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Weighing Applications In Production

Weighing in Production: Value through Data

When most people think of weighing, their mind tends to picture “Retail”.
“How many ounces of cookies are in this box?”
“Do I need 1 or 2 gallons of milk?”
“How many lbs. did I gain over the holidays?”

For those of us in the material handling industry, we may think a little more beyond retail, but still primarily “post-production”:
“How much lumber is on this truck?”
“How much does that pallet weigh?”
“How much “stuff” did we make today?”

In fact, there is a place for weighing throughout the entire supply chain; raw, refinement, production, quality control, packaging, logistics and retail. Having a good understanding of effective placement and use (including proper scale selection, maintenance, and calibration) of these tools can be incredibly beneficial in reducing overhead, identifying bottlenecks, and in the end increasing production and/or efficiency and profitability.

In production, scales do more than “weigh”. They create value.

To exemplify, let’s imagine you operate a facility that makes plastic fenders for golf carts. Of course, as we walk through, actually consider your own position, where it falls within the overall supply chain process, and if you are taking advantage of all of the weighting and cost saving tools that are available.

Let’s assume our fenders are going to be molded of thermoplastic resins. These are materials that become liquid in high heat only to harden again when cooled. Easily molded into various shapes and structures, this gives thermoplastics applications in many industries.

To visually grasp the extreme number of materials and production options of thermoplastics, let’s list out some of the most common here: Commodity Resins: ABS, Acrylic, High Density Poly, Ethylene, Polypropylene, Polyethylene, Polystyrene, PVC, Styrene, Engineered Resins: Acetyl, PBT, PET, Polycarbonate, Peek, PEI, PES / PSU, PPE, Nylon, PPS, TPE, TPU, Teflon, TPR, Specialty Resins:, COC, COP, LCP! AND… of course each of these types have multiple different producers, each with their own “recipe” to create specific characteristics!!! To say there are thousands of varieties is not an exaggeration:

Scale use 1: Raw production

Each of these different choices are individually manufactured in unique chemical production facilities which would use a variety of scales (silo/tank scales, gain-in-weight/loss-in-weight feeders, belt scales, pneumatic transporters on load cells, etc) in their manufacturing process. But, we will jump ahead to our plant.

 
Scale use 2: Raw Supply/Logistics

Let’s say, our material requires a resin, a plasticizer, a fiber, a heat stabilizer, a UV stabilizer, and various pigments (for color) In actuality there are probably more! These base materials are typically transported by rail or truck, each of which would be weighed by NIST certified scales prior to leaving their respective manufacture point for both production verification as well as state and national “legal for trade” and “over the road” requirements and limitations.

 

Scale use 3: Intake

Once arriving to our site, these containers are often “re-weighed” to verify delivery quantities. Done by using any combination of rail scales, truck scales, weight monitoring a “receiving vessel” (a silo on load cells for example) or checking bulk packaging like a “bulk-bags” with a forklift scale, at this point our raw material has become an “ingredient”.

 

Scale use 4: Ingredient inventory management

In order to efficiently produce, we would need to know how much ingredient we have on hand at all times. Primarily, this prevents us from running out of an ingredient and halting production (extremely costly), BUT… this also allows us to make smart economically driven decisions, like when and how much of an ingredient to purchase so we might take advantage of advantageous market pricing, bulk discounts, logistics savings etc. While some plants might use volume measurements (level probes) to track ingredients, bulk densities can vary, so using scales to WEIGH the materials on hand is much more accurate. Volume varies, weight does not.

 

Scale use 5: Batching/Quality Control

Now its time for us to make our material. Here, the use of scales if of utmost importance. As we bring our six (in reality more) ingredients together, we must be absolutely sure we have the right amount of each. Too little UV stabilizer would cause our golf carts to “yellow” or become brittle, too much plasticizer could lead to our panels being flimsy, or too much or too little pigment would lead to variability in the color our finished product (no golf course would want 15 different shades of cart!) Depending on how the ingredients are transported to the batching/blending tank, this weighing might occur through multiple types of scales; again, gain-in-weight/loss-in-weight feeders, belt scales, pneumatic transporters on load cells, or in some cases simply hand scooping an ingredient into a tote sitting on a small bench scale to be manually added. All of these are yet another check point where we can make sure we are optimizing our ingredients (cost savings), identifying points of ingredient loss (waste), reducing the chance of “bad batches” (waste reduction), and quality improvement (higher value final product) each of which improves profitability.

 

Scale use 6: Production

As we now put our mix into the molds, we again would weigh out. This makes sure we have sufficient material to form the entire piece (eliminate voids) but that we do not OVERfill (and create waste). Additionally, supplying the molds or injection equipment with the proper amount of material increases the longevity of the machinery (maint. costs reduction and downtime avoidance) plus reduces additional labor costs needed for post-production finishing,

 

Scale use 7: Finished Goods Quality Control

Post trimming and finishing, we would now scale weigh our finished panel during the quality control process. This additional quantitate check measures product consistency and “red flags” potential concerns. This scale might help us identify panels that are too “thick” (a waste of production materials), or too thin (a source of customer concern), each of which might also suggest the need to examine the production line to find the root cause of variance, perhaps preventing expensive downtime or repairs.

 

Scale use 8: Packaging/Logistics

Now as we package our panels for transport to our customer, we once again would scale weigh and label each panel if selling individually, or weigh and label a pallet holding numerous. Strategically planning packaging and transportation weights may allow us to take advantage of shipping savings.

This quick example of a single product has utilized DOZENS of scales, each with an opportunity to improve efficiency, reduce costs, and increase profitability.

 

Again, in production, scales do more than “weigh”, they create value.

Of course, we could imagine this for any material, product, or industry. Maybe trees in a logging yard, trucked to a mill, processed with other chemicals to make a cookie box. Grain from the field, sent by train with other ingredients to a bakery to make those cookies. Bulk Bags of silica from a quarry, mixed with additives to form the glass on top of our personal scale.

We invite you to think about your own position and products and how property selected, installed, maintained and calibrated scales could improve your operations and success.

Let us know how American Scale Company can be of help.

 

The Author has over a dozen years experience in dry material handling, processing, manufacturing and weighing including consultative system design, equipment and component recommendation, provision and supply.

 

Closing Words

At American Scale we strive to bring you informed and useful content on all things scale related. Be sure to check out our legal for trade truck scale system articles about truck scale foundation or how much do truck scales cost. We even have a guide to warranties. We also have articles on scale accessories, common problems to prolong your scales lifespan, weighing applications as well as what scale indicator works best with your junction box. To learn more about bench scales, it would be good to check out our other articles such as “Bench Scale Basics'' andHow Much Does A Bench Scale Cost?”. These articles will help with the basics of bench scale ownership.

Types Of Belt Scale Maintenance

Regular Belt Scale Maintenance

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Regular belt scale maintenance is imperative to make sure your scale stays in proper working order and lasts for a long time. This maintenance should include clearing the scale area of debris, checking the condition of the idlers, check the scale frame and the conveyor belt, and zero testing the scale daily. Before maintenance can even begin make sure you install your belt scale in the correct location, checkout this blog post to learn more.

 

Clean Around The Belt Scale Frame

The most important part of belt scale maintenance is keeping the weigh frame clean. Debris in the scale area is generally caused by material falling off the conveyor belt and building up. This material can get wet and even freeze. Material buildup will cause issues like mechanical binding, inaccurate zero test results, and incorrect totalizing.

 If a belt scale weigh frame has just five pounds of buildup, the scale could register several extra tons every hour, causing a false totalization. In colder weather, we recommend running the conveyor belt for 10 to 15 minutes without a load to warm up the belt and make it more pliable.

 

Don’t Forget About The Belt Scale Speed Sensor

The speed sensor on the belt scale also needs periodic attention. The speed sensor (wheel sensor on return belt or a shaft-mounted encoder), it must be clear of debris use.

 

Keep Your Belt Scale In Top Shape

Performing a daily zero test on the belt scale is recommended and will help the user determine if and when the scale needs to be inspected. In good weather, the zero test should have normal results close that are showing good repeatability. If the zero test isn’t showing good repeatability, the belt scale should be checked for ice buildup.

 After clearing debris away from the belt scale frame, perform another zero test, and then run a span test (or static calibration test). If the span test results are not normal compared to periodic span tests, it is best to call a certified scale dealer to perform a thorough inspection and any calibrations necessary.

Belt Scale Calibration Program

Having a regularly scheduled calibration program with your scale company is always recommended to keep your belt scale weighing and performing at top shape. At the end of the day, performing a material calibration is the best method to use.

To learn more about the different belt scale manufactures, checkout this blog post.

Closing Words

At American Scale we strive to bring you informed and useful content on all things scale related. Be sure to check out our legal for trade truck scale system articles about truck scale foundation or how much do truck scales cost. We even have a guide to warranties. We also have articles on scale accessories, common problems to prolong your scales lifespan, weighing applications as well as what scale indicator works best with your junction box. To learn more about bench scales, it would be good to check out our other articles such as “Bench Scale Basics'' andHow Much Does A Bench Scale Cost?”. These articles will help with the basics of bench scale ownership.

How To Test My Magnet?

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Testing Your Magnet

Because magnetic fields are transparent to the human eye, measuring their strength requires specialized tools that measure the working air gap of the magnetic circuit. Currently, there are two accepted ways of testing your magnetic separation equipment and this subject itself is not without controversy. The first is with the use of an instrument called a Gauss Meter or Magnetometer and a probe, and the second is with a Pull Test Kit using a scale and a selection of different sizes of ferrous test pieces; a ¼” ball, a ½” ball, a 1” ball and a 1” x 3” plate. Make sure you understand the different type of magnets prior to testing, checkout this blog post to learn more.

Gauss Meter

A Gauss Meter is an electronic device that measures the flux density at any given point on your magnet. As the probe is pressed against the surface of the magnet it senses the flux density and translates it into an electrical voltage read by the gauss meter. Gauss readings are displayed on the meter. When the maximum number is found while moving across the face of the magnet (usually at a pole piece), it is recorded.

PROS

It is a scientific piece of equipment that can be calibrated. In clinical environments where the working air gap can be plotted and the probe placed repeatedly in the exact same spot within the gap, Gauss is incredibly accurate.

CONS

In real-world environments Gauss testing has serious limitations. Gauss profiles change significantly depending upon the location and angle at which the probe is placed within the working air gap in relation to the line of flux travel. Because magnet circuits vary from one magnet to the next, and because of “human error,” accurate readings are difficult to attain making the manually taken gauss value an imprecise determination of the magnets strength. Simply placing a different amount of pressure on the probe to the surface of the magnet will create drastically varying results. Because of the length of time that lapses between testing, it is not uncommon for different individuals to execute them, which further limits accuracy. Lastly, any mechanical damage to the probe or cable will degrade the precision of the instrument. They are essentially “consumables” that require regular replacement. These factors add time, cost, and technical training to the equation.

MPI’s Magnetic Pull Test Kit

A Pull Test Kit utilizes a compact digital scale or a spring scale, and a series of ferrous test fixtures (a ¼”, ½”, and 1” ferrous ball and 1” x 3” ferrous plate). The magnetic pull strength is measured by using the calibrated scale and a ferrous test piece to determine the breakaway force, typically measured in pounds or ounces. The test fixture has one end attached to the scale and the other end securely attached to the working area of the magnet at a predetermined position (on the surface with a specified air gap). It is then slowly pulled away at a perpendicular direction to the magnet until it is released. The pull strength is registered on the scale.

PROS

The digital scale offered in MPI’s Pull Test Kit is also a scientific device that can be calibrated and NIST (National Institute of Standards and Technology) certified. In practical applications, the pull test approach is advantageous because the testing equipment is less expensive to acquire, more efficient to operate, and achieves more consistent repeatable values than the gauss approach regardless of the individual operator. The ferrous test fixture is drawn to the magnets peak energy point with every repetition of the test, as opposed to the gauss approach which requires the operator to find the peak energy point within the working air gap using the probe. The pull test is also performed much more efficiently than the Gauss method, minimizing production downtime.

CONS

Just as Gauss meters have evolved over the years, so have mechanical pull test kits. Akin to a fish scale, some company’s pull test kits are still offered with simple spring-loaded gauges that measure the force required to pull a small metal sphere or ball. MPI’s magnetic pull test kit is the most accurate and easiest method to test the strength of your magnets. This easy-to-use, compact gauge fits into tight areas and is battery- operated (four AA batteries included.). Boasting a capacity of 44 lbs. (20 kg), MPI’s magnetic pull test kit can measure pull in pounds, ounces, kilograms, newtons, or kilonewtons. It can maintain the last reading after release. Packaged in a hard-sided foam-padded carrying case, this compact unit includes all needed accessories and can be used to test a complete range of magnet types and configurations. The documentation generated from this test can be used for compliance in a Hazard Analysis and Critical Control Point (HACCP) plan or for documentation requirements under the Food Safety Modernization Act (FSMA).

To learn more about the magnets that American Scale offers click here.

How Often Should I Clean My Magnet?

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How often Should I Clean My MaGnetS?

How often should you be cleaning your magnet is another question that is dependent upon your individual process. Obviously, the more metal you receive or produce in your process, the more frequently you should be cleaning your magnets. A general rule is the more frequently, the better. As a magnet gathers ferrous metal, the magnetic field is dispersed over a larger surface area. This happens because ferrous metal is paramagnetic, meaning it takes on the properties of the magnetic field. When this happens, the magnetic field strength is reduced. It is better to begin cleaning your magnets more frequently after the magnet is placed and reducing the frequency as possible without jeopardizing the effectiveness of the piece of equipment. Each manufacturing facility will be different as well as locations within the same facility may very well need to be cleaned at different intervals. “More is better.” To learn more about the lifespan of a magnet checkout this blog post.

Establishing A cleaning schedule:

1. After installation, inspect your magnet after the first hour of production

2. If an insignificant amount of metal is observed, return in 2 hours to inspect magnet

3. If magnet continues to have insignificant amount of tramp metal, it is recommended that maximum time between cleaning is 8 hours

4. If significant amount of metal is found on magnet, increase the cleaning interval as required to ensure the magnet does not reach maximum tramp metal capacity

Key to magnet performance is also testing, checkout this blog post to learn more about testing your magnets to ensure proper function.

What's The Lifespan Of A Magnet?

 
 

How Long Will My Magnet Last?

Your permanent magnet should lose no more than 1% of its magnetic strength over a period of 100 years provided it is specified and cared for properly. There are a few things that may cause your magnet to lose its strength:

HEAT:

Heat above the maximum level rated for the magnet material in your separator will decrease the strength of the magnet. Standard rare earth material from MPI has a maximum temperature of 176°F and standard ceramic material has a maximum temperature of 400°F. Higher temperature materials are available and may have been used in your system. Consult the factory if you have questions on what the maximum temperature is for your system.

IMPACT

Sharp impacts to the magnet from physical abuse or handling can result in the decreased magnet strength. The magnet material inside your separator is brittle and these impacts can lead to fractures in the material, weakening its strength.

WELDING

Welding on or around the magnet can lead to decreased magnet performance. This can be a result of the heat or current generated from the welding process.

LIQUID INGRESS

If your magnet housing is compromised, moisture can enter the housing of the magnets. This can lead to oxidation of the magnet material which will eventually lead to a weakened magnetic system. If the housing is compromised, the magnet should also be replaced for sanitary concerns.

Closing Words

At American Scale we strive to bring you informed and useful content on all things scale related. Be sure to check out our legal for trade truck scale system articles about truck scale foundation or how much do truck scales cost. We even have a guide to warranties. We also have articles on scale accessories, common problems to prolong your scales lifespan, weighing applications as well as what scale indicator works best with your junction box. To learn more about bench scales, it would be good to check out our other articles such as “Bench Scale Basics'' andHow Much Does A Bench Scale Cost?”. These articles will help with the basics of bench scale ownership.

Magnets: What Are The Different Types?

Magnets magnetically capture and control ferrous contaminants in material process systems. The proper magnetic applications and magnet placements will help you achieve success for removing tramp metal from your product flow.

Magnets magnetically capture and control ferrous contaminants in material process systems. The proper magnetic applications and magnet placements will help you achieve success for removing tramp metal from your product flow.

Magnetic Application – Primary Magnets

Primary magnets are designed to be used in high volume process flows placed inline so as not to introduce any foreign contaminants from external sources into your production facility. They will remove large amounts of ferrous tramp between cleaning cycles giving you peace of mind. These magnets are typically located in plant receiving areas and handle large amounts of materials that tend to damage equipment or bridge in many magnet applications. The magnet circuit design is such that the magnetic field reaches out is maximized while maintaining adequate holding values to gather large amounts of tramp before reaching the saturation point. Primary magnets help to identify risks associated with bringing in ingredients from outside sources allowing you to monitor your vendor product quality.

Primary Magnet Function:

  • Process high volume product flows

  • Remove incoming tramp ferrous

  • Retain large volumes of tramp ferrous between magnet cleaning cycles

  • Vendor monitoring

Where it is used:

Plant receiving areas

MPI Primary Magnets:

Chute Magnets, Free-Flow Magnets

Magnetic Application - Secondary Magnets

Secondary magnets are used in processing areas in front of sensitive pieces of equipment for protection, as well as throughout your process for redundancy which helps to detect process equipment malfunctions. The material flow is typically metered at this point, which enables us to specify your exact application requirements. The magnetic circuits are designed with specific functions, whether that be to maximize the magnetic fields reach out, holding force, or a combination of both.

Secondary Magnet Function:

  • Protect specific plant equipment

  • Detect process equipment malfunctions

Where it is used:

hammer mills, airlocks, screw conveyors, sifters, roller mills, bucket elevators, screeners, pumps

MPI Secondary Magnets:

Plate Magnets

Magnetic Applications Finishing Magnets

The function of a finishing magnet is to maintain your end product quality to your customer. Finishing magnets capture small metal fines from your process ensuring product shipped from your plant, whether going to another manufacturer for further processing or to a shelf for consumer use, contains no ferrous tramp contamination. This protects your brand reputation and financial liability for recalls, as well as consumer protection.

Finishing Magnets Function:

  • Maintain end-product quality

  • Ensure that the product to be shipped from the plant does not contain any tramp ferrous contaminants

  • Consumer protection

  • Brand protection

Where it is used:

packaging systems, bulk load-out areas

MPI Finishing Magnets:

Tube MagnetsGrate MagnetsDrawer MagnetsPneumatic Line Magnets

So what is the best type magnet for my application?

That depends on your reason for looking into magnetic separation equipment, to begin with. Are you looking to protect equipment or the integrity of your product? Your desired results will determine which type of magnet to put into place and where. Keep in mind that no magnet is 100% effective in removing all tramp metal. The amount of tramp it is exposed to couple with the frequency of cleaning has a dramatic effect on your success. If you are finding a lot of metal on your magnet, you can be fairly certain metal has gotten by. Because of this, redundancy in your process is critical with magnetic separation equipment. You should feel comfortable in the amount of metal you are collecting on the last magnet in your process.

Closing Words

At American Scale we strive to bring you informed and useful content on all things scale related. Be sure to check out our legal for trade truck scale system articles about truck scale foundation or how much do truck scales cost. We even have a guide to warranties. We also have articles on scale accessories, common problems to prolong your scales lifespan, weighing applications as well as what scale indicator works best with your junction box. To learn more about bench scales, it would be good to check out our other articles such as “Bench Scale Basics'' andHow Much Does A Bench Scale Cost?”. These articles will help with the basics of bench scale ownership.