Transportation Practices
Carton material should be of sufficient strength to withstand rough export handling conditions. The packaging must be able to support a stacking height of up to 2.5 metres (for 8’ 6” high containers) and 2.85 metres (for 9’ 6” high containers) and withstand humidity without collapsing. Carton blanks and erected cartons must be stored in accordance with manufacturer's instructions. Chilled produce unloaded in South East Asia (and other areas with similar weather conditions) inevitably becomes wet from condensation due to the high humidity in these countries.
A carton should be formed carefully from the fibreboard blanks, according to the manufacturer's instructions. Ensure the vent blanks are removed otherwise they may become dislodged and clog up the drain outlet. Clogged drain outlets can result in quality and out-turn problems.
All packages must be clearly labelled with the appropriate trade description and bear the manufacturer’s statement, and in line with labelling requirements as laid down by the regulatory bodies of the importing countries. If local language is required on the label, ensure that the translation is accurate.
Packages should not be over packed beyond the recommended weight. Any overfill of cartons should be kept to a minimum, and should be consistent between cartons, and should be such to ensure produce does not incur “pressure” damage during transit. Any bulging of cartons should be kept within acceptable limits.
Where appropriate, pallet loads of cartons should be allowed to settle before loading.
Polystyrene boxes (eg. the 5 or 10 kg grape or broccoli box) must have integral lids, and be approved by the manufacturer for export under refrigeration.
The selection of packaging usually depends on product type and it may be advisable to ascertain whether there are existing designs, trialled and proven by other exporters that would suit the commodity.
Consideration should be given to the size of the packaging to improve utilisation of the container, without overfilling or restricting the airflow.
Although ventilation holes are usually made on the sides of the cartons, it must be borne in mind that air circulation is usually from beneath, so for optimal circulation, ventilation holes must be located at the top and bottom of the carton. Excessive ventilation may however lead to excessive weight loss if additional wrapping or packaging is used within the cartons consideration must be given to the effect it will have on the ventilation process.
Dehydration of the produce can be reduced by utilising the appropriate packaging.
Packaging material should be chosen not only for its durability during transport but also its ability to permit the removal of respiratory heat and other gases emitted by the produce (if required).
Bulk Bins
These bins are suitable only for produce able to be bulk stacked, e.g. apples.
Custom size bins make better use of the available space. Bin sizes 1100 mm x 1100 mm and 1065 mm x 1065 mm and 1085 mm x 1117 mm.
Palletising
A pallet is a flat transport structure, which supports goods in a stable fashion while being lifted by a forklift, a pallet jack, a front loader, a jacking device, or an erect crane. A pallet is the structural foundation of a unit load which allows handling and storage efficiencies.
Packages should remain within the pallet dimensions (i.e. no overhang) to maintain stacking strength and stability as well as ease of stowing into the container.
Euro-pallet 1200 mm x 1000 mm requires specifically designed cartons to maximise the efficiency of use of the container volume (eg. 395 mm x 295 mm for the grape carton and 595 mm x 395 mm for the potted plant carton).
Custom size pallets will make more efficient use of the container volume (eg. NZ pallet 1080 mm x 980 mm for integral containers). Be aware pallet boards/slip sheets etc may cause airflow restriction.
Handling procedures at the point of import must be arranged.
Slip Sheets
Slip sheets are thin pallet-sized sheets made of plastic, heavy laminated kraft paperboard, or corrugated fiberboard used in commercial shipping. Often, these replace the use of traditional wooden pallets. The unit load is usually stretch wrapped or shrink-wrapped for stability.
Stabilising
Any stabilising method used must keep the pallet firmly together to ensure ease of stowing into the container. Stabilising may be achieved by using pallet adhesive, adhesive tape, stretch wrap, shrinkwrap, stretch netting, or strapping. Right angle corner supports, of metal, fibreboard or plastic, may be used in conjunction with any of the above methods. Stabilising methods must not restrict air circulation throughout the cargo stow.
Loading
During the loading of transport vehicles, the following handling practices should be followed to prevent an excessive loss of quality during the transportation step:
Avoid bumping pallets during handling
Avoid puncturing MA plastic bags
Load together produce that is compatible
Load produce in centerline loading pattern
Apply bracing between the pallets and both sidewalls
Apply bracing to secure the rear pallets
Do not load produce sensitive to vibration damage directly above steel-spring, suspended axles.
The most effective ways to load a truck
Containers should be loaded so that they are away from the sidewalls and the floor of the transport vehicle in order to minimise the conduction of heat from the outside environment.
If a truck is side-loaded with a central circulation space and the cartons loaded are positioned on Slip sheets, in a general load, there would be approximately 151 cartons of fresh produce making contact with the walls and floor of the trailer.
If a truck is centre-loaded with circulation running down the sides of the cartons and the cartons are positioned on Slip sheets, in a general load, there would be approximately 50 cartons fresh produce making contact with the floor of the trailer.
If a truck is side-loaded with a central circulation space and the cartons loaded are positioned on Pallets, in a general load, there would be approximately 113 cartons of fresh produce making contact with the walls of the trailer.
If a truck is centre-loaded with a central circulation space and the cartons loaded are positioned on Pallets, in a general load, there would be 0 cartons of fresh produce making contact with either the walls or the floor of the trailer.
Only the fourth load example is fully protected from heat transfer. The use of pallets keeps the cartons off the floor, while centre-loading leaves an insulating air space between the pallet loads and the outside walls.
Bracing the Load
There should always be an air space between the last stack of produce and the back of the transport vehicle. The load should be braced to prevent shifting against the rear door during transit. If the load shifts, it can block air circulation, and fallen cartons can present a great danger to workers who open the door at a destination market. A simple wooden brace can be constructed and installed to prevent damage during transport.
Wooden braces for sidewalls can be used, but they are heavy and can become expensive to build and transport. Air-filled bags made of vinyl can provide excellent bracing and 5cm of added insulation (2" thick) against sidewalls. The bottom of the pallets are braced with wood blocks to prevent load shifting.
Additional considerations
Some produce, such as green onions and broccoli, are sometimes shipped with crushed ice in waxed corrugated cartons or plastic container units. They should never be stowed on top of other produce not packaged in ice. Water from the melting ice damages packages that are not water-resistant. If ice packed produce must be shipped with produce packed in conventional corrugated boxes, use moisture-proof divider sheets to protect corrugated boxes. However, dividers should not extend to the floor where they can block the airflow through pallet openings. Never distribute crushed ice on top of a load of fresh produce except if the produce has been packed in containers specifically designed for this purpose. Furthermore, an excess height of ice could block airflow passages.
Protective wrapping should cover the top, sides and bottom of the pallets or the load. Reflective wrap is more effective than opaque plastics or paper for reducing heat gain when the load is exposed to the sun. Do not use clear plastic film as a pallet cover. Solar heat passes through it and it is then trapped under it as in a greenhouse, resulting in a very rapid temperature increase. Insulated covers add some protection from heat gain, but the benefit is relatively small compared to the use of a simple reflective cover. Covers that incorporate gel ice are also available.
Handling at the final destination and retailing
When the produce arrives at a destination, pallet covers and wraps should be removed and temperature and quality of the produce should be inspected. Produce still within 2°C of its optimum temperature range should be immediately transferred to a refrigerated room. Produce more than 2ºC above its recommended temperature range needs to be rapidly cooled again.
At retail, produce should be refrigerated upon arrival. Since display cabinets or counters do not have the refrigeration capacity to cool produce, fruits and vegetables should be at their optimum temperature before being stacked for display. To prevent an increase in temperature during display, produce should not be stacked above the load line of the display cabinet or counter.
