Technical field and scope of the inventionThe invention is applicable to the automotive industry interior trim, namely seat covers. It belongs to the international patent classification B60N2/58.
The present invention relates to a wool textile fabric for automotive seat cover application. It is composed of natural fibres, primarily wool.
In any given car, 18% of textile raw material is applied to seat covers. The most popular fibres found in the textile industry are polyester, polyamide (nylon 6.6) and polypropynol. However, on a smaller scale we also come across acrylic, viscose, wool, cotton and aramid. Presently, polyester is the preferred fibre used in seat cover production.
Over the last 20 years, the usage of synthetic fibres in technical textiles has increased considerably and steadily. The continuous and noted development of synthetic fibres in more technical areas results in an average global increase of 4.1% per year, since 1970. The automotive industry and its diverse applications, has been the main instigator for this growth. As an example: the total weight of textiles found in the VW Golf I (1974-1983) was 2.3%. In the VW Golf IV (1977-2003) this figure had gone up to 7.8%.
The automotive market requires textile solutions that promote a new interior concept, more comfort, more environmental awareness and, when possible, offer overall vehicle weight reduction that will contribute to lower fuel consumptions. This tendency has given way to the progressive introduction of fabrics in other areas, as well as new ways of thinking about existing textile applications in an attempt to find environmentally friendly fabrics, and at the same time, increased functionality.
If we take into consideration the above, the invention in question offers a wool textile fabric to be applied to automotive seat covers. It combines functionality and technical characteristics that improve the comfort level, thermal efficiency and appearance as well as improving fabric upkeep without compromising wear and tear, and being affected by external agents that can affect the life cycle of this type of article.
We should also emphasize that sustainability was an important consideration in the selection of materials, technologies and processes. These functionalities were possible through usage of micro and/or nano materials together with functional additives in optimising the yarn fibrous composition, fabrics and structure - two and three dimensional:
- 1. Fibre composition:
- i. Fibre type
- ii. Content composition
- 2. Yarn production process
- i. Equipment set-up
- ii. Fibre processing control
- iii. Equipment rentability
- iv. Yarn structure and quality parameters
- 3. Weaving process:
- i. Equipment set-up
- ii. Equipment rentability
- 4. Functionality process:
- i. Technology selection
- ii. Optimisation of recipes and process parameters
- 5. Lamination:
- i. Technology selection
- ii. Application process optimisation of thermoplastic polymer by type
- iii. Concentration levels and other process parameters.
The research in the state of the art, carried out to access if the same invention had been thought about or created by other manufacturers, the following patent documents were identified:
- US 5617904 - D1 disclose a textile substrate development for woven or knitted seat covers (especially Raschel or Malimo), and contains at least 40% wool and 15% ramie, but always the combination of the two making up 85%. The substrate can be made up of wool and ramie only but can also include other fibres, preferably of animal or vegetable origin such as cotton, linen and hemp or another natural rubber. In order to obtain anti-static properties, metallic yarns may be added. Small quantities of synthetic fibres, such as polyester are also possible. The substrate can be made up of 80% wool yarn and 20% ramie yarn in the warp and ramie yarns in the weft. This type of substrate has excellent absorption and water retention properties and a high comfort level.
- US 5070915 - D2 disclose car seat covers where natural fibre content is higher than synthetic fibre content. The substrate includes a mix of natural yarns made up of wool fibres and/or ramie fibres. The substrate can contain 15% to 30% synthetic fibres such as polyester.
- US 5167264 - D3 disclose a textile substrate for car seat covers, which can be woven or knitted, especially raschel fabric, Malimo fabric or Malimo that contains 45% to 65% natural fibres whereas at least 40% is wool and 5% to 25% is ramie. It contains 35% to 55% synthetic fibres such as polypropylene, polyamide, polyacrylic, aramid and mostly polyester. In cases of woven or warp knit fabrics, the warp yarns can be synthetic and the weft a combination of wool and ramie or vice-versa, or in the warp and weft wool and ramie yarns as well as synthetic fibres.
- US 4555425 - D4 disclose textiles manufactured using specific sturdier yarns; typically carded yarns (for example, ring-spun yarn, OE yarn, MJS yarn, friction yarn), generally presenting low furriness and a low wool content. This is achieved in one or two of the textile surfaces; a remnant of fleece is present as the original wool fibre. The fibre penetrates the yarn structures through the substrate thickness.
- US 5806925 - D5 disclose to a car seat cover that is breathable and washable, through various layers where a pocket like structure fits over the top of the seat, having an elongated part that covers the front of the seat. The top layer includes an absorbent, the bottom layer blocks liquids and is vapour permeable. The top layer keeps the humidity away through evaporation; the bottom layer allows the fabric to breathe whilst blocking out water, sweat, mud etc., thus protecting the layers of fabric, contributing to a more comfortable seat. The fabrics used and the stand alone seat structure, facilitates seat fitting and cleaning. The lower layer, a polymeric membrane, gives the seat a rubber-like texture in order to prevent movement.
- US 3857727 - D6 disclose to flame resistant properties of natural fibres and synthetic polyamide. Particularly for wool and wool mixes, they are improved by an application of one organic chelate or by a titanium fluoride complex on the fibres, preferably for an enlargement of 0,2-2,5% calculated as titanium dioxide. The complexes can be dissolved in water and spray applied, padded on or via exhaust dyeing process. Alternatively, the complexes can be formulated in situ in liquid format by mixing the complex agent to soluble titanium in water or on the fibre, as by treatment with a solution of fibers in fluoride already treated with a titanium compound, which can be a chelating complex. Where the titanium complex is applied in a bath, the dye can be applied to the fibres at the same time or separately.
In fact, in the state of the art, products are disclosed in which the textile substrates developed for automotive seat covers are normally knitted, especially Raschel or Malimo, with a composition of 40% wool and 15% ramie. However, the current invention uses higher than 80% wool fibre content, improving even further odour neutralisation, dirt repellence, antimicrobial properties, UV protection, breathability, thermal insulation and overall comfort.
With regards to its multi-functionality, defined as the simultaneous incorporation of various functions without a decrease in individual effectiveness, we understand that there is no other product in existence. There is no similar product that contains the same wool fibre construction, high thermal resistance, breathability, odour neutralisation, antibacterial properties, UV protection and ease of cleanability that meets all technical requirements of a 100% polyester fabric used in automotive seats.
Tables 1, 2 and 3 show tests results carried out
for the technical specifications described,
Table 1| Test | Standard | Result Required |
| Abrasion Resistance Martindale | STD 1024, 7122 Pressure: 12kPa | Max grade 1: |
| - Light pilling |
| - 2 broken yarns |
| - 3 some whitening |
| Pilling | Volvo testing code 850 000 06 Pressure 415+/-2g | Minimum grade 4 |
| Resistance to Light | STD 1027,359 | Min of 4 - grey scale (change in colour not allowed) |
| Flammability | Volvo testing code VCS 5031,19 | Length: |
| - Maximum 80 mm/min Width: |
| - Máximum 80 mm/min |
| Cleanability | Volvo testing code 850 000 10A | Cleanabilty: |
| - Analyze stain formation Easy of cleaning: |
| - Grade 3 after cleaning |
| - No water marks visible |
| Velcro | Volvo testing code 850 000 25 | ≥ grade 4 |
| Seam strength (seat cover seams) | Volvo testing code 850 000 25 (breaking strength) | Checked with similar seams to those on seat covers |
| Linting | Volvo testing code 800 000 05 | Minimum grade 4 |
Table 2| Odour Neutralization |
| Test | Standard | Result Required |
| Smell - odour | VCS 1027, 2729 | ≤ 3 |
| Anti-bacterial properties |
| Test | Standard | Result Required |
| Antibacterial activity on finished goods | ISO 20743 | At least 80% ofstaphylococcus aureas |
| Cleanability |
| Test | Standard | Result Required |
| Cleanability | Volvo testing code 850 000 10A | Cleanabilty: |
| - Analyze stain formation Easy of cleaning: |
| - Grade 3 after cleaning |
| - No water marks visible |
Table 3| Thermal insulation |
| Test | Standard | Results Required |
| Specified value -state of the art | Result proposed in application |
| Thermal resistance | EN 12667 | Without foam: 0,0568 m2.K/W With foam: 0,1541 m2.K/W | Without foam: 0,062 m2.K/W With foam: 0,170 m2.K/W |
| EN 12939 |
| Breathability |
| Test | Standard | Results Required |
| Specified value-state of the art | Result proposed in application |
| Resistance to water vapour | EN 31092 | ≥ 40 m2.Pa/W | < 40 m2.Pa/W |
| ISO 11092 |
The present invention relates a wool textile fabric for automotive seat cover application which presents itself as a driving technical option for the automotive subsector. It is a multifunctional innovative structure composed of wool (over 80%), that offers technical and functional properties:
- Increased thermophysiological comfort, sensorial, ergonomic, psychological or aesthetic properties
- Easy to clean and to maintain
- Odour neutralisation
- Anti-microbial properties
- UV protection
These properties are possible by incorporating micro and/or nano materials as functional additives, to optimise the fibre composition of yarns and fabrics and through laminations with three dimensional structures.
For a better understanding of this invention, it is important to point out that regarding resistance, the unit of measurement is the resistance of the structure as a conductor of heat (m2.K/W). This is a global unit of measurement in terms of thermal insulation and its importance in the market in question is paramount. For the textiles currently in use, maximum heat resistance is 0,0568 m2.K/W and 0,1541 m2.K/W - fabrics laminated with foam.
In line with the above and with regards to the thermal resistance of our invention - face fabric only, the values obtained are 0,062 m2.K/W (0,170 m2.K/W - once the fabric has been laminated with foam).
Resistance to water vapour is an important test parameter that determines the breathability level of the car seat structure. In turn, it is a key characteristic for drivers with high levels of perspiration. Values obtained for conventional fabrics are over 40 m2Pa/W. The present invention obtains values of under 40 m2Pa/W.
Mites live in all sorts of textile substrates, primarily on fabrics that attract more dead skin cells (their food supply). For example: car seats, mattresses, pillows, carpets, sofas etc. Protection against mites is possible through application, directly or indirectly of additives. For example via the usage of an anti-microbe agent that eliminates the bacteria the mites feed upon. Recent epidemiological studies have proven that in recent years asthma cases, caused by bacteria, fungus and mites, in the European Union and United States has risen consistently.
The absorption and neutralisation of unpleasant smells is one of our aims. The main function of antibacterial agents is to inhibit the transfer and spread of pathogenic micro-organisms (personal hygiene) and as a consequence odour reduction caused by microbial degradation (deodorant) whilst avoid losing fibre characteristics.
The active elements mainly found in anti-microbial substances are grouped in two categories, active complexes and passive complexes:
- Passive complexes do not contain bioactive properties but due to their structure offer protection, avoiding the micro-organism to settle (e.g.: anti-adhesive surfaces)
- Active complexes contain anti-microbial properties. Active substances that can be applied on textiles are: organic molecules (Triclosan - derived from diphenylether), inorganic complexes (zeolites and heavy metals - copper, silver, and zinc) as well as natural substances (chitosan and casein).
Inorganic agents mean less of the agent is required, offering good thermal stability, resistance to solvents and detergents and lower toxicity when in contact with the skin. However, the main disadvantage is the yellowing of the fibre caused by metal reduction during processing.
For the absorption of unpleasant odours, our invention uses a product of mineral origin.
The present invention offers a rate of over 80% of anti-microbial protection against Staphylococcus aureus (as per ISO 20743 standard). The antimicrobial agents are applied to the surface during the finishing process, whilst keeping in consideration basic requirements of safety, compatibility and colour.
With regards to the odour neutralisation, the cover is graded less than 3, as per Volvo method 1027,2729.
With regards to cleanabilty, one way we can check the hydrophobicity and oil repellencey of the textiles is by modifying the surface tension by using fluorocarbons. These compounds give a surface tension of between 10 and 15 dyne/cm. Therefore, when applied to the textile will cause a decrease in surface energy. As water offers a surface tension of 72 dyne/cm at room temperature, the water droplets will not penetrate the fabric and will roll around on the surface.
The fluorocarbons are chemical compounds deriving from the carbon perfluorinated chain. They are normally cationic but can be non-ionic or anionic. Some groups of these compounds are perfluoro-acrylate Aquil giving them characteristics similar to acrylate resin. The fluorocarbons most widely used in the textile industry include PFOS (perfluorooctanoic sulphonic acid) and PFOA, another fluorocarbon compound of active nature (perfluorooctanoic acid). However, PFOS are not biodegradable and can be harmful to humans. For this reason, major chemical producers are optimising fluorocarbon compounds and have introduced into the market fluorocarbons C6 (PFOS free and low levels of PFOA) replacing C8.
Fluorocarbon application is usually carried out through impregnation or coating, but there are also other application techniques, although still in the experimental phase, like spray form technology and via ultra-sound. Fluorocarbons are the only product known in the market with a dual functionality of both water and oil repellency with consistent results when applied to textiles.
This is achieved by finishing the fabric with a fluorocarbon resin-C6 that is applied through impregnation or coating.
The seat cover of the present invention, offers good dirt repellency and is easy to clean, (formation of stain and ease of removal) obtaining a grade 3 without leaving any type of water mark, as per 85000010A Volvo standard.
It is important to refer that the fabric offers low toxicity for the passengers and should not cause allergies or skin irritations, as well as offering some selective protection against undesirable microorganisms, whilst in line with prevailing laws, should not have a negative effect on the textile properties or in its appearance - it is odourless and should be compatible with normal textile processing; not effecting colouring agents or other finishing products needed.
Electromagnetic radiation emitted by the sun is composed of a broad range of wave lengths across the electromagnetic spectrum. Approximately 43% of this radiation falls within the visible range, whilst the remainder falls within infrared (49%) and ultraviolet (7%) with 1% falling within x-ray, Gama rays and radio waves. Ultraviolet radiation (UVR) falls between 100 and 400 nm that is divided in UVA, UVB and UVC. Sunlight passes through our atmosphere and all UVC radiation and approximately 90% of UVB radiation is absorbed through the ozone layer, water vapour and carbon dioxide that exists in the atmosphere. Therefore, the ultraviolet radiation that reaches earth is made up of UVA radiation and a small percentage of UVB radiation that, apart from being a serious health concern, causes colour degradation of organic compounds; textiles.
Cars spend most of their lifecycle exposed to sunlight. This means fastness to colour starts to deteriorate and consequently the protection decreases as well as the material's resistance. Therefore, this property was studied and enhanced via an innovative construction (raw material composition, structure and sketching) and through the addition of UVR inhibitors, absorbers or blockers of UV radiation - chemical, organic or inorganic. For the current invention, the methods used for adding the compounds were physical/chemical deposition, through saturation in order to enable efficient binding of colourless compounds with absorption potential, the radiation zone of de 280 to 400(metal oxides, ceramic materials and other chemical aids). Therefore, the current invention offers a UV protection factor, in line with UV Standard 801, of over 80 UPF average.
The thermal comfort that the invention offers is obtained through the use of textiles with high breathability and insulation/temperature control, through design and production innovative means that allow for the creation of specific ventilation areas. The level of thermal comfort satisfaction was over 70%.
The fibre composition of the present invention is made up of:
- 1. Wool/polyester mix of 80/20 respectively with a tolerance of 10%, as stipulated by standard ISO 1833.
- 2. Applies to all colours and is developed in yarns, produced with wool fibres (average diameter of 21 microns, as per standard ISO 137).
- 3. Polyester fibres (average diameter of 2,2 den (2,4 dtex), as per standard NP 3160).
With the following technical characteristics:
- Linear mass (NP EN ISO 2060) of Nm 2/34 with a coefficient variation lower or equal to 3%.
- Twisting (ISO 17202) of 700 (S) v/m with a tolerance of 80 v/m.
- Torsion (ISO 17202, NF G 07079) of 740 (Z) v/m with a tolerance of 80 v/m;
- Tensile strength and elongation (NP EN ISO 2062, ASTM D 2256) minimum values of: breaking strength of 450 cN, breaking tenacity 7,5 cN/tex and breaking strength of 15%.
The fabric construction is flat and meets the following technical requirements:
- Abrasion testing (Martindale STD 1024,7122) with a minimum rating of 1 (some pilling, 2 broken yarns, some whitening present).
- Pilling formation resistance (Volvo testing code 850 000 06) with a minimum rating of 4.
- Fastness to light (STD 1027,359) with a minimum grey scale rating of 4.
- Velcro testing (Volvo testing code 850 000 25) with ratings of over 4;
- Linting resistance (Volvo testing code 850 000 05) with minimum rating of class 4.
- Seam strength (Volvo testing code 850 000 25) with values exceeding 480N.
- Flammability (Volvo testing code VCS 5031,19) maximum values 80mm/min - length and width.
The seat cover in question, was created with the laminating of a flat textile, 80/20 (wool/polyester) functionalised, with a tri-dimensional structure (100% polyester), through thermoplastic polymers using hotmelt and flatbed laminating technologies, and polyurethane foam using flamebond lamination.
It is not our intention to limit the invention as exactly described above, but allow for modifications and variations in light of the above teachings. We chose to describe and explain the aims of the invention and its practical application to allow an expert in this field to make use of the invention in various manners. It is intended that the scope of the invention be defined by the claims herein presented and its dependents.