X-Ray Basics
X-Ray Basics
August 24, 2021
X-ray Contaminant Types Photo
X-Ray Contaminant Types
November 1, 2021
X-Ray Basics
X-Ray Basics
August 24, 2021
X-ray Contaminant Types Photo
X-Ray Contaminant Types
November 1, 2021
Show all
Metal Contaminant Types

Metal Detection Contaminant Types

Metal Contaminant Types

Metal TypesWhen it comes to metal detection, there are 3 types of metal contaminant types you should always use. Standards for the food industry are: Ferrous (Chrome Steel), Non-Ferrous (Brass) and Stainless Steel 316. These are the 3 categories of metal commonly used in food production and other manufacturing (pharmaceutical, textile, etc.). Each type of metal has different magnetic and conductive properties.

Ferrous Metal

Ferrous (Chrome Steel) material is the most conductive and magnetic. Because of this, it’s the easiest metal to detect. You can expect to find smaller sizes of Ferrous metal than the other two. Ferrous metals emerged much later than Non-Ferrous. Production of these type metals probably started around 1,200 BC. The first known steel pieces were found in modern-day Turkey, dating back to 1,800 BC.

The biggest difference between ferrous and non-ferrous metal contaminant types is that ferrous contains iron and non-ferrous metals do not. Sounds simplistic, but each has specific characteristics that make them different enough to be separated. Ferrous metals have strength and durability. Non-ferrous metals are used because they are malleable, corrosion and rust resistance, and have more non-magnetic properties. Ferrous metals are sturdy and robust. They are a mainstay in the construction industry and are used to build all sorts of important structures:
Skyscrapers
Bridges
Shipping containers
Automobiles
Railroad Tracks
These types of metals fall under the umbrella of ferrous metals:
Cast steel
Carbon steel
Alloy steel
Cast iron
Wrought iron

Non-Ferrous Metal

Non-Ferrous metals are the “middle of the road” in terms of magnetic and conductive properties. They have a long history of use in civilization. Copper, for instance, was discovered in 5,000 BC. Bronze, an alloy of copper and tin, was likely first used even earlier. Non-ferrous metals are malleable and used in manufacturing industries where metal parts need to be molded into a particular shape.

Non-ferrous metals have no iron content.  They are not as susceptible to rust and corrosion as ferrous metals are, making them the best choice for structures that need to withstand heavy weather conditions:
Gutters
Liquid pipes
Roofing
Road signs
Non-ferrous metals are also useful for electronic and wiring applications because of their non-magnetic properties.

Stainless Steel 316 Metal

Stainless Steel 316
In 1907, Harry Brearley was in charge of the Brown-Firth Research Labratory in England. He was investigating ways to eliminate rust in gun barrels. By accident, he noticed a discarded steel sample that was not rusting. The result was a chrome alloy steel, much more rust resistant than seen before. Two months later, on August 20, 1912, stainless steel was cast for the first time.

Stainless Steel 316 is used for:
Heat exchangers
Pulp and Paper Equipment
Dyeing Equipment
Film Processing
Pipes
Solenoid Valves
Clamps
Materials for exterior use in coastal areas and marine environments, and
Food Grade Equipment – 316 is the industry standard.

So in terms of testing for these metals, you should generally expect the Ferrous to be your smallest sample. Non-Ferrous would be in the middle, and Stainless Steel 316 at the top. In other words, if you can achieve 1.5mm Ferrous, you might expect 2.0mm Non-Ferrous and 3.0 Stainless Steel 316.  Regal Packaging Services can provide all you need to make certain your systems are working accurately.

Leave a Reply

Your email address will not be published. Required fields are marked *


Some applications involve large tubs, vats, or some other type of product travel where it would be nice to have a test piece that floats. Once again, our thermoform cards provide the simplest solution. We simply insert some type of structure that forces the thermoform card to retain air, which, of course, is what makes it float. We have also manufactured floating rods, which are more difficult because there is less space to close in enough air to make the rod float but is doable.

We took an ordinary plastic “chip clip” as defined by the customer and embedded the contaminant into the clip. The clip can be attached to the product on the line without damaging or opening the product for testing purposes.

Bone is a difficult contaminant to find because it can vary widely based on the size, age, and calcium content (as well as feed used) of the animal. After working with several customers, Regal Packaging Services offers Pork, Beef and Chicken Bone Simulate. We have a small range of sizes at a variety of depths to simulate whatever you might expect to find in the product. Our recommendation (assuming your x-ray has visual display) is always to start with a multi-card. Using a multi-card gives you an easy way to test several sizes and depths to determine what matches the bone you’re using. Once you’ve made a comparison, testing the card against the bone you’re looking for, you can purchase a card with a single contaminant for regular testing.

This small pill shaped test piece is used in a system with a vacuum tube that shoots the test piece through the aperture and returns it to the “home” base. Your system may never be like it, but the point is that we can make a customized solution no matter how unusual or impossible it might seem.

As you may have seen in some of the other thermoform card descriptions, we can put nearly as many seeds as you can imagine on a single card. Pictured here you will find a wide variety of configurations and contaminants. Just let us know your specs: size of the card (up to 8” x 8”) along with size and type contaminant(s) and we’ll get you a quote as quickly as possible. Working with a multi-card is especially helpful when you are looking for multiple types of contaminants or when you want to determine what size of the same contaminant you are able to detect. In that event, once the size is chosen, you can order individual card(s) for regular, standard inspection and detection.

There are a wide range of applications that require a test piece much longer than our standard 5” or 6” Testrods. We can make up to 3/8” x 34” or 1/2” x 34” rigid test pieces which can then be extended well beyond that length with a “handle” made of acetal cylinder larger than the 3/8” or 1/2” extension. In the photos, we used a 1” x 24” cylinder handle with a 3/8” x 24” inch extension.

Test pieces can be made in a variety of sizes and given a pointed end in applications that require the contaminant (metal) to be inserted into a food package such as sugar or some other soft packaged food product. This allows the metal to reach the center of the aperture.

Double-End Test Whips are also available, with metal in both ends. One consideration is to make certain that the whip is long enough to keep the metal on the non-testing side of the whip outside the metal free zone of your detector. If you insert, for instance one end of a whip with 2.0mm and 3.0mm Ferrous, you need to make certain that the 2.0mm metal doesn’t affect the detection of the 3.0mm metal (and vice versa). If the 3.0mm metal is inside the metal free zone, then the detector will be reacting to the 2.0 as well as the 3.0 as if they were combined.

Multi-seed laminate test cards are designed for seeds 4.0mm or less. Multi-cards are useful in x-ray inspection to determine what sizes and types of contaminants your system can achieve. They can be especially useful in temperate environments and applications. If your application is rugged or wet, or your standards are larger, we recommend our thermoform multi-cards.

We can simulate a variety of packaging in an application where you need the test piece to mimic what is traveling down the production line. In this case, we manufactured a clear “package” with the seed inside. With this method, the customer is able to reject the container appropriately, and, in the event the package is not rejected, it is easily seen by the line worker for manual removal.

There are two types of “candy bars” pictured here – one similar to a flat candy bar and the other in a custom, near perfect copy of a candy bar. Since we’re now able to produce many variations using colored material, the copy was made in red (Fe), green (NFe) and blue (SS 316). We have the equipment to accomplish nearly anything you can imagine, and these kinds of designs are proof positive.

Need a test piece that looks and handles like chicken nugget? We can do it. Interestingly enough, in this situation, our first version for the customer left too much “void” in the hole where the metal was placed. Given the sensitivity the customer system was using, the void had the effect of causing false positives. We were able to minimize that hole and supply the test piece with almost no void. It’s an example of how we can work with you before, during and after manufacturing to ensure all the specifications were met.

Our standard acetal card is 2 1/4"x3 3/8,” but if needed, we can cut that size down to as small as 1 1/4” x 1 1/4” (with limited engraving). If a larger card or a card with multiple seeds is needed, see our Custom Shape-Size Blocks and Tablets.

This distinctive test piece was created to mimic an actual hamburger patty. The customer supplied photos of the raw product, which we were able to reproduce and then we placed blue glove contaminant. Using this configuration, the customer was able to determine what size piece the vision scanning system could detect with the raw burger as the background. Had they simply used a blank card with the glove, the system could easily have achieved contaminant rejection, but they needed to be sure the system could “see” the blue against the product itself.

A card with 100 seeds in a 10x10 configuration is used to place beneath whole chickens on a production line. This gives the x-ray system operator the ability not just to see IF the equipment can detect the metal in the card, but also WHERE the equipment can detect it. If there is a problem, the operator (or company) can make any changes necessary to achieve the end goal – safe chicken in this case. This card really highlights another valuable facet of our thermoform cards.

In this scenario, a company processing sugar needed to have a “bag” simulated with the same weight in order to accurately fall through the reject mechanism. A lighter test piece had the risk of passing over the reject mechanism.

Our standard cubes are 1” and 1.5,” but we can also manufacture other sizes if needed. The cubes shown here are 1/2" in dimensions. Cubes can be helpful in applications where a ball or cylinder may bounce or roll away during testing, making their retrieval difficult, or, in some cases, present a hazard to the product or production equipment.

This is a test piece that is dropped into a bottle. It’s designed so that the metal appears in the center of the aperture when testing the metal detector. In addition, the round stop makes the test piece easily removable after testing.

Hexagonal Shaped test pieces can be very useful in places where a cylinder or ball might roll or bounce around a production floor whether dropped by a line worker or ejection from a reject mechanism. Hexagons are similar in weight to the 1inch cylinders without having the smooth, rounded cylinder edge.

Our customer in this plant needed a test piece with a thickness less than 5.0mm. Because we have the capacity to customize sizes and shapes, we were able to mill down a product that met their specifications. That’s always our goal, meeting the specs you need for your product, testing environment and contaminants.