In freight, container, trucking, and warehouse logistics, both cable seals and plastic seals are used to detect unauthorized access to cargo or equipment, yet they address slightly different needs. Plastic seals serve primarily as low-cost tamper indicators, whereas RFID cable seals combine a mechanical steel cable lock with an RFID electronic identity; this allows for verification not only of whether the seal has been opened but also of whether it is the original, specific seal applied at the start.
Consequently, neither type is inherently superior to the other. The choice depends on factors such as cargo value, the transport environment, the sealing location, inspection frequency, and whether the business requires automatic logging of seal numbers into systems like a WMS (Warehouse Management System) or TMS (Transportation Management System).
Plastic Seals: Low cost, ideal for frequent, basic tamper indication
Plastic seals are typically made from materials like polypropylene or nylon and feature a single-use, pull-tight locking mechanism. Once cut, they cannot be restored to their original state, allowing personnel to identify irregularities based on the seal's number, color, and appearance. Their primary advantage lies in simplicity and low cost rather than mechanical strength. For applications such as pallets, totes, warehouse roll cages, cargo bags, and standard domestic transport-where the main goal is preventing unauthorized access and manual verification of seal numbers during handover is feasible-plastic seals are often sufficient.
This distinction is reflected in the ISO 17712 classification: the primary function of an "Indicative Seal" is to provide visible evidence of tampering rather than to offer protection through high mechanical strength.
RFID Cable Seals: Electronic identity added to mechanical protection
RFID cable seals typically consist of a steel cable, a locking body, and an RFID chip. The steel cable provides mechanical security, while the RFID chip supplies a unique electronic identification code. Some products also retain visible serial numbers, barcodes, or QR codes, enabling the simultaneous use of manual inspection and electronic scanning.
When paired with UHF RFID equipment, an RFID reader can capture the seal's electronic ID and link the data to specific vehicles, containers, orders, or transport tasks. RFID cable seals on the market today utilize this "mechanical lock plus RFID identification" design.
It is important to note, however, that the addition of RFID does not automatically upgrade a standard seal to the status of a "High Security Seal." The mechanical structure's compliance with ISO 17712 standards and its tensile strength rating still require separate verification; RFID adds an electronic identification layer rather than replacing the mechanical security rating.
The primary difference between the two lies in the inspection method
Plastic seals typically require personnel to get close to the seal to visually verify the serial number, color, and integrity (checking for signs of tampering or breakage). While this method is manageable for operations handling only dozens or hundreds of seals daily, manual verification can become a bottleneck at logistics nodes as the volume of vehicles and cargo increases.
The advantage of RFID cable seals lies in non-contact identification. Personnel do not need to locate and manually record text on each seal; as long as the RFID tag is within the reader's effective range, identification data can be captured. This method is better suited for establishing automated seal verification processes at warehouse entrances/exits, container yards, and vehicle checkpoints.
However, RFID systems entail additional infrastructure investment, including RFID readers, antennas, middleware, and data interfaces with Warehouse Management Systems (WMS) or Transport Management Systems (TMS). Consequently, if a facility does not already utilize RFID technology, the cost-benefit advantage of adopting RFID seals solely for low-risk cargo may be negligible.
Which type is better suited for container and truck transport?
For domestic distribution, palletized transport, or internal warehouse handling, plastic seals are usually more economical. They are quick to install, require no reading equipment, and offer a lower unit cost when purchased in bulk.
RFID cable seals are more practical for high-value cargo, cross-border transport, scenarios involving multiple handovers, or operations requiring automated seal verification. They are particularly useful for container door locking mechanisms with irregular configurations; the RFID seal's flexibility allows it to thread through various locking holes and connection points, while the integrated RFID technology eliminates the need for repetitive manual data entry.
For international container transport, it is essential to verify that the mechanical seal meets the relevant ISO 17712 requirements; the presence of RFID technology alone does not determine the security rating. ISO 17712 classifies freight seals into categories such as Indicative, Security, and High Security, and the appropriate seal should be selected based on transport risks and compliance requirements.
