Staying on the conveyor track
March 1, 2014
by Dan Malovany, Baking & Snack
Belts and conveyors are the Rodney Dangerfield of equipment. All too often, they get no respect. They’re taken for granted. That is, until they break down, and when that happens, profitability plummets as everything grinds to a halt. That’s when things get really ugly. And only then do they get the attention they need.
So, what are the telling signs that something bad is about to happen? If operators listen carefully, they can hear their conveyors quietly — and sometimes loudly — telling them that something is about to go wrong, according to Jim Kline, president, The EnSol Group, Erwinna, PA. If it’s the latter, it’s probably too late to avoid costly repairs.
“Conveyors should be relatively quiet if they are operating properly,” Mr. Kline said. “If you are hearing a lot of noise, it could be a sign of trouble.” That trouble may include problems with ball bearing alignments, unnecessary drive friction, sprocket problems or belt tracking.
Keeping a close eye can provide additional warning signals, he added. Such visual cues as surface cracking, fraying or other signals of deterioration on the edges of belts should prompt a rescue call to maintenance before deadly downtime ensues. Another clear indicator? Mr. Kline suggested the inability to pass an AIB International or food safety audit could indicate that belting or conveyors need to be replaced or repaired.
It doesn’t matter if the belt is metal or plastic. The signs are obvious to the trained eye, noted Kenneth King, commercial support manager, Ashworth Bros., Winchester, VA. “Some of the key signs that Ashworth looks for when assessing the condition of a metal belt are excessive material wear caused by an inappropriate interaction with the conveyor structure, metal fatigue due to over-tensioning the belt and uneven stretch across the width of the belt,” he explained.
“In the case of plastic belts, we look for extensive damage due to contact with the conveyor structure, module fatigue due to high tension or connector rod damage due to excessive product build-up between the rod and module,” he added.
“We also determine whether the modules have become brittle due to age, exposure to light or exposure to prolonged use of stringent sanitation chemicals.”
In some cases, conveyor design can adversely affect the belt’s performance, which can ultimately damage the belt. “In other cases, production requirements change over time, and the original belt selected for the given system may no longer be capable of handling increased product load or increased belt speed requirements,” Mr. King explained. “These changes often can lead to excessive fatigue due to high tension and accelerated belt stretch. These are common occurrences that often result in belt damage on spiral systems.”
And then there are those surprises that seemingly come out of nowhere. For example, accidental or undetected damage can result in a loss of tracking, which can hurt yields and result in downtime, according to Rick Spiak, vice-president of sales and marketing, Wire Belt Co. of America, Londonderry, NH. “You could have a second-shift forklift operator bump into a conveyor, and you might not even know it until you see the belt not tracking,” he said. “Even an inch out of alignment or out of square for a conveyor that is 30 ft or more in length can disrupt the proper tracking belting easily.”
Up and operating
A strong maintenance program often remains the linchpin to keeping a conveyor operating smoothly. In some cases, Mr. Spiak said, spending too much time fixing and repairing a system could suggest that it’s time to rebuild or replace it. An ounce of prevention is one thing. A ton of maintenance, however, often weighs on the bottom line.
“If you monitor the time spent on preventive maintenance and compare it with the time you spent from breakdowns, you can pretty much calculate how much an older conveyor is costing your bakery or snack operation in terms of lost product, productivity and efficiencies,” he explained. “If you are repairing a conveyor once a shift, once a day or even once a week, you might look at rebuilding or replacing it.”
Often, planned maintenance can avoid unplanned disruptions, Mr. King advised. “Lubrication of bearings, cleaning the belt and belt support structure and true tracking must be maintained over the lifetime of the equipment to keep production and profits up,” he said.
Having spare parts in inventory is also a good idea. “One $600 motor can save you $20,000 in downtime, especially with bakeries running up to 140 to 160 hours a week with little maintenance,” Mr. Spiak explained.
Moreover, routine monitoring and diligent detection of potential belting issues can be a quick way to determine if and when a belt should be replaced. “The key here is to be proactive in making sure your spiral belt is in good condition so your plant avoids any unscheduled downtime,” said David Daylor, corporate account manager, Intralox, Harahan, LA. “Our customers usually consider the spiral as a ‘mission critical’ piece of equipment, and the cost of a major crash can easily outweigh the cost of replacing your belt.”
In ovens, the clear indicator involves decreased baking quality and throughput, observed Daniela Weiszhar, marketing manager, Berndorf Belt Technology USA, Gilberts, IL. “When the existing belt has lost optimal surface qualities such as the dark mil finish, flatness or has become coated with burnt product or other debris, it affects the desired baking temperature and, ultimately, the finished product quality.”
Repair or replace?
So what are the tough questions to determine whether to build a conveyor or install a new belt? Some are obvious, and some are not.
“Do you take swab counts, and if so, are your counts high where a new belt could reduce them back to a normal or acceptable level? Are your splices failing or starting to come apart?” suggested Sebastian Miles, industry segment manager, dry foods, Habasit America, Suwanee, GA. “On confectionary or sticky bars, we may ask more about release issues and waste. In cookie, cracker and other products that may be using palm oil, we may ask if they have problems with delaminating of the belts.”
Most suppliers to the industry consult with bakers to tailor conveyors to the process. “In a simple interview, we need to know what kind of products have to be processed, such as pieces per hour or kilograms per hour, as well as processing time for proofing, cooling or freezing,” said Paolo Gonella, area manager, Alit USA, Luverne, MN.
As companies grow, manufacturers also should evaluate whether their systems have become overloaded over time. “Is your current conveyor system at production capacity, hence, causing a bottleneck and limiting your growth?” wondered Anthony Salsone, senior associate, G&F Systems, Roosevelt, NY.
Often a change in a bakery’s product portfolio might prompt the need for a change, or advances in technology might provide an opportunity to make an operation run better. “Is there new product development in the spiral world that will help my efficiencies versus dealing with inherent limitations to my existing technology?” Mr. Daylor urged companies to ask.
Many times, Mr. Miles added, the questions turn out to be more application-oriented or industry-specific. “We try to focus past the obvious and instead focus on difficult applications or issues where the customer may not be aware there is a solution,” he said.
When selecting a conveyor, perhaps the $64,000 — or $640,000 — question (the cost may even get higher depending on the bakery) involves predicting the future. “The biggest challenge is not only designing a conveyor for what you are producing today, but designing it in a way so that it can handle a variety of new products in the future,” Mr. Spiak explained.
Sometimes that new product might be as simple as producing donut holes on an existing donut line. The wrong belt, design or pitch of a conveyor can have those little round sweet treats rolling all over the place.
Choosing the right belt for a conveyor or spiral system requires analyzing a host of criteria. “When selecting a belt, bakers and snack food producers must keep the following factors in mind: ease of sanitation, ease of repair, durability, product support characteristics, product loading and registration requirements,” Mr. King explained.
Getting from one point to another is rarely as straightforward as it seems, according to Bob Harrington, vice-president, sales, Capway Systems, York, PA. “On any operation, transporting from A to B is the main objective, but keeping the symmetry and alignment of the product between the two ends is just as important,” he said.
As companies expand, maximizing space is critical to avoiding high construction costs. As a result, many conveyor systems are designed to handle a high volume of product in the smallest footprint possible. More flexible systems and new spiral designs create a low-in/low-out production flow, noted Mr. Gonella of Alit.
Stewart Systems, Plano, TX, uses an endless conveyor system with open construction and a double helix design to minimize space requirements, noted Dave Machette, sales and marketing specialist. “Products travel up an outer spiral, cross over and return down an inner spiral,” he said. “Both the infeed and discharge take place at the bottom tier.”
When it comes to belting, spiral and conveying systems, a little respect — and paying a lot of attention to details — can go a long way.