![\"Volta](\"https:\/\/www.voltabelting.com\/wp-content\/uploads\/cleated-belt-cashew-incline-conveyor-3x2-1.webp\")
Why a Flat Belt Fails on Inclines<\/h2>\n\n\n\n
A flat belt is effective at holding most products stationary on a horizontal plane and even at small angles of incline, but gravity works against it at some point where the angle exceeds what the product can bear and where it begins to slide back along the moving belt. This can happen for some products, slippery (e.g. large fish), or round product (e.g. fresh dates and berries) which may even slide backwards on a faster moving, horizontal belt. For other products, even very shallow slopes may be enough to trigger backwash\/rollback. (e.g. potatoes). The result is product bunching at the tail end or falling off of the conveyor altogether. This interrupts the feed to the next process, makes throughput inconsistent which means that the bunching may also cause belt failure due to overloading, and can introduce product to areas it is not wanted, the floor, or worse still, inside the conveyor and the belt path.<\/p>\n\n\n\n
Portioning Lines<\/h3>\n\n\n\n
Portioning, separation and packaging lines present a different version of the same problem. A flat belt moves everything at the same speed with nothing to regulate spacing. When the line feeds into a dosing system or packaging system for weighed portions, maintaining a physical gap between portions can assist and speed up the process. A vertical form-fill-seal (VFFS) deposits separated, sealed packs from under the filler and the packs are often guided to the next stage of boxing via small decline conveyors with cleats preventing product damage and regulating the flow.<\/p>\n\n\n\n In another iteration used in slaughterhouses, sets of offal or organs are kept separated while the meat is tested as safe for human consumption. This saves a valuable by- product as without the hermetic separation between sets of organs on the belt, an unfit set would mix in and contaminate any other organs on the conveyor at that time, and all would be wasted.<\/p>\n\n\n\n Cleats solve all the issues mentioned above by simply creating a physical barrier integral to the belt. A belt mistakenly commissioned without cleats will fail but there are many failures that can occur by not considering the variables of cleat design. As noted, the height, pitch and thickness all play a role and the mechanical and hygienic reliability of cleats is measurably enhanced by selecting thermoplastic belts.<\/p>\n\n\n\n As a footnote, a common failure is met when attempting to elevate heavy loads. The most common instance in food processing is when moving 25kg frozen blocks; a challenge that fabric-based belts cannot meet and where modular belts suffer catastrophic damage. Thermoplastic belts can be gusseted to support loads and this is yet another design parameter demanding a precise calculation and engineering solution.<\/p>\n\n\n\n The main design features of cleats are height, length, pitch, and shape. When commissioning a new elevator there is often more freedom to design alternative solutions than when replacing an existing belt. Nevertheless, even a refit can offer improved performance in many cases and care should be taken to evaluate the requirement and to study where the belt needing replacement might have failed to meet expectations. A Volta cleated belt gives an immediate improvement in hygiene and lifespan but in many cases, expert technical insights and amended designs can improve the overall performance. Most of the following discussion relates to new conveyors.<\/p>\n\n\n\n Getting the design right requires some basic information including the conveyor angle, product bulk density (simply put; how many kg in a cubic metre), a confirmation that the flow is fairly constant (not intermittent batching) and the appraising of constraints such as belt speed which may arise from the process in hand or from the space where the conveyor operates.<\/p>\n\n\n\n Commonly, more than one configuration of the variable parameters may yield an acceptable design. The target is simple: to move a given quantity of one or more products in a defined time period. A comparison between options should look at both belt cost and overall conveyor cost as this can be affected in some cases.<\/p>\n\n\n\n The first thing is to establish the invariable parameters, primarily the product bulk density and probably the angle of incline. (A small exception might be where the location has free space to position the foot of a new elevator closer to or further from the target discharge point. If the conveyor base is moved closer to the discharge, the conveyor will be shorter which might make it cheaper but the steeper angle of incline will reduce the carrying ability of the cleats by reducing their fill and also increasing the overall strain of a given load on the belt). As can be seen in the short notes on cleat design that follows, different designs for a given application can affect the conveyor design.<\/p>\n\n\n\n Every base belt on a conveyor has its defined \u2018minimum pulley diameter’. This can be affected by belt speed and ambient and product temperature.<\/p>\n\n\n\n Belt speed is often a variable but the majority of elevators in food processing run at speeds between 15-25 metres\/minute. These speeds will not affect a thermoplastic belt at room temperature but in cold ambients, larger pulleys may be required. Running a belt at high speed in cool or frozen ambients will usually dictate larger pulley sizes than an average speed at room temperature.<\/p>\n\n\n\n If the conveyor is used for conveying different products, a separate calculation should be made for each product type looking at each product’s bulk density and intended hourly throughput on the conveyor. However, if the intended throughput is identical for all products (e.g. 1000kg\/hour regardless of product type) the product having the lowest bulk density is used to determine the cleat parameters as this product will need the largest volume of cleat space (a minor exception may be where the \u2018angles of repose’ are radically different – this term will be elaborated on later).<\/p>\n\n\n\n The main variables for cleats are thickness, height, length, and pitch (the spacing between two cleats).<\/p>\n\n\n\n As mentioned before, thickness will relate to cleat height and expected product load.<\/p>\n\n\n\n Cleats welded onto a belt increase the \u2018minimum pulley’ that can be used and this affects the overall cost of the conveyor. However, different heights, length, and pitch of cleats will not alter this requirement.<\/p>\n\n\n\n After understanding the above guidelines, let us now assume that we have a concept as follows: a product with a known bulk density and required hourly throughput, a given angle of incline and an estimated belt speed. It is prudent to add to the throughput any expected future increase for the coming few years so that the conveyor is not rendered obsolete too quickly.<\/p>\n\n\n\n We now need to define which cleat height, length, shape and pitch give the necessary throughput. In all cases, several designs will work: for example, imagine a high, long cleat positioned on a wide pitch compared to low, short cleats positioned closer together.<\/p>\n\n\n\n In order to assess what is optimal, we must consider two parameters that relate to the product; angle of repose (mentioned above) and an estimated \u2018coefficient’ of filling.<\/p>\n\n\n\n The two parameters are connected to some extent. The angle of repose is the point at which a bulk material no longer piles up but collapses leaving a slope on either side. By way of comparison, grains like wheat and barley fall off at 21-22\u00b0 while sticky brown sugar can come close to 60\u00b0 and thus increase the volume held by each cleat. The coefficient of filling is an educated estimate as to what percentage of the maximum volume of a given cleat will be filled. If we compare a high cleat and a low cleat at the same pitch and belt speed, the coefficient of filling will be lower on the high cleat and we may have incurred the cost of larger cleats for no reason. The increase in cleat height does not always add to actual throughput. A longer cleat across a wider belt can also increase throughput and may be more efficient if the infeed is spread out but this makes both the conveyor and belt wider. If cleats are too close together, we may find that the cleats cannot fill to their maximum for a given product or that due to belt speed we have not allowed enough time for a good fill. Conversely, with a fragile product requiring some separation, more cleats may be preferred.<\/p>\n\n\n\n In some cases, especially on wide belts, cleats may be welded on in rows with gaps between rows. This offers more options for holding the belt in place on the return path.<\/p>\n\n\n\n These are the variables that need to be combined in a well-thought out model to maximize efficiency and minimize conveyor and belt cost.<\/p>\n\n\n\n Cleat shape can also be useful in meeting the required throughput. \u2018Scoop’ cleats have a bent lip that holds about 20% more product and is a common feature of elevations over about 60\u00b0. They become a virtual necessity in many cases with inclines over 75\u00b0. As a result of the very steep incline, the available transfer volume per cleat is low and thus the extra volume afforded by the \u2018scoop’ shape helps redress the throughput as well as ensuring that the product does not spill from the steep climb.<\/p>\n\n\n\n Finally, as noted above, a slippery or near spherical product may roll back on a horizontal belt. Here profiles can be added to push the product along the belt. Some extruded textures such as Volta’s \u2018Crescent Top’ can do this without welding on extra elements, in other cases, profiles are welded on with a common option being V profiles<\/a> forming a chevron pattern.<\/p>\n\n\n\n Volta offers consultation on the reconfiguring of existing belts and on designing new conveyors.<\/p>\n\n\n\n From the standpoint of food safety, cleats are a food contact surface. As such, the EU food contact materials regulation EC 1935\/2004<\/a> and FDA food contact compliance requirements<\/a> apply as they do to any material that routinely contacts food. This is not a technicality and subjects the \u2018fabrication’, the attaching, of the cleats to the stringencies of Hygienic Design.<\/p>\n\n\n\n The fabrication is fraught with pitfalls both in the material selected for the cleat and the method of joining it to the base belt.<\/p>\n\n\n\n Cleats should be made from one material and not include fabric. They should have smooth, finished edges without machining marks and without flash from cutting.<\/p>\n\n\n\n A cleat that is bonded to the belt with adhesive has a chemical join that will weaken over time with the continuous loading action and resulting flexion. Before ever being used, in its prime state, this type of cleat still poses a hygienic risk, as capillary action can cause the ingress of pathogens into the join. Even a high frequency welded cleat, where the mold is imperfectly shaped, does not form a hygienic radius at the cleat base. The seemingly insignificant but visible seam is no obstacle to bacteria. E. Coli has a width of about 1 micron, Salmonella and Listeria are even narrower and can be harbored in any imperfection assisted by the water content of the product or by the water used to clean the belt. Even if the fabrication mold welds a cleat perfectly but does not create this radius, the foot of the cleat adjacent to the base belt is a \u2018dead zone’ where cleaning fluids do not have enough wall shear stress to flush out the dirt. EHEDG Guidelines on hygienic design<\/a> offer a general definition for a sufficient radius as R3mm. Volta cleat fabrications are based on this rule.<\/p>\n\n\n\n To summarize, Volta’s approach to cleated belts eliminates the risks of fabrication by cutting cleats from homogeneous materials on specialized machinery and by ensuring they are joined hygienically to the base belt without adhesive, without faults in the seam, and without dead zones where trapped food residue can harbor pathogens. Interestingly, in the light of a recent failure to pick up listeria at a processing facility, the USDA-FSIS has just announced more stringent swab sampling on food contact surfaces. Using correctly designed belts is not an insurance policy, it is a necessity.<\/p>\n\n\n\n A further aspect of cleat design, is mechanical stability. Volta calculates the load and forces and selects cleats that will not detach in normal use. This is a critical failure point of modular belt cleats which have been observed to routinely shed cleat fragments which often end up undetected in the product flow. The hard, rigid plastic used for modular cleats are unsuited to any impact or load and a recent academic study has raised another worrying consequence of this; the continual attrition of plastic can deposit pathogen-bearing micro- and nano-particles into the product flow. Modular belts are particularly prone to this as are other plastic belts without sufficient abrasion-resistance.<\/p>\n\n\n\n Volta’s food-grade belts<\/a> carry FDA compliance and EU food contact certification across the range, and that compliance extends to the cleats as part of the same homogeneous construction. They are also tested for abrasion resistance (DIN 53516) and outperform all other thermoplastic belts.<\/p>\n\n\n\n Engineering the right cleated belt comes down to a defined list of parameters that must be considered before any fabrication decision.<\/p>\n\n\n\n To recap; a product needs to be transferred cleanly and efficiently in a sufficient hourly volume to justify the investment and prevent a bottleneck before or after the conveyor’s location in the line. It must permit the discharge of as much of the material as is possible without spillage to the sides or under the belt, and should conform as far as is possible to the three fundamental constructs of Hygienic Design: cleanability, accessibility and drainability.<\/p>\n\n\n\n As noted, the first stage is to assess and note the constraints. For an existing refit, these might not permit any change in design whereas, for a new elevator, there is more leeway. After considering the parameters discussed earlier, the key lies in assessing the flow of material and the design of the intake area to enable successful loading to the belt, and the likely effects of impact on the cleats.<\/p>\n\n\n\n Finally, in some cases such as when sticky product is being conveyed, a textured belt and textured cleats may be part of the overall solution.<\/p>\n\n\n\n One subject not fully examined in this article (where bulk density and throughput are not the main issues) is where the belt must elevate heavy loads. These are commonly individual blocks of material. Volta has solutions for carrying even 40kg frozen blocks up inclines and our unique engineering solutions are unmatched for quality and efficiency, showing that Volta defines the highest industry standards for hygiene and mechanical excellence.<\/p>\n\n\n\n With heavier loads, Volta’s positive drive belts<\/a> come into their own, ensuring there is no belt slippage and enabling the use of motors with lower electrical consumption.<\/p>\n\n\n\n Volta’s welding and fabrication tools<\/a> support the splicing of cleated belts, meaning that replacement in a production hall does not require the time-consuming disassembling of shafts. A properly trained maintenance team can fit a cleated belt on-site in the shortest time, which matters because food processing units work round the clock during seasonal work or periods of high activity where planned maintenance is not possible. Breakdowns, by definition occur during work and every hour saved in downtime is a valuable resource.<\/p>\n\n\n\n A cleated conveyor belt transports product on inclines or declines where a flat belt would not hold the product in place, or to separate portions or control product spacing to prevent damage, or to align product before feeding into the next process. Cleat design is based on matching the incline angle and product bulk density to a required hourly flow of product. In food processing, cleated belts are used in almost every sector from dry produce, to wet vegetables, to frozen or cooked meats and fish. While they primarily hold product and keep it moving in the direction of the process, special uses may include separating portions or loads or on Bead elevators where the base belt is perpendicular to the conveyor movement. Volta optimises the specific cleat design for each application rather than applying standard solutions that underperform.<\/p>\n\n<\/div>\n<\/div>\n There is no limitation for angle. On an elevator the belt can work vertically. However, cleated belts can be used on horizontal and troughed conveyors to encourage slippery or naturally rolling products along the belt path. At the upper limit, as noted, Volta cleated conveyors can replace vertical single discharge bucket elevators which are often difficult to clean, maintain and repair. For very steep inclines, Volta advises on cleat shape, such as angled cleats, or scoop cleats, to keep product from spilling.<\/p>\n\n<\/div>\n<\/div>\n The best cleated belts for food processing plants are those where both the belt and the cleats are food certified. Volta’s food-grade cleated belts are FDA and USDA compliant and meet EU food contact regulations. The cleats, made from the same homogeneous material, share that compliance. In addition, all modern food processing facilities should conform not just to the letter of the law in terms of materials, but also avail themselves of state of the art fabrications and Hygienic Design in order to conform to ever stricter auditing demands. Volta’s homogeneous elastomeric belts and fabrication techniques are the benchmark for excellence in hygienic food processing lines.<\/p>\n\n<\/div>\n<\/div>\n Cleat detachment can result from several causes. Firstly, an incorrect assessment of product load. Secondly, from undue impact on cleats or where the cleats are not designed to absorb this impact. Thirdly, the incorrect selection of belt type – the two alternative plastic belts are fabric-based belts and modular belts. When fabricated with cleats, they are sometimes unsuited to the work demands. Cleats on fabric-based belts may have a fabric core, they cannot bond strongly with the thin and porous base belt layer making them prone to water and chemical damage and to delamination from the base belt and they have a wide, unhygienic base which is a mechanical necessity due to the weak bond with the base belt. Once a cleat detaches, there is more load and strain on the next cleat in line and can cause a slow but clear chain reaction.<\/p>\n Cleats need not detach fully to pose a problem. Modular cleats are brittle and even light impact can break pieces off and attrition resulting from continual abrasion will send undetectable cleat particles into the product flow.<\/p>\n Finally, three other causes of detachment are recognized that are not dependent on the belt typology.<\/p>\n A too small pulley will eventually cause cleats to break off. This is common on older conveyors and care is needed in assessing refit from a fabric-based to a homogeneous belt.<\/p>\n Secondly, operator damage – this includes negligent loading of belts and poor cleaning practices such as jamming broom handles under belts to access the underside.<\/p>\n Lastly, faulty workmanship – Volta takes great pride in the high frequency welding systems developed in-house and in a standard of workmanship that leads the market.<\/p>\n\n<\/div>\n<\/div>\n A cleated belt needs a validated sanitation protocol that reaches the top and bottom of the belt and both sides of every cleat. The factory QA team have a duty to assess the cleaning of all machinery (including conveyors and their belts) with two aims in mind: rendering the unit fit for the next shift and minimizing or eliminating any damage to the unit from the cleaning process. Cleaning a cleated belt requires more attention than a flat-surfaced belt and any automated sanitizing system must take the cleated geometry into account. Swab testing should be conducted on both top and bottom surfaces of the belt and both sides of the cleats. The cleats may not be the most difficult area to disinfect especially on positive drive belts. Cleats should be inspected to ensure both full sanitation and to pick up any degradation of the join should this appear. On Volta cleated belts the cleat base is welded with a rounded 3 mm radius to allow wet cleaning to flush out food remnants.<\/p>\n\n<\/div>\n<\/div>\n A homogeneous thermoplastic conveyor belt is a monolithic extrusion and Volta used the same material welded on by high frequency for cleats. Cleat edges are finished with care and the welding forms a hygienic, cleanable radius. A cleated modular belt is assembled from interlocking plastic modules and the cleats are attached by an interlocking design at plate intervals that give the chosen pitch. The joints and connections are hygienic weak points and cleats are very prone to break under impact. The hard, brittle nature of the material makes it susceptible to shed nano- and microparticles (recently highlighted as potential carriers of pathogens).<\/p>\n\n<\/div>\n<\/div>\n Assuming a correct a priori design and no misuse, the lifespan of a belt or a cleated belt depends on the type of material conveyed (sharp, breadcrumbed and frozen materials will cause more wear) how the load is handled to prevent impact (contrast for example, regulated mechanical loading or inaccurate hand-loading) or product lost and ingress into the belt path. It depends on a well-specified and dedicated sanitation protocol and the type of chemicals needed to clean. A correctly specified homogeneous Volta cleated belt will outlast alternative plastic belts working under the same conditions both mechanically and hygienically. It is worthy of noting that modular belts can be very durable but are not hygienic. They can also entail hidden costs with replacement parts rarely being factored in as a cost of the belt. The need for these replacements is eliminated by using the more flexible and durable Volta materials.<\/p>\n\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n\n\n If you are designing or retrofitting a line that needs a belt conveyor with cleats \u2014 whether that is an incline in a fish processing plant, a portioning section in a poultry facility, or a post-VFFS packaging run \u2014 the fabrication and material decisions made at specification stage determine both food safety performance and total cost of ownership for the belt’s entire service life. Volta’s applications engineers have worked through these specifications across 60+ countries and across the full range of food processing environments. Contact Volta’s technical team<\/a> to discuss cleat geometry, belt material, and drive system selection for your specific line.<\/p>\n","protected":false},"excerpt":{"rendered":" Cleated conveyor belts carry products up inclines and keep them apart. When to use cleats, which cleat geometry fits, and how to fabricate them food-safe.<\/p>\n","protected":false},"author":569,"featured_media":68961,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[1],"tags":[],"class_list":["post-68727","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-blog"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.voltabelting.com\/vi\/wp-json\/wp\/v2\/posts\/68727","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.voltabelting.com\/vi\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.voltabelting.com\/vi\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.voltabelting.com\/vi\/wp-json\/wp\/v2\/users\/569"}],"replies":[{"embeddable":true,"href":"https:\/\/www.voltabelting.com\/vi\/wp-json\/wp\/v2\/comments?post=68727"}],"version-history":[{"count":9,"href":"https:\/\/www.voltabelting.com\/vi\/wp-json\/wp\/v2\/posts\/68727\/revisions"}],"predecessor-version":[{"id":69004,"href":"https:\/\/www.voltabelting.com\/vi\/wp-json\/wp\/v2\/posts\/68727\/revisions\/69004"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.voltabelting.com\/vi\/wp-json\/wp\/v2\/media\/68961"}],"wp:attachment":[{"href":"https:\/\/www.voltabelting.com\/vi\/wp-json\/wp\/v2\/media?parent=68727"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.voltabelting.com\/vi\/wp-json\/wp\/v2\/categories?post=68727"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.voltabelting.com\/vi\/wp-json\/wp\/v2\/tags?post=68727"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}![\"Cleated](\"https:\/\/www.voltabelting.com\/wp-content\/uploads\/cleated-belt-sidewall-wrapped-candy-3x2-1.webp\")
How Cleat Geometry Determines Performance<\/h2>\n\n\n\n
Material and Fabrication: What Separates a Safe Cleat from a Risk<\/h2>\n\n\n\n
![\"Volta](\"https:\/\/www.voltabelting.com\/wp-content\/uploads\/cleated-belt-fish-fillet-incline-conveyor-3x2-1.webp\")
![\"Perforated](\"https:\/\/www.voltabelting.com\/wp-content\/uploads\/perforated-cleats-thermoplastic-belt-fabrication-3x2-1.webp\")
Specifying the Right Cleated Belt: The Checklist That Actually Matters<\/h2>\n\n\n\n
FAQ<\/h2>\n\n\n
What is a cleated conveyor belt used for?<\/h3>\n
For an elevator, how steep an angle can a cleated belt work on?<\/h3>\n
What are the best cleated conveyor belts for food processing plants?<\/h3>\n
What causes cleats to detach and why is this a serious risk in food industry?<\/h3>\n
What special attention is needed when sanitizing a cleated conveyor belt?<\/h3>\n
What is a cleated homogeneous conveyor belt, and how does it compare with a modular belt with cleats?<\/h3>\n
How long does a cleated conveyor belt last in food processing?<\/h3>\n