Introduction
In many industrial fields, the visual and optical properties of functional film materials are key parameters for their quality evaluation. Among them, haze and light transmittance are two basic and interrelated indicators, which together determine the transparency, clarity and light scattering characteristics of the material. Traditionally, the measurement of these two indicators often relies on independent instruments, which has problems such as cumbersome operation and weak data correlation. The testing equipment that integrates haze and light transmittance measurement functions provides a more efficient and accurate solution for the quality control and research and development of functional film products.
Overview of the measurement principle
Haze refers to the ratio of scattered light flux to transmitted light flux that deviates from the direction of incident light through the material, which characterizes the degree to which the material diffuses or becomes turbid. Light transmittance is the ratio of the light flux passing through the material to the light flux incident on the material, reflecting the overall light transmission ability of the material. The design of integrated measuring instruments is usually based on the integrating sphere principle and standard lighting observation conditions, and the collection and calculation of total transmitted light, scattered light and other signals are completed synchronously during the process of sample placement.
Its basic calculation can be expressed as:
Light transmittance Tt = (Φt / Φi) × 100%
Haze H = (Φd / Φt) × 100%
Where, Φi is the incident luminous flux, Φt is the total transmitted light flux, Φd It is the scattered light flux. The instrument is designed with precise optical paths and sensors to ensure that the data meets the requirements of relevant standards.
Technical advantage analysis
The use of an all-in-one machine for measurement shows a practical improvement in many aspects compared to the split equipment. Firstly, it reduces the number of sample loading and unloading, reduces the measurement error introduced by sample position changes, and improves the repeatability and comparability of test results. Secondly, the integrated measurement realizes the real-time synchronous acquisition of haze and light transmittance data, which is convenient for direct analysis of the internal connection between the two, which is particularly beneficial for studying the comprehensive impact of material structure and surface treatment process on optical properties. Finally, it simplifies the operation process, improves testing efficiency, and is more suitable for the needs of rapid sampling on the production line or large-scale sample testing in the laboratory.
Examples of application areas
This technology is widely used in the evaluation of functional film materials with clear requirements for optical properties.
| Packaging materials | Evaluate the transparency and hazy effect of food packaging, cosmetic bottles. |
| Display and touch | Measure the optical clarity of protective films, polarizers, and brightening films. |
| Automotive & Construction | Detect the light transmission and privacy performance of car window film and architectural glass film. |
| energy sector | Analyze the light transmission characteristics of materials such as encapsulating films for photovoltaic modules. |
Measurement considerations
In order to ensure the accuracy and reliability of the measurement results, the following points need to be paid attention to in actual operation: the flatness and cleanliness of the sample will directly affect the optical path; The instrument needs to be calibrated regularly using a standard plate to maintain its measurement traceability; The test environment should avoid stray light interference; For textured or anisotropic films, a uniform test direction and position should be specified and indicated in the report.
Reference to standards and specifications
At present, there are a series of standard methods for the haze and light transmittance testing of transparent materials at home and abroad, which specify the requirements for light sources, geometric conditions, specimen preparation and calculation procedures. The design and operation of all-in-one machines often follow or comply with these standards, which is the basis for the credibility and comparability of their measurement data.
| ASTM D1003 | Standard test method for haze and light transmittance of transparent plastics. |
| ISO 13468 / ISO 14782 | International standards for light transmittance and haze determination are specified respectively. |
| GB/T 2410 | Chinese national standard, which involves the determination of light transmittance and haze of plastics. |
Epilogue
The haze transmittance integrated measuring machine provides a stable and efficient detection method for the optical quality control of functional films through technology integration. It is closely aligned with the actual needs of production and R&D, and its data helps guide the optimization of material formulations, the adjustment of process parameters, and the determination of final product performance. With the advancement of materials science and the continuous improvement of industry standards, such integrated and intelligent testing technologies will play a more significant role in improving product quality and consistency.
References
1. Principle: Refer to the relevant descriptions of haze definition and measurement optical path in ASTM D1003 and ISO 14782 standards.
2. Application Fields: Comprehensive technical literature on the requirements of functional film optical properties in multiple industrial fields.
3. Standard list: from the published texts of the current and effective international standards (ISO, ASTM) and Chinese national standards (GB/T).