Multi-ballistic-impact resistant article

Abstract

The invention relates to a multi-ballistic-impact resistant article comprising a plurality of stacked monolayers ( 103 ), at least part of the monolayers ( 103 ) containing at least one polyolefin tape, characterized in that said plurality of stacked monolayers ( 103 ) has a total areal density of less than 200 Kg/m2 and wherein said article is able to withstand at least three ballistic impacts from 20 mm FSP without complete penetration.

1 . A multi-ballistic-impact resistant article comprising a plurality of stacked monolayers, at least part of the monolayers containing at least one polyolefin tape, characterized in that said plurality of stacked monolayers has a total areal density of less than 200 Kg/m 2  and wherein said article is able to withstand at least three ballistic impacts from a 20 mm FSP without complete penetration. 
     
     
         2 . The article of  claim 1  wherein the 20 mm FSP projectile travels with a velocity of at least 300 m/s, preferably with a velocity of between 500 and 650 m/s. 
     
     
         3 . An article according to  claim 1  able to withstand at least 4, preferably at least 5, impacts from a 20 mm FSP. 
     
     
         4 . An article according to  claim 1  having a final back face deformation (BFD) of at most 300 mm. 
     
     
         5 . An article according to  claim 1  wherein the article is a non-ceramic article. 
     
     
         6 . An article according to  claim 1  having a flexural strength of at least 10 MPa as measured before impact. 
     
     
         7 . An article according to  claim 1  having an areal density (AD) of at least 10 Kg/m 2 . 
     
     
         8 . An article according to  claim 1  wherein at least 50% of all monolayers comprise at least one polyolefin tape. 
     
     
         9 . An article according to  claim 1  wherein the monolayers are woven monolayers. 
     
     
         10 . An article according to  claim 1  wherein the monolayers are unidirectional monolayers. 
     
     
         11 . An article according to  claim 1  wherein the polyolefin is ultrahigh molecular weight polyethylene (UHMWPE). 
     
     
         12 . An article according to  claim 1  having an upper surface, a lower surface and lateral sides and wherein a first fibrous wrap encircles at least a portion of said upper surface, said lower surface and at least one lateral side of said article; and wherein preferably, a second fibrous wrap encircles said article, the second fibrous wrap encircling the first fibrous wrap in a direction transverse to the encircling direction of the first fibrous wrap. 
     
     
         13 . An article according to  claim 12  wherein the fibrous wraps are a woven fabric comprising polyolefin tapes. 
     
     
         14 . A process for manufacturing an article according to  claim 1 , comprising the steps of:
 a. Providing a plurality of monolayers, said monolayers having an upper face and a lower face, at least part of said monolayers comprising at least one polyolefin tape;   b. Subjecting the upper and/or the lower face of at least a number of monolayers comprising at least one polyolefin tape to a flame treatment;   c. Stacking the monolayers in such a manner that in at least part of the stack, at least one of the two adjoining faces of adjacent monolayers comprising at least one polyolefin tape is flame treated; and   d. Compressing the stacked monolayers under a pressure of at least 50 bars at a temperature below the peak temperature of melting (T m ) of said polyolefin tape, said T m  being determined by DSC under restrained conditions.   
     
     
         15 . An armor, a vehicle, a building or a building component comprising the article of  claim 1 .