Food lines do the same basic job as every other packaging line: move product from a primary package into a case and onto a pallet. What differs is the standard the line must be kept to. Food contact surfaces and the equipment around them are cleaned on a schedule. Products with allergens must not leave traces on products without them. Products that need cold storage are packed in rooms that are cold and wet. The page belongs to the packaging industries section and sits next to the beverage, bottled water, and brewery pages.
Packaging chain overview
The three stages are the same as elsewhere, but each has its own hygiene profile, and the line is divided into zones that affect the equipment. Where product is exposed, the design is strict and washdown is routine. Where only sealed cases move, the demands relax. The packaging engineer’s first job is to decide where each machine sits.
Primary packaging is the package in direct contact with the food: a bag, a pouch, a tray with lidding film, a tub, a can, a jar, or a tray in a carton. Forming, filling, sealing, weighing, and coding happen here, often inside a high-care or controlled area. These machines are usually process-specific and outside the scope of this knowledge base.
Secondary packaging collects primary packages into the unit that goes to a retailer, a distributor, or a foodservice customer, through case packing, tray packing, bundling, and carton forming. Case packers and case erectors are often the most hygiene-sensitive machines in the end of line, because they handle the primary package.
The end of line covers case sealing, labeling, palletizing, and wrapping. In many plants it sits in a drier, less strictly controlled space where equipment can be cleaned by dry methods, and the main concern is loads that reach distribution intact and traceable.
Typical containers and packages
Bags and pouches are packed into cases, often by robots or pick-and-place machines that handle soft, irregular shapes. They slide, squash, and have limited rigid surfaces for grippers. Rigid trays with film lidding are used for fresh and ready-to-eat products, and they are usually packed in trays inside cases or in returnable crates. Tubs for dips, spreads, and yogurt-like products stack well, but lids and rims can be damaged in handling.
Metal cans and glass jars are common for shelf-stable products and follow the same logic as beverage containers, with the addition of pallet loads that can be heavy. See beverage packaging automation for container-handling parallels. Folding cartons carry dry goods and frozen foods, and they are packed into corrugated cases.
The main outer packs are regular slotted cases, wraparound cases, trays, and display-ready cases. Frozen foods often use cases rated for cold and damp conditions.
Because food products vary so widely, one plant often runs several of these in the same hall. The case handling page describes the transfer and orientation of cases, and the bottle handling page covers jars and bottles.
Key challenges
Hygiene and cleanability
U.S. food plants are subject to FDA’s current good manufacturing practice and preventive controls rule, 21 CFR Part 117. Among other things, it requires that people working directly with food, food-contact surfaces, and food-packaging materials follow hygienic practices to protect against allergen cross-contact and contamination. Equipment does not comply on its own, but its design makes compliance easier or harder. Open frames, smooth welds, sloped surfaces, and minimal ledges and crevices reduce the places where residue can hide.
Washdown
A packaging conveyor supplier explains that washdown equipment tolerates direct water, foam, and chemical cleaning, using stainless steel construction, sealed components rated IP65 to IP69K, and sloped surfaces that shed water. Specific points include sloping horizontal surfaces by at least 3 degrees and preferably more, using open tubular frames with drain holes at low points, grinding welds smooth, and avoiding painted or galvanized steel in washdown areas. The same source distinguishes light washdown, such as a low-pressure hose with mild detergent, from heavy washdown with hot water, high pressure, and caustic or chlorinated foam. It adds that no standard rating exists for heavy washdown, since the phrase is only industry shorthand. So ask each supplier what cleaning method their equipment is actually built for.
Allergen changeover
Allergen control depends on cleaning, scheduling, and equipment design. The FDA rule defines allergen cross-contact as the accidental transfer of a food allergen into a different food. For packaging equipment, that has four practical consequences:
- Surfaces that touch product or packages should be cleanable without disassembly beyond what the sanitation team can manage.
- Format and recipe changeovers should be repeatable, with clear settings rather than operator judgment.
- Change parts should be easy to clean and store, and ideally color-coded or tagged by allergen group.
- Dry cleaning tools and wet cleaning steps should be separate and written into the procedure.
Plants decide how thorough the cleaning must be and how it is verified, as part of their food safety plan.
Chilled and frozen environments
Cold rooms bring condensation, ice, and stiff lubricants. Motors, bearings, and belts need to work at low temperature, and surfaces that sweat make cartons slippery and weak. Case packers using vacuum grippers or friction belts lose grip when product is wet or frosted. Frozen cases may be heavier and need interlocking palletizing patterns because the cases slide easily. Plan for dryers, air knives, or moisture-tolerant equipment, and leave enough space in the cold area for service access.
Product variety and delicacy
Food products squash, break, stick, and shed, so packers must handle them gently and detect defects. Vision systems, weight checks, and metal detection or X-ray often sit near the end of the primary line to catch foreign objects or short packs.
Recommended equipment stack
For a typical filled-and-sealed product that is packed into cases and palletized, the stack looks like this:
- Infeed conveying that presents primary packages to the packer in an organized flow. See case conveyors for case-level conveying and accumulation conveyors for buffering. For jars and bottles, see bottle conveyors.
- Case erector to form cases or trays without manual folding. See case erectors.
- Case packer. Use a case packer for repeatable formats, or robotic case packing where product shapes and pack patterns change often.
- Case sealer, which closes cases with tape or hot melt. See case sealers.
- Elevation and transfer. Vertical conveyors carry cases between floors or to a mezzanine.
- Palletizer. Case palletizers suit stable cases at moderate to high rates, and robotic palletizers suit mixed-case, mixed-SKU operations such as distribution-style loads.
- Stretch wrapper and labeling, addressed with the pallet handling page.
- Depalletizer at the infeed when empty jars, cans, or trays arrive on pallets. See case depalletizers and bottle depalletizers.
Design considerations
Line balance
Rate the packer against the primary line, not only against the average. Food lines often have uneven flow because of upstream cooking, forming, or filling cycles, so a case packer must absorb bursts. Capacity above the rated primary rate is the usual answer.
Accumulation
Accumulation in food lines absorbs short stops and also separates the product zone from the case zone, so that a jam in one does not force a washdown in the other. Wash-friendly accumulation tables and open belts keep buffers cleanable.
Reject and rework
Rejected packs may need to be destroyed, reworked, or quarantined, and each path should be traceable. Plan reject stations with their own bins and clear labeling. Open or opened product usually cannot rejoin the flow without procedures that the quality team approves.
Floor space and zoning
Lay out the washdown product area, the drier case area, and the palletizing area so that traffic flows one way and never crosses from dirty to clean. Pallets, forklifts, and wood stay out of the product zone. The packaging line layout guide and the layout page cover these trade-offs.
Cleaning access
Leave room around each machine for cleaning crews and maintenance. Hygienic design works only if the surface can be reached. Tool-free belt removal, hinged guards, and drain paths matter as much as the stainless steel.
Example line configuration (illustrative)
Illustrative example. Imagine a plant that packs sealed trays of a chilled prepared food into corrugated cases. Trays leave the sealing machine on a stainless open-frame conveyor with a metal detector and a checkweigher, and a reject station removes failures into a bin. A short accumulation conveyor feeds a vision-guided robotic case packer built for washdown, which places trays into cases formed by a case erector. A case sealer closes the case, and a labeler applies the shipping label. The sealed cases leave the washdown room on a conveyor that passes through a wall opening into a drier, cooler area where a robotic palletizer builds pallets, and a stretch wrapper secures them.
The same plant runs a product that contains an allergen on certain days. For those runs, the packer uses a dedicated set of change parts and a written cleaning procedure that includes checks before the line restarts on a non-allergen product. The conveyor design allows the belt to come off without tools, so the sanitation crew can clean beneath it. This configuration is a sketch of how the pieces connect and not a real customer project. Speeds, zones, and the cleaning method depend on the product and the plant’s food safety plan.
Standards and references
The main U.S. food reference is FDA’s 21 CFR Part 117, the current good manufacturing practice and preventive controls rule under the Food Safety Modernization Act. It defines allergen cross-contact and sets hygiene and sanitation requirements. For equipment design, two bodies publish detailed hygienic criteria. 3-A Sanitary Standards develops standards and certifications for hygienic food equipment design, and EHEDG publishes a guideline catalogue that includes topics such as conveyor systems, packaging machines, and robotics. Neither is a legal requirement for all equipment, and which one applies depends on your customers, product, and plant.
For machine safety, OSHA’s general requirements for all machines require guarding for hazards such as nip points and rotating parts, and lockout/tagout covers servicing. Washdown ratings follow IEC 60529 IP codes, and suppliers should state the cleaning conditions behind their rating. Your quality and regulatory teams decide how these references apply.