SYSTEM AND METHOD FOR DETERMINING GAS PERMEABILITY OF POLYMER FILMS BY MEANS OF IMAGE ACQUISITION

摘要

System for determining gas permeability (O2, CO2, N2, air) in films, especially edible films, wherein the system comprises a receptacle (A) containing a liquid of low solubility to the gas that is not reactive to it or dissolves the film; gas bubble generating means comprising a cylinder that contains the gas (G); a driver (E) that regulates gas flow and drives the syringe plunger (F); an image acquisition system comprising a high resolution camera (C); lighting (B) that uses a lighting means; and image processing means, preferably a computer program (D); and a method that comprises placing the liquid in an receptacle and letting the gas (G) flow, generating uniform bubbles in the liquid, and placing the film over the liquid; taking photographs or images for a determined time range and frequency and with an auxiliary lighting means; processing photographs or images in an image processing means, and determining variation in the bubbles volume at different times, wherein the bubble volume is determined based on the pixels corresponding to the bubble maximum diameter (Dmax), the diameter of the contact area between bubble and film (Abp) and the bubble height (h); correlating the number of pixels with a determined length measuring unit and calculating the variation in the gas bubble volume, (ΔVb), the contact area between bubble and film (Abp), and the pressure inside the bubble (ΔP); constructing the linear relationship of variation in the bubble volume in the course of time and from the slope of said linear relationship, calculating gas transmission rate, and then, permeability to gas.

主权项

1. A system for determining a film permeability to gases selected from O2, CO2, N2 or air by means of image acquisition, that it comprises a receptacle (A) that contains a liquid of low solubility for the gas to be determined (O2, CO2, N2 or air), and not reactive to said gases; gas bubble generating means that comprise a cylinder containing the gas (G); a driver (E) that regulates gas flow and drives the syringe plunger (F); an image acquisition system that comprises a high resolution camera (C); lighting (B) for which a lighting means is used, and an image processing means (D).