Transparent armor with improved multi-hit performance by use of a thin cover glass.

(54) Title: TRANSPARENT SHIELDING WITH MULTI-IMPACT PERFORMANCE IMPROVED THROUGH THE USE OF A THIN COVER GLASS.

(54) Title: TRANSPARENT ARMOR WITH IMPROVED MULTI-HIT PERFORMANCE BY USE OF A THIN COVER GLASS.

(57) Summary

The disclosure is directed to a transparent armor laminar unit having a glass, glass-ceramic or ceramic impact face layer, one or a plurality of glass, glass-ceramic (GC), ceramic (C) or polymer (P) behind the blasted face layer, one or a plurality of chip capture layers (SC) behind the backstop layer (s), and a laminated thin cover glass layer to the impact face , the thin layer being the first layer to be hit by any incoming projectile or debris; the cover glass has a thickness = 3 mm; in another embodiment the thickness of the cover glass is = 1 mm; in addition, a defrost / defrost element is laminated between the cover glass and the impact face.

(57) Abstract

The disclosure is directed to a transparent armor lamínate having a glass, glass ceramic or ceramic strike face layer, one or a plurality of glass, glass ceramic (GC), ceramic (C) or polymeric (P) backing layer behind the strike face layer , one or a plurality of spall catcher (SC) layers behind the backing layer (s), and a thin cover glass layer laminated to the strike face, the thin layer being the first layer to be impacted by any incoming projectile or debris. The cover glass has a thickness á # n3mm. In another embodiment the cover glass thickness is á # nlmm. Additionally, a defrosting / defogging element is laminated between the cover glass and the strike face. The disclosure is directed to a transparent armor lamínate having a glass, glass ceramic or ceramic strike face layer, one or a plurality of glass, glass ceramic (GC), ceramic (C) or polymeric (P) backing layer behind the strike face layer , one or a plurality of spall catcher (SC) layers behind the backing layer (s), and a thin cover glass layer laminated to the strike face, the thin layer being the first layer to be impacted by any incoming projectile or debris. The cover glass has a thickness á # n3mm. In another embodiment the cover glass thickness is á # nimm. Additionally, a defrosting / defogging element is laminated between the cover glass and the strike face. This invention relates to NPC-1 antigen on the MUC5AC protein and 16C3 antigen on CEACAM5 and CEACAM6 proteins, and 31.1 epitope on the A33 protein are differentially expressed in cancers including, lung cancer, ovarían cancer, pancreas cancer, breast cancer, and colon cancer , and diagnostic and therapeutic usages. Further, NPC-1,16C3, and / or 31.1 epitope specific antibodies and diagnostic and therapeutic methods of use.

TRANSPARENT ARMORING WITH MULTI-IMPACT PERFORMANCE

IMPROVED THROUGH THE USE OF A THIN COVER GLASS

PRIORITY

This application claims the priority benefit under 35 USC § 119 of US provisional application serial number 61 / 360,232 filed on June 30, 2010, the content of which is based and incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

The description is directed to transparent armor that has improved multi-impact performance through the use of thin cover glass. The transparent armor includes a glass or glass-ceramic impact face layer, one or a plurality of glass, glass-ceramic or polymeric backing layers, and a chip capture layer, and further includes a cover glass layer Thin ahead of the face cape all at once.

GOVERNMENT RIGHTS

The material in this description was made with support from the United States Government under Agreement No. HR0011-10-C-0005 awarded by

DARPA. The United States Government has certain rights in the material in this description.

BACKGROUND OF THE INVENTION

The “multi-impact” requirements for transparent shielding (“TA”) are driven by need in conflict. In today's military missions, the encounter with the adversary is at closer distances than in most of the previous "conventional" war situations, and there is a greater occurrence of sniper situations. Consequently, in consideration of current situations, multi-impact specifications for TA generally require that the distance between shots received by the TA be much less than the distance of 100-120 mm used in older specifications. A specification that is widely used today requires a "T-pattern" in which a 50mm firing gap is required along the two axes of the "T." To be within the allowable specification tolerances, the shot gap may be as small as 20mm during testing and still qualify as 'valid'

For a glass-based ΤΑ, meeting the new T-pattern specifications is a broad industry challenge.

In addition to multi-impact requirements, new TA sheet systems or units are required to be lighter in weight than previous sheet systems or units. As a result, new materials are beginning to play a role in TA weight management. These new materials include clear spinel, ALON, and sapphire ceramics, clear glass-ceramic, and other high-performance glasses such as z

like borosilicate glasses. However, due to cost / performance balances, these materials are typically used as an impact face material to effectively break or deform a hard projectile; and layers of glass and / or polymer are placed behind the impact face to form the remainder of a laminar TA unit and annul the projectile.

To meet the tight multi-impact requirements, it is imperative that the impact face material remains part of the TA's functionality for all shots, and not just the first impact. The key to multi-impact capability is to retain the integrity of the impact face and, ideally, also reduce the size of damage during impact, thereby allowing effective multi-impact cancellation.

A sheet or layer of glass covering over the impact face is a natural choice. A plastic-based cover is lightweight, and can be effective in retaining material, but lacks the scratch resistance required for an outermost layer. Conventional knowledge appears to have prompted manufacturers to use a 6mm or 10mm layer of glass as a cover to provide the perceived need for scratches and stone shock resistance. However, the use of such 6mm or 10mm cover glass added weight to the TA laminar unit and has also been found to greatly reduce the performance of the impact face, making the entire multi-laminar unit less effective in performance. One possible explanation is that weak cover glass may be the starting point of a fast travel failure wave that preconditions and weakens the impact face in front of the projectile. This is not desirable.

Consequently, there remains a need for an effective cover that improves multi-impact performance without compromising the properties of scratches and stone shocks.

BRIEF DESCRIPTION OF THE INVENTION

In one aspect, the disclosure is directed to a transparent shielding sheet unit having a glass, glass-ceramic, or ceramic slammed face layer, at least one glass, glass-ceramic layer ("GC'j, ceramic ( "C") or polymeric ("P") of the bumped face layer, at least one chip capture layer (s) "SC" behind the backing layer (s), and one layer of laminated thin cover glass, using adhesive materials as described here, to the impact face, the thin layer being the first layer to be impacted by any incoming projectile or debris. In one embodiment, the cover glass is <3mm thick. In another embodiment, the cover glass thickness is s 1 mm. In yet another embodiment, a defrost / defrost element is laminated between the cover glass and the impact face. In a further embodiment, the TA laminar unit having a cover glass has a layer of IR absorbent adhesive behind the thin cover glass, and ahead of the face-shot layer, to absorb most of the solar heat and dissipate heat through the thin layer of glass. In one embodiment, the TA laminar unit having a cover glass has both an IR absorbent adhesive layer and a defrost / defrost element between the cover glass and the impact face.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a drawing of a TA laminar unit without a cover glass illustrating how the loss of the impact face during the impact of the first projectile or shot (# 1) guides the projectile or shot # 2 without "seeing ”The impact face.

Figure 2 is a drawing of a TA laminar unit with a thin cover glass illustrating how, after impact of the projectile or shot # 1, the loss of the impact face is reduced, resulting in improved cancellation of projectile # 2.

Figure 3 is a schematic illustrating the four-shot T-pattern and further illustrating the maximum distances between the shots as required by the T-pattern specification.

Figure 4 is a photograph showing the front of a 35.56 cm x 35.56 cm TA laminar unit 5 with a GC impact face, without cover glass, which has a glass-ceramic bump after shots # 1, # 2 and # 3, the sample having a significant GC loss near the site of impact # 4 as indicated by the white arrow.

Figure 5 is a photograph showing the front of a 30.48 cm.35.56 cm TA laminar unit 10 with a GC impact face, with a 1.6 mm polycarbonate (“PC) cover sheet after shots # 1, # 2 and # 3, the laminar unit holding the GC close to the shooting location # 4 as indicated by the white arrow.

Figure 6 is a photograph showing the front of a 35.56 cm x 35.56 cm laminar unit 15 with a GC hit fact and with a 6 mm cover glass after shots # 1, # 2 and # 3, the laminar unit holding the GC near the shot location # 4 as indicated by the white arrow.

Figure 7 is a photograph showing the front of a 35.56 cm x 35.56 cm laminar unit 20 with a GC knockout and with 0.7 mm Eagle® Glass cover glass (Corning Incorporated, Corning, NY) after shots # 1, # 2, and # 3, the laminar unit holding the GC near the shot location # 4 as indicated by the white arrow.

Figures 8A and 8B are photographs illustrating the performance of a 6mm Borofloat® glass (Figure 8A, Schott Glass, Elmsford, NY) and 0.7mm Eagle® glass (Figure 8B) in a simulated stone slab using a 1.9 cm diameter stainless steel ball that has a speed in the range of 96.56-11361.99 km / hr.

Figure 9 is a schematic in which a heating element is located behind an 8-10mm glass impact face of conventional TA sheet units.

Figure 10 is a schematic in which a heater is located behind a 0.7mm Eagle® glass cover in accordance with the present disclosure.

Figure 11 is a schematic in which a layer of IR absorbent adhesive is located behind a 0.7mm Eagle® glass cover in accordance with the present disclosure.

DETAILED DESCRIPTION OF THE INVENTION

Herein, the terms "projectile" and "shot" may be used interchangeably and should be understood to include, in addition to a bullet shell fired from a firearm, debris that may strike the TA laminar unit as a result of a explosion, high winds such as those occurring in a hurricane or tornado, or from other causes. The bonding of the laminar unit layers to each other, including the bonding of the cover glass with or without a conductive layer, and the wire mesh used as a heating element, is carried out using bonding materials in the form of a fluid, gel , paste or film. Bonding materials are typically polymeric adhesives in the form of a fluid, gel, paste, or film.

Also herein, transparent shielding ("TA") means any transparent shielding laminar unit comprising a blow face layer, one or a plurality of backing layers, and one or a plurality of chip capture layers, the layers being laminated or bonded together by using an adhesive layer, for example a fluid adhesive applied to at least one of the surface that is bonded together or a sheet of between polymeric layer of adhesive placed between the surfaces to be bonded together. Although this description describes the placement of a transparent thin cover glass, the glass cover layer or cover as the first layer that will receive an incoming projectile of any type (bullet or shell, fragmentation grenade, stone, etc.), the The term impact face is used here for the first layer of clear glass, glass-ceramic or polymer (not including the bonding layer) behind the glass cover. The glass cover can be selected from, but not limited to, the group of Aluminosilicate Glass, Alkaline Aluminosilicate Glass, Borosilicate, Alkaline Aluminoborosilicate Glass, and Soda Calcium Glass. Glasses that contain alkali metal ions can be chemically reinforced by ion exchange of the alkali metal ions in the glass with large metal ions, preferably larger alkali metal ions.

The present description describes the novel concept and results of experiments that demonstrate the use of a thin glass cover to improve the multi-impact performance of transparent shielding. A thin cover glass, less than or equal to 3 mm thick, is placed in front of a multi-layered TA pile as the first layer to face the incoming threat (projectile or debris). The TA stack may contain high performance impact face materials such as a clear glass-ceramic type, a clear ceramic, or other types of glass and ceramic. The thin glass cover effectively causes retention of the material impact face during the ballistic event, thus allowing the most effective cancellation of a subsequent impact near the first impact area. In one embodiment the thickness of the cover is less than or equal to 1 mm thick. The cover glass can be a melt-stretched glass, a slot-drawn glass or a floating glass. For example, without limitation, the cover glass may be an LCD display glass, for example without limitation, XG Eagle® glass (Corning Incorporated), the glass being in the thickness range of 0.5mm-1mm. For improved low speed impact resistance, such as that against stones or other debris bumps, as well as additional protection for the impact face, a chemically reinforced glass, for example without limitation, Corning Gorilla® glass can be used in a thickness of

0.5mm-2mm.

Using a cover glass as described here has a number of advantages to used clear shielding. These advantages include:

one. Very low “pre-conditioning” of the impact face material of fault waves generated in the cover layer, as is the case with the use of thick glass cover.

2. Effective retention of impact face material during impact.

3. Negligible weight increase from the use of cover glass less than or equal to 5 mm.

Four. Allows the use of unpolished impact face sheet, eg, the use of laminated glass-ceramic, thus reducing costs.

5. Superior performance in terms of stone impacts.

6. The potential to absorb and dissipate solar heat in the thin outer shell glass layer improved performance at hot temperature, which is an advantage in desert conditions.

7. Increased defrosting and defrosting efficiency through the placement of a heating element between the cover glass and impact face layers.

In the examples and samples described here, a glass-ceramic was used as the impact face material. Other impact face materials such as clear ceramics or high performance glass materials could be used with similar results. The laminar TA unit used in the examples and samples, with or without the cover layer (glass or polymer), comprised the GC impact face, one or a plurality of intermediate or backing layers, and a capture layer of splinters. The layers were bonded together using a polymeric adhesive which can be a sheet of polymeric adhesive or a polymeric adhesive fluid.

The function of an impact face and typical configurations

A strong impact face material usually has superior mechanical properties such as hardness and firmness. For example, Corning 9665 glass-ceramic (GC) has a -50% higher hardness than floating glass. The high hardness helps to break or deform the projectile making penetration less likely. For this reason, the hard material must be placed in front of the TA pile where it will serve as the impact face. A typical configuration that results in V50 of 899.75 m / sec is as follows:

10mm GC / 15.9mm Borofloat / 6.4mm Borofloat / 12.7mm PC

This stack has an area density (AD) of 91.74 kg / m2, and by making the unit laminate the "tin" side of the Borofloat layers, the side of the glass that was in contact with the molten tin in the process of floating, he was facing the incoming threat. The GC and glass layers were laminated using a commercial adhesive, eg, 0.381mm polyurethane ("PU") adhesive such as Deerfield 4700 or Huntsman 399. As illustrated in the following experiment, the GC layer needs to be in front of the stack. If the 5.9mm Borofloat layer was placed in front of the pile to serve as the impact face and the GC layer was placed behind it within the pile, the resulting stack (lamellar unit) produces a V50 of ~ 808.25 m / sec, which is a decrease of 91.5 m / sec compared to when the GC layer is the hit face layer.

Cover glass effect on V50 and Multi-impacts

The exact mechanism for greatly reduced GC performance when the GC layer is embedded or buried in the stack is not known at the same time. A possible explanation is based on a "fault wave" as described in Stephan Bless et al, "Failure Waves in Glass, Journal of the

American Ceramic Society, volume 75 number 4, pages 1002 -1004. Bless et al observed that the impact event on the striking surface of a glass material creates a “fault wave” that travels faster than and ahead of the impact projectile at typical projectile speeds of interest in transparent shielding applications. . Behind the fault wave there is a total loss of tensile strength and a substantial drop in shear stress resistance. In fact, the fault wave will fracture the material in the path of the projectile; and consequently the projectile will be attached to a weakened material. If glass-ceramic is the material to which the projectile first attaches, the interaction will be between the projectile and the "undamaged" glass-ceramic; a weaker cover glass gives the "failure wave" time to pre-condition and therefore weaken the glass-ceramic. Assuming this is correct, then the thickness of the cover glass can play an important role. A thicker shell can create a more damaging "fault wave" and allow more time for the glass-ceramic you are facing to weaken and vice versa.

To quantify the influence of a thin glass cover on V50, a 0.7mm Eagle® glass cover was placed forward (in the direction of the incoming projectile) of the GC in the typical configuration described above. A 0.381mm PU adhesive was used to bond the Eagle to the GC. Although the cover glass and additional PU adhesive added some weight to the target, ~ 2.44 kg / m2 (kg / m2 means kilogram per square meter '), V50 was seen to drop by -21.35 m / sec (m / sec means meter per second). This is not an insignificant decrease and the multi-impact benefit must outweigh this loss of V50 to justify its use. In contrast, when a 6 mm thick soda lime glass was used, the air density increased by 15.13 kg / cm2, and it was also observed that V50 fell by -21.35 m / sec. Therefore, while AT systems that had a 0.7mm Eagle® glass or 6.0mm Borofloat® glass cover both achieved multi-impact capability, the last approach (Borofloat) does so with significantly less weight efficiency (which is a much larger increase in area density).

A discussion of the effect of thin glass cover on multi-impacts, in particular when used with the "T-pattern" test procedure, is required to fully understand this description. The "pattern T" procedure is illustrated in Figure 2 where # 1, # 2, # 3, and # 4 represent shots 1-4 fired in order against the target: the circles, as illustrated by the circle represented by the number 150, are target circles for shots 1-4; number 152 indicates the edge of width and number 156 indicates the edge of length, the length being the longest of the two dimensions of the largest part and the width being the smallest of the two dimensions of the largest part; number 154 indicates the center line of the length: number 158 indicates the center line of the width. Shots # 1 and # 2 are directed at the circles above and below the center line of width 158. The distance between the centers for shots # 1 and # 2 is 50 mm, and the distance between the centers for shots # 1 and # 2 and the center line of the width is 25 mm as indicated. In Figure 4, shots # 3 and # 4 are to the right of shots # 1 and # 2; and the center of the firing circles for shots # 3 and # 4 are on the center line of the width and are 50 mm apart. As illustrated, the horizontal distance between the center of the circle of shot # 1 (or # 2) and the center of the circle of shot # 3 is 125 mm. As also illustrated, the horizontal distance between the center of the circle of shot # 1 (or # 2) and the center of the circle of shot # 4 is 175 mm.

The T-pattern requires that four shots must be stopped by the TA sample without penetration. As stated before, shot # 1 and shot # 2 are separated by 50mm, as are shots # 3 and # 4 relative to each other. The typical fracture pattern for a shot extends in a circle with a radius of 50-100 mm depending on the type and speed of the projectile. Seeing shots # 1 and # 2 as one of the T pattern and shots # 3 and # 4 as the second set of the pattern, the most severe problems are with shot # 2, and especially with shot # 4. Each of these shots hits an area that is already weakened by a closely adjacent shot. The purpose of cover glass is to confine damage to the impact face and retain the glass-ceramic material so shots # 2 and # 4 reliably fit the glass-ceramic, even when it is partially fractured material.

Figures 1 and 2 illustrate the importance of retaining the material from the impact face when carrying out the T-pattern test. Figure 1 illustrates a laminar TA unit having an impact face 200, one or a plurality of backing layers 210 and a chip capture layer 220. When projectile # 1 hits impact face 200, the material can be ejected and a "crater" or severely damaged area 211 can be formed as illustrated in right of figure 1. When projectile # 2 hits inside the "crater", it can hit a smaller amount of the impact face material 200 or the backing material 210 with the result that the TA will be severely weakened. When the additional # 3 and # 4 shells hit a far distance as illustrated in Figure 3, the result may be a failure of the TA system or the severe damage seen through the TA is severely unaltered or not possible. In contrast to FIG. 1, when a thin cover glass 230 is placed before the hit face layer 200 as illustrated, the impact of projectile # 1 creates a much smaller "crater or damaged" area 212 as illustrated to the right of figure # 2. When projectile # 2 hits, it will first hit the cover layer and then hit a material from the retained impact face resulting in much less damage than the case in Figure 1. When additional # 3 and # 4 shells strike a far distance as illustrated in Figure 3, the TA system will resist damage without penetration and at least some visual ability will remain. Without being limited to any particular theory, it is believed that the use of a thin cover glass having a thickness <3 mm, when attached to the impact face uses an adhesive material, presents a surface that has some flexibility of so that when the projectile hits the cover glass it bends slightly, which helps dissipate the energy of the projectile and therefore decreases the intensity of the "fault wave" and reduces it with the impact on the TA laminar unit .

Figures 4-7 are a comparison of TA sheet units without a cover glass (1 example) and with cover glass (3 examples).

The comparison is for samples, from left to right, after receiving shots # 1, # 2 and # 3. Shot # 4 is to be directed to the place indicated by the arrowhead on the right side. The laminar units are:

Figure 4: TA with GC impact face and without cover glass.

Figure 5: TA with GC impact face and ~ 1.6mm cover glass (polycarbonate).

Figure 6: TA with GC impact face and a 6mm soda lime glass.

Figure 7: TA with GC impact face and cover glass

Eagle® Glass 0.7mm from the images in Figure 4-7, the benefit of adding a cover to the GC impact face is highly observable. Without giving any consideration to scratch resistance or weight, a PC (polycarbonate) cover is desirable for its preferred advantage. However, the addition of such scratch resistance to the requirements of the TA regulation (specification) the use of some plastic-based cover material due to the fact that such materials are already worn. Consequently, glass becomes a material of choice. Among the choices of a thin cover glass (<3mm) and a relatively thick cover glass (> 6mm), a thin cover glass (in these examples a cover glass <1mm) was chosen from weight considerations Low and reduced adverse ballistic impact.

Other considerations that favor the thin glass cover

There are other auxiliary requirements that must be considered when choosing the thickness of the cover glass; for example:

Stone shock, found while using TA, must be analyzed and considered before the TA end user adopts a new impact face configuration. At first glance, a glass layer <3mm, and particularly a £ 1mm thick layer of glass, appears to be weak in resisting a high mass rock hit at low speed. However, this turns out not to be the case. When the performance of a 0.7mm Eagle® glass cover, Figure 8B, was compared to a 6mm Borofloat® glass cover, Figure 8A, in resisting a 1.9 cm diameter steel ball traveling to a speed in the range of ~ 96.56-112.65 km / hr, while both glasses were cracked by the ball, the Eagle glass cover showed a much less damaged damage area with minimal visual impact. Compared to Eagle glass, the 6mm glass cover showed a larger area of ​​damage. The use of chemically reinforced glass, for example without limitation, commercially available Gorilla® glass (Corning Incorporated) may provide better performance in the steel ball test than Eagle® glass. The higher the compression stress and layer depth, the better the scratch resistance. Thermal tempering of thin glass can also improve performance in the steel bullet test.

Abrasion resistance, which can reduce ballistic performance and cause visual degradation, is another desirable requirement for TA. The soda lime glass and polymer layers are susceptible to abrasion, for example, by blow sanding. Both thin Eagle® glass and thin Gorilla® glass outperform soda lime glass, with Gorilla® glass being the best performing glass of the three. Although soda lime can be chemically reinforced, both the depth and the degree of ion exchange in the soda line are much less than what is possible with Gorilla® glass, therefore its resistance to abrasion will be less.

Thawing, defrosting and defrosting efficiency can be greatly improved when a heating element, be it a transparent conductive coating, or a wire grill, is placed behind the cover glass and heat is conducted through the cover glass to the outer (unbonded) surface as illustrated in figure 9. A bonding material, for example polyurethane, can be applied to the conductive coating side of a cover glass to bond the cover glass with its conductive coating to the impact face. When a wire mesh is used as the heating element, the bonding material can also be used to bond the cover glass, wire mesh, and impact face to each other. The bonding material may be in the form of a fluid, gel, paste, or film as known in the art. When a bonding film is used, the film will soften during the bonding process and will bond the cover glass to the impact face with the thin heating wire mesh embedded in the bonding film.

In FIG. 9, as illustrated, a heating element 250 is located between the blow face layer 200 and the first of a plurality of glass backing layers 210 that are followed by the polymer chip capture layer 220, for example, PC. Compared to a typical 6-10mm first layer TA thickness as depicted in Figure 9, a 0.7mm cover glass is -1 / 10a thick, which would aid in heating efficiency from the point of view of thermal mass and heat conduction. FIG. 10 illustrates an embodiment of the disclosure in which a heating element 250 is located between the thin glass cover 230 and the bump face layer 200 which is followed, in this embodiment, by a single layer of glass back

210, one layer or acrylic backing layers (illustrated as a single layer)

240 having a selected thickness roughly equal to the glass backing layers of Figure 9 it replaces and a chip capture layer 220. The use of thin cover glass 230 to improve multi-impact performance allows the replacement of some glass backing layers with approximately equal thickness of polymer backing layer (s) resulting in significant weight savings. A “standard” glass all glass, such as the one illustrated in figure 9, with an overall thickness of 62 mm would have an area density of 136.44 kg / m2 while the solution illustrated in figure 10 using glass Thin cover and partial replacement of glass backing layers with a polymer layer (s) will have an area density of -102.48 kg / cm2, 25% reduction in weight.

Solar heating is a known problem for TA that arises due to the interlayer of adhesive between the TA laminar unit layers that absorb IR in the solar spectrum. The thick glass surrounding the adhesive makes heat dissipation inefficient, leading to overheating of the adhesive layers, which in turn weaken the TA performance. When a thin glass cover is placed in front of the face layer at once the adhesive layer behind the thin cover glass can absorb most of the IR radiation and dissipate the resulting heat through the thin glass layer. This strategy could help increase AT performance under severe solar load such as that found in desert conditions. In addition to protecting the bonding adhesive on the impact face, backing layer, and chip catching layer from overheating and loosening the bond between the layers, the adhesive used to bond the thin cover glass to the face layer at once reduces the load thermal that will enter, for example, a vehicle. This in turn will reduce the energy requirements for any cooling that needs to be done; for example, in an ambulance or armored personnel carrier. In FIG. 11 as illustrated, an absorbent adhesive 260 is used between cover glass 230 and knock-face layer 200, and bond cover glass layer 230 to shot-face layer 200. As illustrated, the bump face layer 200 is followed by a single glass backing layer 210, an acrylic backing layer or layers (illustrated as a single layer) 240 having a selected thickness approximately equal to that of the Figure 9 glass backing replacing it and a chip capture layer 220. The embodiment illustrated in Figure 11 has an area density of 102.48 kg / cm2 like that of Figure 10, and the reduction in weight is also 25% over the 136.64 kg / cm2 of a standard all glass TA system.

In a further embodiment, cover glass 230 has a conductive element for heating, defrosting, and demisting on one side of the glass, and the adhesive bonds the conductive side of the cover glass to the impact face. In a further embodiment, the heating, defrosting and demisting element is a wire mesh element, and the adhesive bonds the cover glass, the wire mesh element and the impact face to each other.

Although the invention has been described with respect to a limited number of embodiments, those skilled in the art, who have the benefit of this disclosure, will appreciate that other embodiments may be envisaged that do not depart from the scope of the invention as described herein. Accordingly, the scope of the invention should be limited only by the appended claims.