Hybrid Process Chain for the Integration of Direct Ink Writing and Polymer Injection Molding.

Area of Science:

• Materials Science
• Manufacturing Engineering
• Polymer Science

Background:

• Additive manufacturing (AM) and injection molding (IM) are key manufacturing processes.
• Integrating AM direct-write technology with IM offers a novel approach for functionalized plastic parts.
• Mass customization of molded plastic components requires advanced manufacturing techniques.

Purpose of the Study:

• To introduce and validate a hybrid manufacturing process combining direct-write AM and injection molding.
• To enable the mass production of custom-molded plastic parts with integrated conductive features.
• To investigate the interfacial interactions between printed conductive inks and thermoplastic polymers.

Main Methods:

• Direct-write technology was employed to deposit conductive ink traces onto an injection mold surface.
• The printed ink traces were cured on the mold.
• Thermoplastic polymer melt flow at high temperature and pressure facilitated the transfer of ink traces into the plastic part during injection molding.
• Interfacial analysis included feature fidelity, mechanical properties, adhesion, mold topography, surface energy, and hot polymer contact angle.

Main Results:

• The hybrid process successfully transferred conductive ink traces onto plastic parts.
• Strong plastic/ink interfacial bonding was achieved through designed mold/ink surface interactions and interlocking with the polymer system.
• Systematic interfacial analysis confirmed the stability and integrity of the ink/polymer interface.
• The process demonstrated potential for mass-manufacturing custom-molded plastic parts with embedded functional features.

Conclusions:

• The proposed hybrid process chain effectively integrates direct-write additive manufacturing with injection molding.
• This method allows for the creation of stable ink/polymer interfaces, enabling the production of functionalized plastic components.
• The study validates the feasibility of mass-producing custom-molded plastic parts with embedded conductive traces through controlled interfacial engineering.