DE2515603B2 - Process for the production of a deformable knitted fabric - Google Patents

Description

The manufacture of three-dimensionally shaped objects from textile materials using Deformation processes are becoming more and more interesting. For most of the deformation processes it has become common Coulierware, which has been knitted from thermoplastic stabilized continuous thread yarns, as special proven useful. Conventional coulier goods made from thermoplastic synthetic continuous filament yarns has been knitted, an area extension of up to 400% (means an area extension of 100% a doubling of the area of the goods when stretched in two directions at right angles), which but has proven to be inadequate when the goods are to be drawn particularly deep. The degree of The area of a conventional coulier fabric can be increased by making yarns undrawn threads are used. However, there are disadvantages such as fragility and lack of strength.

For certain deformation processes, conventional coulier goods made from yarns have already been used was knitted, which was made of stuffer box crimped, partially drawn, unfixed (i.e. unstabilized) Polyester staple fibers were made. The advantages of such a fabric are said to be that first, the total draw obtained during the deformation due to slippage is increased between the fibers and, secondly, the fabric is extremely stable, d. h "that he before the shrinkage has a surface extension which is at least several times smaller than that of a conventional knitted fabric made from stabilized continuous filament yarns. A disadvantage of this fabric in terms of stability it can be seen that

4) the amount of initial area extension is limited as a result

The invention was now based on the object of a method for producing a deformable To create knitted fabrics that have an extraordinary and previously unattained areal extension.

The object is achieved by the method described in the preceding claim 1

The precursor coulier fabric used in the process according to the invention has a low cover factor. This cover factor defines the openness of the textile. A fabric with such a low cover factor as required by the invention is normally worthless for direct use as a fabric. This unusual fabric has a loose and open structure with little tension. This desired construction is achieved in that the knitted fabric is produced under a sufficiently low knitting tension and with sufficiently large stitches so that a precursor coulier fabric with a surface area of at least 100%, preferably 100-200%, results. In addition to the requirement of this surface extension, the weight and light transmission properties of the precursor coulierware should be within certain ranges. The light transmittance of the textile dye is a measure of its cover factor, the designation being such that a lower cover factor means a greater percentage of light transmittance. A precursor coulierware is particularly suitable in accordance with the invention when the weight is in the range of 20 to 80 g / m ² and the light transmittance is in the range of 50-90% and when these properties are within the area ABCD of Figure 1 of the accompanying drawings.

The unstabilized or partially stabilized yarns for the precursor coulierware are yarns which have not been subjected to a treatment to permanently set the bulk of the yarn. It it is preferred that the bulk of the yarn not be fully developed. Bulky yarn of this type, which is made by false twisting and knitting processes are typical of those that are useful here.

With a certain knit construction of the forerunner woolen fabric and with a given bulk potential of the yarns used for this purpose, a low-denier yarn generally gives a higher one Area stretching in the textile fabric after the rolling pad treatment. The reason for this is probably because that a yarn with a lower denier is better able to do so within the knitted structure Develop bulge. Therefore, the decitex value of the yarn should preferably be in the range of 30 to 200 with a range of 50-170 being particularly favorable. The decitex values of the individual threads in a yarn are relatively high. For example, a polyamide thread yarn with 20 Threads and with 78 decitex is superior to a polyamide thread yarn with 34 threads and 78 decitex. It is preferred that the decitex values of the threads are between 3 and 10.

The relaxation treatment at an elevated temperature, which is considered to be a shrinkage of the goods The result is a linear shrinkage of the threads and a further development of bulk in it, the forerunner coulierware in a tumble dryer, which allows free relaxation in all directions

allows exposure to hot air. As a result of a With such a rolling ball treatment, the maximum areal stretch of the knitted fabric can be realized will. The final area extension is above the value that results from the loose, open construction the goods alone result in more than 450%. The surface extension is preferably in the Rolling ball treatment processed goods, measured at room temperature, in the range from 500 to 900%.

The yarns used in the process according to the invention are conventional thread yarns. Yarns where the threads have a heterogeneous structure are not suitable.

The length of time and the temperature of the rolling pad treatment depends on the type of material used Yarns and the particular circulation dryer used. You can, however, by simple experiment determine. In order to obtain a wrinkle-free product, it is desirable to apply the rolling pad treatment after Turn off the heat and continue until the goods have cooled down. Preferably, the goods are in a cold circulating dryer introduced whereupon the temperature during the required time on the The desired height is raised and then finally allowed to cool before the goods is removed. It is also preferred to put the goods in the tumble dryer in such a manner to introduce that the longitudinal extension of the goods coincides with the direction of movement of the machine.

The precursor coulier fabric according to the invention can be produced on flat bed or circular knitting machines or knitting machines which are suitable for producing jersey fabric. The cam settings of the machine are adjusted as much as possible in order to achieve a maximum mesh length in the fabric m . In order to ensure a minimum twine tension, the twine can be fed positively to the rolls of the machine. In order to counteract any tendency to twist in unstabilized or partially stabilized false-twisted yarns in a textile fabric, it is preferred to use yarns made from S and Z twist combinations.

Optionally, the fabric can be treated on a tenter frame so that

a) the fabric width can be regulated and

b) the stretch properties of the textile can be regulated in the longitudinal and transverse directions, i.e., they can be made equal if desired.

If the product is tubular, then it can be slit, after which an adhesive is then applied to the Edge can be applied. The knitted fabric produced according to the invention is particularly suitable for Deform. It can be drawn over a male mold or vacuum formed into one female form can be deformed. In the latter F ^ Il It may be necessary to place an impermeable membrane over the fabric so that it is inside the female Form the necessary pressure drop can be generated. Achieving the desired shape can then go through Application of heat and / or through the use of a softener that is compatible with the textile material, for example water in polyamide yarns.

The goods can be provided with a covering made of a thermoplastic material, for example with polyvinyl chloride before being deformed

is used to produce a coated, deformed fabric suitable, for example, for upholstery. Resin and plastisol finishes can be applied to the underside of the goods, ie on the d ^: e side that is opposite the mold surface, before molding is carried out in order to achieve good deformation behavior. For example, polyethylene and acrylic resins can optionally be used to aid in maintaining the shape of the molded article.

The goods produced according to the invention can serve as stretch and pressure bandages. Such will be preferably knitted on flat bed machines with a suitable border knitted in.

If elevated temperatures are used during the forming process, the Cool molded goods in the mold. Accelerated cooling conditions can be used here, by circulating a cooling medium through the mold.

Suitable deformation temperatures for deforming of a goods according to the invention lie within the range from 125 to 150 ° C.

The invention is illustrated in more detail by the following examples

example 1

A coulier fabric with a smooth simple jersey construction was made on a 28 gauge jersey machine made with a width of 76.2 cm. The machine was set so that a maximum Mesh size and minimum yarn tension was obtained. The goods were made from a shrinkable, partially stabilized, wrongly twisted, bulked yarn made from 10 polyamide-6,6 continuous filaments and knitted with a total decitex of 33. Owned the goods coming out of the machine following properties:

weight 21 g / m ² Light transmission 73% Area extension over 100%

The goods were then relaxed as follows.

Lie goods were circulated in the opposite direction in hot air, starting at 55 ° C and the Temperature then increased to 9CC for 25 minutes and finally again over a period of 10 minutes was lowered to 55 ° C. The goods were constantly being turned over. The goods received had a area extension of 820%.

The relaxed product produced in this way was then loaded under various conditions in order to achieve the to produce the greatest surface extension, and let it relax again, whereupon the permanent increase of the areas was measured.

conditions Exposure at room temperature Permanent Load currency ^r end dry Fliichin ^ unfeeling I. Heating to 140 C 22% II Strain during humid 135% Heating to 140 C III Strain during humid 300% Heating to 140 ° C and IV treated with acrylic resin 430% finish with 90 g / m ^J

Example 2

A textile fabric made of a shrinkable, Partially stabilized polyamide 6,6 continuous filament yarn with 20 threads that has been bulked up by false twisting and knitted in 78 decitex on an 80 gauge machine 66 cm wide. It was creates a smooth single jersey construction. The machine was set so that a maximum Stitch length and minimum yarn tension were obtained. The one coming out of the machine Textile fabric had the following properties:

weight .35 g / m ' I. opaque kit 65% Surface expansion 150%

weight
Area extension

117 g / m ²
750%

Weight 41 g / m ²

Translucent wedge 70%

Area extension 100%

The goods were bulked min in air at 90 ⁰ C in a 5 by Umwälztrockner during relaxation. It had the following characteristics:

The fabric was then put on a masquerade dyeing machine Washed with a biodegradable Dctcrgcnz 20 min at 40 to 45 ° C and then dry-closed. Kr was then finally slackened in air at 88 ° C in a tumble dryer bulked for 5 min. The relaxed fabric had the following properties:

Weight 96 g / m- '

Area stretching 600%

After slitting, the goods were stretched in a frame to a width of 91.4 cm, a temperature of 210 ^° C. and a dwell time of 30 seconds being used. The characteristics of the finished goods were as follows:

Weight 85 g / m

Area stretching 550%

Example 3

A fabric was made from a shrinkable one, not stabilized, false-twisted, polyamide 6.6 continuous filament yarn load with 20 and with a total of 78 Decitex on a 70 Gaugc machine and made with a diameter of 7.7 cm. The Mr. Schinc was so set that the limpest Quality of the goods was received. The goods leaving the machine had the following properties:

Weight 60 g / m ²

light transmission 51%

Area extension 200%

The fabric was relaxed in air at 88 ^C C for 5 minutes in a Umwälztrockner under bulking. The relaxed wat j was then steam ironed by hand. She possessed the following characteristics;

The product was suitable as a tubular shape-retaining material Bandage.

Example 4

A fabric was knitted according to the conditions of Example 2, except that a 15-thread shrinkable, unstabilized and false twisted polyester thread with 85 decitex is used became. The fabric coming out of the machine had the following properties:

weight
Area extension

119 g / m- '
450%

Example 5

Under the conditions described in Example 2 ι - that a product is knitted, but a shrinkable, unstabilisieries falschgezwirntcs bulked continuous filament polyamide 66 _w ith 78 decitex and 17 filaments was used. The fabric coming out of the machine had the following: n Properties:

Weight 36 g / m ⁷

I. opacity 70%

Area extension 200%

After a relaxation bulking in hot air at 88 C in a tumble dryer for development the maximum bulkiness, the product had the following properties:

Weight 140 g / m ²

"'Area extension 870%

After slitting, the goods were stretched in a frame to a width of 91.4 cm and 30 seconds heated to 210 ° C. After that, she owned the following r> Characteristics:

weight
Area extension

120 g / m ²
630%

Example 6

Example 2 was made using shrinkable. unstabilized. puffed up by false twists Polyamide 6.6 continuous filament yarns with

a) 78 Decitex and 13 threads and

b) 78 decitex and 10 threads

repeated. The goods coming out of the machine had the following properties:

away)

41 37 65 75 100 > 100

Weight (g / m ^:)
Light transmission (%)
Area extension (%)

After relaxation, the goods had the following properties:

away)

Weight (g / m ² ) 161 176

Area extension (%) 970 1200

After slitting and tensioning in a frame to a width of 91.4 cm, the properties were as follows:

away)

Weight (g / m ² ) 132 123

Area extension (%) 680 700

Example A.
(Comparative example)

Example 4 was repeated with the modification that a stabilized, bulked by calf twisting Polyester filament yarn made of 15 threads and with a total of 85 Decitex was used. The fabric leaving the machine had the following properties:

Weight 39 g / m- '

Light transmission 70%

Area extension 90%

After bulking by relaxation in the manner described in Example 4, the fabric possessed following properties:

Weight J9 g / m · '

Area extension 90%

This example shows that although a commodity with regard to

dC3 GCiViChiS und uCr LiChidürcriiHSaigKCu ϊΠΓιϋΓιιΞιυ vjCF area ABCD of F i g. 1, but nevertheless no product according to the invention is obtained if the starting material is not capable of developing bulk and does not have sufficient initial surface extension.

Example B.
(Comparative example)

According to the conditions described in Example 2, a product was knitted with the modification that the The yarn used was a doubled, shrinkable, partially stabilized, puffed up by false twisting 20 filament, 78 decitex polyamide 6,6 continuous filament yarn. The goods leaving the machine owned following properties:

Weight 58 g / m ²

Light transmission 60%

Area extension 65%

After circulation drying in hot air at 88 ° C, the product was with a maximum exchangeability and with the following properties:

weight
Area extension

254 g / n
240%

This example shows that a fabric made from a bulkable yarn and having initial weight and light transmission characteristics within the area ABCD of Figure 1 will not result in a finished fabric according to the invention if the initial surface area is less than 100%.

Determination of the area extension

This is determined by the fact that on a sample If a circle is drawn that corresponds to the area Xi This sample is then drawn by hand over a male mold until the stretching stops, whereupon the final area of the circle is determined, which is to be denoted by X2. The percentage area extension is then given by the following equation:

Determination of light transmission

X ₂ - X ₁

χ 100 The light transmission quantities are based on samples made, immediately after exiting the knitting machine, because the possibility exists that the goods will bag up spontaneously when left to stand at room temperature.

The device for determining the light permeability of goods is shown in FIGS. 2 and 3 and consists of an energy source 1, which feeds a projection lamp 2 and a bridge circuit A (see FIG. 3), and of a rectangular box which is divided into three rooms 3a, 36 and 3c.

The space 3b contains a light-sensitive cell 4, and the space 3c accommodates the bridge wiring of FIG. A micro-ammeter 5 is attached to its outside.

The box has a cross-section of 11 cm and: -. ~ ..f ": _". rij ... pj ™ u ;; _c mounted. Λη the front of the section; 3a is a central circular opening 6. The filament of the lamp 2 is 5.5 cm above the base plate and on a common horizontal axis, v.ciche connects the centers of the circular openings 6 and 7. The section 3a is 18.5 cm long and separated from the space 3b by a sample slot 8. The photosensitive cell 4 is located at a distance of 4 cm from the opening 7 of the section 3b, namely centrally on the common horizontal axis of the openings 6 and 7. It is shielded by a tube 9 which has the same inner diameter as that of the opening 7.

A pen frame, which is used to attach textile samples, consists of a piece of cardboard with a 10 cm square cutout with one side of the square open. Around the on the other three sides are pins 1 cm apart and also 1 cm in from the edge of the square appropriate

^{A 10 cm 2} hatch is marked on the fabric sample. The sample to be examined is cut out, leaving a 5 cm waste edge around the marked area. The sample is attached to the pen frame so that the sides of the marked square of the sample coincide with the cutout of the pen frame. The frame thus provided with the sample is then placed in the slot 8 of the apparatus so that the sample lies flat when it is in the slot.

The light source is then switched on and the measurement result is noted. The exam is with repeated two more samples of the same fabric

The reading is then repeated with the light source with no fabric attached. This reading corresponds to 100% light transmission. The amount of light that the light-sensitive cell 4 exposed is reduced by neutral filters of known light transmission, and those of each filter corresponding reading is noted. These results are used to graph the readings in percentage light transmission drawn, from which the percentage light transmission for the respective Fabric can be found

For this purpose 2 sheets of drawings

Claims (5)

Patent claims: 1. A method for producing a deformable knitted fabric, characterized in that that first using a shrink ba- => ren, unstabilized or partially stabilized bulked or potentially bulkable polyester or Polyamide yarn made from endless threads a precursor fabric with a loose and open structure is made so that it has a surface area of at least 100%, and that subsequently the bulkiness in the precursor coulierware by a rolling pad treatment in Air is developed at an elevated temperature, so that the knitted fabric has an areal extension of possesses at least 450 °. 2. The method according to claim 1, characterized in that the Vorläufercoulierware is produced so that its weight and light transmission properties within the area A BCD of the F i g. 1 of the drawings. 3. The method according to claim 1 or 2, characterized in that ais yarn is twisted by a thread made bulk yarn is used. 4. The method according to any one of claims 1 to 3, 2 ^r > characterized in that the surface extension of the precursor coulierware is within the range of 100 to 200%. 5. The method according to any one of claims 1 to 4, characterized in that the surface stretch jo kung after the rolling ball treatment is within the range of 500 to 900%.