US20080214081A1

US20080214081A1 - Fabric

Info

Publication number: US20080214081A1
Application number: US10/599,381
Authority: US
Inventors: Wolfgang Quednau
Original assignee: Mewa Textil Service AG and Co Management OHG
Current assignee: Mewa Textil Service AG and Co Management OHG
Priority date: 2004-03-27
Filing date: 2005-03-24
Publication date: 2008-09-04
Also published as: DE102004015138A1; EP1740064A1; WO2005092132A1

Abstract

The aim of the invention is to create a fabric for protective clothing that provides protection especially from liquid aluminum splashes while being very comfortable to wear and being usable in an industrial washing and drying process. Said aim is achieved by supplying the fiber components wool (fiber component A), thermoplastic fibers, particularly polyamide and/or polyester fibers (fiber component B), and modacryl (fiber component C), the ratio of each individual fiber component ranging between 5 and 55 percent by weight.

Description

The invention relates to a fabric for protective clothing, in particular for protection against liquid aluminum spatters.

BACKGROUND

In many jobs, risks for the personnel are imaginable due to the specific environment, for example through mechanical, chemical, biological, electrical and/or thermal influences. To avoid impairments, protective clothing is used in many areas. By protective clothing, one understands in this connection in particular a personal protective outfit meant to protect the human body, in particular trunk, arms and legs, against damaging influences during work.
The different designs of protective clothing can protect against one or more damaging influences. The protective effect of the protective clothing depends on the design of the clothing, essentially, however, on the properties of the fabric and materials used. All protective clothing has to fulfill, in addition to its specific protective function, a multitude of different requirements concerning in particular the wearing comfort, so that such clothing is accepted and actually worn by the user who is exposed to the particular risks.
Concerning the wearing comfort, the weight of the clothing, its breathing capacity, humidity-absorbing capacity, tactile properties and kindness to the skin play a particularly important role. Depending on the application, sufficient abrasion resistance and wear resistance are also important. In addition to a comfortable design of the cut, enabling, for example, sufficient freedom of movement, the wearing comfort is mainly determined by the transfer of heat and humidity as well as the air permeability of the clothing material or of the fabric.
Protective clothing has to fulfill manifold requirements from the point of view of safety engineering, which are usually fixed by national or international standards. For example, the protective fabric of the protective clothing of industrial workers exposed to heat, with the exception of protective clothing for firemen and welders, has to be in conformity with the requirements defined in the European standard EN 531. Such protective clothing is meant to protect against short-time contact with flames and/or radiation heat, large melted metal spatters or combinations of these risks.
Especially the material aluminum is increasingly applied in the industry, due to its specific properties, such as, for example, low weight (lightweight constructions) combined with relatively good workability. In view of the relatively low melting point of 660° C., it can be processed particularly well. In addition, aluminum is characterized by a low density of 2.7 g/cm³and is, therefore, increasingly used as a light metal in many branches of industry. It is used, for example, as a profile, pipe, sheet or forged piece for component parts, such as, for example, heat exchangers in the automotive industry, in the form of wire as electrical lines, in the form of foils as packaging material and insulation material, and others.
However, with the increasing application of the material aluminum, the particular risks connected with its processing, which is predominantly effected in liquid state, are gaining more and more importance. Consequently, it is becoming more and more important to provide the personnel handling the material aluminum, in particular in liquid state, with protective clothing. Therefore, the European standard EN 531 (ISO 11612) for protective clothing for workers exposed to heat explicitly regulates the requirements imposed on protective clothing for protection against liquid aluminum spatters through code D with the classifications D1, D2 and D3 for increasing intensity of risk.
The above-mentioned standard demands a protection in case of short-time contact with flames. Such a protection will be guaranteed, among others, when the fabric of the protective clothing does not continue to burn after contact with flames and does not drip off, burning or melting, as this may cause injuries and further the spreading of an initially local source of fire. When working with liquid aluminum, the protective clothing shall in particular avoid burns through contact with the hot metal. At present, the fabrics providing sufficient protection against liquid aluminum spatters usually consist of 50% wool and 50% viscose or polyvinyl alcohol. Wool is less flammable than cotton and linen, and is, like viscose, breathing as well as temperature-compensating, while the synthetic fibers polyvinyl alcohol or viscose provide for good forming properties.
When working with liquid aluminum material, the clothing will usually be soiled to such an extent that the dirt may also lead to the impairment of fundamental safety requirements, such as, for example, the restricted spreading of flames. For this reason, a frequent cleaning of the protective clothing is necessary for the very maintenance of the safety standard. For organizational reasons, this can usually only be achieved in a satisfactory manner by an automated industrial washing process for the protective clothing. In this connection, it is, however, a problem that the industrial washing and drying will destroy or at least impair the wearing comfort and in particular the protective effect through the mechanical and/or chemical treatment and stress. Therefore, the fabric of the type of clothing in question should be suitable for an industrial washing and drying process, i.e. it should stand many of such washing and drying cycles without shrinking, wrinkling, seam crimping, etc. and in particular without substantial deterioration of its heat and fire-protection properties. The fibers of the above-mentioned type are, however, in this composition unsuitable for an industrial washing and drying process, as the wool will usually become felted through this treatment and the viscose and polyvinyl alcohol do not possess sufficient thermal stability for the drying and smoothing process and, due to the high degree of shrinkage, the fundamental safety requirements would no longer be fulfilled.

SUMMARY OF THE INVENTION

Based on the above, it is an object of the invention to provide a fabric of the above-mentioned type which is especially designed for protection against liquid aluminum spatters and fulfills the associated safety requirements, in particular in view of the European standard EN 531 (ISO 11612) with code D, even after a multitude of industrial washing and drying operations, without impairment of the wearing comfort.
This problem is solved according to the invention by a fabric containing the fiber components wool (fiber component A), thermoplastic fibers, in particular polyamide and/or polyester fibers, (fiber component B), and modacryl (fiber component C), the share of each individual fiber component lying between 5 and 55% in weight (percent in weight).
Modacryl, defined, for example, under the designation MAC acc. to DIN 60 00, 1, essentially comprises fibers of linear macromolecules, whose chains are composed of more than 50 and less than 85% in weight of acrylonitrile.
The invention is based on the consideration that especially in view of the usability in industrial washing and drying processes, a specific strengthening of the fabric should be provided. It is based in particular on the knowledge that the fabric used up to now for protection against liquid aluminum spatters is altered by the industrial washing and finishing process in such a way that detrimental impairments of its heat and fire-protection properties and also of the wearing comfort cannot be excluded. The volume of charges or loads of industrial washing machines is clearly higher than that of normal household washing machines. This leads to a considerably higher mechanical stress to the material to be washed. Furthermore, in an industrial washing process, washing agents and auxiliary agents are used which clean considerably more efficiently and, therefore, also stress the material to be washed to a considerably higher degree—as is generally known, the alkalinity of the washing bath in an industrial washing process is always clearly higher than in a household. Furthermore, drying is effected in an industrial washing process, among others, preferably by a so-called hot-air finishing process. The clothing to be dried is exposed to a hot air flow of 160° C.; this stress is also clearly higher than in a household laundering process.
To protect the wearer against liquid aluminum spatters even after a multitude of industrial washing and drying operations, as defined in particular in the test procedure acc. to ISO 15797, the fabric of the protective clothing should be finished in such a way that it stands the above-mentioned stress without losing the safety protection through chemical and mechanical alterations, nor the wearing comfort, for example through becoming felted, deformations, seam crimping and the like. Accordingly, a fiber component should be provided which guarantees a corresponding resistance of the fabric to the above-mentioned specific stresses, without impairing its protective properties. The high stability requirements imposed on the fibers should, however, not deteriorate the wearing comfort beyond a certain degree.
Protective clothing is in general made of natural, synthetic and special fibers. The vegetable natural fiber cotton shows after an increasing number of washing or cleaning processes a loss of tear strength, which reduces the mechanical stress-bearing capacity. Furthermore, clothing made of pure cotton tends to shrinking when washed. Cotton fabric burns under carbonization and can be made more resistant against flames and inflammation through glowing metal and cinder spatters by means of a corresponding finishing, e.g. with Aflamman and Pyrovatex and others. However, it has to be taken into account that the protective effect of the finishing may be destroyed through washing and has to be renewed for several finishing means, depending on the number of cleaning treatments. The animal natural fiber wool, on the other hand, is less flammable by nature. When washing it, it must be taken into account, however, that wool becomes felted with washing temperatures over 40° C.
Synthetic fibers, e.g. the synthetic fibers polyamide, polyester and others, generally possess higher strength and better laundering properties than natural fibers.
Surprisingly, it turned out that a fabric mixture consisting of the fiber components wool (fiber component A), thermoplastic fibers, in particular polyamide and/or polyester fibers, (fiber component B), and modacryl (fiber component C) with a share of each individual fiber component between 5 and 55% in weight fulfills the requirements of an efficient protection against liquid aluminum spatters and of a constant wearing comfort even after a multitude of washing and drying operations.
The above-mentioned fiber components possess, for example, a relatively low heat-transfer resistance R_ct, i.e. a relatively high thermal conductivity, as compared with meta and para-aramids, so that heat or thermal energy can be dissipated well and does not focus on one contact point.
Wool offers sufficient protection against liquid aluminum spatters. Furthermore, this fiber component has a breathing and temperature-compensating effect. Polyamide fibers and polyester fibers are light-weight, possess a low tendency to wrinkling and retain their dimensional stability even under the influence of humidity, they have a high capacity of humidity transportation and dry quickly; their high strength guarantees an extraordinary durability. Through the use of modacryl fibers, which are also dimensionally stable and dry quickly, the share of wool can be reduced, thus reducing the tendency to becoming felted. Therefore, the fabric with the before-mentioned fiber components is easy-care and durable and guarantees high wearing comfort and multiple industrial washability, offering at the same time sufficient thermal protection, in particular a protection in conformity with standards, against liquid aluminum spatters.
In order to further improve the stress-bearing capacity against aluminum spatters, maintaining a high wearing comfort, flame-resistant viscose (FR) with a share of 5 to 55% in weight is advantageously provided as a further fiber component (fiber component D). It is especially the fiber component D that contributes considerably to a high wearing comfort.
In a preferred fabric, the fiber components A, C and D together amount to 55 to 95% in weight. A particularly preferred fabric contains 10 to 50% in weight of fiber component A, 5 to 45% in weight of fiber component B, 5 to 55% in weight of fiber component C, and 5 to 40% in weight of fiber component D.
In wool production, mainly three wool categories play a part, the designations of which go back to the respective sheep genera. One distinguishes above all between the merino wool with fine, short and very frizzy wool hairs and the cheviot wools with long, only slightly frizzy, strong and shining wool hairs. The third category is the crossbred wools. These are a mixture of merino and cheviot wools. Their hairs are of medium length, medium thickness and little frizziness. To provide for a particularly high wearing comfort of the protective clothing, preferably merino wool, preferably of fineness AB or finer, which due to its softness is particularly kind to the skin and breathing, is used as fiber component A of the fabric. The fineness is indicated in the usual categories, the fineness of category AB corresponding to a fiber diameter of 21 to 22 μm.
In order to effectively avoid an irreversible felting shrinkage of the fabric during industrial washing and subsequent drying, the fiber component A, whose fiber flakes would otherwise catch on each other under the influence of heat, water and motion, is advantageously provided with an antifelt finish.
To avoid a felting of the wool, various antifelt finishing procedures are applied on an industrial scale. For applying a finish on the formed planar body, the flake edges can in particular be smoothed by oxidative reduction (oxidative treatment) or polymers can be used with the objective to coat the fiber surface or to conglutinate individual fibers with each other (additive treatment). For manufacturing a fully machine-washable fabric, the antifelt finish of the fiber component A is preferably effected through a combination of oxidative and additive treatment.
For haptic reasons, the antifelt finish is preferably effected in the flock, i.e. in unspun state of the textile fiber. In this way, a roughening up or hardening, which might otherwise be caused by a subsequent finish in the yarn or fabric, is avoided, and consequently, an agreeable, soft feel of the fabric is achieved.
The way in which horizontal threads, so-called weft threads, and vertical threads, so-called warp threads, interlace in a fabric, is called the weave. While in a so-called linen weave or plain weave, the weft thread runs alternately in front of and behind one warp thread, the so-called twill weave is characterized by the fact that the weft thread in the first weaving row, for example, runs alternately in front of and behind two warp threads (2/2 twill). In the second row, this is offset by one thread each, so that a diagonal weaving pattern is created. There are numerous variations of twill weave, like diamond and pointed twill or herringbone twill, 2/1 twill, in which the weft thread runs in front of two warp threads and behind one warp thread.
For a slightly structured surface and a relatively stable and firm weave, the fabric for the protective clothing is advantageously made with a twill weave, preferably a 2/1 twill weave. In an alternative advantageous embodiment, also a 3/1 twill weave can be provided.
The area weight of the fabric is preferably approximately 350 g/m². With that, the fabric is in any case in conformity with the classification or efficiency level D2 within the framework of the standard EN 531.
Particularly favorable properties of the fabric can be achieved by manufacturing it advantageously from a fiber yarn with a yarn count of Nm 10 or 20/2 or 30/3 or 40/4 to Nm 38 or 76/2, preferably of approximately 38/2 to 40/2.
A particularly favorable design of the fabric can be achieved by advantageously manufacturing it in the warp with a set of 20 to 50 threads/cm, preferably of approx. 36.8 threads/cm, and in the weft with a set of 15 to 45 threads/cm, preferably of approx. 21.6 threads/cm, as it turned out that the use of such a set with the above-mentioned yarn count, in particular when using the above-mentioned twill weave, will result in a fabric with a microstructured surface showing a particularly favorable beading-off behavior to impacting liquidity spatters. Thus, the fabric possesses clearly more favorable properties than a relatively smoother fabric, which would be created, for example, by a linen weave.
Advantageously, the above-mentioned fabric is used for the manufacture of protective clothing, in particular for protection against liquid aluminum spatters. Preferably, the fabric is used for the manufacture of protective clothing provided for industrial washing and drying procedures.
One characteristic parameter for classifying yarns, defined in addition to other parameters, e.g. in “Technische Berechnungen: Spinnerei, Weberei, Wirkerei, Strickerei”, R. Löcker et al., Bussesche Verlagshandlung GmbH, Herford (1969), in particular page 58 seqq., is the so-called coefficient of twist α_metricfor single yarn. To guarantee for the fabric in question, on the hand, a sufficiently high fiber strength, but to avoid, on the other hand, excessive hairiness or pilling effects due to twitting, the fabric is preferably made of a fiber yarn with a coefficient of twist α_metricof less than 125, preferably of more than 84 and in a particularly advantageous design, of approx. 90 to 110, in particular of approx. 100. The choice of such design parameters takes into account in particular the knowledge that excessive hairiness or pilling effects could be detrimental to the beading-off behavior to liquid metal spatters.
The advantages achieved with the invention consist in particular in the fact that a fabric with the fiber components wool (fiber component A), thermoplastic fibers, in particular polyamide and/or polyester fibers, (fiber component B), modacryl (fiber component C) and preferably flame-resistant (FR) viscose (fiber component D) with a share of each individual fiber components between 5 and 55% in weight will protect the wearer of protective clothing manufactured from this fabric even after a multitude of washing and drying operations, maintaining a constant wearing comfort, in conformity with the safety requirements of the European standard EN 531 (ISO 11612) with code D, against the risks of being injured by liquid aluminum spatters. For fabrics manufactured in this way, safety level D2 of the before-mentioned standard is guaranteed already with an area weight of 350 g/cm², even after 30 or more washing cycles. For a fabric that needs only to comply with safety level D1, clearly lower area weights can be realized; furthermore, with a sufficiently high area weight, even the requirements of safety level D3 can be fulfilled. Due to the particularly favorable beading-off properties, such a fabric is also particularly well suited for manufacturing protective clothing for protection against liquid spatters of other metals or materials, such as, for example, copper or brass.

DETAILED DESCRIPTION

The following are some embodiment examples for the manufacture of the fabric:

Example 1

A fabric with a 2/1 twill weave, with 36.8 warp threads and 21.6 weft threads pro cm and a specific area weight of 344 g/m²was manufactured from 30 weight shares of wool fibers, 20 weight shares of polyamide fibers, 25 weight shares of modacryl fibers, and 25 weight shares of viscose FR fibers. The threads were obtained in the usual way by manufacturing the single fibers in a homogeneous mixture as mixed-fiber yarn and ply yarn Nm 38/2 (“number metric thirty-eight double”). The wool used was a merino wool provided with an antifelt finish. The antifelt finish was effected in the flock.

Example 2

A fabric with a 2/1 twill weave, with 37 warp threads and 21.6 weft threads pro cm and a specific area weight of 330 g/m²was manufactured from 30 weight shares of wool fibers, 20 weight shares of polyamide fibers, 25 weight shares of modacryl fibers, and 25 weight shares of viscose FR fibers. The threads were obtained in the usual way by manufacturing the single fibers in a homogeneous mixture as mixed-fiber yarn and ply yarn Nm 40/2 (“number metric forty double”). The wool used was a merino wool provided with an antifelt finish.

Example 3

A fabric with a 2/1 twill weave, with 36.8 warp threads and 21.6 weft threads pro cm and a specific area weight of 344 g/m²was manufactured from 30 weight shares of wool fibers, 10 weight shares of polyester fibers, 20 weight shares of modacryl fibers, and 40 weight shares of viscose FR fibers. The threads were obtained in the usual way by manufacturing the single fibers in a homogeneous mixture as mixed-fiber yarn and ply yarn Nm 38/2 (“number metric thirty-eight double”). The wool used was a merino wool provided with an antifelt finish.

Claims

1-14. (canceled)

15: A fabric for protective clothing, in particular for protection against liquid aluminum spatters, the fabric comprising:

a plurality of fibers containing the following fiber components:

wool (fiber component A),

thermoplastic fibers, (fiber component B), and

modacryl (fiber component C),

wherein the share of each individual fiber component is between 5 and 55% in weight.

16: The fabric as recited in claim 15, wherein the thermoplastic fibers include at least one of polyamide and polyester fibers

17: The fabric as recited in claim 15, wherein the plurality of fibers contain flame-resistant viscose (FR) with a share of 5 to 55% in weight as a further fiber component (fiber component D).

18: The fabric as recited in claim 15, wherein the share of the fiber component B amounts to maximally 45% in weight.

19: The fabric as recited in claim 15, wherein the fiber share

for fiber component A amounts to 10-50% in weight,

for fiber component B amounts to 5-45% in weight,

for fiber component C amounts to 5-55% in weight, and

for fiber component D amounts to 0-40% in weight.

20: The fabric as recited in claim 15, wherein fiber component A includes merino wool.

21: The fabric as recited in claim 20, wherein the merino wool has a fineness AB or finer.

22: The fabric as recited in claim 15, wherein the fiber component A includes an antifelt finish.

23: The fabric as recited in claim 22, wherein the fiber component A is treated oxidatively and additively with polymers for the antifelt finish.

24: The fabric as recited in claim 22, wherein the antifelt finish is carried out in the flock.

25: The fabric as recited in claim 15, wherein the plurality of fibers are woven in a twill weave.

26: The fabric as recited in claim 25, wherein the twill weave is a twill 2/1 weave.

27: The fabric as recited in claim 15, wherein the fabric has area weight of approximately 350 g/m².

28: The fabric as recited in claim 15, wherein the plurality of fibers include a warp having fiber density of 20 to 50 threads/cm, and a weft having a fiber density of 15 to 45 threads/cm,

29: The fabric as recited in claim 28, wherein the warp has a fiber density of approximately 36.8 threads/cm and the weft has a fiber density of approximately 21.6 threads/cm.

30: The fabric as recited in claim 15, wherein the with a yarn count of Nm 10 or 20/2 or 30/3 or 40/4 to Nm 38 or 76/2.

31: The fabric as recited in claim 30, wherein the yarn count is 38/2 to 40/2.

32: The fabric as recited in claim 15, wherein the plurality of fibers form a fiber yarn with a coefficient of twist α_metricfor single yarn of less than 125.

33: The fabric as recited in claim 32, wherein the coefficient of twist is more than 84.

34: The fabric as recited in claim 32, wherein the coefficient of twist is approximately 90 to 110.