Specifying a Conveyor for a Packaging or Assembly Line: The Decisions That Are Expensive to Change Later

Seven conveyor decisions are expensive to change after the order is placed: the belt type (fabric, modular plastic chain, or cleated), the frame height (low profile or standard), the sanitary tier (painted, wipe-down stainless, or full washdown), the drive location and motor mount (end or center, top, bottom or side), the load, speed and accumulation method, the transfer design between conveyors, and the guarding scheme. Each one sets something physical: the elevation of every machine that mates to the conveyor, the smallest part it can hand off, the chemicals the crew can clean it with, or which side a technician stands on to change a belt. Change any of them after the frame is cut and you are buying a different conveyor. This article works through each decision, using published Dorner Conveyors series data as worked examples, and ends with the checklist a complete spec should contain.

Belt type: fabric, modular plastic, or cleated

A fabric belt is a continuous, friction-driven band running over pulleys. On a Dorner 2200 Series belted conveyor the pulleys are 1.25 in (32 mm) in diameter, and a V-groove bedplate with a guided belt handles tracking under side loads. Fabric belts run fast (up to 400 ft/min on the 2200 belted line, 600 ft/min on the 3200 belted line) and give a flat surface for small parts. Where they fail: tracking and slippage at tight transfers, which Habasit names as the reason modular belts get chosen over fabric there, and anywhere debris gets under the belt.

A modular plastic belt is built from interconnected plastic modules and is positively driven by sprockets, so there is no tensioning or tracking adjustment. Dorner's 3200 modular line offers flat top, flush grid, friction insert, cleated and roller top surfaces, curves (up to four on one conveyor), Z-frames and nose-over configurations. Modular belts are the default for curves, drainage, sanitation and accumulation. Where they generally fall short: as a flat precision surface for very small parts, where the hinge gaps matter.

A cleated belt carries raised cleats for inclines. Dorner rates a high-friction PVC cleated belt for inclines up to 35 degrees, with fixed-angle Z-frames at 25, 30, 45 and 60 degrees. Where cleated belts fail: they generally cannot hand off across a nose bar or dead plate, and cleat pitch has to be chosen against product length up front.

Frame height drives the whole layout

Frame height sets the deck elevation for every machine, feeder and guard that meets the conveyor, and the minimum gap at an end-to-end transfer. Dorner's 2200 Series is its low-profile platform, with belt widths from 1.75 in to 24 in and loads up to 120 lb. The 3200 Series modular frame is a rigid 142 mm (5.6 in) anodized aluminum extrusion rated to 1,000 lb. Pick low profile when the conveyor tucks under machinery or feeds a small-part transfer; pick standard frame when load, length or width demand it. A low-profile frame usually means a lower load rating, so the two decisions are made together.

Sanitary and washdown: required versus nice to have

There are three tiers. A painted steel or aluminum frame is for dry industrial work. Wipe-down stainless is the middle tier: Dorner's AquaGard 7350 has a 304 stainless open frame with minimal horizontal surfaces, is "designed for wipe down and low pressure wash-down with non-caustic chemicals," and carries FDA approved belting and BISSC certification. Full washdown is the top tier: AquaPruf has a continuous TIG-welded 304 stainless frame, tool-less disassembly (cleaning prep in under a minute, full disassembly in under three), tip-up tails for belt release, and BISSC and USDA certification.

The top tier is genuinely required when product contacts the belt and the sanitation program calls for high-pressure or caustic washdown. Ask about the standards your quality team already audits against. 3-A Sanitary Standards, Inc. develops standards "for the design and fabrication of equipment and systems used to process food and beverage products in a sanitary manner," and lists Mechanical Conveyors for Dry Products (41-03) among standards under revision in 2026. The BISSC bakery criteria now live in ANSI Z50.2, with the American Society of Baking as secretariat and the Bakery Equipment Assessment Group (formerly BISSC) advising. If none apply, wipe-down stainless is usually right.

Drive and motor placement

End drive puts the gearmotor at one end. Center drive puts it under the belt in the middle, which "frees up both ends of conveyor for operator and machine interface" and, on the 3200 belted line, raises the load rating from 400 lb to 1,000 lb with 16 in of belt take-up instead of 1.62 in. On the 2200 line the figures are 80 lb for end drive and 120 lb for center drive.

Direction matters as much as position. Dorner's manuals state that because belts are pulled, drive positions A and D are preferred, and "pushing belts (B and C) reduce conveyor load capacity by approximately 66%." A motor on the wrong end for the flow direction is a de-rated conveyor. Motor mount (top, bottom or side) decides guard clearance and technician access; the 2200 universal drive mounts in 21 positions without modification, but only if the spec says which side is walkable.

Load, speed and accumulation

State the load per foot or per part, the belt speed, and whether product ever stops on a running belt. If it does, you need accumulation: either low back pressure (roller top or friction insert modular belts, offered on the 3200 modular line) or zero back pressure. Dorner describes patented pressureless loop technology that "protects your products by eliminating backpressure," with accumulation tables as the next step when in-line accumulation is not enough. Zero pressure is needed when product is fragile, labeled or stacked; otherwise low back pressure is usually adequate.

Transfer points between conveyors

Every transfer is a gap, and the gap must be small relative to the shortest product. Dorner's transfer guidance says an inline transfer gap "may not be ideal for tiny or flexible parts that may fall through," that low-profile conveyors reduce it to as little as 1.25 in, and that a nose bar cuts it to as little as 0.31 in but is "not recommended for high-speed applications." On the 2200 line the 5/8 in high-speed nose bar is rated to 200 ft/min and the 5/16 in nose bar to 75 ft/min; the 3200 powered transfer uses 20 mm rollers and handles parts as small as 3 in. Dead plates bridge the gap cheaply, but Dorner's manual warns "DO NOT use transfer plate with /03, /08, /55, /62, /64, or other high friction belts," so belt choice and transfer choice are linked.

Guarding

The current conveyor safety standard is ASME B20.1-2024, Safety Standard for Conveyors and Related Equipment, an American National Standard revising the 2021 edition and covering "the design, construction, installation, maintenance, inspection, and operation of conveyors and conveying systems in relation to hazards." For the safeguarding hardware, ANSI B11.19-2019 (R2024) sets performance requirements for guards, protective devices and control functions. OSHA 29 CFR 1910.212(a)(1) requires guarding against "ingoing nip points, rotating parts, flying chips and sparks," and 1910.219 requires horizontal power-transmission belts with both runs 42 in or less from the floor to be fully enclosed, and vertical or inclined belts to be enclosed. CEMA publishes consensus safety labels and placement guidelines for end-driven and center-driven belt conveyors. Ask the vendor which standard the guarding was designed to.

What a complete conveyor specification contains

• Product: dimensions, weight, smallest and most fragile item, orientation, temperature, wet or dry
• Belt type and surface, with cleat pitch and incline angle if cleated
• Belt width, conveyor length, frame height, and elevations at each end
• Sanitary tier: dry, wipe-down stainless, or full washdown, and the standard it is audited to
• Drive position (end or center), flow direction, motor mount (top, bottom, side), and which side is accessible
• Load per foot, belt speed, duty cycle, and whether accumulation is needed (low or zero back pressure)
• Every transfer: upstream and downstream equipment, gap allowed, nose bar, dead plate or powered transfer
• Controls: fixed speed, VFD, servo indexing, sensors, E-stop scheme
• Guarding and labeling standard, and the site's lockout requirements
• Utilities: voltage, phase, compressed air, wash chemicals

Hand that list to the vendor and the quote will match the line.