Material Handling Basics
Choose Carousels – For All the Right Reasons
Whether
it’s crossdocking, order consolidation, managing manufacturing
components, staging work-in-process or retail storage, new carousels deliver
high throughput in a small footprint.
by Christopher
Trunk, managing editor
Vendors and
consultants agree that carousels are too often overlooked in the rush to less
automated storage options, but the new speed and utility that carousels bring
to the assembly line, the dock door and to orderpicking cry out for notice.
Innovative carousel designs and application ideas require a fresh look.
New applications, new ideas
“With
inflation held in check, the only way companies drive profit is to lessen cost
for raw material or increase worker productivity with material handling,”
says Larry Strayhorn, president of Diamond Phoenix Corporation. “Every
percentage gain in worker productivity drops directly to the bottom
line.”
Carousels help in
moving your operation from paper picking to higher-throughput, automated
picking. Software controls and integration with WMS are linking carousels more
closely to both orderpicking and order consolidation — “pick”
and “put” environments. Strayhorn points to more carousels in putaway
and returns.
Diamond reports it
has two installations for Duracell and Lockheed Martin with high-speed,
high-volume MaxTractor inserter/extractors. These robots perform eight
transactions per minute with horizontal carousels. Trays of tested batteries
are staged or sent to packaging at Duracell. Lockheed uses carousels at its
central parts warehouse to store consolidated kits produced at manufacturing
workstations.
“We are
pioneering a virtual carousel workstation,” says Strayhorn.
“Typically a worker picks from pods of two or three carousels. With the
virtual workstation, if order volumes are low, software and controls are
reconfigured so one worker picks from six, eight or 12 carousels.” With
high-volume orders or in seasonal times, the buyer can shrink pods to just one
worker per carousel by adjusting controls.
“With
September 11 issues and the economic downswing, we’ve targeted
pharmaceutical, electronic and aerospace/military industries — those less
affected by economic changes,” says Jeff Peters, product manager for
Hanel Storage Systems. “We recently installed carousels and vertical lift
modules to consolidate spare parts for aircraft maintenance at a Midwest Air
Force base. Space savings was important at the base warehouse, as well as
solving lost-part problems and mispicks.”
Carousels are
supporting retail. In Gallman, Mississippi, an automotive part distribution
center for Discount Auto Parts supplies retail outlets. There, a two-level
pallet carousel stores the faster-moving SKUs. A gantry robot lifts a layer of
one SKU off a pallet in the carousel and places it onto another pallet on a
takeaway conveyor. The palletload being built is an order for one store.
“Before this, a store had to order an entire palletload of one SKU, but
this carousel innovation now lets stores keep less inventory and more variety
of SKUs on hand,” says Dave Simon, product manager, horizontal and
vertical carousels for White Systems. “Smaller inventories both at the
store and distribution center justify the system.”
“Apparel
retailers have seasonal inventories that, when out of season, are stored in
back rooms, typically in every which way in a store room,” says John C.
Fink III, director of marketing for J&D Associates. “We can take 115
linear feet of apparel bar and put it into a carousel for garment protection
and access. The carriers are adjustable for garment height and with shelves, so
you can pack even more children’s clothes or shoes into a unit.”
Technological highjumps
A bright, new
example of carousel innovation is the Model MVC 2700 vertical carousel from
Knapp Advanced Technology Engineers. It may represent a breakthrough in
orderpicking. The machine divides a typical vertical carousel into several
independent modules, about 1.5 feet wide depending on product size. While the
worker picks from the first module, the carousel identifies the next pick and
rotates the adjacent module to present the next SKU to the worker. “With
carousel segmentation, I see vertical carousels springing back into
demand,” says Stan Kotowski, sales manager for Knapp. “In years
past, buyers were deterred by significant cost for a machine that picked
slower-moving items. But, now, future verticals can offer faster distribution
speed, light-directed picking, cube analysis, smart slotting and security.”
The MVC’s
pick-to-light display identifies the correct bin location, divided container
location and number of items to pick. Total width is six or seven feet and
offers up to 2,700 SKU locations per module at approximately 200 lines per
hour.
“We suggest
placing a takeaway conveyor in front of the carousel, allowing batch picking
with a light bar showing the worker into which tote to put the items,”
adds Kotowski. Knapp has installed these units for pharmaceutical distributors
filling narcotic drug orders and for high-end jewelry distributors. “If
you’re using the MVC for orderpicking lower-cost items like cosmetics,
the machine transports vertical carousels into new horizons for higher-volume
distribution,” says Kotowski.
Here’s a
snapshot of some current carousel innovations:
J&D Associates.
The company now offers AC drives for its vertical carousels that yield smoother
motion and more precise stopping. New PLC controls make it easier to network
with the buyers’ inventory or shop floor control system and provide a
worker-friendly interaction with the carousel. The operator needs only type in
a part number and the right carrier arrives at the workstation. J&D offers
units with 12,000-, 20,000- and 30,000-pound capacities.
“Manufacturers
position our carousels close to the manufacturing line to shorten set-up time
for machinery and to simplify handling for curing manufactured goods,”
says Fink.
Webb-Triax. A new
horizontal, bottom-drive pallet carousel supports multi-level-column loads
between 8,000 and 18,000 pounds, and up to 30 feet high. “It’s like
a rotating storage rack designed to handle typical-size 1,000-, 2,000 -and
4,000-pound loads,” says Fred Cirino, sales manager for Webb-Triax.
“We’ve located a machine at our receiving dock to sort goods for
different locations in the plant.”
Use it to crossdock
at distribution centers, to sequence work-in-process for an assembly line, to
cure rubber and window products, or to quarantine goods until they pass
inspection. Automotive is another application for sequencing work-in-process
with engine blocks, transmissions, etc. Either lift trucks or robotic
inserter/extractors service the carousel.
“We’ve
quoted the machine to hardware distribution centers for building palletloads
for retail stores — staging pallets on a third shift by delivery route so
orders are ready when trucks pull in the next morning,” says Cirino.
Returns putaway at the receiving dock is another smart application.
Hanel Storage
Systems. A new microprocessor, Model MP12D, better tracks part numbers, bills
of material and kits. It links multiple carousels with one processor. Also a
new Rotomat S Module vertical carousel stores up to 1,650 pounds per carrier at
heights from 10 to 30 feet.
Diamond Phoenix.
The new DirectPick is pick-to-light software and hardware for carousels.
“It’s a flexible system that lets you configure the carousel for
discrete, batch and cluster picking,” says Robert Rienecke, vice
president of marketing for Diamond Phoenix. DirectPick runs on Windows NT2000
workstations or servers and integrates with your existing orderfilling and WMS
software.
The Twin Bin
carousel configuration presents two pickfaces at a time to the worker, doubling
the number of storage locations a picker can reach. “If you’re
slotting items into a family-pick or batch-pick scenario, having two pickfaces
means less carousel rotation and idle time for workers between picks,”
says Strayhorn.
Leveraging your carousel
Carousel experts
suggest these techniques for increased productivity and wiser design:
• Perform an
SKU volume analysis. How many orders do you have? Understanding your
business’ volume, quantity and physical size of items makes for best
slotting decisions in both carousels and gravity flow rack. Diamond Phoenix.
• Pallet
carousels can function like an automated storage and retrieval machine to store
30 to 100 pallets. Pallet carousels can fit nicely into most docks.
“Buyers are sometimes reluctant to spend money on carousels, but they are
easily justified with more accurate orders, better customer service and faster
picking/putaway,” Cirino. Webb-Triax.
• Reslot it
frequently, maybe as often as every three months. “You can’t expect
an initial slotting to work forever, on this or any storage equipment,”
Rick Frye, vice president, sales and marketing. White Systems.
• With
inventory management software, cube use, picking speeds and throughput are
tremendously increased. Remstar.
• Make
carousels an integrated part of your process, not standalone units. Load from
one side and extract from another. Specify carousels with openings on multiple
floors for storing work-in-process, or for replenishing on one floor and
picking from another. J&D Associates.
Daniel Frampton, a
consultant and project manager for Operations Concepts Inc., suggests you arrange
fast movers in the Golden Zone and configure horizontal carousels in a
semicircular pod around a workstation. Frampton advises bottom-drive units for
heavier loads and seismic applications as well as top-drive units for lighter
loads. Twin-bins can double the number of bin locations and improve selection.
Lastly, he suggests horizontal carousels for high pick rates and verticals for
overhead space use and security.
Containers make the carousel
Ken Beckerman of
Flexcon Corporation says containers play a vital role in a carousel’s
success or failure. He offers these tips:
• Containers
should fit within 1/4" of carousel width for maximum cube use. Use one
container per shelf for most parts and another container for large items.
• Containers
must divide in length and width with lockable dividers so parts don’t
move when the carousel rotates.
• Containers
must handle the push/pull motion at full load. Containers should last the life
of the carousel.
Beckerman advises
that for ergonomics and safety you look for containers with a 50 percent open
front for easier picking and those with drain holes in case sprinkler water
flows into the unit.
For fire safety,
code ratings should be UL Flame Class 94HG.
Vertical carousels
can be fitted with electrostatic dissipative containers to safely store parts
for electronics applications.
Custom containers
make for denser storage for surface-mount technology reels used to manufacture
printed circuit boards.
“We pump
nitrogen into vertical carousels, keeping electronic components clean. Before
this, all the reels for one of our manufacturing customers were stored in open
air. Parts were susceptible to dust and dirt,” says Peters of Hanel.
Differentiating vendors
There are many
carousel vendors, and each can specialize in particular industries and product
storage. Here is how some vendors see their strengths:
• “We
have full-pallet carousels with multiple levels, not just single-level
horizontal units.” Cirino, Webb-Triax.
•
“We’re a carousel innovator with key concept developers who seek
new ideas for carousel applications when working directly with customers. One
example is using two pick carousels and some gravity flow rack to consolidate
orders into a third put-carousel. The idea eliminates conveyor sections, reduces
manual labor, consolidates on the spot and pays for itself in a year or
less.” Frye, White Systems.
• “Our
service organization is top notch. We offer spare parts and technicians in
regional service centers for speedier repairs. We train our dealers in how to
use and service carousels.” Ed Romaine, director of marketing for Remstar
International Inc.
• “We
have 10,000 vertical carousels in the home center market, in both commercial
and industrial settings, and we offer problem-solving applications for managing
and protecting print cylinders.” Fink, J&D Associates.
Consultants can
identify vendors with the right technology for your application. Daniel
Frampton of Operations Concepts says consultants can create alternative designs
that build carousels into the “big picture”; conduct and evaluate
competitive bids; keep project and budget on schedule, and train workers and
provide service both before and after installation to smooth the transition to
automation.
Looking ahead for carousels
Vendors and
consultants see a bright future. Targets include building kits with carousels
for replenishing retail store shelves and in applications where handling
multiple size cases in random fashion are important. You’ll see more
carousels in flexible manufacturing operations in electronics and tool and die
industries. Heavy-duty vertical carousels will sprout up in retail outlets to
store vinyl products and wire reels, spa tops and swimming pool liners.
Industrial
applications will include print cylinders and ceramic molds. Vendors predict
there’s a big market for cosmetics, health and beauty, prescription
drugs, medical device manufacturing and electronics.
Bringing a broader
horizon to your orderpicking mix is easier than ever now with the new
flexibility and efficiency that cutting-edge carousel technology delivers. John
Fink of J&D Associates says, “Keep your mind and eyes open for wise
applications of carousels.” MHM
Meet Your New (Vertical) Postal Carrier
MHM first reported
on a vertical carousel proposal for retail parcel delivery for the U.S. Postal
Service in 2000. USPS just implemented the carousels at two retail site in
April in a pilot program with Northrup Grumman. “The post office is
developing a cost-and-decision analysis for return on investment with these
machines,” says Robert Laybourn, marketing manager for Postal Systems,
Northrup Grumman. USPS hopes these carousels may shorten lines at postal
counters and allow more customer convenience.
“With the
commingling concerns of biological contamination, health and safety of postal
workers, losing money and raising postal rates, the USPS is looking at capital
expense automation that can save on costs,” observes Laybourn.
The MIRS-brand
carousels provide automated mail pickup for customers who are away when the
postal carrier calls. The carrier leaves a unique, preprinted, bar-cod
