Case Packing and Palletizing for Glass Bottles: Layout and Protection

The back end of a glass bottling line has three protection jobs: keep filled bottles from touching each other, keep labels and closures intact inside the case, and keep the pallet stable from your dock to the receiving dock. Choose case packing and palletizing equipment around those jobs, not around a speed figure alone. The choices that matter are the case style, how bottles enter the case, what separates them inside it, and how the finished pallet is built and contained.

A requirement document should therefore start with the bottle and the shipping route. Give suppliers the case drawing and board grade, the partition design, the pallet pattern you want, and the retailer or carrier rules you have to meet. Equipment makers can then quote a machine that handles your actual case rather than a generic one. This guide covers each decision in that order and ends with questions to send suppliers.

Start from the packed case, not the machine

Work backward from what leaves the building. A filled, labeled glass bottle is heavy and sensitive to point impacts and scuffing. The pack design is the main protection, and the machine only has to build that pack repeatably.

Schematic of end-of-line protection for glass bottles showing wraparound case, RSC with partitions, tray plus shrink, drop packer versus pick-and-place, pallet pattern, tier sheets, corner boards and stretch wrap — Illustrative schematic of the end-of-line protection choices discussed here; it is not drawn to scale and does not represent a specific machine.

Before comparing machines, collect the inputs that every supplier will ask for: bottle height, diameter and weight when filled; closure type and height; label type and position; the case or tray drawing; and the pack count and pattern.

Case styles for glass

Equipment-maker explainers describe a small set of case styles, and each treats glass differently.

Style	How it is made	What to consider for glass
Regular slotted container (RSC) with partitions	Pre-glued knock-down case is erected, then loaded from the top; cell partitions separate bottles	Familiar and easy to source; partitions give bottle-to-bottle separation; needs a partition inserter or pre-assembled partitions in the process
Wraparound case	Flat blank is folded and glued around the grouped bottles	Case is formed to fit the pack; makers cite corrugated savings; grouped bottles may touch unless a divider is built in
Tray plus shrink film	Open corrugated tray (or pad) holds the bottles, film is shrunk over them	Lower corrugated use and shelf-ready look; offers less enclosure and fewer places to protect labels, so check shipping tests

According to Blueprint Automation’s explainer, the RSC is the typical knock-down case for shipping through distribution, while a wraparound blank is fastened by a machine and can be cut to fit the contents closely. The same source describes tray cases as an RSC variant lacking one side panel, often overwrapped for retail. Treat corrugated-savings claims as supplier statements.

For heavy glass, confirm whether the design includes protection between bottles, whatever the style is called. Smurfit Westrock describes box partitions as dividers made from paperboard or corrugated board that protect several products in one outer case by adding cushioning, restricting movement and improving stability. Wraparound and tray packs need internal dividers or pads to reach similar separation, and that must be in the case drawing.

Drop packing vs. pick-and-place

How bottles get into the case is the main mechanical difference between machine types.

Drop packers gather bottles over an open case. According to Hamrick Packaging Systems’ comparison, the pattern falls through a packing grid while the case is raised and then lowered. The company lists high speed and the lowest capital cost among the benefits, and notes that vertical loading may not suit fragile products.
Gantry pick-and-place packers use servo motion to lift products and set them into the case. Hamrick describes this as gentler handling with recipe-based changeovers, at the cost of a larger footprint, more servo axes and possible tooling changes between products.
Robotic packers use articulated robots. The same explainer rates them as the most flexible for mixed cases and frequent SKU changes, and as a higher-cost option with more complex controls and safety systems.

These are equipment-maker positions, not test results. For glass, ask how the grid or gripper tooling handles your bottle weight and label, and what happens to a bottle slightly out of tolerance.

Protecting glass inside the case

Protection inside the case is a design deliverable. Agree it before you select a machine.

Partitions and pads. Confirm cell size relative to bottle diameter, partition board, and whether the partition is inserted before or after the case is erected. A partition that is too tight can scuff labels; one that is too loose lets bottles move.
Labels. Ask how long labels need to cure or dry before bottles touch partitions, and see bottle labeling methods for what each label system implies at the end of the line.
Closure protection. Silgan Closures’ technical bulletin recommends corrugated dividers between pallets of tray-packed product to protect closure tops and spread load, and advises that finished product not be shipped frozen because glass can fracture.
Case strength. Board grade, flute and compression strength are specified by the case supplier, not the machine maker.

Building the pallet

Pallet pattern

Pallet pattern trades vertical strength against side-to-side stability. One pallet-building explainer describes column stacking as maximizing compression strength by aligning vertical edges, but offering less resistance to side shifts, and interlock or brick patterns as giving more lateral stability at some loss of vertical capacity. For glass, the pattern also decides how much weight bears on the bottles through the case and whether tier sheets are needed. Silgan’s guidance for finished pallets adds that overhang should be minimized and cartons should rest on the pallet deck. A palletizing supplier should show the pattern on a layer drawing for your case and pallet size.

Tier sheets

Tier sheets (layer pads) are placed between layers. Handle-It’s bottle-pallet tips suggest tier sheets between layers for stack stability. Cartonplast describes plastic layer pads for glass containers that have rounded corners suited to shrink film and sheet handling by automated equipment. Both are supplier statements. Tier sheets also matter at the other end of the line, covered in depalletizers and infeed systems. Decide whether sheets are single-use or returned, and who places them.

Corner boards and containment

Corner boards or edge protectors disperse strapping or film force along a rigid edge. Millwood describes them as distributing strapping tension and improving unitization. The pallet-building explainer also says corner boards let film be applied at higher tension without crushing cartons, and notes that three to five tight wraps around the base is a commonly advised starting point for catching the pallet deck. Handle-It cautions against over-tensioning stretch film because it can crack glass, and recommends vertical strapping for tall, narrow bottle pallets. Silgan recommends machine stretch wrapping for consistent tension and advises against excessive tension that buckles cartons. Specify wrap tension, number of wraps, film type and whether a top sheet or strapping is needed, and agree how the wrap pattern is validated.

Logistics and retailer requirements to confirm

Retailers and carriers publish their own rules, so confirm them before you lock layout and pallet pattern. Check at least the following.

Pallet footprint, grade and ownership, such as pooled or one-way.
Maximum pallet height and weight, including the pallet itself.
Overhang limits and whether the pallet must be double-stackable.
Label rules: GS1-128 shipping-container labels, SSCC numbers, label positions and print quality. A labeling vendor’s explainer notes that an SSCC is an 18-digit code in a GS1-128 barcode and that it must agree with the advance ship notice.
Distribution test expectations. ISTA’s Procedure 3E is a general simulation test for unitized loads of retail packaged products shipped by truckload to a distribution center, so ask the customer whether a test like this is required.

Verify each one, because values differ by customer and program and change over time.

Questions to send suppliers

Which case styles can the machine handle for our bottle, and which tooling is needed for each? Please quote any partition inserter, case erector, sealer and pad or sheet placers as separate lines.
How are bottles placed into the case, and which parts of the bottle touch the grid, gripper or partition?
What bottle and label tolerances does the design assume?
How are bottles accumulated and grouped before the packer, and how does this interface with the upstream equipment described in planning a glass bottling line?
Which pallet patterns are supported, how are tier sheets, top sheets or frames placed, and who supplies them?
What stretch wrap, strapping and corner-board options are included, and what tension and wrap pattern are validated?
What case, label and pallet information does the controller print or verify?
Which format changes need change parts and which are recipe-only?
What documentation, spare parts and training are included, and what will be tested at factory and site acceptance? The bottling equipment RFQ checklist lists the points to compare across proposals.

Evidence and limitations

This guide is editorial analysis of publicly available explainers, not hands-on testing. Case style, packer type, partition design and pallet pattern all depend on bottle weight and shape, label, line speed, case supplier and customer requirements. Equipment-maker pages describe general capabilities and carry commercial interests, so confirm their statements for your specific configuration. Figures such as pallet limits, wrap counts and retailer rules differ by program and are not given here.

Four Types of Case and Tray Packers, Blueprint Automation: defines RSC, tray, wraparound and harness cases and loading configurations.
Types of Case Packers: Drop, Pick-and-Place, and Robotic Compared, Hamrick Packaging Systems: compares drop, gantry pick-and-place and robotic packers, including trade-offs.
Box partitions, Smurfit Westrock: describes partitions as protective dividers for multiple products in one case.
End-of-Line Packaging for Bottles, Handle-It: pro tips on tier sheets, pre-stretch, strapping and avoiding over-tensioned film on glass.
Plastic layer pads, Cartonplast: supplier description of layer pads for glass containers and automated handling.
Edge Defender edge protectors, Millwood: explains edge protectors in strapped and wrapped unit loads.
Pallet Building 101, Cleverence: vendor explainer on column versus interlock patterns, wrapping and corner boards.
Steel Closure Operating Guidelines (TAB4), Silgan Closures: tray packing, palletization and shipping guidance for glass with steel closures.
ISTA 3E overview, International Safe Transit Association: scope of the unitized-load truckload simulation test.
SSCC Pallet Labels Explained, Certified Labeling Solutions: describes SSCC and GS1-128 pallet labels and their link to advance ship notices.