Ensure Food Safety with Machine Vision

Government agencies have put food manufacturers under a microscope to ensure they follow food safety standards and comply with regulations. When it comes to the health and safety of consumers, quality assurance is a top priority, but despite this, according to The World of Health Organization, approximately 600 million people become ill each year after eating contaminated food, and 420,000 die.

Using human manual inspection for quality assurance checks in this industry can be detrimental to the company and its consumers due to human error, fatigue and subjective opinions. Furthermore, foreign particles that should not be found in the product may be microscopic and invisible to the human eye. These defects can lead to illness, recalls, lawsuits, and a long-term negative perception of the brand itself. Packaging, food and beverage manufacturers must realize these potential risks and review the benefits of incorporating machine vision. Although machine vision implementation may sound like a costly investment, it is small price to pay when compared to the potential damage of uncaught issues. Below I explore a few benefits that machine vision offers in the packaging, food and beverage industries.

Safety
Consumers expect and rely on safe products from food manufacturers. Machine vision can see through packaging to determine the presence of foreign particles that should not be present, ensuring these products are removed from the production line. Machine vision is also capable of inspecting for cross-contamination, color correctness, ripeness, and even spoilage. For example, bruises on apples can be hard to spot for the untrained eye unless extremely pronounced. SWIR (shortwave infrared) illumination proves effective for the detection of defects and contamination. Subsurface bruising defects become much easier to detect due to the optimization of lighting and these defected products can be scrapped.

Uniformity of Containers
Brand recognition is huge for manufacturers in this industry. Products that have defects such as dents or uneven contents inside the container can greatly affect the public’s perception of the product and/or company. Machine vision can detect even the slightest deformity in the container and ensure they are removed from the line. It can also scan the inside of the container to ensure that the product is uniform for each batch. Vision systems have the ability optimize lighting intensity, uniformity, and geometry to obtain images with good contrast and signal to noise. Having the ability to alter lighting provides a much clearer image of the point of interest. This can allow you to see inside a container to determine if the fill level is correct for the specific product.

Packaging
Packaging is important because if the products shipped to the store are regularly defected, the store can choose to stop stocking that item, costing the manufacturer valuable business. The seal must last from production to arrival at the store to ensure that the product maintains its safe usability through its marked expiration date. In bottling applications, the conveyors are moving at high speeds so the inspection process must be able to quickly and correctly identify defects. A facility in Marseille, France was looking to inspect Heineken beer bottles as they passed through a bottling machine at a rate of 22 bottles/second (80,000 bottles/hour). Although this is on the faster end of the spectrum, many applications require high-speed quality checks that are impossible for a human operator. A machine vision system can be configured to handle these high-speed applications and taught to detect the specified defect.

Labels

It’s crucial for the labels to be printed correctly and placed on the correct product because of the food allergy threats that some consumers experience. Machine vision can also benefit this aspect of the production process as cameras can be taught to recognize the correct label and brand guidelines. Typically, these production lines move at speeds too fast for human inspection. An intuitive, easy to use, machine vision software package allows you to filter the labels, find the object using reference points and validate the text quickly and accurately.

These areas of the assembly process throughout packaging, food and beverage facilities should be considered for machine vision applications. Understanding what problems occur and the cost associated with them is helpful in justifying whether machine vision is right for you.

For more information on machine vision, visit https://www.balluff.com/local/us/products/product-overview/machine-vision-and-optical-identification/.

 

 

The Pros and Cons of Flush, Non-Flush and Semi-Flush Mounting

Inductive proximity sensors have been around for decades and have proven to be a groundbreaking invention for the world of automation. This type of technology detects the presence or absence of ferrous objects using electromagnetic fields. Manufacturers typically select which inductive sensor to use in their application based on their form factor and switching distance. Although, another important factor to consider is how the sensor will be mounted. Improper mounting conditions can cause the sensor to false trigger, decreasing its reliability and efficiency. Since inductive proximity sensors target metal objects, surrounding the sensor with a metal mounting will cause unintended consequences for the user. Understanding these implications will help you select the correct inductive sensor for you specific application. There are several mounting options available for this type of sensor, including flush mount, non-flush mount, and semi-flush mount. We will dive into each type in more detail below.

Flush Mounting

Flush mounting, also known as embeddable mounting, is exactly what the name describes. The sensor is flush with the mounting surface. The advantage of mounting the sensor in this way is that it provides protection to the face of the sensor. The opportunities are endless for how sensors can be damaged but with the flush mounting style, these factors are reduced. The way a flush mounted sensor is designed causes the magnetic field to only generate out of the face of the sensor (see below). This allows the sensor to work properly by avoiding triggering from the mount as opposed to the target. The disadvantage of this is that it creates shorter switching distances than other mounting types.

Non-Flush Mounting

A non-flush inductive proximity sensor is relatively easy to spot because it extends out from the mounting bracket and also uses a cap that surrounds the sensor face. Non-flush sensors offer the longest sensing distance range because the electromagnetic field extends from the sides of the sensor face as opposed to the edges or strictly the front of the face. There are some consequences to consider when selecting this style. The sensor head is exposed to the external environment. These sensors are more susceptible to being hit or damaged, which in turn, can cause failures within the process and cost the company money for replacements. It is important to understand these potential problem factors so they can be avoided in the design phase if you require the longer switching distance.

Semi-Flush Mounting

The semi-flush, also known as quasi-flush, is similar to that of the flush mounting style but requires a metal-free zone around the sensor face to achieve the optimal sensing range. Thus, this sensor is protected and offers a larger sensing field than a flush mounted sensor. The disadvantage is that if metal is touching the edge of the sensor face, this will dramatically decrease the sensing range.

Each style offers advantages and disadvantages. Each style uses a specific technology and design to allow it to adapt to different applications. Understanding these pros and cons will allow you to make a more informed decision for which to use in the application at hand.

Tag, You’re It: Choosing the Right Type of Tags for Your RFID System

Many companies have already discovered the benefits of implementing RFID into their systems. Traceability within the manufacturing process provides a competitive advantage of both efficiency and profitability. RFID tags are a major component of this technology. But it’s important to select the correct type for your specific application. These tags are classified into categories based on how they obtain power and how they use that power. The three categories are as follows:

  • Passive tags
  • Semi-passive tags
  • Active tags

Understanding the difference between these can help narrow down your decision when looking into implementing RFID systems to your process.

Passive tags do not have their own power source. The tag receives power only when the RFID reader is in range. These tags are limited since the power supplied is minimal. The biggest advantages of passive tags are that they are small and inexpensive. They can be useful in specific applications where space is limited. Also, if the environment in which the tag is being placed is harsh, the passive tag may be a good option because it can be cheaply replaced if damaged. Since these tags do not generate power, their read distance of just a few inches to about two feet is much shorter than others. Passive tags are also limited to the amount of data storage they possess. Depending on the application this can be an advantage or disadvantage.

Semi-Passive tags, as the name implies, are similar to passive tags in that they do not have an active transmitter. They still require an RFID interrogator to be in range for the device to work, although the semi-passive tags have their own battery to power the IC. If you are looking for longer read ranges than the passive tag, this could be an option. Since the read range of the passive sensor is solely based on how far away the interrogator can power the device and not the signals coming in, adding a battery unit to the semi-passive tags increases this distance. These distances can range up to 100 feet. Another advantage is the amount of data they can store. These added features do come with added costs. The onboard power supply also makes these tags larger and heavier. The electronics inside the tag are susceptible to harsh environments like high or low temperatures, resulting in shorter lifespans.

Active tags have both a battery and transmitter built within their housings. The typical read range is again increased to around 300 to 750 feet depending on the battery power and the antenna. This allows the tags to store more data with their increased memory capacity. Active tags display the most configurability in comparison to passive and semi-passive tags. They can be set up to conserve battery power when the interrogator is out of range and respond only when the reader is within range. They can also be set up as a beacon, which is when the tag does not wait until it receives a signal from the interrogator. Instead, the active tag can be configured to send the information in set time intervals. Since active tags contain an active transmitter, they can contribute to radio noise. They are also more expensive and usually larger in size and weight due to the increased electronics within its housing.

It’s important when selecting a tag for your RFID system to consider the application needs and the advantages and disadvantages of these different options.