Choosing the Right Plastic Security Seal

Authored By Seals HQ

Important factors to consider when selecting a tamper evident plastic security seal


Plastic seals are the most commonly used tamper evident devices across a broad range of markets and applications, including everyday uses as securing truck trailers, shipping containers, cash bags, utility meters, fire extinguishers and airline food trolleys, to name a few. They play an important role in securing the supply chain system.

In the transportation industry, as the slogan goes, “Without Trucks, Australia Stops”.

Our friendly and knowledgeable team of experts at Seals HQ wants to help you choose the most effective and appropriate seal for your particular application. In this post, we take a closer look at several distinct types of plastic seals and their specific features and benefits.

Adjustable Length Plastic Security Seals

Adjustable length seals are the most versatile of plastic seals, they come in a variety of lengths and strengths, and can be cinched tight to effectively secure objects. These multipurpose seals are used across a variety of industries including transportation, banking and finance, manufacturing, retail, education, food, pharmaceutical, medical and utilities. The versatility and extensive print area makes them a good solution for multitudes of purposes, including securing trucks, freight trains, cash in transit, jewellery and ballot boxes.

Fixed Length Plastic Security Seals

As the name suggests, fixed length seals feature a secure single locking position at a specified length. They are most commonly used in the transportation, supply chain, logistic and loss prevention industries.

Fixed Length vs Adjustable Length Plastic Seals

Fixed length seals are considered more tamper evident due to their single locking position, which offers a more easily visible check on the integrity of the seal. <Sam – can you key in an example here maybe?>. Although adjustable seals have excellent tamper-evident features, users must be aware of the need to pull the seal as tightly as necessary for the particular application to eliminate any circumvention of a loose seal. If the adjustable length seal is not pulled tight, it leaves itself open to someone cutting it off, getting into which is now unsecured and then reapplying the (now shorter) security seal.

Our team at Seals HQ provides a clear diagram of correctly using an adjustable length plastic seal here <here should be a hyperlink to our ‘product use diagram’.

To address this issue, our Heavy Duty I plastic seal has visible indicators that will tell you if a seal has been cut and re-sealed; however, these indicators are usually visible only upon close manual inspection, which is not always part of the receiving protocol. In the case of a fixed length seal, the integrity indication is simpler: the seal arrives either locked or un-locked. Once a fixed length seal is broken, it cannot be reapplied.

<insert image that shows the line markings on the plastic seal tail?>

Padlock Plastic Security Seals
A plastic padlock security seal is also a type of fixed length seal. It’s commonly used to secure utility meters, cabinets and catering carts. They are designed with a larger print area for displaying additional information. They are commonly used in airlines, food service, medical and pharmaceutical industries.

As an example, we can print a customer’s logo, serial number and barcode on the larger print area.

<insert picture Padlock Seal I>

Selecting the Right Seal

Security seals are a trusted and cost-effective solution for two primary purposes. Firstly, to deter tampering and theft. Secondly, to help provide a sense of security and safety. Each customer’s required application is different, and each type of seal are designed to serve a distinct purpose.

Length aside, the tensile or break strength of a seal is an important consideration. A seal securing a fire extinguisher, or a first aid kit will likely require a low break strength to provide tamper evidence security while offering quick and easy access. In contrast, a seal used to secure cash bags would benefit from a higher tensile strength. In these two examples, we would suggest the Light Duty I plastic seal for securing fire extinguishers and first aid kits and the Heavy Duty I plastic seal to secure cash bags.

Our plastic seals have a break strength range of 15 – 40 kilograms. Understanding the desired break strength in your specific application is critical to selecting the correct seal.

Get in Touch

Our team of security seal professionals are always happy to guide customers through the seal selection process. We encourage you to feel free to contact us with any questions.

Scroll To Top