What is a Ceramic Body Armor Crack Arrestor Plate (CAP)?

Our Crack Arrestor Plate (CAP) is a type of crack arresting layer. 

A crack arresting layer is a protective material that covers the ceramic strike face (front of the ceramic portion of the plate).  The purpose of the crack arresting layer is to hold the ceramic in a continuous way and prevent disintegration. It is located under the front armor cover, behind the manufacturer's logo (usually).

All of our GTS ceramic armor plates have some type of crack arresting technology to some degree. Our OA+ plates are equipped with basic strike face protections, while the Model 9409 has advanced crack arresting technology that can stifle all ceramic ejection when shot.  Very thin layers are not as effective but CAPs that are too thick add unnecessary weight and thickness. 

The GTS CAP is a proprietary composite layering that is adhered to the strike face of our armor plates with our methods and adhesives.  The CAP is designed to substantially reduce and often eliminate all visible ceramic fragmentation (often inaccurately referred to as ceramic "spall"). The elimination of these ceramic shards also has a crucial performance function.

While most quality tactical plate carriers retain ceramic particles, that is NOT enough to influence armor system performance.  The real benefit to wearing a well-built carrier is to keep ceramic particles (mostly low to medium velocity) from striking exposed areas of your body.  Ceramic ejection from the strike face is not as serious as bullet fragmentation on steel plates. Even so, it should be managed.

Let's discuss the issue from a performance standpoint.

High quality ceramic should be held in place prior to, during and following bullet impact. Why? Forcing ceramic fragments that have been damaged by previous projectiles to remain in place reserves that physical space, preventing other ceramic (broken or not) from vacating their assigned positioning during the manufacturing process. This restriction of ceramic movement (sliding, eruption or separation from the backer) forces the ballistic energy into the polyethylene backing material and out through the adhesives. This process is like catching lightning in a bottle and the shear through the first several layers of polyethylene fiber are intense. This design - if done properly, provides discrete elements of readiness and redundancy to the armor system.

Here is an image showing the spall circle on the reverse side of the strike face. A monolithic plate (one-piece of ceramic) is on the left and a mosaic style ceramic tile array (multiple 2" tile pieces) is shown on the right.  The monolithic plate was tested with a thin crack arresting layer, while the ceramic mosaics were outfitted with our well-developed CAPs.  Notice the reduction in adjacent tile damage when using CAPs and the 50%+ reduction in overall spall circle size.  This reduction in spall circle size when using the CAP means that full thickness ceramic adjacent to the initial projectile entry point remains available to resist additional incoming rounds (increases multiple-hit performance).

 

Here is another image showing two, .30M2AP rounds on the reverse side of the mosaic strike face (using CAP) versus a monolithic (without a complete CAP) and spall circle damage.  Using the CAP holds damaged ceramic tile in place, limiting adjacent tile damage and maximizing performance. 

 

 

Monolithic plates can benefit from performance enhancements offered from  proper CAPs. Ceramic fragments may be retained but the reverse side of the strike face requires an additional interface layer to reduce spall circle size and be truly effective with multiple projectiles.  This additional interface often results in bonding issues between dissimilar materials.  Most manufacturers avoid this.

Ceramic tile arrays - when used with adequate CAPs are designed to maximize the benefits that CAPs can offer. Our data suggest that mosaic ceramic tile arrays are superior to monolithic designs when evaluating multiple hit performance.

Main benefits:

A multi-hit performer: The CAP is the first thing that incoming projectiles encounter when hitting the strike face.  The material maintains pressure against the mosaic ceramic tiles, protecting the non-impacting ceramic, freezing them into position and making the strike face ready to resist additional projectiles.

Reduces ceramic dust:  The CAP also assists in retaining ceramic dust that may emanate from rips in the carrier or vest material.  This makes for clean entry shots and reduces the distraction related to dislodged ceramic particulate. 

The increase in multi-hit performance and the reduction in ceramic fragment ejection are advantages that make for true, firefight-ready armor. 

We can add a CAP to any RF2/RF3 armor for an additional fee. Please inquire.

OA+ plates incorporate thin crack arresting layers and ceramic will escape these plates when shot.  The only plates that are routinely manufactured as frag control products are Models 9049 and the 6910. 

As always, please let us know if you have any questions!