Process and an apparatus for producing coarse count and tridimensional crimped multifilament bcf yarns, yarns thus obtained and applications thereof

Abstract

The invention relates to a process and an apparatus for the production of coarse count and tridimensional crimped multifilament BCF (Bulk Continuous Filament) yarns, starting from polyamide 6.6, which envisages cooling in water and subsequent non-mechanical treatment with a mixture of air and steam, such that the yarns obtained have controlled chemical-physical and mechanical properties; the invention also relates to the yarns obtained by the aforesaid process and / or the aforesaid apparatus, both in a wound form in a cut form.The coarse count and tridimensional crimped multifilament BCF yarns having controlled chemical-physical and mechanical properties according to the present invention are suitable for non-textile applications and are preferably and advantageously employed in the manufacture of carpets for large surfaces.

Description

TECHNICAL FIELD[0001]The present invention relates to the field of yarns for non-textile applications and, specifically, to the production and use of multifilament BCF (Bulk Continuous Filament) yarns.[0002]More specifically, the present invention relates to the production and use of coarse count and tridimensional crimped multifilament BCF yarns having controlled chemical-physical and mechanical properties.[0003]More specifically, the present invention relates to a manufacturing process, and the relevant equipment for the production of coarse count and tridimensional crimped multifilament BCF yarns, starting from synthetic materials, in particular polyamide 6.6.[0004]Further, the present invention relates to yarns obtained by the aforesaid process or the aforesaid apparatus both in a wound form and in a cut form.[0005]The present invention finds preferred and beneficial application in non-textile applications, and particularly for the manufacture of carpets for large surfaces.State...

AI Technical Summary

Benefits of technology

The present invention aims to solve the problem of yarn interlacing, improve the homogeneity of BCF yarns, and control the physical-chemical and mechanical properties of yarns to create better products. The invention also aims to simplify the production process and reduce costs and material consumption.

Problems solved by technology

An example of a traditional process for the production of BCF yarns is described in the U.S. Pat. No. 6,776,943 B2, which envisages starting with polyamide 6 and performing the step of mechanical crimping by a jet of low speed and high temperature air; the BCF yarns produced with this process have an alpha-crystalline content of about 45% and a yarn hank shrinkage of less than about 12.7 mm (0.50 inches); the disadvantages of this solution consist mainly in the fact that the chemical and physical properties cannot be modified insofar as the conditions that determine them cannot be modified and in the fact that the mechanical crimping forces the yard to take a predefined path whereby the shapes obtained in the process (angles and arcs) cannot be varied.

In addition, the multifilament BCF yarns available generally have uncontrolled chemical-physical (specifically amorphicity / crystallinity degree, basicity and dyeing affinity) and mechanical (specifically elasticity and tenacity) properties.

The bidimensional crimping along with the uncontrolled chemical-physical and mechanical properties of the yarns is the root cause of poor agglomeration problems that occur during the carding of the same, resulting in unevenness of the carded fabric obtained.

To achieve workable multifilament BCF yarns in the manufacture of non-textile fabrics it is necessary to reach total counts equal to or greater than 4,000 dtex and this, up until now, has been achieved by means of twisting and cabling operations using multiple yarns; however, these fitting operations, in addition to making the tooling cycle longer and more complicated, also lead to stressing of the yarns and a consequent reduction in the quality thereof.

The need to produce multifilament BCF yarns with tridimensional crimping therefore remains unsatisfied.

Further, the need to control the chemical-physical and mechanical properties of the BCF yarns produced remains unsatisfied.

Finally, the need to produce multifilament BCF yarns with total counts equal to or greater than 4,000 dtex, preferably up to 8,000 dtex, and a count for single-filament up to more than ten times greater than those currently available remains unsatisfied.

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