machine injects two plastics into one mold, forming two/ multi-color products rapidly. Ideal for automotive & electronics, it boosts aesthetics and functionality efficiently.

Origins and Early Development (1950s-1980s)

Technical Breakthroughs and Popularization (1990s-2000s)

Performance Parameter Analysis

Market Size and Growth Trends

Analysis of Typical Application Cases

Panoramic View of Application Fields

Selection Guide

Future Development Trends

**Industry Outlook

1. Origins and Early Development (1950s-1980s)

Double color injection molding technology can be traced back to the 1950s. KraussMaffei (Germany) introduced the world's first double color molding machine prototype in 1965, using a rotating mold cavity design to achieve step-by-step injection of two plastics. During this period, the equipment could only produce simple two-color products such as toys and knobs, with immature injection system precision and temperature control technology. Limited by the single-stage injection structure, material switching time exceeded 30 seconds, and weld marks often appeared in the color transition areas of products.

2. Technical Breakthroughs and Popularization (1990s-2000s)

1. Hydraulic System Upgrades

Servo Drive Technology: Bosch Rexroth launched the Indramat servo hydraulic system in 1995, increasing injection speed to 300mm/s with a repeatability accuracy of ±0.1%, achieving 40% energy savings compared to traditional fixed-displacement pump systems.

Closed-Loop Control System: KraussMaffei's CX controller achieved pressure-flow dual closed-loop control, reducing injection pressure fluctuations to <5bar and solving color mixing issues caused by unstable pressure in early equipment.

Multi-Cylinder Synchronization Technology: ENGEL's duo series adopted a four-cylinder direct-pressure clamping mechanism, achieving a platen parallelism error of <0.05mm to ensure precision in thin-walled product molding.

2. Multi-Component Injection Technology

Rotary Table Molding System: Demag introduced the DR series double color machine in 2002, using a 180° rotating table for dual-component injection, reducing cycle time to 12 seconds and increasing efficiency by 50% compared to early models.

Angled Injection Unit: Sumitomo's L-type injection system positioned main and auxiliary injection units at 90°, suitable for overmolding products like toothbrush handles with hard 胶 (PP) and soft 胶 (TPR) composite injection.

Multi-Color Co-Injection Technology: Arburg's Multilift robotic integration system enabled three-color and four-color complex structure molding, such as gradient color transitions in automotive three-color buttons.

3. Material Compatibility Expansion

High-Temperature Engineering Plastics Application: LCP (Liquid Crystal Polymer) with a temperature resistance of 350℃ achieved double color molding in 2005 for mobile phone antenna brackets, overcoming a shrinkage rate difference of over 15% between two materials.

Soft Material Overmolding Technology: BASF's TPU-PA66 bonding process solved the problem of combining materials with a hardness difference of 70 Shore A, increasing product peel strength to 5N/mm.

Nanocomposite Material Processing: Toshiba Machinery's screw mixing system uniformly dispersed nanoscale filler materials, increasing product strength by 30% for high-end electronic components.

4. Mold Design Innovations

Hot Runner System Optimization: Mold-Masters' needle-valve hot runner enabled precise material switching with gate marks <0.1mm, meeting appearance requirements for optical products.

In-Mold Labeling Technology: Haier Mold integrated IML (In-Mold Labeling) with double color injection in 2008 to produce high-gloss seamless home appliance panels with a surface roughness of Ra<0.2μm.

Rapid Mold Change System: Hasco's hydraulic clamping mechanism reduced mold change time from 2 hours to 15 minutes, significantly improving efficiency in multi-variety small-batch production.

5. Representative Model Parameter Comparison

Brand & Model	KraussMaffei CX 160	ENGEL e-victory 170	Sumitomo SE-DUZ50
Clamping Force (kN)	1600	1700	500
Injection Volume (cm³)	2×220	2×180	2×60
Positioning Accuracy (mm)	±0.03	±0.025	±0.04
Cycle Time (s)	15	12	8

3. Performance Parameter Analysis

Technical Index	High-End Double Color Machine (e.g., Arburg Allrounder)	Standard Single Color Machine
Injection Unit	Dual-screw independent control, injection speed up to 500mm/s	Single-screw, 200-300mm/s
Positioning Accuracy	±0.02mm (rotary table positioning)	±0.1mm
Temperature Control	350-400℃ (suitable for PEEK and other special plastics)	280-320℃
Energy Consumption	0.35kWh/kg (servo drive)	0.5-0.7kWh/kg
Mold Compatibility	Supports rotary table and sliding plate multi-cavity structures	Single-cavity design

4. Market Size and Growth Trends

According to MarketsandMarkets, the global double color molding machine market reached **\(2.18 billion** in 2023, projected to exceed \)3 billion by 2028 with a CAGR of 6.7%. The Asia-Pacific region accounts for 42% of the market share, led by rapid demand growth in emerging manufacturing countries like China and India, driven by 产能转移 in new energy vehicles and consumer electronics. Medical devices and new energy vehicles have become new growth poles, with medical-grade double color molding machine sales increasing by 18.5% year-on-year in 2023, mainly used for producing high-purity medical consumables and implant device components.

5. Analysis of Typical Application Cases

1. Automotive Industry: Tesla Model 3 Center Control Knob

Equipment: Sumitomo Demag SE50DUZ double color machine

Process: PC (transparent) + ABS (black) secondary injection with In-Mold Roller (IMR) technology

Technical Highlights: Servo motor precision control for turntable positioning, concentricity error <0.05mm, metal texture surface adhesion reaching 5B level (cross-cut test).

2. Medical Field: BD Insulin Pen Housing

Equipment: ENGEL e-motion 170/75 TL all-electric double color machine

Materials: PP (hard plastic) + TPU (soft plastic) with 0.5% silver ion antibacterial masterbatch

Innovation: Dynamic mold temperature control (80-120℃ real-time adjustment) achieving soft-hard plastic interface bonding strength ≥3N/mm, compliant with ISO 10993 biocompatibility standards.

3. Consumer Electronics: Apple AirPods Pro Charging Case

Equipment: Toshiba EC130SX double color machine

Process: PBT (flame-retardant) + PC (high-gloss) double color molding combined with laser engraving

Quality Control: Equipped with CCD visual inspection system for real-time monitoring of color difference (ΔE<0.5) and flash (dimension deviation <0.03mm), yield rate 99.2%.

6. Panoramic View of Application Fields

Automotive: Dashboard two-color buttons (PC+ABS), headlight lenses (PMMA+PC), gear shift handles (PA+TPU overmolding)

Medical Devices: Insulin pen two-color housings (PP+TPU), surgical forceps non-slip handles (ABS+TPE), syringe pistons (PE+conductive additives)

Consumer Electronics: Mobile phone two-color cases (PC+TPU), laptop two-color keycaps (PBT+silicone), smartwatch casings (PA+metal inserts)

Packaging: Anti-counterfeit bottle caps (transparent PS+colored PP), high-end cosmetic containers (PETG+pearlescent masterbatch), children's toys (ABS+soft rubber decorative layers)

7. Selection Guide

1. Product Structure Evaluation

Overmolding Products (e.g., power tool handles): Prioritize angled injection models (90° auxiliary nozzle layout) to avoid material flow interference and improve overmolding uniformity.

Symmetrical Two-Color Products (e.g., two-color buttons): Rotary table models increase efficiency by over 30%, with 180° turntable for rapid mold switching and reduced idle cycle time.

2. Material Adaptability

High-Temperature Nylon (PA6T) Processing: Requires ceramic screws (wear-resistant) and oil-heated barrels (temperature control accuracy ±1℃) to prevent material degradation.

Transparent PC Molding: Use low-compression ratio screws (1.8:1) with mirror-finish molds (roughness Ra<0.1μm) to eliminate weld marks and stress lines.

3. Production Capacity Planning

Annual Output <500,000 Units: Recommended 120-200 ton medium-sized machines (e.g., Haitian MA1600), reducing equipment investment by 25% compared to large models with energy consumption <0.4kWh/kg.

Annual Output >2,000,000 Units: Full-automatic rotary table models (e.g., FCS PQ1800) reduce comprehensive costs by 15%, equipped with robotic automatic part removal systems to compress cycle time to <10 seconds.

8. Future Development Trends

Miniaturization and Precision: Responding to wearable device demands, ENGEL developed a micro double color molding machine with only 50kN clamping force, achieving minimum molding accuracy of ±0.01mm for 0.1g-level micro parts (e.g., hearing aid housings).

Green Manufacturing: The share of all-electric models will increase from 35% in 2023 to 52% in 2028, combined with PCR (post-consumer recycled) plastic-specific screw designs, reducing energy consumption by 15-20% and waste recovery rate >95%.

Process Integration: Combining double color injection with IML (In-Mold Labeling) and hot runner technology to achieve one-stop production of three-color appearance parts, reducing post-processing steps by 60%.

Intelligent Control: AI process parameter self-learning systems (e.g., 威猛巴顿菲尔 iQ series) reduce debugging time by 40%, achieving scrap rate <0.5% through real-time pressure-flow curve analysis.

9. Industry Outlook

Current trends of electrification, intelligence, and miniaturization are dominant. ENGEL's e-motion series integrates motor direct drive with AI process control, further reducing energy consumption by 20%. Sumitomo Demag's micro-injection unit achieves 0.01g-level precision double color molding. With demand surges in new energy vehicles (e.g., dual-color brackets for vehicle cameras) and wearables (e.g., dual-color temple arms for smart glasses), double color molding technology will achieve greater breakthroughs in material composite (e.g., metal-plastic co-molding) and process integration (injection-welding integration), driving manufacturing towards higher precision, multifunctionality, and green production.

Dongguan Sanlixin Plastic Technology Co.,Ltd

Shenzhen Sanlixin Technology Co., Ltd. and Dongguan Sanlixin Plastic Technology Co., Ltd. is a manufacturer integrating precision plastic mold design, mold opening, single (double) color injection molding, IML injection molding processing, producing various single (double) color, IML process high-end appearance decorative structural parts, two-color buttons, USB dust plugs, panels and other plastic products, providing customers with fast, excellent, Midea all-round service, the company has 15 years of experience in precision plastic mold design, processing and production, with a variety of advanced machine injection molding equipment with excellent quality and fast service to win the trust and strong support of our customers.