Pressure Sensitive Film (PSF), also called pressure sensitive film sensor, pressure paper, or pressure measurement film, is an easy-to-use universal pressure surface measurement equipment that helps define contact pressure distribution and its value. The Pressure Sensitive Graphic Film Market size is expected to develop revenue and exponential market growth at a remarkable CAGR during the forecast period from 2023–2030. The market's growth can be attributed to the increasing demand for Pressure Sensitive Graphic Films owned for Food Packaging, Drug Label, and other applications across the global level.
In contrast to conventional pressure transducers, which necessitate expensive and sophisticated equipment for pressure distribution analysis, PSF delivers a straightforward solution. In this blog, we will explore what PSF is, how it works, what purposes it serves, and how you can use it to take precise measurements.
Understanding Pressure Sensitive Film
Prescale®, also called pressure-sensitive film, is a 4—to 8-mil plastic film with miniature microcapsules embedded within the material. These microcapsules contain a pressure-sensitive dye and a colourless acid. When pressure is applied onto the film plane, the microcapsules burst, releasing the dye directly related to the pressure exerted, thus providing a coloured insight into the pressure plan. The intensity of the colour depends on the amount of pressure applied to permit pressure mapping across the contact area.
Benefits of Using Pressure Sensitive Film
PSF offers several advantages over traditional pressure measurement techniques:
- Simplicity: PSF is relatively easy to implement, with little need for elaborate setup or specialization. All that is required is to position the film between two contacting surfaces, then apply pressure, and the colour pattern is formed.
- Cost-effective: In comparing with complicated pressure measurement systems, it will be noted that PSF has lower costs.
- Versatility: PSF can be applied to flat surfaces and even curved surfaces, making it possible to use it on different surfaces.
- Accessibility: Its slim design enables measurements in small areas or locations that are beyond the reach of normal pressure sensors.
- Visual representation: A colour map offers an immediate view of pressure distribution, allowing for analysis and further decision-making.
Applications of Pressure Sensitive Film
PSF is used in various industries because of its efficiency and effectiveness in various fields. Here are some prominent examples:
- Aerospace: Determining pressure distribution in terms of pressure coefficient on various wing sections, the landing gears and panels of the aircraft fuselage.
- Automotive: These include determining the performance of contact pressure between tyres and road surfaces, checking the pressure distribution of the seats, and testing the performance of the gasket.
- Medical Measure forces in artificial limbs, wheelchairs, and other medical types of equipment.
- Electronics: Measuring pressure between electronic components to prevent localized heating between components.
- Manufacturing: Assembling products and checking pressure distribution in the assemblies, improving the packaging designs and evaluating the seals.
- Sports and Ergonomics: Studying pressure distribution between the shoe and the athlete’s foot or between the equipment and an athlete’s body and identifying critical areas that require adjustments to prevent uncomfortable pressure points.
Using Pressure Sensitive Film for Accurate Measurements
Here's a step-by-step guide on effectively using PSF for pressure measurements:
- Selecting the Right Film: PSF is available in different grades, each offering material for a particular pressure class. It is wise to choose a material capable of handling your application's expected pressure range. That is why manufacturers offer selection guides and specify which film grade you should approach your project with.
- Surface Preparation: For optimal accuracy, contact surfaces should be clean, dry, and free from interference. Any substance such as oil, dust, or moisture that comes in contact with the two pressures could cause an error in the pressures measured. To prepare the furniture's surface, use a soft, non-abrasive cleaning solution and a lint-free cloth.
- Applying the Film: Take a piece of PSF slightly bigger than the contact area you intend to measure. Remove the protective layer and place the film on one of the interacting surfaces. Make sure there are no pockets of air between the film sheets and the objects being coated.
- Applying Pressure: Place the two surfaces in contact and apply the desired normal force. The pressure application time may also depend on the particular film grade. Always follow the guidelines provided by the specific product manufacturer regarding how long it should be used.
- Removing the Film: After applying pressure to the two surfaces, slowly peel off the film from the two surfaces that came into contact. This should not involve any contact with the coloured area of the film, as this may affect the results.
- Analyzing the Results: The pressure distribution will be transformed into a colour map on the film. The colour intensity will be compared with the standard chart usually provided by printer manufacturers. The reference chart further equates the tonal intensity to the corresponding pressure value, thus enabling you to assess the pressure profile over the entire contacting surface.
- Documentation and Storage: To avoid this, it is advisable to take a picture of the pressure map or scan it so that you can always refer to it in future. To ensure the used film’s colours are accurate for future use or analysis, keep the used film in a cool, dry environment and out of direct sunlight.
Tips for Accurate Measurements with Pressure Sensitive Film
- Calibrate the reference chart: Some manufacturers advise the user to calibrate the chart against a pressure calibrator, especially for precision in demanding environments.
- Repeat measurements: To correct for variability, perform multiple measurements, especially where the measurements are used for critical applications. Taking averages of the results can further improve the precision of your pressure data.
- Control environmental factors: An increase in temperature or humidity can cause a slight variation in the PSF's colour response. If obtaining consistent results is important, one should consider measuring in a specified area.
- Film limitations: It is also important to know that PSF is not good for use when pressures are dynamic or fluctuating rapidly. It is most appropriate for use on steady or gradually fluctuating pressure measurement systems.
- Software analysis: Several manufacturers offer software solutions for analyzing the scanned pressure map, which can present the pressure data and readings in the form of a graph.
Conclusion
Pressure sensitive film is very useful because it measures and maps pressure areas between contacting surfaces. Thus, it may be concluded that its simplicity of use, possibilities, and relatively low cost make it widely used in different fields. However, with the help of this blog's outlined steps and tips for accurate measurements, PSF will provide helpful insight into pressure distribution in applications.