What are Knife Retention Plates for?:

These plates are a multi-purpose type of protection equipment. They primarily provide resistance to edged threats through retention based mitigation. They also have the capability to retain forensic material, for later retrieval. The "Overt" variant of this plate is designed to give extra protection in the event of a larger threat, and the "Covert" variant offers an extremely lightweight alternative, which provides less energy and impact protection, but greater stacking ability when placed over the top of other, ballistic plates. We always recommend using Home Office approved ballistic plates with our Knife Retention Plates for threat protection. None of our plates are for ballistic protection. They are solely designed to retain pointed knives when struck in a stabbing motion. Plates which are certified as Blunt Trauma protectors, also perform this and additionally as a Knife Retention Plate which can disarm an assailant attacking with a sharp, bladed weapon. Regardless of blunt trauma capability, they are still Knife Retention Plates.

Your plates are flat and rectangular as standard, but can they be convex or cut to shape to stack over existing ballistic plates?

Yes, absolutely. You’ll get the same quality, same construction and knife retention capability, with custom curvature (convex according to needs). You can also choose different cuts to match, such as SAPI cut. Just tell us which ballistic plates you intend to stack them in front of, and we’ll custom build them to whatever you’re using, or your preferred measurements. They will then be manufactured to ISO 9001 standard. We may ask if we can take a look at your plate in person to perform a 3D scan or measure. This in-person measurement service is for mainland GB orders, and is free of charge.
 

How do they work?

They are completely passive, with no electricity required. They are also not magnetic. Plates work to retain a knife via a unique blend of smart materials, which have just the right ratios, stereochemistry, post production treatment and more to ensure that a knife can become retained during a potentially life threatening attack. As the knife passes through, it decelerates and the plate absorbs / dissipates energy from the strike. Once it's in, it is extremely difficult to be pulled out again via the same angle of entry. You can retrieve the knife when you get to safety, but it's deliberately a difficult and time consuming process, and may be futile to attempt to remove it in exactly the same way it went in. This gives the ability to deal with the assailant, get to safety, or get help. It's designed to buy time, and level the playing field. All of this can happen without any skill, or awareness of the threat. Rest assured, the knife can be removed by you when at a place of safety. Instructions for removal are below.

Scenario example: An assailant's goal is to stop a police officer from protecting others nearby during a mass attack. In this case, the officer would be an assailant's initial target. However, it only takes one person wearing the plates to protect those around them. A police officer may be targeted while facing away from the assailant, with a knife strike on the back plate. The assailant will feel the knife go in to the retention plate, giving the psychological impression that they've done what they intended. They then try to withdraw the knife at the same angle of entry by pulling it back, and would likely be forced to give up, or their hand may slip off the handle, leaving it lodged. The officer can then respond accordingly. Once retained, the knife is then forensic evidence controlled by the police, not the assailant.

Whilst primarily a blunt trauma protector, knife retention is a feature of its proprietary design and construction, demonstrated during in-house testing. However, as with any impact mitigating system, actual retention outcomes may vary depending on strike angle, weapon type, and applied force.
 

How do I remove a retained weapon, or discharge thereof?

Once a weapon is embedded in the plate, it can be very difficult to remove by the assailant. In situations such as this, the force to remove a weapon is potentially significantly greater than the energy exerted at inserting the weapon. In some scenarios, their hand will slip safely off of the weapon, leaving it retained. When this happens, you have the ability to remove the weapon yourself, and / or get to safety. To remove it yourself, once you are away from the threat of attack, place the plate down on a hard surface, with the weapon perpendicular to yourself and others nearby, then take a blunt object such as a hammer, and hit the weapon gently back and forth along the angle of entry. Similar to pulling a lever side to side repeatedly. This gradually makes the hole bigger, and eventually, will cause the knife to loosen, and fall out. This process can take several seconds, to several minutes, depending on how deep the weapon has penetrated the plate, and the nature of the weapon itself. An assailant is unlikely to have the time, nor ability, to retrieve their weapon once you have reacted to the strike, and retained the weapon.

For forensic retrieval of liquids or powders captured in the plate, you can extract them via the pressure regulation vent on the wall of the plate if it is safe to do so. You should not attempt this yourself. Biohazard or chemical attack residue can be life threatening, and retrieval of such materials should only be done by qualified professionals, with suitable equipment, authorisation, and experience. Retrieval after exposure to such an attack is extremely dangerous, and may result in serious injury or fatality.

NEVER attempt to remove sharp objects stuck in the plate by hand. Always use a blunt object such as a hammer to give yourself space between you and the weapon when removing it. Attempting to remove retained objects by hand may result in serious injury.

NEVER attempt to pull the weapon out at the same angle of entry. Efforts to do this will either be futile, or dangerous. The force at which you need to pull the weapon out in this way, can be greater than the force it when in at. This means it could suddenly dislodge at an accelerated rate, or otherwise cause serious injury.

NEVER reuse plates that have been struck. Whilst these plates can offer continued retention capabilities after a single strike during a multi assailant attack as a "worst case scenario" potential benefit, they may not offer the same blunt trauma protection, nor can it be guaranteed that a further knife strike will be in a different location from the last one, meaning a hole in the plate or damage could compromise safety and retention capability. Whilst we have done our utmost to offer protection from multiple strikes, you should not rely on this, and we cannot guarantee continued performance. Testing standards do not test for this capability. Therefore, we still advise that you should never reuse a struck, damaged, or otherwise compromised plate. If in doubt, or you believe the plate has been struck, even once, you should always replace the plate. In many circumstances, we can still recycle the plate free of charge.

ALWAYS wear the correct PPE when extracting weapons from the plates.

ALWAYS contact us if you require further assistance, or are unsure about how to use, or care for your plates. We can provide product support.

Why doesn’t it always retain everything?

Firstly, the retention feature of these plates is proportional to the threat it is presented with. Meaning, gently shoving a ballpoint pen into the strike face, will likely not cause it to retain the pen. The sharper, more knife like an object is, and the greater the force applied, (essentially, the more intentional and the more chance of harm there is) the more likely it is to become retained. Secondly, it depends on the motion of the article before it strikes, whereby near vertical upward or downward strikes (slashing) by a sharp weapon may mean that it is more likely to move across the plate, the same as with any traditional ballistic plates, rather than become retained within it. Intentional stabs with a sharp weapon at an angle perpendicular, or similar, to the strike face increases the chances of retention. This means the plates should not be compromised by unintentional damage, such as bumping into every day objects, but will likely offer protection from intentional, or potentially life threatening action.

Is this a handheld shield?

There are situations where you may wish to operate the plate as a shield instead. You can transition from wearing the plate in a carrier, to holding it as a shield very quickly if your variant has a built in handle. You can choose to add an optional retractable handle on some models when ordering. If your plate has this option, remove the plate from its vest / carrier / holder or otherwise, and deploy the handle. Some models are designed with an affixed handle for continuous shield use, without plate carrier use. These are purpose built shields, and are available only in "Overt" variation, not "Covert". Always have other PPE to protect yourself when using as a shield.

Why is there a circular hole at the edge of the plate? Is this deliberate?

You may notice a small, roughly 4mm circular hole near the top of your plate(s). This is a deliberate gap for multiple reasons, and is primarily known as the air pressure regulation vent. It is designed to prevent expansion or damage in situations where the plate is exposed to air pressure changes, such as those experienced at high altitudes, or those caused by temperature fluctuations. It further doubles up as a drainage point if liquids become captured by the plate, such as those ejected by tranquilliser darts, biohazard, forensic, liquid materials or similar remnants of payload delivery weapons, retained in the plate. (See above "How do I remove a weapon, or discharge thereof?" for details and safety information). It is essential for the vent to remain clean and unobstructed at all times.

Another purpose of the vent, is for cleaning. In which case, see the next FAQ to learn how to do this.

How do I clean the plates?:

For external cleaning, wipe with a cold damp cloth. Plates that have been certified to “wet testing” can be immersed for cleaning internally. This is where, after immersion in water at 20°C, they are then tested to the same Blunt Trauma standard. This means plates are not affected in their blunt trauma effectiveness by water at this temperature for this time frame. Plates can survive water immersion in these circumstances. You can also clean out the inside of the plate, where forensic material is retained, by placing it in cool or room temperature water, letting the water enter the ventilation hole, shaking the water around to ensure it reaches all areas, and then draining via the same point of water entry. Repeat as necessary. 

Which should I use, Overt, Covert, or Custom?:

All of our plates should be worn in front of your existing ballistic plates / body armour. However:

Overt plates are designed for extra threat protection, such as retaining crossbow bolts to prevent shattering or the assailant reusing a bolt. The ballistic plate can stop harm to you, and our retention plate can retain the bolt. Overt plates also have the potential to retain dart gun darts and their chemical / biohazard contents, as well as offer better protection from (and retention of) knives due to the thicker layers, whereby armour underneath is also better protected, lessening damage to the armour and thus, potentially preventing the need for expensive replacement.

Covert plates are more for tactical use, as well as reducing weight and bulk. When you want to reduce the chance of an assailant realising you have the Knife Retention Plates on you, or if you already have bulky ballistic plates, where thickness and weight matters, you may wish to opt for something slimmer and lighter. They therefore have these benefits, but forgo some of the extra capabilities outlined above, in “Overt plates”. Rest assured, both models are still Knife Retention Plates, just with different capabilities and features.

What do I need?: You should use the plate most suitable for not only the threat posed, but also what you’re already using, and you should consider the potential cost savings of preventing damage to PPE underneath versus weight and thickness when stacking. Don’t forget, these aren’t the only two options. If you need more protection, or a middle ground between the two, we can make custom Knife Retention Plates to order. This includes handheld shields, and unusual sizes or curvature. However, these will not be HOSDB 20/07 Blunt Trauma certified.

Why must the plates be kept below 50°C at all times?

For plates that have been certified to HOSDB (20/07) testing standards, the plates will have been subjected to at least 2 hours of heat at 50°C, followed by a blunt trauma strike. This means that these plates have only been certified and tested to this temperature. We therefore, cannot claim operational protection or effectiveness past this point. If 50°C is exceeded, even briefly, including on Knife Retention Plates not certified to HOSDB 20/07 Blunt Trauma standards, it is possible that the plates will not continue to work as intended, and this may invalidate any warranty. Therefore, there are some steps you can take to keep the plates cool. We recommend the following to keep your plates below 50°C at all times: Keeping plates in carrier vests, not exposing them to direct sunlight on warm days, never leaving them in vehicles without active cooling on warm days, and wrapping plates in heat resistant material, such as Mylar, or similarly heat reflective materials.

What if I need further help?

For general enquiries: Please click the Contact page from the menu at the top for details on how to get in touch. We recommend getting in touch via email: enquiries@celantex.com

For product support: We are always happy to help, and if you have a contract with us (likely, if you’ve ordered from us before) we may even be able to arrange on-site product support at a location of your choice, anywhere within mainland Great Britain, should you require physical assistance with your products. Please check your contract to see if this service is included. Otherwise, we offer remote support via video link, telephone and email. This may apply to other products and services where you have a contract with us, not just Knife Retention Plates.