1.
Slot coating technology is a high-precision fluid coating process. It employs a Narrow gap Coating Die Head(slot Coating die head) to uniformly extrude liquid at a preset pressure and velocity, coating it onto a moving substrate to form a wet film with controllable thickness.After drying or curing, the wet film transforms into a solid thin film. This technology enables ultra-thin, highly uniform coating results, adapts to various flexible substrates, and achieves large-area coating.meanwhile, it performs exceptionally well with high-viscosity or sensitive fluids and offers high material utilization.
Working Principle: Fluid flows from the storage tank through a metering pump at a constant flow rate into the die feed chamber. The internal design of the Die Head enables fluid to achieve pressure equilibrium before extrusion, ensuring uniform distribution of the extruded liquid. The liquid drawn through the die lip slit forms a wet film as it is driven by the substrate. The wet film thickness is controlled by the combination of the gap between the shim and the substrate, the substrate speed, fluid viscosity, and surface tension. The wet film enters the drying zone where the solvent evaporates, ultimately forming a solid film. In actual production, it is necessary to optimize parameters such as the coating gap and substrate speed to avoid defects like orange peel, streaks, or fractures in the wet film.
2.
The Narrow gap Coating Die Head(slot Coating die head) from Suzhou Jwell is one of the core components of the slit coating equipment, featuring:
High Precision and Uniformity: This is the most core technical advantage. Through precise internal flow channel and slit design, it ensures the fluid achieves pressure balance before extrusion, thereby spreading the coating onto the substrate with extremely high consistency. This not only means that the coating thickness can be controlled at an accurate level but, more importantly, eliminates the "edge effect" where the edges are thicker than the center, achieving a highly uniform coating effect across the entire surface.
Wide Material Compatibility: The coating die head exhibits strong versatility and can effectively process various functional liquids, including conductive slurries containing solid particles, polymer solutions sensitive to shear force, and high-precision photoresists. This excellent compatibility with complex fluids significantly expands its range of applications.
3.High Efficiency and Material Utilization: Designed specifically for modern continuous production, it matches high-speed production lines, significantly enhancing production efficiency. Its enclosed quantitative feeding system can precisely allocate coating materials on demand, minimizing waste, which is particularly economically valuable for scenarios using expensive raw materials such as silver paste and special chemicals.
High Stability and Cleanliness: Utilizing a robust mechanical structure and premium materials, the Die Head maintains stable performance during prolonged continuous operation, ensuring production continuity. The fully enclosed flow channel system effectively isolates contamination from external dust and impurities, meeting the stringent requirements for clean environments in semiconductor manufacturing and high-end medical device production.
High Process Controllability and Flexibility: The coating process is not fixed. By precisely and independently adjusting key parameters such as material feed flow rate, pressure, substrate speed, and the gap between the Die Head and the substrate, engineers can flexibly customize the width, thickness, and even specific patterns of the coating, enabling rapid response to diverse product development and production demands.
3.
Suzhou JWell's Narrow gap Coating Die Head(slot Coating die head) is an indispensable key component in the field of modern high-precision manufacturing, directly determining the quality and output of coated products. As a precise coating equipment component, the slot die coating head has become a critical process tool driving the development of multiple high-tech industries, thanks to its outstanding coating uniformity, high precision, and efficiency. The slot die coating head finds extensive applications, primarily including:
Lithium Battery Energy: In lithium-ion battery manufacturing, the Narrow gap Coating Die Head(slot Coating die head) serves as the "heart" of the electrode coating machine. It is directly responsible for uniformly applying the positive and negative electrode slurries onto the metal foil current collectors. The uniformity of the coating's areal density is a core parameter that determines the capacity, internal resistance, safety, and cycle life of individual battery cells. More importantly, it serves as a prerequisite for ensuring consistent performance across the hundreds or thousands of cells within a battery pack. High-precision slot die coating technology minimizes coating weight deviation, thereby enhancing the energy density and overall reliability of batteries at the source, providing higher-quality "energy cores" for electric vehicles and energy storage systems.
Semiconductors and Circuits: In the front-end processes of semiconductor manufacturing, slot coating is used for the uniform application of photoresist. The uniformity of film thickness directly affects the resolution and fidelity of lithographic patterns, forming the foundation for chip microfabrication. In the printed circuit board (PCB) industry, it is employed for applying solder mask inks and build-up dielectric materials, ensuring high-quality insulation and protection between circuits, thereby enhancing the signal integrity and long-term reliability of electronic end devices. This technology meets the increasing demands for coating precision and cleanliness.
New Display and Optics: From LCD to OLED, and further to Micro-LED, every advancement in display technology relies on precision coating. Narrow gap Coating Die Heads(slot Coating die heads) are used to apply critical functional layers such as liquid crystal alignment layers, OLED light-emitting layers, quantum dot color conversion layers, and thin-film encapsulation layers. Their exceptional uniformity ensures consistent and stable screen brightness and color performance. In the field of optical films, whether for brightness enhancement films, polarizers, or various protective hard coatings (Hardcoat), slot die coating enables high-quality manufacturing with ultra-low defects, determining the visual performance and durability of the final display products.
Photovoltaic Future Technology: For next-generation solar technologies with significant potential, such as perovskite solar cells, the key challenge in moving from the lab to factory production lies in achieving large-area uniform film formation. Narrow gap Coating Die Heads(slot Coating die heads) are currently the mainstream technology for this purpose, enabling stable control of the film thickness variation in perovskite active layers within a narrow range. This meets the requirements for continuous roll-to-roll or sheet-to-sheet mass production. Similarly, in areas like organic solar cells (OPV), it offers a reliable process pathway for efficient and cost-effective thin-film deposition.
Transportation Vehicles and Interiors: In the modern automotive industry, slot die coating technology is applied to various functional coatings for automotive glass, such as heat insulation, UV protection, hydrophobic, and anti-fog coatings. This directly enhances driving safety and comfort. In terms of automotive interiors, it can be used for surface treatments of materials like instrument panels and seat fabrics, providing them with improved scratch resistance, stain resistance, weather durability, and a comfortable tactile feel, continually enhancing the user's driving and riding experience.
Healthcare: The medical field imposes extremely stringent requirements on the safety and functionality of coatings. Narrow gap Coating Die Heads(slot Coating die heads) can be used to prepare hydrocolloid adsorption layers in advanced wound dressings and drug-loaded matrices in controlled-release patches, enabling precise drug delivery. On the surfaces of interventional medical devices (such as catheters and guidewires), applying hydrophilic lubricating coatings or anticoagulant biological coatings can significantly reduce patient discomfort and lower the risk of complications, enhancing the technological contribution of these devices to the healthcare field.
High-end Packaging and Printing: In premium packaging for food, pharmaceuticals, and other sectors, slot die coating technology is used to apply high-barrier coatings (such as oxygen and moisture barriers), antimicrobial coatings, or gloss protective layers, significantly extending product shelf life and enhancing aesthetic appeal. In the printing industry, it can be employed for surface pre-treatment or functional finishing of paper and films, greatly improving ink adhesion, color vibrancy, and abrasion resistance. This results in high-quality printed products that combine both aesthetic and practical value.
Exploration of Frontier Applications: In the cutting-edge field of flexible electronics, slot die coating is an ideal technology for large-area, low-cost manufacturing of devices such as flexible circuits, sensors, and electronic skins. It can adapt to the deformation of flexible substrates and precisely deposit functional materials. In sectors with extreme requirements, such as aerospace, this technology is used to prepare composite material prepregs, stealth or protective coatings for aircraft skins, and more, meeting the stringent demands for lightweight, high-strength, and specialized functional materials in equipment.
4.The advantages of Suzhou Jiewei's Suzhou JWell's Narrow gap Coating Die Head(slot Coating die head) in various industry applications
Excellent Coating Quality: The applied coating exhibits superior uniformity, with film thickness variations generally controlled within an extremely narrow range. This effectively avoids common issues in traditional coating methods, such as uneven coating thickness and edge effects, thereby enhancing product performance and quality. In the field of optical films, for example, it ensures uniform and stable optical performance of the membrane materials.
High Material Utilization: The coating process allows for precise control of the coating fluid usage, significantly reducing material waste and lowering production costs. This advantage in material savings is particularly pronounced for coatings involving expensive materials, such as photoresist coating in semiconductor chip manufacturing.
High Production Efficiency: Compatible with a wide range of coating line speeds and featuring stable material properties, it meets the demands of high-speed automated production lines. This enables efficient batch production, enhances a company's market competitiveness, and offers distinct advantages in large-scale manufacturing across industries such as photovoltaics and electronics.
Strong Adaptability: It is not only suitable for various slurries but also capable of coating different substrates, such as films, paper, metal foils, and sheet materials. Additionally, it can be adjusted and optimized under diverse process conditions to meet varying production needs and product characteristics, demonstrating high versatility and flexibility.
High Cleanliness: Utilizing an enclosed feeding system, it effectively prevents external contaminants from mixing into the coating fluid, ensuring a high level of cleanliness during the coating process. This enhances the purity and performance stability of the products, making it particularly suitable for high-tech fields with stringent cleanliness requirements, such as semiconductor packaging and the manufacturing of medical sensor films.
5
Summary: Slot die coating is a high-precision, high-efficiency fluid coating process, with the slot die coating head at its core. The Narrow gap Coating Die Heads(slot Coating die heads) from Suzhou JWell serves as the essential equipment for advanced precision coating applications. Through unique flow channel design and precise control, it achieves exceptional coating uniformity and micron-level thickness accuracy, significantly enhancing product performance and consistency. Additionally, the coating head offers broad material compatibility, efficiently accommodating a variety of functional fluids—from conductive pastes to photoresists—while its enclosed quantitative feeding system substantially improves material utilization.
In practical applications, the coating die has emerged as a critical enabling technology across multiple strategic emerging industries, including lithium batteries, semiconductors, displays, photovoltaics, automotive, medical devices, and packaging/printing. It directly determines the core performance of end products. By integrating strengths such as superior coating quality, high production efficiency, robust environmental adaptability, and excellent cleanliness, it effectively reduces the overall cost of high-end manufacturing. As an indispensable process cornerstone, it plays a vital role in driving technological advancement and enabling large-scale industrialization in these sectors.
