Abstract: Fiber made of cellulose formate and fiber made of cellulose regenerated from cellulose formate. These fibers exhibit high tenacity and modulus properties, combined with improved values of elongation at break and of energy at break. Their elongation at break, in particular, is greater than 6%. Methods for producing these fibers. The fiber made of cellulose formate is obtained by spinning a liquid crystal solution of cellulose formate according to the so-called dry-jet-wet spinning method, the coagulation stage and the neutral washing stage which follow both being carried out in acetone. The fiber made of cellulose formate in a highly concentrated aqueous sodium hydroxide solution. The spinning and regeneration methods can be employed in line and continuously. Reinforcing assemblies based on such fibers. Articles reinforced by such fibers or assemblies, these reinforced articles being in particular tires.

Abstract: An aramid monofilament having high mechanical properties is provided. This monofilament has a slightly structured skin and resists fibrillation and abrasion. In addition, a process for the production of this monofilament is also provided. The process includes the following steps: (i) a solution of aromatic polyamide(s) is extruded as a liquid jet in a spinneret through a capillary; (ii) the jet is drawn from the capillary in a non-coagulating layer of fluid and (iii) the drawn liquid vein is introduced into a coagulating medium in order to form the monofilament, which is subsequently washed, dried and contacted with a solvent for said monofilament to produce the slightly structured skin. The aramid monofilament is characterized by the following relationships:1.7.ltoreq.Ti.ltoreq.260;50.ltoreq.D.ltoreq.480;T.gtoreq.180-D/3;Mi.gtoreq.1600;Ar>2.00; andEr>20.0 D/30.In the above relationship, Ti represents linear density in tex, D represents diameter in .mu.

Abstract: An aramid monofilament having high mechanical properties is provided. This monofilament has a slightly structured skin and resists fibrillation and abrasion. In addition, a process for the production of this monofilament is also provided. The process includes the following steps:(i) a solution of aromatic polyamide(s) is extruded as a liquid jet in a spinneret through a capillary; (ii) the jet is drawn from the capillary in a non-coagulating layer of fluid and (iii) the drawn liquid vein is introduced into a coagulating medium in order to form the monofilament, which is subsequently washed, dried and contacted with a solvent for said monofilament to produce the slightly structured skin. The aramid monofilament is characterized by the following relationships:1.7.ltoreq.Ti.ltoreq.260;40.ltoreq.D.ltoreq.480;T.gtoreq.180-D/3;Mi.gtoreq.1600;Ar>2.00; andEr>20-D/30.In the above relationship, Ti represents linear density in tex, D represents diameter in .mu.

Abstract: A reinforcement assemblage formed at least in part of continuous monofilaments of liquid crystal organic polymer or polymers, characterized by the following features:(a) the diameter D.sub.m of the monofilaments is at least equal to 40 .mu.m and less than 400 .mu.m;(b) the tenacity T.sub.a of the assemblage is greater than 80 cN/tex;(c) the secant tensile modulus M.sub.a of the assemblage is greater than 2000 cN/tex;(d) at least one of the monofilaments is practically wound helically around an axis, the acute angle .gamma. which each monofilament makes with this axis, which is assumed rectilinear, being less than 30.degree.;(e) the twist of each monofilament on itself is less than 10 turns per meter of assemblage.Articles reinforced by these assemblages, in particular automobile tires.

Abstract: An aramid monofilament (20), characterized by the fact that it has the following relationships: 1.7.ltoreq.Ti.ltoreq.260; 40.ltoreq.D.ltoreq.480; T.gtoreq.170-D/3; Mi.gtoreq.2000, Ti being the linear density in tex, D being the diameter in .mu.m, T being the tenacity in cN/tex, and Mi being the initial modulus in cN/tex for this monofilament.A method of obtaining said monofilament (20) in which a solution (2) of aromatic polyamide(s) is extruded in a spinneret (9), the jet is drawn into a non-coagulating layer of fluid (13), and the drawn liquid vein is introduced into a coagulating medium (19).Assemblies of such monofilaments. Articles reinforced by these monofilaments or these assemblies, such articles being for instance tires.