Definition
A laboratory film maker is a device used to prepare homogeneous thin film samples under controlled conditions. It mechanically coats liquid or molten materials onto the surface of the substrate, creating a film with a controllable thickness for subsequent physical or chemical property testing.
How it works:
The core of the equipment is based on precision mechanical transmission and clearance control technology. The drive system drives the coated part to move at a uniform speed and spread the material evenly across the substrate. The thickness of the film is controlled by adjusting the gap between the scraper or coating roller and the substrate, according to the rheological characteristics of the material. The curing system forms the film by hot air, UV or room temperature curing according to the material properties.
Measurement method
Film thickness measurement is typically done using contact or non-contact methods. Contact measurement uses an ISO 2808 compliant micrometer to average the measurement at multiple points. Non-contact measurement uses optical interferometry to calculate thickness by analyzing interference fringes according to ASTM D1003. The CV value of the thickness coefficient of variation is calculated by using the grid method, and the CV value of the thickness coefficient of variation is calculated by the formula: CV = (σ/μ)×100%, where σ is the standard deviation and μ is the average thickness.
Influencing factors
The quality of the film is affected by multiple factors. The viscosity of the material directly affects the leveling, and the viscosity is related to the thickness of the film. Ambient temperature and humidity affect the rate of solvent volatilization, which can lead to orange peel or pinholes. The surface of the substrate can determine the degree of wettability of the material, and the difference in surface tension will cause edge shrinkage. The speed of equipment operation and the accuracy of the gap determine the thickness consistency, and vibration causes periodic thickness fluctuations.
Applications:
In materials science research, it is used to prepare polymer films to test barrier properties. The coatings industry is used to make paint film samples for weather resistance assessment. In the field of electronics, it is used to prepare conductive films to test square resistance. The optical industry makes optical thin films to measure light transmittance. In the textile field, functional coatings are prepared to test abrasion resistance. In the development of food packaging materials, it is used to prepare composite films to test the oxygen transmission of water.
Key points of selection
The selection of the type should comprehensively consider the technical parameters and application requirements. The coating width should match the commonly used substrate size. The thickness adjustment range should cover the target film specification. The minimum adjustment accuracy determines the thickness control capability. Compatible material types include solutions, slurries, or molten polymers. The curing method should correspond to the curing characteristics of the material. The material of the equipment should be resistant to the corrosion of the solvent used. The operating speed range affects the preparation efficiency. Additional features such as in-line thickness monitoring improve preparation consistency.