Scientific Achievement Registration: Paint-Free Injection Molding Mold

The Zhejiang Provincial Department of Science and Technology, as the highest administrative authority for S&T work in the province, is responsible for organizing and implementing S&T achievement registration. S&T achievement registration is an important part of S&T achievement management, implemented in accordance with the “Measures for S&T Achievement Registration” (Guo Ke Fa Ji Zi [2000] No. 542). All research projects that have passed appraisal, acceptance inspection, or have obtained patents may apply for registration. Registered S&T achievements are uniformly numbered by the Zhejiang Provincial Department of Science and Technology and, after public announcement, are issued an S&T Achievement Registration Certificate. This certificate is a required attachment for applying for the Zhejiang Province S&T Award and is also an important basis for enterprises to qualify for High-Tech Enterprise, Technology-Based Enterprise, High-Tech Enterprise R&D Center, and other qualifications. Paint-free technology falls under the green manufacturing process direction and has significant promotion value in the context of the “dual carbon” policy. After registration, it can serve as important supporting material for high-tech product application and green factory assessment. Zhejiang SINOMOULD Co., Ltd.’s independently developed “Paint-Free Injection Molding Mold” was registered as an S&T achievement by the Zhejiang Provincial Department of Science and Technology. The registration of this technological achievement signifies that SINOMOULD’s technological breakthrough in the field of high-end appearance parts molds has received provincial-level authoritative certification.

Paint-Free Technology: Core Process Pathway of Green Manufacturing

Paint-free technology involves directly adding special effect pigments such as metallic powder, pearlescent powder, and high-gloss color powder into the plastic base material, producing products with metallic luster or special color effects in a single step through injection molding, eliminating traditional surface treatment processes such as painting and electroplating. This technology pathway has significant dual environmental and economic benefits: eliminating the painting process reduces VOC (volatile organic compound) emissions and labor costs, while also avoiding product rejections caused by poor painting. For end customers, paint-free molds mean shorter delivery cycles, lower total manufacturing costs, and compliant products that meet international environmental regulations (such as RoHS and REACH).

In mold design, paint-free molding places extremely high requirements on mold surface quality and gating system design. The injection material needs to flow evenly within the mold cavity to avoid appearance defects such as flow marks, sink marks, and weld lines. SINOMOULD’s R&D team optimizes gate position, runner layout, and mold temperature control systems, combined with high-gloss surface treatment and texture etching processes, to ensure that paint-free products directly present high-quality appearance after injection molding. In injection molding, the paint-free process requires precise mold temperature control and melt flow management. SINOMOULD uses mold flow analysis software to conduct simulation verification of the filling process, optimizing process parameters such as injection speed, pressure, and temperature to ensure uniform dispersion of pigments in the melt and avoid color differences and flow marks.

Technology Synergy: Deep Integration of Hot Runner Systems and Paint-Free Processes

Paint-free injection molds place particularly demanding requirements on gating system design — the shear heat and residence time of pigments in the runner directly affect the appearance consistency of the product. SINOMOULD deeply integrates hot runner system design with the paint-free process, precisely controlling the temperature distribution in each zone of the hot runner and melt flow balance to avoid pigment degradation and flow mark formation. The application of hot runner systems also further saves raw materials and shortens molding cycles, highly synergizing with the cost-reduction and efficiency-improvement goals of the paint-free process.

In mold manufacturing, paint-free molds require far higher cavity surface quality than ordinary molds — any minor machining marks or surface defects may be magnified as appearance flaws on paint-free products. SINOMOULD relies on high-precision CNC processing equipment and mirror EDM processes to ensure that mold cavity surfaces achieve mirror-level smoothness. Each paint-free mold undergoes strict trial mold verification and appearance inspection before delivery.

Triple Value of Shortened Delivery Time, Reduced Cost, and Compliance Assurance

With the deepening advancement of the “dual carbon” strategy, paint-free technology is becoming a key pathway for the green transformation of the plastic products industry. SINOMOULD’s “Paint-Free Injection Molding Mold” technological achievement, by eliminating the painting process, brings customers the triple value of shorter delivery cycles, lower total manufacturing costs, and compliant products meeting international environmental regulations. The technological maturity assurance certified by provincial-level S&T achievement registration provides reliable technical support for customers’ high-end appearance parts production.

According to the management requirements of the Zhejiang Provincial Department of Science and Technology, the S&T Achievement Registration Certificate is a required attachment for applying for the Zhejiang Province S&T Award, and registered achievements are incorporated into the provincial S&T achievement database for unified management. SINOMOULD will continue to advance in-depth R&D and industrialization of paint-free mold technology, consolidating its technological leadership position in the field of injection molds for home appliances, automotive, and other high-appearance-requirement products.