Camera technology has been advancing steadily over the last century. These tools “see” faster and better than the human eye.

The sorting industry utilizes video cameras to identify and categorize material at high speed. This is a form of optical sorting.

Today I will be writing about commonly used sorter cameras. These are:

  • Charged-coupled Device (CCD) cameras
  • Near-infrared (NIR) cameras

CCD Cameras

 

Simply put, CCD cameras convert reflected visible light into data. The data is then ready by software and a “accept/reject” signal is sent to the ejector system.

CCD cameras are a form of the digital camera. They take visual information and convert it to digital signals without using film.

CCDs use millions of tiny photosensitive panels inside the camera to capture light. Individually each sensor will capture Red, Green, or Blue colors.

The captured colors then form a picture that the software reads. It can identify size, color, and shape.

 

Advantages

  • High image quality

CCD sensors are the older relative of current CMOS camera sensors. The age in this case means that the image quality has been improved over time.

  • Low noise

The high-resolution sensors generate images with very high clarity. This allows for a high level of throughput and speed.

  • Spots color, shape, and size differences accurately

Since the image quality is high with low noise the sensor can accurately capture differences.

  • Customizable parameters

The touch display panel is convenient and easy to use. We provide full customization in terms of defining acceptable or rejected material.

Disadvantages

  • Can’t be used for material that does not have color or size differences

CCD cameras operate in the visual spectrum. Material that is indistinguishable visually will then be difficult to sort without more advanced sensors.

  • Only sees the surface of the material

Going back to our previous point, the cameras are not able to penetrate any covering of the material. For example, pistachios or shelled nuts are not easily sorted with CCD cameras.

Our color sorting machines will have 2 or more CCD cameras by default.

Now, let’s talk about NIR cameras.

NIR Cameras

 

NIR cameras utilize sensors to see in the near-infrared spectrum. This spectrum is invisible to the human eye. It is often used to identify material that does not have clear color differences.

Different materials have unique NIR wavelengths. This allows for the sorting of material that is visually indistinguishable.

An example of this is plastic sorting. Let’s imagine two orange bottles of laundry detergent: Both are the same color, but one bottle is made from PET and the other from HDPE plastic.

A CCD camera would not be able to sort the bottles correctly. A NIR camera can see the difference.

Each type of plastic has a unique chemical composition. This composition reflects a certain wavelength in NIR. Using NIR cameras, a sorting machine can sort many types of plastic easily.

Advantages

  • Can accurately pick out material by using NIR wavelengths

Everything reflects a certain wavelength of infrared radiation. The exact wavelength depends on the chemical composition. By inputting the desired range, many materials can be easily identified.

  • Does not need to rely on color

By using the wavelengths instead of color, material that has the same color but different compositions can be sorted. For example, plastic can have the same color but different material types.

  • Detects impurities that are hard to distinguish from material
    • Example:
  • Can be used to identify damaged or inconsistent material
    • Example: It can see bruised fruit because the bruised areas have more water

Disadvantages

  • Higher cost vs CCD

Although CCD and NIR cameras use similar technology, the specialized use of NIR makes it a bit more costly.

We equip our machines with NIR cameras on request. It really depends on what kind of materials you are working with.

How Do Color Sorting Cameras Work?

 

A color sorting machine has a few elements. The cameras are one of the most important.

  1. After the raw material is input, it gets channeled down a chute
    • A chute has multiple grooves called channels
  2. The material is scanned by cameras
  3. The cameras convert visual information into digital signals
  4. The signals are sent to the sorting software
  5. Sorting software then decides on “accept” or “reject” based on preset parameters
  6. The signal then goes to the ejection system
  7. The ejection system will blow pressurized air at material to divert it to the proper channel
  8. Your product is sorted!

Why Should I Get A Color Sorting Machine?

 

Customers like products that are visually uniform. The color, shape, size of the product often represents quality. The good-looking product will look more valuable of course.

But it’s a waste of time for humans to sort through millions of grains of rice. One color sorter can do the sorting work of 100 humans.

Color sorters are the best way to maximize sorting efficiency. They can sort tons of material accurately every day, which would be impossible for humans to do.

The sorting process will group similar things together. It will also remove impurities that can lower the value of your product.

Which Camera Should I Use In My Color Sorting Machine?

 

You need the right camera for the right job. I would recommend emailing us to start a discussion about your needs.

In general, CCDs are used for materials that have different colors. For example, you can separate stems and sticks from tea leaves. The leaves can be sorted according to size and color.

NIR cameras are used for visually indistinguishable material. For example, you can sort different types of same-colored plastics.

We offer CCD, NIR, and X-ray cameras for our color sorting machines. Our team will provide the most appropriate solutions for the material you want to sort.

How Do I Order A Color Sorting Machine?

 

Once you’re ready to make an order, simply email us to start the discussion. Be ready to let us know more about your business.

We will provide recommendations on what machines the best suit your needs. Machines can even be custom-built for specialized service.

We are more than happy to answer any questions you may have. Our color sorters are produced in one or two weeks. They can be shipped door-to-door, worldwide. They come with a 14-month warranty.

Thank you for reading about our CCD and NIR cameras. I hope you know more about how they function and where best to use them.