Welcome to Nercon’s on-demand webinar “Leveraging Sanitary Conveyor Construction Levels for Food Plant Operations”Brought to you by Nercon Eng. & Mfg., Inc.I want to thankMike Weickert, Dennis Buehring and Jim Streblow for their expertise in developing this material – all are long time conveyor application and engineering experts with more than 60 years of combined experience in the product and process conveying industry.And I’m your host, Jessica Jacobson and I develop communication materials like these webinars for Nercon.
In this on-demand webinar…I’m going to review six levels of conveyor construction. Starting with the basic construction level, and then wipe-down conveyor design followed by the wash down and the sanitary levels of caustic wash-down conveyor designs.
I’ll talk about how to leverage the different construction levels for different areas of the plant and best practices by manufacturing industry and food handling application.
Also…I’ll compare equipment cost versus the cleaning efficiencies and sanitation quality levels.
The presentation includes comprehensive look at Clean in Place features that can be specified on any type of sanitary construction level, as well as some Clean Out of Place or removable components for cleaning processes.
And I’ll talk briefly about some of just the top trends and advancements in Sanitary Belting Technology.
Throughoutthe webinar references are made to materials, finishes, welds and frame type, so let’s start with some definitions and comparisons. On the left is a typical aluminum conveyor and on the right is a conveyor system constructed from stainless steel. So, what are the main considerations when choosing materials for conveyors in sanitary environments? When considering a choice between aluminum and stainless steel, you need to consider aluminum properties, and your sanitation requirements. It’s well known that bare aluminum does not stand up well to the harsh chemicals used during sanitation and must be protected with coatings such as anodizing, ceramic or PTFE, which have become increasingly popular because of their corrosion and wear resistance properties. Even with protective coatings, aluminum still more vulnerable to scrapes, dents, and nicks which can be more difficult to clean and serve as initiation sites for corrosive attack by cleaning agents used in the food industry. This can also lead to bacterial contamination. Overall, the life cycle cost advantages of stainless steel over aluminum outweigh the incremental additional cost.Aluminum designs are used throughout many industries in packaging and process capacities, which is why we called it out in this comparison. However, Nercon’s expertise and offering is mild steel and stainless steel construction, so that’s where this presentation is focused.
The next thing to talk about is the comparison of polished stainless steel finish and a bead blasted finish. The two most common finishes in stainless steel equipment is #4 Dairy or sanitary finish, the other being a glass bead polish. #4 Dairy finish is much finer then #4 architectural finish. In the polishing process one takes great care to remove any surface defects in the metal such as pits, that could allow bacteria to grow. A #4 dairy or sanitary finish is produced by polishing with a 180 – 240 grit belt, or wheel finisher softened with 120 – 240 grit greaseless compound.Glass bead polishing is achieved by using spherical abrasive glass beads manufactured from chemically inert soda lime glass. When used in the polishing of stainless steel equipment, the process peens the surface of the material. The peening process does not remove any metal. The impact of the rounded beads blasting medium results in microscopic craters in the surface, giving a satin looking finish. The edges of these small craters are not however sharp and so the clean-ability of peened surfaces are similar to a #4 Dairy finish.Both finishes are equally sanitary, however if extensive welding has to be done on the equipment the more cost effective method is to glass bead polish over the hand polishing of welds.
Shown here are three types of welds, they are shown starting with the most economical on the left which is a stitch weld. This weld is used for the dry environment and the wipe-down environment conveyor designs.On caustic wash-down designs, those construction levels will have the continuous, non-pitted welds as shown in the middle.And on the far right is a continuous non-pitted weld shown on the bead blasted stainless steel material, which are used in the sanitation environments.Yet another level that isn’t shown on this slide, is a continuous ground and polished weld. There really isn’t a weld to show because it is mechanically polished to blend into the parent material. Though it adds cost to the system because of the labor involved, it is a highly sanitary weld type and sometimes it is a customer or plant level preference.
Now to introduce the frame designs, open-top and closed top designs and box tube.The standard for an open top design on tabletop style conveyors feature inverted “L” side frames that provide chain and guide rail bracket support, shown on the left photo. Open-top frames are used in all construction levels.And the closed top cross section shown in the center, is intended for use in cleaning where the raised wear strip blocks spilled product from becoming trapped inside the frame. A quick hose flush will normally remove spilled product.The closed top is utilized in most construction levels EXCEPT for the highest sanitary levels that utilize open concept frames like the tubular frames on the right..The tubular frame design is used in the extreme sanitary conveyor construction levels. Tubular frames are found in process rooms for handling raw food. This is the most costly option because there is extensive labor involved with welding, grinding and polishing.
Now that we have clarified some of the construction terms, we’re going to go through six conveyor construction levels, beginning with the dry wipe or air blow off conveyors (green), the moderate moisture wipe-down design (orange) and there are four levels of wash down and sanitary level designs that are represented in blue. I’ll review the construction and best uses in more detail in the following slides. This chart is simplified for ease of viewing in a webinar format, but for additional detail of these levels be sure to download our white paper – and that link is provided at the end of the program.
Also, keep in mind that the presentation starts with the most economical construction level and will finish with the highest degree of sanitary construction design and features.Since we have a number of people interested in this webinar representing many different food industries, all who have different governmental regulations to consider, the presentation focuses on the construction and the level of cleaning for these designs and how that impacts your food safety compliance and cleaning efficiencies.
One of the ways you can leverage the purchase cost of conveyors is to select the construction level required by the application and environment.This is an example of a food manufacturing plant with a range of areas from process rooms, to secondary packaging areas, to case handling operations. I’ll refer to these areas throughout the presentation and make recommendations on the type of conveyor construction to use according to the environment and application.
The Dry Level Conveyor Design is best utilized in dry areas of the plant where there is no use of corrosive cleaning chemicals or detergents.So what areas of a manufacturing plant would typically be characterized by a Dry Environment?We would normally see dry conditions at the beginning of a production line. Examples would be from the discharge of a depalletizer, case or carton erecters, or when the product is sealed in a package with no chance of spillage. We would also see this condition at the end of the production line, such as the discharge of the case packer in the warehouse areas. We would also see products that are dry packaged such as flour, coffee and some areas of bakeries in this environment.
This slide shows the construction of the Dry-Level Environment design.THE DRY LEVEL DESIGN CONSISTS OF A mild carbon steel conveyor frame, with bolted construction, and an open top design. We refer to the finish as coated, which can be either sprayed on or powder coat painted.The motors , reducers and bearings also have coated finishes, and the bearings typically have standard, non-food grade lubrication.The guide rail brackets are carbon steel, with a coated finish.How can this design be leveraged in a food plant?Secondary packaging and case handling lines often do not require the additional cost of stainless steel and wash-down components. Look at the application and review your sanitation requirements to see if this economical design can be used to save overall purchase cost for those types of applications.
Now to introduce the Wipe Down Design - which is best utilized in areas of the plant characterized by minimal low humidity with no use of corrosive chemicals used in cleaning process.These conveyors are constructed with stainless steel so it can be cleaned by hand, or with mild detergents- but not using highspray hoses.
Here is a slide that calls out the construction of the Wipe-Down Level design.Wipe Down construction is stainless steel, bolted, open-top design.The Main Difference between dry and wipe-down construction is the upgrade to Stainless Steel Frames, Brackets, Supports and Hardware.It offers UHMW guiderails with stainless steel brackets.The bearings, motors and reducers are coated, and the bearings use standard lubricationSeveral supports are available, this picture shows a formed angle support with an adjustable foot.How can this design be leveraged in a food plant?This design can be used for secondary packaging lines after the process room. It’s fairly economical and can be used in areas of the plant that don’t require a caustic wash-down. We’ve seen this design used in food packaging industries delivering sealed primary packaged goods to the shrink bundler or case packer.
In this segment we’ll focus on these four wash – down sanitary conveyor construction categories, starting with the wash-down level and continuing through the caustic wash-down designs, Sanitary Levels 1, 2 and 3.
Briefly some comments with regards to chain and belting in sanitary environments.Chain categories include fabric belt, tabletop, modular plastic chain, and homogeneous belts. The fabric belt can be sealed for exposure to caustic chemicals and is the least expensive (shown on the left.) Most of the tabletop and modular belts will operate in a wet environment, but can be very difficult to clean. The homogeneous belt (shown on the right) has a higher purchase cost, but most manufacturers choose this type of belt for its cleaning efficiency and hygienic benefits.Also affecting chain selection is the high water pressure environment and the chemicals used for cleaning. For example chloride or peroxide will attack Acetal chains. Polypropylene will be able to withstand a wash-down environment. In heavy wash-down settings, the pin material cannot be nylon because nylon absorbs water and causes functional problems with the chain.Other things to consider, is the ability to clean the chain or belting to the sanitation levels required, as well as the time it takes for those cleaning processes. Nercon is seeing some development with modified hinges and sprockets that I’ll talk about in the “new technologies segment” later in this presentation.
Next the base wash – down conveyor design. This conveyor type is used in environments with moderate to high moisture and humidity, but with somewhat limited use of corrosive chemicals for cleaning. This is a low pressure wash design.
Shown on this slide is a base wash-down design …The main difference between this base wash down design and the wipe down design is the bearings, motors and reducers. The bearings are upgraded to a polymer housing plated inserts and the motors and reducers are corrosion resistant. Otherwise it has the same stainless steel bolted construction. A formed angle or sanitary channel or a square tube support (like in the photo) can be used in this level of conveyor. What applications would you utilize this base wash-down level?Secondary packaging lines that might have minor spillage, like a pouch line, also bakeries may use this level. It would have be a product with a low bacteria count. The cleaning for this level is a low pressure wash.
The next category is Caustic Wash-down Sanitary Level - 1. The environment would be characterized by moderate to high moisture or humidity with moderate to high use of corrosive cleaning chemicals to minimize bacteria growth. This design IS pressure wash-down compatible.Sanitary Level I construction is stainless steel and bolted. The frame design can be either open-top or closed top.Welds are continuous and non-pitted.Also, there are polymer housed bearings with stainless steel inserts and upgraded seals, white epoxy motors, corrosion resistant reducersIn this Caustic Wash-down Level – 1 Design, there are bolted stand-offs for the brackets, electrical components, photo eyes and terminal boxes for increased cleanability.What is the main difference in the basic wash down level and the Sanitary Level I in terms of components and also cost?The main difference is the upgrade to continuous welds, bearings with stainless steel inserts and this design has stand-offs; this adds about 7 to 10% to the cost over the wash – down design.
Our Sanitary Level II is an extreme sanitation design. These conveyors are used for direct food contact. This conveyor type is used in environments with moderate to high moisture and/or humidity, aggressive cleaning chemicals and processes. This level is used for primary food packaging lines.
The Sanitary Level II caustic wash-down conveyor design offers a higher degree of sanitation for high spillage areas in food packaging lines. This level has a stainless steel, bead blasted finish.Notabledifferences between sanitary level 1 and sanitary level 2 are that the standoff spacers are now welded to the frame instead of bolted. Additional standoffs have been added at the conveyor splice plates, the floor supports and the bearings.The bearings remain unchanged with polymer housings and stainless steel insert.The motors and reducers can remain as epoxy coated corrosion resistant, but are often upgraded to stainless steel to guard against damage to the coating that may result in corrosion.What plant areas or manufacturing processes use this design and in what types of applications?This design can be used in process areas with direct food contact or primary packaging areas around fillers and baggers. The design is intended to withstand the aggressive cleaning typical of food process equipment where bacterial growth or allergen control is a high concern.
Our Sanitary Level III is an extreme sanitation design. This design has the same environmental characteristics as level II including:Its use for direct food contact, andIt is used in environments with high moisture and aggressive cleaning chemicals and processes.We show a bulk food application in our example which is common for this Sanitary III tubular frame design.
Here’s a walk through of the Sanitary Level IIIBead Blast Stainless finishContinuous non-pitted weldsAll welded stand-offsStainless steel motors, reducersSealed Tube Frame DesignThis level is used when handling raw food such as meat, starches (such as pasta and potatoes.) We also have seen the cheese processing industry heading toward this level of sanitation. What are the gains for food manufacturing using this level, compared to the cost?The principle reason to move to this class of equipment is the ability to use aggressive cleaning procedures and chemicals. This equipment is also designed to allow for ease of cleaning with many features to facilitate the cleaning process. The cost of this equipment is also pricey as all components have to be rated for the application and the tubular construction (while prevents harboring of bacteria) is also added expense. You can expect a 15% to 20% cost impact over Sanitary Level II.
This picture shows a positive drive on the Sanitary Level III design.The positive drive belt has integral drive bars molded into the bottom of the belt, allowing the belt to be driven by sprockets with very low tension. The integrated drive bars also guide the belt, eliminating off – tracking and belt slippage. The belt gives all the advantages that a modular plastic belt would have with the key addition of a smooth homogeneous surface. The smooth solid surface makes cleaning the belt easy and effective with minimum water and chemicals.This photo shows the quick release take-up that releases tension on the belt for easier cleaning under the belt.
When developing this webinar, the discussion came up with strategies that manufacturers have when making the decision between seal tube versus sheet metal frame choices.Some food manufacturers have environmental concerns with the sealed tube design. Though the tubes are all sealed as the equipment arrives in your facility, it is very difficult to manage the other “trades” from penetrating into the tubes during the installation phase, which allows for internal bacteria growth.Both designs work very well, but the sheet metal frame design offers more safety advantages.
Here are a few very good questions from previous live events:What is the cost difference between the DRY environment mild steel design and the WIPE DOWN stainless steel conveyor design? On the stainless steel design, the frame, legs and guide rail brackets are manufactured from stainless steel. The bearings, sprockets and motors are the same on both the mild steel and stainless steel design. As a rule of thumb, the price difference would be 12 – 15% to upgrade to stainless steel.Why is tabletop chain difficult to clean? chain design with an integrated hinge with an internal barrel is just too difficult to access and clean to acceptable levels in most sanitary applications. To what wash-down level can you use fabric belts? Nercon sees these belts used in the baking industry. Fabric belts are only suited for a base wash-down conditions. All fabric belts are made up of multiple layers and covers. This leaves the edges of the belt unprotected and allows bacteria to grow internal to the belt coverings. This technology is starting to get replaced by the homogeneous belting types for the higher levels of caustic wash-down.
Sanitary design options starting with Supports:Highlighted on the slide – starting from left to right - are a formed angle support, a formed sanitary channel, an all welded sanitary angle and a square tube support. These supports also appear in order of cost; the formed angle is the most economical and the square tube is the most expensive support.The formed angle is typically used in secondary packaging lines, while the other three examples can be used in caustic and heavy wash-down environments.
Continuing with Supports…We want to take a minute and highlight this support in particular, the Sanitary Channel. When compared to a tube support, the sanitary channel shown here offers a higher degree of sanitation at a lower cost point. Tubes by their very nature have a potential for bacteria growth inside the tube, particularly if the tube has a threaded foot, or if the tube is ever penetrated for other reasons. The sanitary channel design features wide angles that do not harbor bacterial and are very easy to clean. The adjustable foot is spaced off the support leg with bolted standoffs, and has a widened adjustment slot for easy cleaning.By simply choosing the sanitary channel support instead of a tube support, you can save nearly 30%.
Drive components:For a review on the motors and reducers, I’ll highlight these 3 categories of motors, as well as environmental conditions and cost.The main focus from a sanitary perspective is on the finish and the seals. The primary finish types are coated, epoxy and stainless.The term coated simply means that it is a mild or carbon steel housing with a spray on or powder coated paint. This finish is usually only found in areas that are not subject to wash down. Epoxy coated motors and reducers (shown in the lower left) still have a mild or carbon steel housing, but the coating has been upgraded to an epoxy finish that resists corrosion. This type of drive is often found in primary and secondary packaging areas that are subject to occasional wash downs. The downside of this finish is that eventually the drive will become scratched or nicked and begin to corrode.Stainless Steel motors and reducers (shown in the lower right) offer the best corrosion protection. These drives are most common in areas of direct food contact, or when the environment will be subject to aggressive sanitation processes. The housings are generally free of nooks and crannies to allow for easy cleaning. The major drawback has to do with the capital cost, but this cost needs to be looked at over the life of the project.
Now to talk about CIP:Clean-out holes allow for CIP or clean-in-place processes and these holes provide access for cleaning. They can be designed for either the open top or closed top frame designs.The Clean-out hole with a hinge cover on the right is an added safety feature.
Spray Nozzles are also an Clean in Place solution. Depending on the application and the food product, the nozzles may utilize an air blow-off or water based detergent spray.The application in this photo shows spray nozzles which are integrated into the frame design and positioned actually on both sides of the belt return. Nercon has engineered spray bars in a multitude of different applications. The most common use is where we have product that is being spilled in the filling or capping operation and we do not want the spillage to be transmitted to downstream conveyors. The spray bars can run continuous or actuated when the spill is detected. Normally, there is a blow off manifold downstream to remove excess water. Spray washing bars have in incorporated into all types of conveyors be it Tabletop, Modular Plastic Belt or Fabric belts.
On this slide we wanted to demonstrate the concept of a chain washer in a drawing…A chain washer is an all enclosed, continuous clean-in-place tank that can run in either a continuous or intermittent mode. It is capable of removing most process food in various states. For product that is more difficult to remove, there are options for pre and post tank spray headers as well as air blow options for drying the chain.These options are most typically seen in the raw food handling areas before any primary package handling.
Wear-strips are another component of sanitary conveyor designs that can be designed for easy removal. These wear-strips are designed with locating notches that aid in the ease of reassembling the conveyor after cleaning.On the right is a roller return, it is another COP feature where the roller is simply lifted out of the notch for removal and easily replaced after cleaning with no tools required.Check out the video links at the end of this presentation where we have demonstrations on the removable and accessible components on these sanitary designs.
This is an example of a conveyor design that aids in C O P or clean-out-of-place procedures.On the left you can see that this conveyor has a C-style (cantilever) frame design. It has a quick belt release that allows for easy belt removal. The belt is driven by a shaft mounted drive to the pulley and the V-guides allow for positive tracking (which we are showing in the lower right photo.)
COP Sanitary Guide Rails:Here is an example of a tool - less removable rail. There is a tethered pin that uses a T-block so the guide rail is easily removable and easily replaced after cleaning.
There are a few up and coming technologies that we want to briefly address – and to start we want to talk about New Chain Designs.On the left is a zoomed-in photo of a chain tooth profile in the red circle.One of the cleaning challenges with plastic modular belt is cleaning the underside of the chain and also getting access to the hinge areas for washing. In this new chain design sprocket teeth are offset in a double row (as shown on the left,) the sprocket-to-belt contact is minimized. The design allows belt hinge areas to be 100% exposed across the entire belt width. The photo on the right shows a close up of how the water can easily access the chain through the oblong openings.
Another new technology is this CIP spray system. On the left is a drawing that shows an idle shaft spray bar with special profile sprockets and spray components that allow cleaning of the hinge of the chain. The spraying pattern (shown in blue on the drawing) allows access to the entire belt. And an outside tube also has nozzles for cleaning the carrying surface of the chain.On the right is a photo with this HYCLEAN spray bar system in place. It uses low water pressure and warm water to effectively clean the belt which reduces water consumption.
TRENDS.Overall, Nercon has seen an increase in projects utilizing direct drive belting. It is ultra hygienic, with full plastic extrusion and no mechanical parts and no joints. Positive drives of this type of belting meet more stringent sanitation regulations over PVC and modular belting. This trend is in the forefront because:This drive is low maintenance The belt has superior hygiene benefitsAnd there is significant cleaning speed for these belts.
The No. 2…Trend is focused onhygienic cleaning efficiencies. Manufacturers look to:Reduce or remove horizontal surfaces from equipment design.Minimize internal surfaces.Removable components with no tools required.Every component is easily accessible for cleaning.This adds up to cutting downtime and increasing margins.
And finally we are seeing is an overall attention to sanitary construction details, including a focus on controls, to meet and exceed governmental compliance. What are some ways to leverage the placement of controls in sanitary wash-down environments? Much like the conveyors, control devices require special consideration in sanitary environments. We’re showing a heavy wash-down cover in the photo.For Sanitation level 1 the sensors should be Nema 4X / IP 67 rated. This means they can withstand a low pressure caustic wash down.Sanitation levels 2 & 3 have an elevated level of sanitation involving high pressure wash downs. For these levels devices should be rated IP-69 / Nema 4X.We also see in sanitation levels 2 & 3 that some actuating devices like solenoid valves and filter regulators are placed into stainless steel enclosures, commonly referred to as Air Outlet Boxes, this is done to prevent bacterial growth in the nooks and crannies common to these devices.Lastly, when considering your controls application there are some ways to reduce your overall controls costs and increase their life expectancy. One simple approach is to relocate the control enclosure to a non wash-down room which eliminates the possibility of water egress and lowers cost.More information on these and other cost saving ideas were featured in a previous Nercon webinar titled “Planning for Controls Integration” which can still be listened to at our website www.nercon.com.
And a few final questions that we want to share from previous live events:Can a conveyor system be designed with specifications from combined construction levels? Yes, customers sometimes have a plant spec to maintain, but Nercon has created the categories depending on the needs of the environment to provide the best value.Which conveyor levels are used for USDA and which level can be used for FDA compliance? USDA and FDA has stringent guidelines, our Sanitary Design Level II and III are designed to USDA and FDA requirements.Do roller conveyors meet sanitary requirements? It is difficult and expensive to get roller conveyor systems to meet the sanitary levels of caustic wash-down.Can lifts or elevators be designed for caustic wash-down? Yes, lifts and elevators like Drum Spirals and Indexing Case Lifts can be designed for caustic wash down. Unlike Gripper Elevators or Lowerators which are not typically used for transporting raw or open product.What is the company doing to reduce the cost of sanitary designs? Whenever possible, Nercon has taken the manual operations out of part production and redesigned it for high speed and accurate CNC production. The sanitary channel leg is an example of that which is 30% less expensive than the tube support.
On behalf of Nercon Eng. & Mfg., Inc. I want to thank you for taking this on-demand webinar and Sanitary Conveyor Construction. Here are some links you might be interested in:The Sanitary Conveyor Web PageA feature web page on Sanitary Level III conveyorsAnd the white paper corresponding to this webinar.Also, check out our website with more webinars and white papers on automation objectives at www.nercon.com.
Leveraging SanitaryConveyor Construction Levels
Leveraging Sanitary Construction LevelsToday’s Topics• Review six levels of conveyor construction
Leveraging Sanitary Construction Levels• Review six levels of conveyor construction• Best use practices by environment, industry
Leveraging Sanitary Construction Levels• Review six levels of conveyor construction• Best use practices by environment, industry• Leverage equipment cost versus outcomes
Leveraging Sanitary Construction Levels• Review six levels of conveyor construction• Best use practices by environment, industry• Leverage equipment cost versus outcomes• CIP and COP conveyor features that improve cleaning processes
Leveraging Sanitary Construction Levels• Review six levels of conveyor construction• Best use practices by environment, industry• Leverage equipment cost versus outcomes• CIP and COP conveyor features that improve cleaning processes• Advancements and Trends in Sanitary Belting Technology
Construction Materials Aluminum VS. Stainless Steel
FinishesPolished Stainless Steel VS. Bead Blast