How to Seal a UN Product – A Guide from Emballator
Posted 2025-01-07
Ensuring that your hazardous goods are correctly packaged and sealed is crucial for safety during transport. At Emballator, we want to help you understand how to properly seal our UN packaging to meet international safety standards. Here is our step-by-step guide with examples from our own range of metal cans.
In general
The UN-certificate is a proof document stating that the total package, lid and can together, meet the requirements for dangerous goods according to UN recommendations. It is not sufficient that can, lid and other components separately are manufactured according to specified demands. The mentioned items need to be used together to achieve the intended function for the package and for the proof document to be valid. Furthermore, it is crucial that the sealing after filling is executed correctly. On the following pages you will be given the information required to be able to seal your UN-packaging correctly, and that it will be according to present UN certificate. The information fulfils the requirements in part 6.1.1.5 in ADR-S.
Cans with press lids
UN-cans with press down lids are available in ø 99, 105 and 153 mm. These cans have TT-type (Triple Tight) lids and rings. Glue is applied in the bottom of the ring, which will come in contact with the lid when sealing. The glue in combination with friction makes sure that the lid will not come off when the packaging is exposed to force of any kind, as in a fall for example. It is therefore crucial that the lid, when sealing is pressed against the can with such force that it will come in contact with the glue inside the ring. To secure this, the amount of force from the pressure plate when sealing the lid should be minimum 2200N for ø 99 and 105, and 3000N for ø153. After sealing, the lid should be in level with the seam edge of the can. If needed, a special pressure plate could be used when assembling the lid. This tool is designed to press the lid below the edge’s level.
Press lid for ring latch UN
The UN packaging consists of a pail, UN +press lid and a UN ring latch with lock pin. The combination guaranties that the lid does not come of if the packaging is exposed to an increased internal overpressure or external damages, as for example a fall.
The design is first assembled with the UN press lid and the pail. A conventional lid-press with a plate and an air-cylinder is used to assemble the lid. The recommended force for pressing down is ca 2000 N.
After the UN press lid and the pail is assembled the UN ring latch is closed around the lid and the pails profile.
When closing an UN ring latch, ensure that the ring latch enclosures the ring latch lid and the lower edge of the pails profile. When the ring latch is closed, a correct locking pin must be mounted in the handle of the ring latch so that the ring latch cannot be opened.
Pails with lug lid
UN-pails with lug lids are available in ø 180 and 285 mm.
The lid has so called lugs, which when sealed are pressed in under the top of the can, holding the lid attached to the pail. A special tool is necessary to able to seal a pail with a lug lid. It is crucial that the lugs are pressed correctly in under the top rolled edge of the can. Furthermore, it is necessary to ensure that by a visual control, or through measuring the height of the roll after the lid is mounted.
If you notice deterioration in the sealing, it could be a sign of the sealing tool is damaged or worn. It could also depend on the power from the axle being too small, because the air pressure is insufficient. This causes the tool not reaching required bottom level.
EasyOpen UN
The UN-Package consists of a pail and a lid. The lid is provided with a safety-ring of plastic that guarantees that the lid stays in place when exposed to inner overpressure or external violence, as for example a fall. The design allows for the lid to be assembled in a conventional lid-press with a plate and an air-cylinder.
To keep in mind when sealing the pail:
· Place the lid centered on top of the pail.
· The required force for pressing down the EasyOpen 180 UN lid is ca 4000 N.
· For EasyOpen 285 UN the required force is ca 6000 N.
· For an easy assembly the lid must have a temperature of at least 20° C. If the lids are stored in a cold room, they shall be moved into room temperature at least 24 hours before use on the pail.
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