China
Africa
Explore chapters and articles related to this topic
Strategies for Achieving Electrically Conducting Textile Fabrics
Published in Robert Mather, John Wilson, Solar Textiles, 2023
Another option is coating with a doctor blade (Figure 4.7). A sharp blade is placed at a fixed distance from the surface of the substrate to be coated (normally 10–500 µm). The ink is then placed in front of the blade. As the blade is moved across the substrate, a thin film of ink is deposited uniformly on the substrate. The thickness of the film is governed by a variety of factors: the distance between the blade and the substrate, the surface energy of the substrate and the surface tension and viscosity of the ink. Although optimisation of the conditions for applying an ink can be quite laborious, the technique can be readily adopted on an industrial scale. A related technique is slot-die coating, whereby an ink is fed to a substrate through a thin slit. Proponents of slot-die coating maintain that the technique gives better reproducibility of coating.
Slot-die simulations for 3D printing of Perovskite Solar Cells (PSCs)
Published in Paulo Jorge da Silva Bartolo, Fernando Moreira da Silva, Shaden Jaradat, Helena Bartolo, Industry 4.0 – Shaping The Future of The Digital World, 2020
Slot die coating is a method which deposits a large homogeneous wet film at a high cross-directional uniformity and reproducibility. A solution seeps from a slot gap onto the substrate; afterwards, solidification takes place resulting in a dry film on the substrate. Depositing different thickness layers is achievable by controlling the flow rate, and the movement speed of the die head. Di Giacomo et al. (2018) used a slot die coating process to make a module with 25 cells connected resulting in an area of 168$/m2 and a PCE of 11%. This is a promising result in the manufacturing of large-area PSCs and shows that other techniques can produce similar and improved results. Key parameters which are typically used and highlighted in fabricating thin films are the gap height between the meniscus guide and substrate and/or the height between head and substrate, coating speed, and pump rate in order to achieve the desired film thickness.
Manufacture of Pressure-Sensitive Products
Published in István Benedek, Mikhail M. Feldstein, Technology of Pressure-Sensitive Adhesives and Products, 2008
Generally, highly viscous melts with a viscosity up to 400 Pa · s can be coated by slot-die and coating weights of 7–200 g/m2 are obtained. The introduction of offsetting rolls between the die or application cylinder and the substrate (see above) is a useful technique to lower the coating weight. In slot-die the shear rate is lower than in roll coaters; thus, dispersions that need a high shear rate to be coated are not adequate for slot-die coating. The most prepolymer-based acrylic HMPSAs belong to the lowest viscosity range and can be coated with die systems. With such systems coating weights of 20–200 g/m2 acrylic HMPSA are applicable.
Numerical study of slot-die coating on film formation for different die lip configurations
Published in Journal of the Chinese Institute of Engineers, 2021
Chin-Cheng Wang, Yan-Yang Zheng
Slot-die coating is a promising technology for the development of integrated circuits, printed circuit boards, and liquid crystal displays. It was invented by Beguin (1954). It is a method to have the photoresist on a plate or substrate and applications such as integrated circuits (IC), printed circuit boards (PCB), and liquid circuit displays (LCD), etc. The principle of slot-die coating is to feed the photoresist into the coater using the pump. After the photoresist leaves the coater, it will be coated on the substrate. To achieve uniform distribution, both the coater and the pump are required to provide steady speeds and mass flow rates, respectively. The film thickness is decided by mass flow rates, coating widths, and the substrate moving speeds. Also, viscosity of the photoresist is very important for the slot-die coating, especially the quality of coating. In recent days, the price of photoresists has been increasing due to the trade war between South Korea and Japan. Japan has the secret recipe for the photoresist, and they know how to make good quality photoresists, so they can decide the price of the photoresist. South Korea needs photoresists to develop their semiconductor industry. To save cost on photoresists, the film thickness needs to be as thin as possible and the film needs to be as uniform as possible.
A critical overview of thin films coating technologies for energy applications
Published in Cogent Engineering, 2023
Mohammad Istiaque Hossain, Said Mansour
Slot-die coating is an enormously multipurpose deposition technique to insert solution through a slot, which is close to the surface (Hengyue Li et al., 2022; Khambunkoed et al., 2021; Seo et al., 2022; Xu et al., 2022). The controlled deposition process depends on wet-film coating thickness, the flow rate and the speed of the coated substrate relative to the slot. In addition, this technique is capable of achieving uniform films across large areas. This technique can easily be adapted to develop large area samples. Many research labs have adapted this technology to develop polymer and perovskite PVs, organic light-emitting diodes, quantum dots, and photonic structures with the highest ability of scaling-up process.