How to Choose Liquid System Pumps

comparing liquid system pumps

Pumps are one of the most valuable and integral parts of a liquid system. Whether you are working with liquid systems in food processing, pharmaceutical products, chemicals, or something else, it’s important to get the right pump. Choosing the right pump for your liquid system design depends on the characteristics of the fluid, as well as metering, volume, continuous flow or pulsation, and other factors. Let’s take a closer look at the most common types of liquid system pumps.

How to Choose Liquid System Pumps: Comparing the Most Common Liquid Pumps

Centrifugal Pump

Centrifugal pumps use an impeller to generate centrifugal force and move liquids. These pumps are some of the most commonly-used across a wide variety of industries. However, when it comes to liquid systems in food processing, centrifugal pumps can run into challenges. These liquid system pumps are ideal for liquids with relatively low viscosity, such as water and light oils. Centrifugal pumps are also ideal for steady flow applications. Slippage or cavitation can occur when conditions change, so centrifugal pumps are not ideal when metering is required.

Diaphragm Pump

positive displacement pumpA diaphragm pump is a type of positive displacement pump which uses a flexible, reciprocating layer of plastic or rubber to change the volume of a chamber and force liquid through. While a centrifugal pump is designed to work continuously, a diaphragm pump uses a pulsing motion. This makes it ideal for metering liquids. Diaphragm pumps can also work with thick, viscous liquids and suspensions with abrasive solids. The pump drive can be pneumatic or electric, so it can be used in liquid systems installed in challenging environments as well.

Gear Pump

A gear pump uses the intermeshing teeth of gears to move liquids. These pumps are repeatable and capable of generating high pressures, so they’re suitable for many different applications. However, suspended or abrasive solids can wear down the gear teeth, so these pumps work best with liquids with high lubricity, like fats and oils. These liquid system pumps should not run dry, so it’s a good idea to use a sensor on the supply tank to shut off the pump when liquid isn’t present.

Sinusoidal and Progressive Cavity Pumps

Sinusoidal pumps use a wave-shaped rotor to create moving chambers and move liquid through. This pump is gentle and predictable, making it ideal for thick suspensions in food processing, such as pie fillings, jams and salad dressings. Though these pumps are more expensive than the previous models, they are also easy to maintain and highly effective for challenging, viscous liquids.

Progressive cavity pumps are similar to sinusoidal pumps in many ways. Progressive cavity pumps use a corkscrew-like rotor inside of a flexible sleeve to create moving chambers and move liquid. This pump also generates low shear and gentle force, so it works well with thick liquid suspensions.

Peristaltic Pump

A peristaltic pump uses a flexible hose and an outside rotor to move liquid through. This type of pump is most commonly used in medical applications; you’ll see this pump at work in heart-lung machines and hemodialysis machines. A peristaltic pump is ideal for medical applications because the liquid is completely enclosed. The rotor moves over the flexible tube, but never contacts the liquid, so there is no chance of contamination. For this reason, peristaltic pumps are often used in liquid systems producing pharmaceutical and medical products. They can also be used for caustic chemicals which can be contained by flexible plastics, but can react with other parts of the machine.

Peristaltic pumps operate with tight tolerances and very repeatable flow rates, so they’re ideal for metering exact amounts. The repeated pinching and flexing of the hose will cause it to wear out over time, so a regular maintenance and replacement schedule will be important when working with this type of pump.

General knowledge of the most common types of liquid system pumps will give you a better idea of what you’re looking for, and risks to look out for. As you compare liquid systems pumps, consider the characteristics of the liquid that you’re working with, as well as how you are metering liquids, and the surrounding environment. With the right type of pump, you can minimize maintenance, waste and downtime, increase accuracy, and install a high-performing, long-lasting liquid system.

6 Hidden Expenses Eliminated Through Automation

expenses eliminated through automation

The ROI calculation for automated systems too often comes down to direct labor costs versus the cost of automation equipment. However, there are many aspects to consider. The value and cost-savings realized through automation goes beyond direct labor. If you are thinking about adding or enhancing automation at your facility, consider how the following hidden expenses can be eliminated.

6 Hidden Expenses Eliminated Through Automation

1. Downtime

People are more sensitive to their environment than machines, and will need to rest more often in extreme temperatures or humidity. A person will also become tired or distracted when performing repetitive tasks for long periods of time. Socializing is also important to maintain good productivity and morale, and part of what makes a workplace more desirable. All of these things ultimately amount to additional downtime; required breaks, chatting between tasks, late starts and more. It’s unrealistic and, often, negatively impacts productivity to strictly forbid these types of downtime. However, a machine requires only enough downtime for maintenance. Eliminating these small breaks can add up quickly.

2. Error

People make mistakes. These mistakes might be small, within tolerances, or they might result in product defects and waste. In other cases, these mistakes result in more downtime or slow-downs to fix, or might even endanger other employees. Mistakes can also put expensive assets at risk and increase liability insurance costs.

Of course, machines will do as they are programmed. If they are installed, programmed and maintained correctly, a machine will perform a task within a margin of error every time. Ideally, a person will oversee and verify that a machine is working properly, and have the skills and expertise to fix any problems that arise.

3. Quality Control

Mistakes can cause problems with finished products, however contamination and adulteration are also concerns. Contamination can occur if an employee doesn’t wash their hands properly before handling products or ingredients, or isn’t wearing proper protective gear, such as hair nets. Adulteration occurs when an employee purposely changes a recipe, either adding too much or too little of an ingredient, or adding a foreign ingredient. Whether added deliberately or accidentally, some foreign ingredients, such as pest repellent or cleaning chemicals kept on-site, can be extremely dangerous.

Automation can help to keep recipes on-track with exact measuring, and prevent adulteration or contamination by reducing hand-add opportunities. This can eliminate a variety of costs and risks, including product and ingredient losses, lawsuits, liability insurance, lost reputation and lost sales, and more.

4. Indirect Labor Costs

Automated equipment will reduce total wage expenses, but that is far from the only labor cost. Indirect labor costs such as healthcare benefits, retirement benefits, sick leave, vacation, worker’s compensation, and more all contribute to labor costs, and can be eliminated with automation.

5. Lawsuits

Keeping employees and customers safe requires vigilance and attention to detail. A lapse in safety protocols, training, or a simple mistake can endanger human health and safety, and create grounds for expensive litigation. Taking humans out of harm’s way and automating especially dangerous tasks can help to reduce dangers and lawsuits by employees. Automating processes that are vulnerable to contamination can also help to reduce liability. When considering automation, take a closer look at lawsuits and hazards in your industry, and consider how these costs and risks might be eliminated.

6. Regulatory Compliance

OSHA, the FDA, the USDA and EPA all require that certain safety and quality control standards be met to protect employees, consumers and the public. Record-keeping is an important part of this process. Automating production, labeling, tracking, and cleaning processes can make record-keeping easier and more accurate. A person might forget to mark a sheet, mark the wrong column, or enter the wrong number into the system. A machine or a sensor can send information directly to the system, making real-time records that are accessible at any time.

To get an accurate ROI valuation on automation, consider all the costs associated with labor, quality control, liability and production. Some of these costs may be small and add up over time, while others may be big, infrequent expenses. Consider each carefully when making your decision, and consider how these expenses might grow or shrink in the future with production.

Why Is My Load Cell Inaccurate? 11 Problems and Solutions for Troubleshooting Load Cells

Accurate load cells are critical to get the right mix. There are many different types of load cells for different processes, all of which can become inaccurate for different reasons. In this blog post, we’ll discuss a few of the ways your load cell may become inaccurate, what these problems look like when they occur, and how to troubleshoot load cell problems. We’ve updated this post as of July 2020 to include more common problems, solutions and troubleshooting strategies for load cells.

11 Problems and Solutions for Troubleshooting Load Cells

hermetically sealed digital load cell

Figure 1. APEC’s Digital Capacitive Load Cells

1. Total Combined Error

All measurement devices will have some degree of error that is not preventable. In load cells, this is shown through non-linearity and hysteresis. Since some level of error is unavoidable, there aren’t load cell troubleshooting strategies for this. However, this is acceptable as long as the error is less than the error tolerance of any ingredient. Additionally, non-linearity and hysteresis are less problematic in particular situations.

Non-linearity describes the weighing error over the entire load cell range. Smaller changes will create less error due to non-linearity, while a change from zero to maximum capacity will cause the greatest effect. Hysteresis is the difference in the results between increasing the load from zero and decreasing from maximum. Similar to non-linearity, error due to hysteresis is more noticeable when dealing with larger loads. So, when working with batching, this inevitable error is generally less of a problem compared to larger loading operations.

2. Temperature Changes

Dramatic temperature changes cause metal to warp. Traditional load cells are built using strain gauges, which are delicate metal pieces. Dramatic temperature changes will affect the function of the strain gauge, and therefore the load cell. If the load cell is exposed to cold nights and then hot, direct sunlight, or surrounding equipment heats up the area, this can cause inaccuracy. To troublehshoot this load cell problem, you might take temperature readings at different times, and shield the equipment from the sun if it causing dramatic temperature shifts.

3. Creep

If a load cell remains under pressure for a long period, it becomes susceptible to creep. This isn’t a problem in batching operations at two or three minute intervals, but load cells measuring storage silos or other containment units for extended periods will need to account for creep.

Want to Get Inside the Mind of A Master Engineer?
Download the Engineer’s Guide to Weighing and Batching

Written by APEC’s Owner and Founder Terry Stemler

4. Load Cell Response

All load cells require a set time to return to zero before they can accurately measure a new load. If the process begins to refill the vessel before the load cell(s) return to zero, the measurement won’t be accurate within the error tolerance. Allow enough time between measurements for the load cells to stabilize and response time will not be an issue. To troubleshoot this load cell problem, test the load cell response upon installation and with calibration, to ensure it remains stable.

5. Balanced Load

The load must be properly balanced on the load cell, or the load cells must be arranged to accommodate for unbalanced loads. Where multiple load cells are used, they must be mounted so no other part of the vessel or container takes on a part of the load. For a sitting vessel, this generally means the load cells must be situated between the vessel and the floor. For a mounted load, bumpers and checkrods used to stabilize the load cannot also support its weight.

6. Vibration

Excessive vibration, usually from other nearby processes or sometimes from passing trucks or heavy equipment, can disrupt the reading. Troubleshooting this load cell problem might involve moving the source of the vibration or moving the load cells and attached equipment. Dampening devices such as layers of rubber or cork can also absorb the vibration. If the vibration is cyclical, it can also be electronically filtered out by a weight controller.

7. Windforce

Air currents exert force on a load cell that can disrupt the weight of the load alone. Usually, this is not enough to cause significant inaccuracy, but strong, consistent windforce can disrupt the reading. This might come from intense winds outdoors, or from strong air currents used to prevent dust buildup.

8. Noise

When the load cell transmits its electrical signal to the weight controller, interference, or noise, can disrupt it. Radio signals and electromagnetic signals both cause noise, which includes electrical currents, other data transmission signals, even strong wireless signals. Proper shielding around the load cell cables and grounding of the shield can prevent interference from noise. Using a capacitive digital load cell can also help to prevent signal loss due to noise. In a capacitive digital load cell, the signal is converted to digital locally within the load cell, so there is no loss of signal across the cable length or at bad connection point.

9. Moisture

Moisture can also inhibit the signal from the load cell to the weight controller. Moisture, perhaps from steam, excessive humidity, or equipment washing, most often enters the load cell through the cable entry area. Hermetic sealing will prevent moisture from damaging the load cell and internal components.

10. Signal Jitter

A number of factors can cause the weight signal from a load cell to “jitter;” moving unsteadily upward (or downward, as in a loss-of-weight feeder) instead of in a smooth line. The hopper’s or vessel’s movement while weighing, material entering the vessel unevenly, an agitator preventing sticking, or unshielded noise can all cause the signal to fluctuate. A weight controller averages the fluctuation and creates a smooth analog signal, then converts the signal to digital. However, if the weight controller isn’t working properly or isn’t installed properly, signal jitter will disrupt the measurement.

11. Damaged Load Cell Connections

Often, multiple load cells are used to measure a load. When these load cell signals are not combined and summed properly at the weighing instrument, it can cause noticeable error. This can occur due to faulty connections between the load cells and the instrument. Corrosion from acids or salts can cause connections to corrode, thereby disrupting the signal.

12. Scale Instrument

Both the load cell and the scale instrument are important in determining accurate measurements. The scale instrument, or the scale head, must be able to integrate effectively with the load cell. A typical load cell is accurate with 5,000 divisions, which might not be accurate enough for the application. However, a finely-tuned scale instrument can divide by 10,000 or even 20,000. This would allow a 100 lb load cell to show increments of .01 or even .005 lbs, respectively. Though this would not be considered standard, the ingredient or application could call for additional accuracy.

13. Conductive Dust

Most load cells use a strain gauge, layers of very thin, conductive metal, to measure weight. Just as moisture can disrupt the load cell’s function, so can conductive metal dust and debris. If a load cell is not properly sealed and environmental metal dust or even salt. Capacitive load cells do not use a strain gauge, but can also be disrupted by conductive dust. However, capacitive load cells are easier to hermetically seal and prevent disruption.

14. Damaged Components

Though a load cell can be reinforced to withstand difficult environments, the internal components are delicate. A heavy impact, as well as corrosive chemicals or salts, can damage the inner workings of the load cell and cause it to malfunction. If you notice intermittent misreadings, or if there is more error than usual, the strain gauge or capacitor within the load cell may be damaged.

15. Calibration

To stay accurate, load cells require regular calibration. A regular maintenance schedule is the best way to stay on top of necessary maintenance. If the load cell is not calibrated, it is more susceptible to every form of disruption. When making repairs to the load cell, remember to recalibrate afterwards.

One of these load cell problems alone will probably not create a noticeable problem, unless it is extreme. However, several of them occurring at once can cause measurements to be noticeably inaccurate. Careful attention to the environment around the load cell and the equipment, as well as the installation and use of the load cell itself, can prevent many load cell problems.

Preventing Feeder Bridging and Flushing with the TSS Feeder

Ratholing, bridging, and flushing are just a few of the problems that can arise as material flows through a hopper and into a feeder. Instead of dealing with these issues as they arise, it’s best to optimize and feeder and hopper design to prevent or reduce these problems. The TSS Feeder uses a unique dual-auger, triple-flight design to prevent bridging and flushing, and improve accuracy.

Preventing Feeder Bridging and Flushing with the TSS Feeder

What is the TSS Feeder?

The TSS Feeder is specially designed to solve the common problems arising as material flows from a hopper to a feeder, like bridging, ratholing and flushing. Multiple parts of the feeder are powered by a single motor and multiple sprocket and chain drives. One sprocket and chain drive powers the primary screw flights, where materials first enter the feeder from the hopper. Another sprocket and chain drive powers an agitator above the feeder to keep material moving. The final sprocket and chain drives powers an additional, triple-flight section at the end of the feeder. This section moves faster than the primary screw. Each of these components work together to solve flow problems and increase accuracy.

Preventing Bridging

Bridging is a common material flow problem that can occur just above the feeder, where material sticks or clumps together and stops moving into the feeder. This is especially challenging for materials with high fat content, or those that might mat together, or stick together with static electricity.

The agitator on the TSS feeder prevents bridging for materials of all types. The agitator spins slowly through the materials to break up clumps without damaging the materials themselves. Running off the same motor powering the screw flights, the agitator works in tandem with the feeder. This improves flow without requiring extra maintenance or an additional power source.

Preventing Flushing

Flushing is another common problem that can occur with screw feeders, especially when working with fine powders. A traditional screw feeder releases material in pulses as the screw turns. This can cause excess material to flow out and flush after shut-off. Flushing ultimately upsets the accuracy of the measurement, and can cause too much of an ingredient to be added to a mix.

The triple flight section at the end of the feeder is designed to prevent flushing. This section turns faster and the additional flights dispense smaller amounts of material at faster rates. When the feeder stops, only a small amount of excess material flows out.

Improving Accuracy

Flushing, bridging and other problems can make traditional screw feeders inaccurate. The faster, triple-flight screw at the end of the feeder not only helps to prevent flushing, but the feeder is also more accurate. By dispensing a small amount of material at a faster rate at the end of the feeder, the feeder works quickly and efficiently, while reducing the margin of error and maintaining consistent performance.

Traditional screw feeders are relatively simple, and they can be easily overlooked in the overall ingredient system design. However, the wrong feeder can create multiple problems, reducing the accuracy and efficiency of the system. If material flow problems are affecting your system, or you are working with challenging materials that can cause problems, the TSS Feeder may be a solution. Contact us to learn more about this proprietary feeder system and other options to customize your feeder.

How Do I Know When a Process Should Be Automated? 7 Considerations

Electric Robot Welder

Automation can improve the efficiency, safety, accuracy and speed of a process, but it also requires careful planning. There are many factors to consider and it can be difficult to know when a process should be automated. If you are wondering about automating a process at your food processing plant, manufacturing plant, or another facility, consider the following.

How to Know When a Process Should be Automated

1. Current Process Time vs. Projected Process Time

Time is one of the most important factors to consider when deciding whether a process should be automated or not. A machine will perform most simple and repetitive processes faster than a person can. However, it is not only the individual process itself that should be considered, but the surrounding processes as well.

For example, when comparing an automated weighing and batching system to a manual system, it is important to consider the time it takes a person to open and transfer materials, as well as weighing and batching the materials. Automating this process may mean using bulk bags, which will reduce the time needed to open and dispense bags. Conversely, if a process takes only a moment for a person to perform, automation may not provide much in the way of time-savings, unless multiple processes can be automated at once.

2. Accuracy Requirements

Accuracy is another important factor to consider when a process should be automated. If machines are installed, maintained and programmed correctly, they will perform the same task, the same way, within a set margin of error, each time. A person, on the other hand, may be tired or distracted, and push a button or lever twice, add in too much or too little of an ingredient, or perform a process in the wrong order. Automating a process can increase product quality, decrease material waste, and reduce liability from potentially dangerous defects.

3. Process Complexity

In the last decade, automated machines, robots and computer programs have become increasingly advanced. Powered by the right AI, a machine can perform very complex tasks and even apply a version of critical thinking. However, these machines are also expensive. For this reason, process complexity is important when considering whether a process should be automated or not. Simple, repetitive tasks will be most effective and most economical to automate. Conversely, monitoring processes, inspecting finished products, performing maintenance, and other, more complex tasks, are best performed by people.

4. Safety and Hazards

Some processes introduce humans to dangers and health hazards. These processes are ideal to automate. Eliminating stress injuries due to repetition are among the most common benefits of automation. Processes involving dust, toxic chemicals, or fumes should also be considered for automation. While machine parts can be reinforced and shielded from caustic chemicals, it is much harder to adequately protect a person, especially over a long period of exposure. This is why many cleaning, painting, and coating processes are among the first candidates for automation.

5. Material Stability

Some materials are relatively predictable and easy to handle, while others are more chaotic and difficult. A sheet of steel, for example, will move through a process in a very predictable manner. A machine can easily handle these materials and move them along an assembly line. Powders, on the other hand, are more sensitive to outside forces like changes in temperature or humidity. Even slight changes can make them behave in unpredictable ways. Processes working with powders and other difficult materials can still be automated, but these machines may require additional supervision and more careful planning.

6. Labor Costs vs Automation Costs

This is the most common consideration when determining whether a process should be automated or not. When comparing automation and labor, it is important to take all costs into account. Automating a process not only eliminates direct labor costs such as wages and overtime, but it can also reduce indirect costs such as those from work injuries, worker’s compensation, liability, paid leave, overtime, retirement benefits and more. From the automation standpoint, consider costs of maintenance and installation, as well as the equipment itself.

7. Future Growth

Consider your markets, and gauge your expected future growth or contraction. Machines can work much faster than people, and can help you keep up with increased demand and continue growing. However, if you expect a decline in demand in the near future, this added speed and productivity may not be worth the investment at this time.

There are many factors impacting whether a process should be automated or not. In some cases, it is easy to automate a process that is otherwise long, arduous or unsafe. In other cases, it can be a more difficult decision. It can be helpful to make a list of estimated costs and time-savings, safety considerations, advantages and disadvantages when making this decision. Compare these items, and you can be confident in your decision to automate or leave the process the same.

Process Verification in Manufacturing: Trust, But Verify

process verification in manufacturing

In our previous post, we discussed the benefits automation equipment can have on business and on workers. One of the benefits of automation equipment and robots over humans is the machines’ ability to perform the same task continuously, consistently and reliably, without risk of injury and little risk of variation. However, this can only work if the machine is installed and programmed correctly, and regularly maintained. To optimize automation performance, it’s important to keep in mind a simple, but powerful maxim; “Trust, But Verify.”

“Trust, But Verify”

“Trust, But Verify” is a Russian proverb that first made its way into popular English during the Cold War and nuclear missile disarmament. It’s now used in many contexts, including automation. “Trust, But Verify” essentially looks at the process and the result; trust that the process works correctly, but verify that the result is correct.

This is especially important for optimizing automation performance, and ensuring that the process is working. While a person may perform an error a few times and then fix it themself, a machine will continue to perform the process incorrectly until the source of the problem is fixed. This means, without verification, a process may be incorrect for long periods of time. These errors can also multiply across the production line, turning a small problem into a dangerous product defect.

Process Verification in Manufacturing: Then and Now

Previously, a battery of tests was the best way to determine whether a process was running properly. Usually, this involved taking a sample and delivering it to a lab. The lab might test for values such as PH, humidity, temperature, fat content, protein content, sugar brix content, water content, weight, product hardness, elasticity, and manufacturing defects that might affect the visual appearance or the structural integrity of the product. This verification process was slow, with many potential pitfalls.

Now, many of these factors can be tested in real time on the factory floor, often with sensors or spot tests. There’s no need to halt the process while waiting for lab results, or recall product that turned out to test badly. However, this also means that a faulty sensor can cause product defects and incorrect processes to go unnoticed. Though it’s reasonable to trust that a quality sensor works, it’s necessary to verify this as well.

These process verification procedures can help to ensure that the information you’re receiving from sensors is accurate, and that automated machines are performing the process properly.

6 Verification Procedures to Optimize Automated Equipment

1. Calibration

Sensors, weighing instruments and other equipment must be regularly calibrated to maintain accuracy. This is one of the most important verification procedures to optimize automated equipment, and should not be left to chance. Otherwise, the machine’s accuracy is left to chance as well. Establish a clear calibration procedure for each instrument using the manufacturer’s instructions. Make sure workers know who should carry this procedure out, and when.

2. Redundancy

For procedures that must be very precise, or for processes that are prone to error, you can optimize automated equipment by using redundant sensors. While one sensor may fail, it’s unlikely that two would fail at the same time. Using two sensors can also help you see if one has become inaccurate.

3. Reduce Interference

Where possible, use instruments that are digitized locally to the sensor. Electromagnetic interference, vibration, or damage to wires can cause signal transmission errors across longer distances. If you’re transmitting analog values, be sure that you have a secure ground reference, and that the signal is properly spanned.

4. Use Reference Values

Reference values give you a baseline for what is accurate and correct. Without reference values, it’s difficult to know when your sensors and machines are working properly. Use test weights, optical references, voltage outputs and other measures to verify that the process is working properly.

5. Regular Maintenance

Regular maintenance is an essential process verification step to optimize automated equipment. The machines as well as the sensors should both be regularly maintained according to manufacturer’s recommendations. This includes cleaning procedures to prevent the build-up of dust and debris, visual inspections of wires and faceplates, replacing seals where necessary, and more. Some measurement devices, like hermetically sealed load cells, generally do not need maintenance as frequently as other, unsealed devices.

6. Visual Inspections

Establish visual standards and inspections so workers can spot a problem if it occurs. This might include visually inspecting the finished product, or inspecting the product as it moves through the process. Consider the product’s color, size, consistency, or other notable features. Be sure there is a procedure in place for reporting and fixing a problem if a worker detects it.

“Trust, But Verify” works on a fairly simple principle; you need to trust that your process works, but also make sure that it does. Using process verification procedures will not only help you optimize automated equipment, but also prevent problems, reduce costs and give you peace of mind.

8 Benefits of Automation for Businesses and Employees

benefits of automation

The costs of keeping workers safe in dangerous manufacturing environments is high and will likely continue to rise as the need for PPE and appropriate workplace distancing increases. In these situations, automation not only presents an opportunity to reduce costs and improve efficiency, but also reduce the human costs—workplace injuries and illness. While automation has always had the ability to disrupt labor markets, the benefits of automation to businesses and to human health and safety far outweigh their drawbacks.

8 Benefits of Automation for Businesses and Employees

According to MIT, automation equipment has the potential to replace 3.3 workers in a given position in the U.S. While this can shrink labor markets, it also has the potential to create the distance between employees now necessary to prevent the spread of illness. Giving repetitive, dangerous, close-proximity work over to machines also has multiple benefits.

1. Reduced Direct Labor Costs

Reduced labor costs are one of the first benefits of automation that comes to mind. With the jobs of three or more workers completed by a machine, the costs of wages must be balanced against the costs of initial investment, upkeep and maintenance. With a proper maintenance schedule, a machine can continue operating effectively for many years for a fraction of the cost of three employees.

2. Reduced Injuries

Looking at work-related injuries, manufacturing is one of the most dangerous industries, second only to social assistance occupations, such as emergency response. Research shows automation can reduce three out of the five leading causes of workplace injuries, including contact with harmful objects, heavy lifting, and repetitive stress injuries. In total, robots and automation equipment have the potential to reduce workplace manufacturing injuries by up to 72%.

3. Reduced Indirect Labor Costs

In 2017, the National Safety Council found the total costs of workplace injuries amounted to $161.5 billion. This includes not only medical costs, but also costs due to lost time and administrative expenses. One of the benefits of automation includes reducing workplace injuries, and also reducing the associated administrative and paid leave costs. This also reduces other indirect labor costs, such as 401k benefits, overtime, sick leave and more.

4. More Accurate Record-Keeping

While a person can easily mismark a sheet or push the wrong button, a machine that is installed and set up properly will always perform the task as directed. This is especially helpful when detailed record-keeping is mandatory, such as tracking required by FSMA and other regulations. When inaccurate record-keeping can create hazards, such as tracking and recalling tainted food, a machine’s diligent record-keeping can also help to protect consumers.

5. Improved Consistency

Machines do not get distracted or side-tracked with another task, and there’s very little variability in a machine’s performance. This means the task will be performed the same way every time. From dispensing ingredients to assembling parts and everything in between, automation improves consistency across the process and in the final product, improving quality and reducing costs of product defects.

6. Increased Efficiency

A person cannot be expected to work continuously without breaks. A person also has limits to the speed with which they can work safely. A machine also has limits, though they’re much greater than a person’s. With proper installation and programming, automated equipment can work almost seamlessly together, running at the same time and all but eliminating downtime completely.

7. Freedom From Monotony

Automated equipment is ideal for repetitive tasks. A machine can be programmed one time and work quickly and consistently for the rest of its useful lifetime. By contrast, humans perform better when tasks are engaging, requiring critical thinking and multiple skill sets. Removing monotonous, repetitive and, often, dangerous tasks, allows employees to take on more challenging and important tasks. Machines should not be expected to monitor themselves, and trained personnel must be able to calibrate, test and verify that the machines are working properly.

8. Continuous Improvement

With automated equipment performing the same tasks consistently, there are fewer variables to measure. This makes it easier to monitor a process and isolate problems. By placing sensors at key points in the process, managers can track variation and maintain accuracy, or make corrections to improve the process. With different workers performing a process in slightly different ways, it is more difficult to uniformly make improvements.

Automation equipment can upset labor markets, however this equipment can also protect workers from hazards. Giving dangerous and monotonous tasks over to machines and reducing the total number of workers in a facility has the potential to reduce the spread of illness and reduce workplace injuries, while also reducing costs. For these machines to perform properly, installation and verification are essential. In our next blog post, we’ll discuss the “Trust, But Verify” principle and its importance in  automation.

The Myth of Chasing Cheap Labor

workplace safety regulations for grain and pet food 2018

Recent events shed a light on the potential downside to setting up manufacturing in other countries in order to cut labor costs, and the instability that can occur without established links in the labor force. More and more companies are looking at the long-term costs to these operations, rather than just the direct labor costs.  The following are some of the other factors to consider in going offshore for cheap labor.

The Consequences of Chasing Cheap Labor

Intellectual Property Loss

One large factor to consider is the potential loss of intellectual property.  This can include your product recipes as well as your manufacturing expertise.  It is of course possible to sign non-compete clauses and other agreements to help alleviate this concern, but we all know that getting an agreement that lasts forever is not going to happen. If an agreement is broken, good luck with the litigation in another country.  So in the long run you may be setting up a global competitor.

Loss of Control

Another factor to consider is the loss of control to your process and product.  In order to make sure that your product is being manufactured to specification, you will need a trusted employee on-site.  This may be a difficult position to fill. Employees from your home office with enough managerial experience are unlikely to want to uproot themselves. Employees with managerial experience in the destination country are likely already working for a competitor.

It will also be more difficult to control quality.  The ingredients that are required for your product may be more difficult to source locally, or you may have to pay shipping costs to get the ingredients shipped to your remote plant.  If the logistics are not set up just right, you run the risk of significant delays in manufacturing as you wait for materials.

Language and Culture Gaps

The differences in language and culture can also play a role in product quality.  These differences can make it more difficult to train employees in good manufacturing practices and quality control.  Employees are eager to please and they may not want to admit that they do not understand instructions.  This same tendency also makes it difficult to get answers if there is bad news.  In some cultures, it is not proper to say ‘no’ to your boss.  Because of this, you may not know about a production problem until it results in late deliveries.

Employment Creep

Another problem that you can encounter in these manufacturing environments is a slow uptick in the number of employees that you have.  There is a natural tendency for employees to try to get family members hired at all levels of the business.  This can result in more workers than you actually need to do the work, or hiring workers that do not have the required skills. This can very quickly offset your potential labor savings.

Law and Policy Gaps

Navigating workplace safety regulations domestically can already present challenges. Navigating these laws and policies in other countries is even more difficult. Inspections, safety procedures, time off and many other rules and regulations may be governed by national or local organizations, and understanding how these groups work is essential to running a safe and successful workplace. In some areas, these rules may be an unwritten part of local culture, and finding the specifics can be a challenge.

Current Events

A number of events can create delays in production and shipping, both for raw materials and for finished good. Strikes, political unrest, weather events, and, as we’ve recently seen, widespread illness can all bring the production or shipping processes to a halt. While many of these events are beyond your control, familiarity with the local language, culture, news, laws and government can help you anticipate these events and plan accordingly.

 

Whether you are going to manufacture domestically or offshore, the solution to all of these problems is to refine the manufacturing process with a high degree of automation.  Regardless of what country that you are in, your competitors in that country will have the same fixed labor costs that you do.  The automation system will always allow you to get virtually instantaneous information on your process and will greatly simplify your quality control procedures and record keeping.  This type of system will also allow you to limit access to your intellectual property and make it easier to put procedures in place to keep it secure.  With automation, you can cut manufacturing costs domestically so you don’t have to go offshore and if you must go offshore, automation can help to address many of the problems that you could encounter.

8 Mixer Maintenance Tips to Extend the Life of Your Equipment

Ribbon blenders, paddle mixers and other types of mixers are integral to an ingredient system. With proper maintenance, these mixers can last for decades. Without proper maintenance, they may wear out prematurely. Setting aside time regularly to perform ingredient system mixer maintenance can save you thousands in the long run. Keep these mixer maintenance tips in mind to extend the life of your ribbon blender, paddle mixer or other mixers.

8 Mixer Maintenance Tips to Extend the Life of Your Equipment

1. Check Components for Lubrication

Regularly checking lubricant levels and ensuring that the moving parts in the mixer are properly lubricated can extend the life of your mixer for years. This is one of the most important general mixer and ribbon blender maintenance tips to keep in mind, and one that is easy to take care of. Some parts within the mixer, such as the drive components, make up a significant part of the mixer’s cost, so replacing these will be almost as expensive as buying a new mixer. Pay special attention to the lubrication around the drive, reducer, and shaft bearings especially. Set aside time once a month to check these levels.

2. Maintain the Seal

Mixer and agitator seals keep ingredients in the mixer, and also protect the movement of the shaft. If a seal is damaged, material will escape or the alignment of the shaft may shift. There are many different types of mixer seals, and the best mixer maintenance tips for each will depend on which your machine has.

  • Air-Purged Seal: Check the air pressure and air quality to make sure this air-tight seal is holding.
  • Stuffing Boxes: Check the packing material for wear or damage and tighten or replace the stuffing boxes where necessary.
  • Lip-seals: Check for leaks and damage regularly. If these mechanical seals wear out more frequently than normal, the seal material might be incompatible with the material being mixed, especially if you are working with corrosive or abrasive materials.
  • Single seals: Measure and adjust the spring compression to meet the manufacturer’s recommendations. Replace the seal faces if the wear is obvious or the seal isn’t holding.

3. Monitor the Drive System Tension

The drive system is one of the ribbon mixer’s and other mixer’s most valuable components. Keeping the reducer, belt, or chain-and-sprocket mechanism properly lubricated (see the first point, above) is one of the best ingredient system mixer maintenance tips to keep in mind. It is most important to regularly check the tensioning on the belt or chain. The the belt or chain slip if it is too loose and could cause damage to the sprocket or burn the belt. If the belt or chain are too tight, they will start to wear out bearings prematurely. Keep the tension within the manufacturer’s recommendations and check it monthly to be sure it is correct.

4. Check the Discharge Gate Operation

Over time, dust, dirt, powder, or foreign objects can get lodged in the discharge gate, causing it not to completely close. Check limit switches to make sure the gate is completely closed or open when the limit switch is used. Observe the discharge gate during operation to make sure it opens and closes properly. If the gate does not fully open, it can cause material to remain in the mixer. If the gate doesn’t fully close, material will leak out.

5. Protect the Mixer Tub

The body of the mixer is also an important part of proper ingredient system mixer maintenance. Whether you have a ribbon mixer, paddle mixer, or another type of mixer, the body of the machine can be damaged if the agitator is too close to the walls. Foreign objects, such as bits of metal or small rocks, can also damage the mixer as it operates.

Over time, the shaft can shift, causing the mixer blades to move too close or too far away from the tub. This will not only damage the mixer, but it can introduce metal fragments into the mix, and disrupt the overall mixing operation. Remember that the mixer is designed to best meet the needs of your ingredients—if the mixer components are not in proper alignment, it will not mix properly. If you hear scraping sounds or the mixer is vibrating excessively, the shaft may be out of alignment and the blades are too close to the tub.

6. Clean Intervents

Intervents allow displaced air to escape as ingredients enter the mixer. These intervents can easily become clogged with dust. Clean them regularly to allow air to escape and your ingredients to enter the mixer easily. If the air can’t escape through intervents, dry materials can create clouds of dust as it escapes through other exits. Dust introduces risks of fire and explosion.

7. Inspect Electrical

Check electrical cords for breaks. As people and machines move around the facility, cords often get in the way. A broken electrical cord is a safety hazard, exposing workers to risk of shock and fire. Combine a damaged electrical cord with the previous issue—clogged intervents creating clouds of dust—and two seemingly minor problems can become a very serious problem, including a powder fire or explosion.

Using a damaged electrical cord can also damage the machine’s internal components. To make sure your ribbon blender or other mixer operates at the proper level, check the current consumed while it’s operating. If it’s consuming too much or too little, there may be damage somewhere in the electrical system or motor.

8. Check the Coefficient of Variation

One of the best ways to make sure your mixer is working property is to check the coefficient of variation (CV). Once a year, take a number of samples of your mix and send them to a lab to check the CV. This might seem like an overly-meticulous step, but it can help to prevent over- or under-mixing, and it can show if your mixer is not operating properly.

If your process changes, such as automating a hand-add step, you might also be able to speed up your mixing time to suit the new speed. Checking the CV will show if the new mixing time is adequate, or if other adjustments should be made.

These mixer maintenance steps may seem time-consuming all together, but setting aside a bit of time for these tasks will make maintenance much more manageable. Also, consider the time, money, and energy it takes to replace or repair a mixer that is not properly maintained. When comparing the two, setting aside maintenance time will always be faster, cheaper, and easier.

How to Customize Your Powder Feeder

questions to ask manufacturers

A powder feeder can improve your system efficiency by metering the right amount of materials from the ingredient source—such as a bulk bag or another container—into a mixer or another downstream process. Many ingredients can be challenging to work with, and knowing how to customize your powder feeder can prevent flow problems like clogging, flushing and inaccurate measurement.

How to Customize Your Powder Feeder

An experienced engineer can help you customize your powder feeder to prevent common problems that might affect your materials. However, your engineer must know some critical information about your system and ingredients to get started. As you consider customizing your powder feeder, the following information will be helpful. These don’t have to be exact, but more accuracy will mean better system customization.

  • Material properties: angle of repose, viscosity, fat content, moisture content
  • Volume: how much of the ingredient are you measuring in what time frame?
  • Accuracy: what is your margin of error?
  • Dimensions: what is the available horizontal and vertical space around the system?
  • Environment: are the temperature and humidity conditions stable, or will they change as the weather changes?

Type of Feeder

There are many ways to customize your powder feeder, and this starts with two different types of feeders. Each uses a different method for moving the materials through the feeder. The first, a vibratory feeder, uses vibration to move materials. A vibratory powder feeder can be effective for many ingredients, but it can also introduce noise and interference to the surrounding system. This can disrupt weight and volume measurements.

The second, an auger feeder, uses mechanical force from either a spring or a screw-shaped shaft. An auger feeder is highly versatile and preferable for most ingredients. There are many ways to customize this powder feeder further to perfectly suit the materials and the surrounding system.

The Feeder Core

You can customize powder feeders using augers with a spiral core or a shaft core. In a spiral auger, a spring inside the powder feeder creates the mechanical motion needed to move the material. In a shaft core, also called a screw auger, the flights around the core rotate and move the material. Either of these types of powder feeders can be effective. If your material is likely to bridge or clump, a screw auger can provide the additional movement needed to keep the material flowing.

Screw Auger Flighting

If you are using a screw auger powder feeder, you can customize the size, type and arrangement of the screw flights. The spacing between the flights, called the pitch, will partially determine how much material moves through the feeder. At full pitch, the spacing between the flights is equal to the diameter of the feeder. At half pitch, the spaces between the flights is half of the diameter of the feeder.

The screw auger flighting pitch will not only determine how much material moves through the feeder, but also the rate at which it moves. A full-pitch feeder will release a larger amount of material in slower intervals, while a half-pitch feeder will release a smaller amount of ingredients, but in faster intervals. This will change the overall flow of the ingredients through the system. Higher pitch will feed material in pulses, while lower pitch will create more continuous movement.

Variable Pitch

In a screw auger, it is important to alternate the pitch of the flights at the start of the feeder. If the flights are spaced and sized equally throughout, pressure will build up at one end of the feeder as it moves material. This requires the drive to work much harder than it needs to. Simply starting with half pitch and moving to full pitch will help to equalize the pressure across the screw auger. Conical-shaped flighting across the auger or variable pitch at the inlet will also solve this problem.

Diameter of Feeder and Auger Shaft

The feeder diameter is another obvious way to customize your powder feeder. Changing the feeder diameter will change how much material moves through it. When working with a screw auger, it is also important to consider the auger shaft. Widening the auger shaft will cause it to take up more space in the feeder, allowing less material to move through.

The ideal diameter of the feeder and the auger shaft will both depend on the desired volume. If the material must be carefully metered with more accuracy, a smaller feeder diameter or a larger auger shaft will move smaller amounts of material more steadily. However, if you want to move material through the feeder quickly, a larger feeder diameter and a thinner shaft will be best.

The Drive

The drive on the powder feeder must be powerful enough to drive the screw or spring auger while delivering the right RPMs. The drive must also be accessible for maintenance or repairs. You can customize your powder feeder drive by changing the mounting position of the drive, the reducer, and the RPMs of the drive. This is another way to customize your powder feeder according to the material moving through it. Raising the RPMs will move material at a faster rate, and vice-versa.

There are many ways to customize your powder feeder to suit your materials and your overall process. This can seem complicated, however it also presents a number of different solutions if you encounter a problem with your particular ingredients or process. If your process repeatedly stalls at the feeder stage, or material moves too quickly or too slowly through the feeder, consider these customization options. Work with an experienced equipment manufacturer to ensure your powder feeder works with your materials, not against them.