Application of X-rays, CT scans and 3D images in the production of shoes
Digital imaging has eliminated the delay in shooting that occurs in X-ray images. This dramatic breakthrough has paved the way for many industries to be more creative with the simultaneous use of X-rays and digital imaging. For example, CT, or CAT, which is mostly used for medical purposes, uses hundreds of two-dimensional X-ray images to create a three-dimensional image of the body’s internal organs.
New tools that use this technology on a small scale (called micro-CT scan) have paved the way for progress in some industries.
Conventional X-ray systems have defects; For example, they provide only a 2D image and are not fast. Micro-CT scan fixes some of these defects and provides even more possibilities.
Micro-CT scans in the field of shoes are also the basis for advances and give the opportunity to control the quality and produce new products with its help.
There are several techniques for scanning and examining plastics and similar materials.
One of these methods is the use of lasers. The SATRA research institute has examined various scanning and imaging techniques that can be effective in the shoe industry.
For example, in the shoe industry, metal detectors are needed to find metals that may have been accidentally left inside the shoe. The process of finding possible metals in shoes may be performed individually or in bulk. However, the location of the metal must be accurately identified. These are issues where the use of micro-CT scans can work.
New X-ray and CT scan technologies
X-ray computerized tomography, sometimes called CT scan, is a non-contact, non-destructive method of obtaining internal and external information about objects that scales the object down to the smallest unit.
This method allows the operator to use X-rays to take hundreds of two-dimensional images of the inside and outside of the object and examine its internal and external features. Then, these two-dimensional photos are converted into three-dimensional photos with the help of software, and it can be cut and viewed from different angles.
Older methods of using X-rays were limited due to the need for more time to produce film and photos. The proliferation of digital imaging has led to an increase in the use of load-bearing devices or CCDs. These tools and other similar technologies help to take high quality photos. They are also widely used in CT scans.
Non-Destructive Testing (NDT)
SATRA tests a wide range of products and goods, many of which are not possible to disassemble and cannot be easily disassembled. For example, some of them are integrated objects or it is very difficult to separate them. Measuring the thickness of the hull, cracks or fractures and defects in plastic and metal materials are some of the things that are difficult to test and measure.
Micro-CT scan in such cases solves a large part of the problem. For example, shoes that have high heels or shock absorbers must be installed and the exact location of these tools must be determined and confirmed. Conventional metal detectors confirm the existence of these instruments, but CT scans and 3D imaging are much more effective in determining their exact location and possible defects.
With this method, not only both metallic and non-metallic materials such as fabric and wood can be examined. In this way, a non-destructive evaluation can be provided without destroying the product. Information that may be obtained with the help of micro-CT scan can be mentioned below:
Three-dimensional image projections created with digital X-ray projections, segmentation information from all three dimensions that can be rotated and reviewed, examining slices or layers, and image transfer from one layer to another.
Software that stores the information and data of scanned images gives the user the option to record the images as desired and show them to another person in the desired way.
In digital imaging, the resolution must be carefully considered. For example, an image of a large area may be of lower quality when magnified, or an image of a small area with a higher resolution will produce a better image.
Utilization of data
An X-ray image can be edited and changed. These images can be made lighter or darker with the histogram to see the details better. The histogram allows light and darkness to be distributed in the image.
Image tonnage analysis of images has a great effect on revealing or hiding high-density or low-density areas and identifying defective areas. It is revealed even if an object or metal is left inside.
Empty or incomplete parts of an object can be easily identified by fading. The user also has the opportunity to focus on one of the shortcomings by zooming and rotating the cuts and to have a better assessment of the situation while examining more closely.
3D CT scanning tools are a valuable investment. Some of these devices have special parts or benefits such as air conditioning and cooling.
Such imaging devices are ideal for situations where an object must be photographed at a certain temperature and humidity. 3D imaging devices require at least one workstation.
A workstation is a computer designed for technical or scientific applications. More working devices can be added to both imaging devices to speed up work and to have enough memory to record information and software and analysis methods such as FEA.
The FEA “finite element method” is a method by which one can predict how a product or commodity will perform under different conditions.
New technology applications
Using X-rays, another level of flexibility, resolution and quality can be added to CT scans and even a fourth dimension can be added. The fourth dimension is time. To add a fourth dimension, images of changes made to the object are recorded at a specified time interval. Of course, this method has some limitations.
If there are several objects to be examined, the location of each of them must be fixed in order to be photographed in its own area. This can be done manually, and after each shot of one part, move the object in its place so that it can be photographed from another part and produce four-dimensional videos.
This special feature paves the way for the use of micro-CT scans in the shoe industry to find interesting and useful applications; For example, it can measure the impact of certain materials or properties that are designed to cool and improve the airflow inside the shoe.
In this example, an air transfer pump is installed, and X-rays are taken of its operation. Then the pressure is measured on the sole of the shoe and the heel.
3D CT scan images can be used in more analytical techniques. These files have the ability to be used in 3D modeling and used in computer aided design or 3D printers.
In fact, these files also help to improve design methods in 3D software. As mentioned, CT scans help a lot in virtual tests and predict performance and structural and mechanical defects.
Product quality evaluation
X-ray image analysis is useful and useful not only in examining the remaining parts inside the shoe but also in examining and confirming the exact production of the product. Recently, research has been done on some shoe insoles, some of which could not be used due to defects in the production method.
In order for the exact type and location of these defects to be visible and eliminated, it was necessary to tear the sole of the shoe. But in this case, the whole final product would be damaged.
However, in the early stages of shoe production, CT scan images could be a great help in solving this problem. As mentioned earlier, the use of CT scan imaging techniques requires the use of new and accurate tools such as histograms. The histogram makes it possible to select or delete different tones of the photo as desired and observe the density of the material inside the shoe.
Of course, some materials are not easily detected by X-rays, and this is where the work becomes difficult. For example, X-rays may not detect the adhesive well because it is transparent and can be detected as part of other materials.
Or at best, it can be detected when the amount is low. Adding some iodine or potassium iodate to the adhesive can solve this problem. Of course, this must be added before applying the glue and then applied to the shoes.
Another way is to use trace chemicals in X-ray images. These materials must also be added to the raw materials before the start of the manufacturing process, and the way it is used must be such that it does not harm the quality and nature of the materials.
There are other ways to take CT scans and larger image samples. For example, in the case of long or long products, spiral scanning can be used. In this method, the sampling or imaging tool rotates 360 degrees around the desired product, and while rotating, the tracker or imaging panel moves upwards to examine all its parts. The goal is to create a spiral path.
The software then converts this spiral image into an image in which all the dimensions of the product are visible. In products that are very large, one of the methods is to scan the different parts separately and then connect these scans. Relevant software can put these images together and determine its dimensions correctly.
Another feature is the use of CT scan images in computer aided design (CAD). In computer design software, the dimensions of the images are specified, and changes can be made on them and the design can be changed or modified.
In general, 3D imaging makes it possible to examine a product from any point of view and from any dimension that is necessary and to observe, measure the various parameters that are needed in different stages of production, and to apply possible changes and corrections in them.
Access to this technology
Access to X-ray CT scanning machines is a significant and valuable investment. Companies that want to buy such equipment, there are different types of them in the market that can meet their different needs according to their budget and cost. This equipment does not require special and complex maintenance conditions.
Such devices, of course, are very heavy and should be taken into account. Steel and lead are an important part of this equipment, and this is due to the safety issues in which such materials are used. The average weight of some of these devices is about 6.5 half tons and they need to have their own location.
Some of these devices may have unique features, such as additional servers or air conditioning. In order for such systems to be used in relation to different goods, the necessary space must be provided for them. This is because in enough space, different goods of different sizes are easily scanned by these devices.
3D imaging technology offers many benefits to manufacturers, distributors, importers and anyone involved in quality control and material analysis.
This tool or technology will be very valuable and useful for reviewing and evaluating the quality and design of any product, because 3D photography makes it possible to identify and accurately fix a defect without slicing a product.
The benefits of micro-CT scan go beyond what is mentioned in this article. The purchase of this equipment may not be in the wealth and financial capacity of all companies, but through rent and contracting services, the ground has been provided for researchers, manufacturers and technicians to access it and carefully examine their product.
Seeing the internal details of a product is a unique opportunity that anyone who thinks of improving the quality of their product can use it. Many people who are active in shoe production and research in this field are becoming more and more interested in using this technology. The use of this technology is expected to grow further in the near future.
Translator: Hormoz Baradaran
Source: world lether/ august-september 2017
This post is also available in: Persian