The invention relates to a method for the production of high-strength ribbons having a high modulus of elasticity made of a highly molecular polyolefin, wherein the polyolefins, particularly polypropylene and polyethylene, are extruded through a slotted nozzle, are then subjected to a temperature of 85° to 135° C. for a duration of at least one second, the films are then cut into individual ribbons, if necessary, and stretched at temperatures between 90° and 165° C. in one or more steps, are rolled up or further processed directly into textiles or technical flexible sheet materials. The ribbons can be laminated into multi-layer flexible sheet materials by using adhesives or adhesion promoters, the flexible sheet materials being particularly suitable as protection from ballistic projectiles. In this case particularly in the form of plate-shaped or flexible compound bodies.