Choose the palletizing method from the pallet rate your line demands at peak, not from annual volume, and choose the layer pattern from the outer unit, not from the bottle. Rotatable cases are normally interlocked for export, bare bottles go in column or pinwheel layers with a pad on every tier, and shrink-wrapped trays stack as solid blocks. Whatever the machine, the pattern, the finished height and the gross weight fixed at the palletizer are what determine the container load, so they need to be written down before a 20GP or 40HQ is booked.
Palletizing here means stacking closed cases, trays or crates onto a pallet at the dispatch end of the line. Putting loose bottles into the box is the step before it and is covered under case packing for glass bottles. Unstacking a pallet at the receiving plant is a separate operation with its own logic. Machine cycle rates and commercial terms depend on the equipment installed and the order placed, so none are quoted below; the aim is to let you compare quotations on the same basis.
Six figures every dispatch pallet must carry
A dispatch pallet is a base, a stack of outer units in a defined pattern, pads or dividers between tiers where needed, sometimes a top cap, and film or banding holding it all down. Once it is built, six values are fixed, and the loading plan needs all of them.
| Figure | What it decides |
|---|---|
| Pallet footprint | How many pallets cover the container floor, and whether the palletizer can run on one guide setting |
| Units per layer | The pattern the machine is set to build |
| Number of layers | Together with units per layer, the pallet rate the station has to sustain |
| Finished height, cap included | Door clearance and the number of tiers that can be stacked in the container |
| Gross weight | Forklift capacity, container payload and manual handling risk |
| Exact count | Whether the receiving plant can book the pallet into stock without recounting |
That last line is the commercial reason for palletizing a repeat order at all. A plant that both receives and dispatches pallets reads the same six figures at each end, but for opposite decisions: unloading and pallet return on arrival, loading and freight at dispatch. One plan should not serve both.
Pallet standard, load height and weight limits
Settle the footprint first, because the palletizer, the forklift and the container all depend on it. Two industrial sizes dominate: 1200 by 800 mm, the EUR and EPAL pool pallet, and 1200 by 1000 mm, common in export trades. Their nominal dimensions belong to the ISO 3394 family. A dock that ships both cannot keep a fixed guide rail or fork entry height, so the pallet standard should be a written line in the packing specification, not something inherited from the previous order.
Wooden pallets that cross borders normally fall under the ISPM 15 heat treatment or fumigation scheme. Buyers usually have this on their compliance checklist, and the mark should be something you can verify at the plant, not take on trust.
Height and weight are the limits that tend to surface late. A tall load may fail to clear the container door, the wrap hood or the palletizer gantry. Glass is dense, so a pallet of filled bottles can easily exceed what one operator should shift by hand or what a light-duty forklift should lift. Print both values on the pallet label and in the shipping instruction: they are checked at the container door, and neither can be changed once the load is wrapped.
How the pallet envelope sets the 20GP and 40HQ load
Container fit is tested twice, in a fixed order. First the floor: how many footprints sit side by side and end to end with no overhang, after allowing for the internal corner posts and any blocking and bracing. Then the height: how many tiers of the finished pallet fit under the door opening, with room left for a top cap or dunnage. A pallet that passes one test and fails the other was not designed for that container.
A 40HQ gives more length and more height than a 20GP. A short pallet load can often pick up a third tier in the taller box; a tall one gains nothing from the height and benefits only from the length. The pallet deck takes a slice of every tier, which is why thin-deck and thick-deck pallets can give different container loads for the same height of goods. Which limit you hit first depends on the product: dense loads of filled glass tend to reach payload first, light loads of small bottles tend to run out of cube first.
The pallet counts and the cube lost to pallet height are worked through in our container loading and CBM guide. The point to hold on to here is the direction of cause: pattern and finished height are chosen at the palletizer, and the container load follows from them. It is not something to negotiate separately at the loading dock.
Layer patterns compared
The layer pattern is the main setting on any palletizer and the one that decides whether a load arrives square or leaning. Buyers often leave it to the machine supplier. That is a mistake, because the choice is a trade-off: patterns with the best vertical compression strength tend to resist shear worst, while tying the load into one block gives up a little of the column strength underneath.
The outer unit limits the options more than the machine does. A cubed case can be turned to interlock, but a long narrow tray cannot. Bare bottles can be pinwheeled with pads between layers, yet the same bottles in a shrink-wrapped tray act as a solid block that cannot be rearranged. The comparison below is general engineering guidance. The pattern for a specific load depends on the bottle, the unit and the route, and should be confirmed on a load drawing.
| Pattern | How it is built | Stability | Best suited to | Pads, dividers and film | Container fill |
|---|---|---|---|---|---|
| Column (straight) stack | Each unit sits squarely on the one below; no layer is turned | Strongest in vertical compression, weakest in shear, since the columns are not tied together | Identical squared units with good corner strength on a stable route with little transhipment | Pads where surfaces are uneven; film taken around the bottom board; edge boards or banding on tall loads | Usually the highest count per pallet, as no place is lost at the corners |
| Interlocked (cross-stacked) | Alternate layers turned, commonly a quarter turn, so units bridge the joints below | Good against shear and lateral shift; the load behaves as one block | Rectangular cases or trays that can rotate without overhang; the normal export pattern when the load is transhipped | Pads still needed wherever glass meets glass; a cap on the upper layer under the film | Slightly lower than a column stack if the turned layer cannot fill the corner, which may cost a place or part of a row |
| Pinwheel | Round units, bare bottles or round trays, set around a small square core so each locks its neighbour | Good lateral hold for round units, provided each layer is mirrored so the core does not become a weak point | Bare bottles without a case; round or oval units that would roll or shift | A pad on every tier is effectively mandatory, plus a top cap | Uses a square footprint well with round units, but the core of each layer is lost |
| Divided or partitioned layer | Units placed in a divider with cells sized to the unit | Each bottle is isolated from the next, and the divider stiffens the load | Tall, slender or thin-walled bottles; products where one chipped bottle is unacceptable | The divider does part of the pad's work; its thickness must be allowed for in the footprint | A little under a plain case pattern, because the cell walls take space |
| Shrink-wrapped tray as layer | A layer is closed into a tray or shrink bundle, then trays are stacked as blocks | Strong in compression, but trays do not lock to each other; relies on film and square alignment | Retail-ready packs, and mixed orders where tray formation is fixed upstream | Often no pad between trays of equal footprint; a pad and top cap advised on tall stacks; film tied to the base | Good, as trays are normally designed to the pallet; tray lips can waste the edge |
| Mixed or partial top layer | One layer left incomplete on purpose to reach an exact order total | The weakest point of any load; units beside the gap tend to rotate under film tension | Orders written to an exact bottle or case count; mixed-size shipments | A cap or full board over the partial layer, held by banding as well as film | Fills the cube more completely but puts the stability risk on top of every pallet |
Two practical rules follow. Record the pattern in a load drawing, tier by tier, with each layer's rotation marked: a palletizer set to the wrong rotation produces a load that looks stable and then fails at sea. And treat every pattern change as a changeover. Layer-forming guides, pitch and often head tooling have to be reset, so the number of pattern changes per week belongs in the machine comparison alongside the purchase figure.
Manual, semi-automatic or automatic: matching the method to the pallet rate
These are three operating models, not three grades of one product, and each breaks down differently when used outside its range.
| Method | How it works | Strength | Where it fails |
|---|---|---|---|
| Manual | An operator lifts or slides units from an accumulating table and builds each layer by hand | Unlimited flexibility: any pattern, mixed order or partial layer, with no tooling and no changeover | Consistency and cumulative strain. The pattern drifts between hour one and hour seven, film tension varies with fatigue, and a heavy filled case at shoulder height is a growing handling risk |
| Semi-automatic | The layer is formed on a separate table or lowered to the pallet on a hoist or mast; the operator still feeds the lane and places pads | Controlled descent largely removes the drop-height problem and makes the pattern repeatable | Throughput follows how well the operator can feed the machine |
| Fully automatic | Units arrive in lanes from the closing machine, are grouped into a layer, picked by a head or robot arm and placed on a programmed motion; pads come from a magazine | Identical pattern, drop height and film tension on every cycle | Rigidity. The machine is built around one unit envelope, pallet footprint and lane pitch; anything else means new tooling and guides |
Labour for hand stacking is high, so its case rests on flexibility alone. Semi-automatic equipment is where most export packing lines with a frequently changing bottle range end up.
No single volume figure marks the crossover. What matters is pallets per hour. Take a filler running twelve thousand units an hour and a pallet holding two thousand four hundred units: the station must turn out five pallets an hour, one every twelve minutes. Stacking that many units by hand in twelve minutes, while also keeping pads, film and empty pallets moving, is a standing labour commitment, not an occasional task.
Expressing each option in operator minutes per pallet makes the three comparable. The crossing point shifts with the labour rate, machine uptime and weekly pattern changes, so confirm it against a quotation for your actual line.
When layer pads are needed and what stretch film must do
Pads and film do different work, and neither can stand in for the other. Loads fail with both present when one is asked to do the other's job.
Layer pads
Fit a pad wherever the top of one tier does not give the next tier a dependable surface. In practice that covers:
- bare glass resting on bare glass;
- cases with top flaps that are not flat or not fully closed;
- corrugated board that has absorbed moisture and gone soft;
- layers whose units stand at slightly different heights, so the weight above bears on a few high points.
You can usually omit the pad between shrink-wrapped trays that each present a flat face, or between identical cases with solid, square tops. Specify pad material, thickness and edge size in writing. A thin pad folds where it should bridge, a pad narrower than the layer leaves the outer units overhanging, and a pad that soaks up moisture in a humid container sticks to the tier above.
Stretch film, caps and banding
Film has three functions. Holding the tiers together is the familiar one. Protecting against dust, spray and casual handling is another. The one most often missed is anchoring the bottom tier to the pallet, so the stack cannot slide as a block when a forklift brakes or the container is moved. Film that starts above the bottom board gives the classic leaning load: tiers intact, whole stack shifted on the deck.
Tall loads should have a top cap or edge boards, and heavy units or a partial top layer normally call for banding as well. Set film tension to unitize the load without crushing the outer units; too much tension on a partial layer causes the very damage the wrap was meant to stop.
Film and a cap keep water off the outside but do not keep the inside dry. On a humid route, moisture can condense within the wrap. Where that matters, the pack specification should state how the load is ventilated or which desiccant is used.
Checks before the first layer and after the last
Most palletizing failures are already present before the machine starts, in the pallet or in the units fed to it. The checks take less time than clearing one jam.
- The pallet. It must be sound, dry, level and free of protrusions. That describes a condition, not a model: a standard pallet can turn up in non-standard shape. A broken or missing deck board, a missing bottom board at the fork entry, a proud nail or a repair that raises one side all leave the outer units sitting lower than the inner ones, and the outer ring is what falls. Rejecting a bad pallet beforehand is free; finding it after wrapping can mean losing the load.
- The units. Inspect each case or tray for closure, squareness and damage. A crushed corner in the bottom tier passes its distortion up every column above.
- The count. Fix it beforehand as layers times units per layer, a whole number for every full layer. If the order needs an exact total, plan the partial layer deliberately; do not let it appear at the end of the run.
- Orientation. For retail-facing product, set the label or display face in the pattern. A pallet built with faces reversed becomes rework in the customer's warehouse.
- The finished pallet. Confirm the pattern matches the load drawing, nothing overhangs the footprint, film passes around the bottom board, the top cap is on, height and gross weight agree with the shipping instruction, and the label shows the count and pallet reference.
Where lots are inspected by sampling, name the scheme and acceptance level in the order, following the widely used ISO 2859-1 and AQL approach. A claim then rests on an agreed method, not on one side's opinion.
Empty bottles and filled goods are palletized to different clocks
The same type of machine serves both ends of the industry, but the logic differs. Empty bottles are palletized at the glass plant or at the dry end of a filling line, as bare bottles or trays of them. The governing constraint is contact: bare glass pressed against bare glass under film tension is what every glass supplier wants the line designer to avoid. The usual answer is a column or pinwheel arrangement, padded on every tier and capped. Because no filler is waiting on the pallet, the machine can be sized to the forming and annealing rate.
Finished goods arrive as closed cases, trays or crates, and the palletizer sits downstream of the filler. Any stop backs product up through the closing machine and eventually to the filler itself. The station therefore has to be paced to the filling line, and a short buffer ahead of the infeed is worth more than a faster head. The pallet is also far heavier than an empty-bottle pallet of equal footprint, so gross weight, forklift capacity and handling risk all change with the unit.
Returnable crates are a third case. They are generally interlocked or column-stacked as solid cells, and crate geometry, not the bottles inside, fixes the count per pallet. Cleaning and the commercial side of that loop are dealt with on our returnable bottle crates page.
Where bottles break during palletizing
Breakage at this station is seldom random. The useful question is which known cause is present in your plant, not how to make the machine gentler in general.
- Layer transfer. A head that grips by squeezing puts a sideways load on bottles never designed for it, and releasing a layer from even a small height drops the case base onto the tier below. Set release height as low as the layout permits and make squeeze pressure a defined parameter, not the factory default.
- Infeed. Guide rails sized to the bottle instead of the outer unit push on the wrong part of the pack. If conveying outruns layer forming, units queue under contact load, and pressure between glass surfaces is exactly the condition to prevent.
- Wrapping and turntable. Film will drag an out-of-square load into line, not correct it, and the shear lands on the outer columns. Excess tension on a partial layer pulls loose units inward and turns them.
- Handling after wrapping. Fork tines in the wrong pallet opening, or a load shoved against a container wall or a neighbouring pallet, crush the bottom-tier corner. This is a discipline issue, and a pallet condition and handling clause in the shipping instruction is the cheapest remedy.
Two structural choices cut across all of these. A pattern without partial rows removes the uneven lift behind most transfer damage. A fully supported bottom tier, meaning a sound pallet plus a pad under any layer that is not flat, prevents the settlement that makes a load lean mid-voyage instead of at the dock.
Loading the container and who holds the pallet under each trade term
The container loading pattern has to match the pallet footprint. A load that overhangs its pallet wastes a floor slot, risks being crushed by the container wall and cannot be braced properly. Standard practice is to load the heaviest, most regular footprints first as a block, then strap or brace the last pallets against the void and fill gaps with dunnage. If a glass load moves in transit, no care taken at the palletizer will have saved it.
The trade term fixes where risk passes and who deals with the pallets.
| Term | Position on goods, loading and pallets |
|---|---|
| EXW | The buyer owns goods and pallet from the supplier's dock, so loading and pallet supply are on the buyer's account |
| FOB and other F-group terms | Goods are delivered on board and risk passes at the ship. The pallet usually leaves the country with the cargo, so a pooled account is hardest to balance and a one-way pallet is often the practical choice |
| CIF and CIP | The supplier arranges and pays carriage to the named place. Check what that place means in practice: carriage to the destination port excludes unloading at the buyer's plant and removal of pallets |
| DDP | Delivery extends to the buyer's premises, so unloading and pallet handling are part of the purchase. The delivery point and the equipment available there become contract items |
The pallet is a second material flow with its own cost and its own ownership model. A one-way pallet is bought with the shipment and stays with the load. A pooled pallet, as in the EUR and EPAL exchange system, moves against an account whose balance is carried between the parties. An owned fleet or returnable crate on a fixed route costs least per trip when the route is stable and the loop short, but returnable units must be counted, washed and reissued, and that administration sits with the crate and pallet supply arrangement, not at the palletizing station.
Supply models, order tiers and mixed-load rules for the bottles themselves are explained in our overview of how empty glass containers are supplied in bulk.
Cost items that belong in a palletizing comparison
Arguing palletizing cost on labour alone is why the comparison so often comes out wrong. Five items belong in it, each stated per thousand units palletized so that options line up.
- Labour, in operator minutes per pallet. Include layer building, pad placement, wrapping, pallet supply, labelling and recovery after a jam, not just the seconds spent moving product.
- Equipment, spread across the pallets it will really handle in a year instead of taken at purchase value, with maintenance, spares and layer-forming tooling added.
- Consumables: pallets, pads, dividers, film, top caps and banding. They recur on every shipment and should not disappear into packing overhead.
- Floor space for the palletizer, layer-forming area, staging lane, wrap station and forklift route. Space one option occupies is unavailable for anything else.
- Lost product, valued at landed cost, not ex-works, because a bottle that breaks here has already been filled, labelled and cased.
Plants that have run the figures carefully add two more. One is the container load: a taller pallet or thicker deck can cost a tier in a 40HQ, and the loss shows up as freight per unit, so it belongs on the same sheet as labour. The other is peak versus average. A comparison built on twelve months of average volume understates every option that has to be sized for the peak month.
Questions buyers ask about bottle palletizers
How do I choose between manual, semi-automatic and automatic palletizing?
Divide peak line speed by the units on one pallet to get pallets per hour, then convert that to operator minutes per pallet for a hand crew. Hand stacking remains viable while one or two operators can keep up, and it is the only method with no changeover penalty. Semi-automatic equipment fits a recurring, moderate rate. A fully automatic machine becomes the normal answer when the rate is high, formats are stable, and a backed-up filling line costs more than the equipment spread across the pallets it handles.
Which layer pattern should a glass bottle pallet use?
Let the outer unit decide. Cases that can be turned on the pallet are normally interlocked so the load survives transhipment as one block. Bare bottles are column or pinwheel stacked with pads throughout, tall or thin-walled bottles often get a divided layer, and with shrink-wrapped trays there is nothing to interlock. Whatever you choose, draw it tier by tier and check it against the bottle, unit and route; do not copy it from the previous order.
Is stretch film ever enough without layer pads?
Only where each tier already offers a flat, reliable surface, such as shrink-wrapped trays or cases with solid square tops. Even then a top cap and a pad beneath the top layer are still recommended. Film binds tiers to each other; it does not separate them, so it cannot replace a pad between bare glass, uneven case tops, damp corrugated or units of unequal height.
How does the pallet format change what fits in a 40HQ or 20GP?
Through floor and height. Footprint sets the pallets per floor without overhang, and finished height sets the tiers under the door, less the slice each pallet deck takes. A shorter load can often gain a tier in a 40HQ, while a taller load gains only from the added length. Filled glass tends to hit the payload limit first; small, light bottles tend to hit the cube limit.
Do filled pallets need a different pattern from empty-bottle pallets?
Usually, because the unit is different. Empty-bottle pallets are arranged to manage glass-to-glass contact and can be built at the glass plant's own output rate. Filled goods travel in closed cases or crates, the station must keep pace with the filler, and the load is much heavier for the same footprint. With returnable crates, crate geometry fixes the count.
Where does palletizing breakage usually occur?
At four points: the layer transfer, the infeed, the wrap and turntable stage, and handling after wrapping. Squeeze pressure, release height, back pressure, out-of-square loads and careless fork entry are the usual mechanisms. Removing partial rows and fully supporting the bottom tier take out most of the structural risk.
Who owns the pallets once the container is loaded?
Ownership follows the trade term and the pallet model, as set out in the table above. Whichever applies, write the pallet model, the return obligation and the treatment of losses into the order instead of settling them at the dock.
What should I send to get a useful palletizing recommendation?
Three things. First, peak volume in units per hour and pallets per shift at the palletizer, with the number of pattern changes per week. Second, the product: bottle weight and dimensions, the outer unit and its footprint, the finished load height you expect, and whether any layer has bare glass touching glass. Third, the destination: port, trade term, and whether the load travels on one-way, pooled or returnable units. Add the pallet standard and any loading equipment at the destination, since both affect pattern and pallet choice.
From that, we can propose a palletizing method that fits the pallet rate, a pattern fixed tier by tier with its pad, divider and film requirements, a footprint and deck height that make the container load work, a pallet ownership model suited to the trade term, and a cost comparison per thousand units at peak. A line designer, a pallet supplier and a freight forwarder can then all work from the same dispatch plan.