By Kevin Gingerich
Conventional wisdom grossly – and wrongly – devalues conveyors, regarding them as cheaply -built, non-value added units that simply move product through successive packaging steps. Indeed, conveyors are often the last elements considered in the planning cycle and are among the last items bought. Purchase decisions are usually made on the basis of acquisition cost, or expense, and not on value.
This view of conveyors as a commodity is full of risk. The wrong conveyor system, or even a suitable system incorrectly applied can quickly undermine a packaging operation strategy and dissolve profitability and competitive advantage.
With thoughtful analysis and application, though, modern conveying systems offer many advantages to automated packaging operations. In addition to basic transport, conveyors advance packaging line efficiency with the best possible material flow routes and processing rates. In pharmaceutical packaging, for example, conveyors are used as a “highway” system to coordinate product flow between consecutive process machines, and to balance production.
For any packaging application, the best time to select the right conveyor components and arrange them is during initial planning. Failure to do so leads to waste, excess costs, and high cycle times.
The ideal conveyor system should simply, flexibly, and cost-effectively adapt to changes prompted by internal or external influences, such as branding and marketing strategies, retailer demands for various bulk packaging formats, or changes in regulatory standards.
For example, consider the relationship between a conveyor and a package labeling system. Marketing departments continually introduce innovative container shapes and graphics. Consequently, labeler changeovers are routine. Frequent changeovers, however, can create significant waste in the form of machine idle time and lost production.
Properly arranged conveyors will buffer product accumulation ahead of the labeler, which allows production to continue even during brief labeler stoppages. Line output can increase as much as 25%.
Typically, transfers to and from a labeler are trouble spots, especially for lightweight plastic containers. Poorly designed in-feed and out-feed conveyors can cause container tipping and jamming, which can lead to high product spoilage rates and low profits. Attention to such details helps improve labeler efficiency.
Conveyors are critical elements in any packaging process. They form bridges between and coordinate independent stations of packaging automation. In pharmaceutical manufacturing, for example, profitability is heavily influenced by the performance of the packaging line. Conveyors must aid marketing priorities, and balance them with reduced operation and labor costs.
Packaging Flow Management™ (PFM) is a strategic approach to conveyor system planning and deployment that identifies and makes the most of critical points between a packaging process and conveyor system. Unlike conventional approaches to conveyor selection and deployment, PFM offers a complete focus that evaluates the following factors for flexibility and lowest total cost of ownership: Packaging process attributes, product mix and packaging formats, process and product quality requirements, product evaluation, and trends.
In packaging process attributes, detailed factors to consider include:
- Process speeds, infeed-outfeed characteristics, and mechanical dynamics between interconnecting packaging machines, as well as the required mean time between failures.
- Finding and analyzing the nature, extent, and frequency of production disturbances, whether planned or unplanned. For example, how frequent are labeler changeovers, and what is the extent of unplanned stoppages associated with the case packer?
- Exploring whether a buffering conveyor system will ensure constant product flow during stoppages and line speed changes.
For product mix and packaging formats, the PFM approach examines current and possible future product and packaging variants. What unique and common handling properties are presented by these variants? How will retailer requests for different bulk packaging formats affect productivity? How can conveyor systems strategically harmonize marketing and production priorities, providing cost-effective flexibility to reduce time-to-market cycles?
With process and product quality requirements:
- Examine opportunities for product tipping, jamming, and degradation of value-added packaging content.
- Determine where packaging process waste is greatest.
- Find where direct labor productivity is lowest. Look at places where containers are dropped or crushed at conveyor-machine interface points.
- Examine improper conveyor alignment, which can incorrectly present the product to a vision inspection system and cause false rejects.
- Check whether the conveyor system arrangement reduces the distance between machines for less wasted movement.
With the production environment, investigate inherent space constraints. Can operators and maintenance personnel access packaging processes? Do operators excessively move among labeler, checkweigher, case packer and palletizer devices. Can the conveyor system be configured to reduce operator movement and improve ergonomic qualities?
And, for trends;
- Examine potential shifts in process requirements, regulatory standards, and marketing priorities. Determine whether the conveyor system can be structured to adapt to such shifts.
- Understand RFID mandates and how they will affect labeling standards and labeling process strategies.
- Consider whether non-English or multi-language labels will be introduced for newly defined customer segments.
- Stay abreast of evolving safety and security standards. Know whether you will need inspection systems to comply with these standards and how they will interface with the conveyor system.
- The PFM “audit” is the basis of a packaging flow analysis and will help uncover ways to increase packaging line efficiency, productivity, and flexibility.
Buffer conveyor systems, including this vertical inline spiral accumulation system, offer ultra-compact accumulation to reduce floor space and keep production going.
The ideal conveyor system
The common requirement of conveyor systems is to transport containers or packaging units through successive process steps. In addition, conveyors may also function as accumulating buffers– temporary production “reservoirs” – that permit ongoing production through backups or local downtime.
Specific features to seek out when evaluating and selecting conveyor systems include:
Modularity. Whether you specify an aluminum or stainless steel conveyor system, it should be modular. Look for pre-engineered modules and components such as turns, guide rail structures, and motor and drive systems that can be freely combined for custom layout and function. The ideal conveyor will require minimal assembly time and integration, for low direct labor and implementation costs. Also consider how easily ancillary equipment, such as vision systems and marking systems, can be directlymounted to the conveyor body.
Flexibility. Look for conveyors that can simply and quickly accommodate different packaging container sizes, geometries, and formats. The ideal conveyor should include lateral guidance systems with quick-adjust and positive-positioning elements for quick, repeatable changeover. The ideal conveyor will also offer a range of transport media – usually variants of multi-flexing plastic chain with special surface features such as cleats, rollers, and friction pads to handle the broadest range of packaging content and transport tasks. For example, cleats – which are easily snapped in or out – can elevate cartons en route to palletizing cells, opening floor space and reducing operator movement. The conveyor should also be easy to assemble and disassemble for easy inspection, cleaning, and maintenance.
Conveyors form a “highway” system to
coordinate product flow and balance production, and are the foundation
of an adaptable packaging operations strategy.
Size and configuration. Select a conveyor with a small footprint. Go for systems that can be configured as vertical accumulation conveyors to save floor space and to keep upstream and downstream packaging equipment running during brief stoppages of other equipment. The ideal conveyor system will also have compact motors with flexible mounting options.
Adaptability. The best conveyor system can be tailored to a layout and adapt quickly to subsequent – and certain – changes in product mix, process routing, or market priorities. Purpose-built conveyors, or conveyors designed for one application, typically do not survive beyond their original deployment. Choose conveyor systems that can be configured and reconfigured quickly and easily, without costly engineering intervention and equipment disposal. Adaptability will improve responsiveness and time-to-market cycles, as well as lower total cost of ownership.
Buffer conveyor systems, including this
vertical inline spiral accumulation system, offer ultra-compact
accumulation to reduce floor space and keep production going.
Pre-engineered modules – like this 90°curve
assembly – fit into tight spaces and can be redeployed easily in
alternate configurations, saving time and money.
Scalability. Select a conveyor that adjusts to rapid production increases. The ideal conveyor system will be modular and flexible for custom applications while accommodating a range of product and packaging types. Select conveyor systems that can be extended – and reconfigured, as required – in conjunction with your marketing and production plans.
Finally, get familiar with the relationship between marketing priorities and packaging operations. Understand your packaging line. Perform downtime analyses and rigorously study the results. Identify process constraints and leverage conveyor systems for optimal product flow.
While more detailed than conventional approaches to selecting and implementing conveyor systems, use of the PFM review helps focus on the linkage between the packaging process and conveyor capabilities, and provides a framework for designing conveying systems that improve productivity and reduce total cost of ownership. Like any other audit, Packaging Flow Management requires time and discipline, but the investment will yield packaging processes that are simpler, more flexible, more adaptable – and, ultimately, more competitive.
Whether aluminum or stainless steel,
modular conveyor systems feature components that are freely combined
for layout and function, and are quickly assembled to cut
Bosch Rextroth Corporation
5150 Prairie Stone Parkway
Hoffman Estates, IL 60192-3707
Tel: +1 (847) 645-3600
Fax: +1 (847) 645-0804
:: Design World ::
Filed Under: Packaging, Conveyors