CS198616B1 - Method of preparing polyester and copolyester tows - Google Patents

Description

The invention relates to the preparation of polyester and copolyester cables for heating

-. . Cutting Converters Lets you prepare a polyester cable with a very high uniformity of properties important to the converter technology, through a short production process.

It is now known that the decisive criterion for good processability of pelyester cables on converters is the uniformity of the geometric and surface properties of the fiber. For example, uniform fiber elongation can be achieved by drawing the fiber ha rif 'elongating a ratio of about 1: 3 to 1: 5 in hot water at temperatures close to the temperature of the glass fiber transition. This method entails drawing věak disadvantage topics) that further-jo operations necessary to ensure the crystallization of the fiber and its výsuěoní so that 4>^yl; á é e ^Λ ná uniform deposition of the preparation upon final softening. Currently, ^seven shifting setoho dosahujeza- II stage stretching in water at 90 ° C for one with extra fiber dodlužujo? And inclusion calender one fixation takes place under tension, and drying the fibers before avivováním.

This procedure is demanding both in the design and maintenance of the attenuator and in energy consumption.

The process proposed in the application makes it possible to combine crystallization, extension and drying ^of polyester and copolyester cables into one operation. The cable, after drawing in a water bath in the 1st drawing zone, is heated in the II, zone to a temperature of 100 to 200 ° C and at the same time to a drawing ratio of 1: 0.9 to 1.3. In the second attenuation zone, however, a device for heating the filament with a stream of hot air or superheated steam is installed on the spent grains of the hot water channel. The cable treated in this way is only softened, crimped and fixed in the free state in the dryer,

In contrast to the method used to produce cables in the II. attenuation zone Integrated three technological operations: adjustment of physico-mechanical properties, fibers by extension (strength, ductility, modulus); stress crystallization which improves some of the utility properties of the fiber (tensile recovery properties, flexural recovery angle, sorption properties, etc.); surface properties, in particular by uniformly drying the fiber before entering the fabric softener bath, thereby achieving the necessary processing properties for the converter technology (friction coefficients, antistatic treatment of the fiber, etc.).

Example 1

In the pilot plant, the polyethylene terephthalate fiber was drawn in zone 1 to a longitudinal ratio of 1: 3.8 at a hot water channel temperature of 70 ° C. In the second zone at a long ratio of 1: 1.05 and a hot air temperature of 170 ° C. Then the cable entered the fabric softener bath, was crimped and fixed at 135 ° C in the free state in an oven. During drawing and the resultant fiber, the properties listed in Table 1 were achieved.

Example 2

A copolyaster fiber containing 2 moles was drawn on the same pilot plant. % sulfoisophthalic acid, at a draw ratio of 1: 4.1 and a water temperature of 66 ° C v. drawing zone. Ve II. A zone ratio of 1: 1.12 was then set and the hot air temperature was 140 ° C. The cable was then fabricated, crimped and fixed in the free state at 125 ° C. During drawing and the resulting fiber, the properties listed in Table 1 were achieved,

Parameter Thread properties from the example

2

Moisture of cable behind I. longitudinal zone (%) 15 - 20 15 - 23 Cable humidity before fabric softening (%) 2 2.3 Evenness of moisture before softening: (var. coefficient) longitudinal (%) 5.1 4.6 laterally (%) 6.5 6.3 dtex 4.6 4.5 average strength (oN / dtex) 5.2 3.2 elongation (%) 32 36 coefficients of friction: fiber - metal static 0.25 0.28 fiber - metal dynamo 0.33 0.40 . fiber - static fiber 0.48 0.49 fiber - dynamic fiber 0.31 0.35

/ The stated fiber parameters are comparable with the values achieved in the production of shear cables and the use of calenders.

At present, the proportion of polyester staple fibers is processed in the form of cutting and especially shredding cables. This technology saves many operations in textile processing and significantly improves the quality of the produced yarn. At the fiber manufacturer, however, cable production entails significantly higher energy requirements and requires substantial modification of the drawing lines. This application solves the technical difficulties and energy demands of existing cable production while maintaining the required quality.

Claims (1)

OBJECT OF THE INVENTION A method for preparing polyester and copolyester cables containing comonomer into 5 mol. % for tear-off and cutting converters drawn in zone I in water, characterized in that the fiber in zone II is heated to a temperature of 100 to 200 ° C, and simultaneously drawn to a draw ratio of 1: 0.9 to 1: 1.3; further is. softened, curved and fixed in a free state in an oven. 2. A method for producing polyester cables and copolyester cables according to claim 1, characterized in that to heat the fiber in II. zone, preferably using a stream of hot air or superheated steam.