Leaving behind debris
June 1, 2015
by Joanie Spencer
During the production process, as product is moving down the line, it can be easy for bakers to forget about what they can’t see. But when it comes to Sanitation Standard Operating Procedures (SSOPs), what might be out of sight on the conveyor has to remain top of mind for the operator.
“The challenge is not only to clean the belts but also the conveyor framework, sprockets, scrapers and other areas,” said Richard Brouillette, food safety director, Commercial Food Sanitation, an Intralox company, New Orleans. “The belt may be easily accessible for cleaning and inspection, but if the other parts of the conveyor are not, they will re-contaminate the belt.”
While there are seemingly endless options for cleaning methods and techniques depending on the type of belt and the product it has to move, it’s important to consider all the factors included in a bakery’s SSOP to ensure the belt is clean and minimizing food safety risks.
Baking with the enemy
Some of the most seemingly harmless ingredients — and possibly the most pertinent to product formulations — can actually pose some of the biggest threats to keeping a conveyor belt and system clean.
Sticky ingredients often used for toppings and coatings, such as chocolate or caramel, can create problems, not just for food safety but also for wear on the belt. “Left unchecked, shortening, sugar and other product debris can fill the voids in our [metal] oven BakingBand,” explained Ken King, commercial support manager, Ashworth Bros., Winchester, VA. “That debris will become a solid deposit and exert pressure the spiral wires from the inside out,” he added. This kind of pressure can result in fatigue breaks and broken spiral wires.”
For example, sugar left on the belt can be problematic to good housekeeping. “A lot of sugars are tough because when they mix with water, they actually create a slurry that’s a real challenge to clean,” said Bill Schiltz, director of sales and marketing, Kofab, Algona, IA.
And speaking of water … it’s probably the greatest enemy in this regard. The adage “A little water never hurt anybody” couldn’t be further from the truth when it comes to sanitation and wet cleaning methods in the bakery. When water puddles, it creates a harbor for bacteria.
For this, the best defense is to eliminate the places where water can accumulate — and that includes all the spaces that can’t be seen, too. “We like to say, ‘No place to hide,’ ” said Rick Spiak, vice-president, sales and marketing for Wire Belt, Londonderry, NH. “You don’t want spaces for pathogens or bacteria to grow or hide in places where you can’t see them growing. You need to make sure that the water runs off; there can’t be any puddling.” Wire Belt uses food-grade materials, including stainless steel, in its conveyor designs. “Stainless steel is easy to clean and works with USDA acceptance,” he added.
Bakers should also consider the belt in terms of combating water. Metal lotension spiral system belts from Ashworth are designed with a slotted hinge to help the rod freely move within the hinge area. “This helps keep the slot within the hinge clean while processing product,” Mr. King explained. “It also facilitates movement of water through the hinge area, resulting in less water consumption and less time cleaning the belt.”
One way to combat pooling of water and other buildup is making sure there’s no place for it to gather on the conveyor itself. “When the application calls for a wire mesh or modular plastic belt, the bigger openings you can have, the better,” said Joe Gongaware, sales engineering manager, Eaglestone, Inc., St. Charles, IL. “As a general rule, you want a more open area and fewer hinge points on the belt; the hinge points are often the most difficult to clean,” he added. “But you really have to consider the product and the type of transfers you’re going to have as the first priority.”
Today, many belts are designed to protect against water, too. For example, AMF Bakery Systems, Richmond, VA, engineered its dough conveyor to include a solid urethane belt, which does not fray or absorb water.
It is also important for the belting to have no exposed fibers or fabric at the edges. “The edges should be capped
and sealed,” Mr. Schiltz said.
However, it’s not just the equipment where the water can be a problem. To avoid puddling, Mr. Brouillette recommended that bakers should make sure that the plant is equipped with floor drains before using any kind of wet cleaning method.
What lies beneath
A critical issue for conveyor cleanliness is remembering the parts that can’t be seen, including cross bars, shafts and rollers that might be hiding inside the conveyor frame or underneath the belt itself.
For instance, waxy substances like pan release oils that contain lecithin can accumulate on the belt, observed Bob Harrington, vice-president of sales, Capway Systems, Inc., York, PA. “This, along with minute amounts of atmospheric dust and toppings can accumulate and carry to the underside of the belt,” he explained.
Mr. Schiltz agreed, “The back side of the belt is always a challenge because it’s not exposed.”
It’s all about getting to the underside. “If a flat belt cannot be lifted, it’s difficult to clean and inspect,” Mr. Brouillette said. Intralox’s thermoplastic belting, along with sprockets and shafts, address sanitary design expectations. “The belts do not run under tension, so they can be lifted for easier access during cleaning and for inspection,” he added.
Open-frame designs also provide a view of the conveyor beyond what’s happening on top of the belt. “We are designing and building our conveyors to have an open frame and components that are not bolted in place, such as toolless removable bed rails and rollers,” Mr. Spiak said.
Eaglestone also uses open-frame designs with its conveyors, as well as conveyors with what the company calls a “Flip-Clean” design, which is a cantilevered design with a locking mechanism at the infeed. “On smaller conveyor systems, the sanitarian can unlock it, flip up the infeed and, since it’s cantilevered from one side, remove the entire belt for full access to the conveyor’s skeletal structure,” Mr. Gongaware explained.
Mr. Harrington added that for modular plastic, the belting can be removed in sections, which can make removal easier.
But for larger systems, it’s not always possible to completely remove the belt. This is where belt lifts come into play. Eaglestone manufactures belt lifts that pick the belt up off the carryway or sliderbed and help with manual sanitation inside the conveyor frame.
To do their jobs correctly, sanitors often have their hands full — quite literally. “A sanitation person might have a hose in one hand and a scrub brush in another while trying to lift the belt up. They’re trying to do three things with two hands, and it’s almost impossible,” Mr. Schiltz added, explaining that Kofab designs conveyors with a quick-release mechanism to release the belt tension and create slack for the belt lift.
“If you make it easier for the sanitation crew to clean the conveyor, chances are, it’ll be cleaned better,” Mr. Gongaware said.
Working with ‘the help’
One of the most important things an operator should remember in good conveyor housekeeping is to simply follow the directions. It seems quite obvious, but it’s not uncommon for someone to create a makeshift “home remedy” for a cleaning solution. “For various reasons — lack of understanding, training or incentive — belts sometimes get cleaned with excessive amounts of cleaning agents or beyond the recommended cleaning time,” said Sebastian Miles, industry segment manager, food, for Habasit America, Suwanee, GA.
Some people want to assume that using an undiluted caustic cleaner on a metal belt will clean it faster, but that kind of flawed logic will only bring consequences, including reduced belt life as well as cracking and voids, which can create more hygiene risks.
“It’s simple; follow the instructions from the chemical supplier, and your belts will get clean, your conveyors will get clean, and the cleaner won’t harm them,” Mr. Spiak said.
Mr. King suggested that using a caustic wash on plastic might not end well, either. “Using caustic chemicals on plastic belts, support rails and cage bar caps can soften plastic materials and lead to damage or belt failure.”
It’s just as important to consider the belt material as it is the cleaning agent. “It’s common in bakeries to find soft alloys and hard metal combined in one piece of equipment that may not be compatible with stronger cleaning chemicals,” Mr. Brouillette suggested. Some metal combinations include galvanized steel, aluminum, copper or iron.
In terms of stainless steel, it’s all about the grade. “The higher grade of steel you can use, the better,” Mr. Spiak said. “Within the 300-series of stainless, if you want better chemical resistance, you would use a 316 if you’re looking for heavy chemical resistance.” However, he added, somewhere between 302 and 304 is probably most common, and the key is to rinse it well every time. “If you put a lot of caustic into a 304 belt, it could develop pits in the metal over time,” he said.
The coating on a conveyor can also lend itself to a good relationship with its cleaning agent. Mr. Miles noted Habasit’s Cleanline belts offer chemical resistance, allowing use of a stronger chemical combination when needed.
For some conveyor systems, such as in coolers, it’s not feasible to remove belts for cleaning. In those cases, there is clean-in-place (CIP) technology, such as Capway’s ultrasonic belt cleaning system. Here, the belt surface passes through a tank containing a wash solution, where ultrasonic waves are generated to loosen and remove debris.
Cyclone belt washers from Douglas Machine Corp., Clearwater, FL, offer CIP cleaning for metal or plastic belts. The washers are placed on a cart that can be transported from one belt to another, and both types of washers can be stored on the same cart.
Scrapers can also help keep the belts clean. “On dough conveyors, the use of scrapers is the simple and most effective way to continuously clean a conveyor belt,” said Alain Lemieux, engineering product manager, AMF Bakery Systems. The company offers a poly belt scraper system for its Volta Superdrive dough conveyor.
Mr. Gongaware suggested a dual durometer polyurethane scraper to clear ingredients such as icings and toppings or a spring-tensioned scraper, which more aggressively scrapes a belt and works well on modular plastic belts, conforming better to the cordial action.
Consider the frequency
So, what’s the magic number when it comes to the timing of keeping conveyors clean? The resounding answer: It depends. Factors can include protocols such as HACCP, USDA’s sanitation rules, the products being made or the facility’s overall operations.
“The frequency of the cleaning process will vary based on the system’s process environment and product type,” Mr. King said, advising that when conveying products with heavy sugar or salt content, the support rails should be cleaned daily. “Sugar and salt are abrasive, and when either become embedded in the support rails, tension forces between the rail and the bottom belt surface increase and can result in a dramatic change in drive performance, belt damage or eventually structural damage to the spiral system,” he explained.
While hot-water sanitation can happen as often as daily, continually keeping the belt clean with tools like scrapers is an easy trick. “On dough conveyors, using scrapers is the simplest, most effective way to continually clean the surface,” Mr. Lemieux said. “Proper adjustment of these devices can be required over time, and changing the scraping blade will maintain the original system performance.”
Mr. Gongaware agreed scrapers are ideal for cleaning icings, toppings or high-fat products continually and between CIP sessions.
Taking care to clean and maintain the conveyor system and all its parts — seen and unseen — will move product down the line without leaving the unwanted behind. “Bakers should strive to constantly maintain the cleanliness of their belting,” Mr. Harrington said. “Continually maintaining belt surfaces will minimize the amount of in-depth cleaning needed to properly maintain their belt surfaces.”