Comparative study on the testing of textile materials used in the automotive industry.

Coman, Diana ; Neagu, Ioan

Abstract: The authors' purpose is to improve the interchangeability of different standard methods, hence the paper is conceived as a comparative study of different special performance textiles designed for automotive fields. We aim at analyzing and comparing the possibility of changing the testing methods required by various clients by using similar standards for automotive textiles.

Key words: automotive textiles, performance, standards, testing

1. INTRODUCTION

Performance is the basis of any textile composite used in the automotive industry and on a universal scale there are norms which regulate the comfort assurance, security and safety in the means of transport.

Textile materials consist of elements, such as: constant fireproof properties, increased superior mechanical resistances (high module, high tenacity), resistance to splice, bursting strength, resistance to delaminating, and comfort characteristics depending on the user's requirements.The explanation for using technical textiles with performance characteristics is to be found in the complex of hidden requirements, of those attributes that are to be activated while in use, in direct interaction with the person who uses the means of transport.

These textile products can be seen as products in themselves, with complementary finishing of the main characteristics given by the textile fabric or by textile in the form of flexible composite which have the advantage of special finishings. This flexible composite is layered and has been obtained through cover technologies -lamination or deposition (Dorogan, 2005).

For the quality assurance of automotive textile composites the essential material requirements are translated by means of standardized technical specifications with no superlatives.

Standards for automotive textile products are essential in this area, compared to the level (method standards) and range (product standards) requirements associated with a traditional product which can be replaced by a technical textile product (Visileanu et al, 2005). Manufacturers of seats, airbags, door panels, rugs and headrests have developed and implemented their own standards and tests (Brad & Coman, 2006).

2. EXPERIMENTAL WORK

2.1 Materials

The materials used in the manufacturing process are the complex materials used for automobile seat covers displaying the following characteristics: knitted fabric 100% PES laminated with foam PUR, cross section 650 dTex, weight 290g/[m.sub.2], total mass 440g/[m.sub.2], complex thickness 3 mm ([+ or -]0.7).

2.2 Procedures

The performance characteristics have been measured by means of different testing methods in concordance with required standards. The testing method is different according to the standards imposed by famous construction firms in the automotive industry.

Knitted fabric adherence--foam is tested on a testing device on a Hounsfield traction according to the client's standards. Thus, the Japanese constructor imposes the testing through TSL2100/4.39.1 method, the German constructor requires DIN 53357 standard, and the French D41 1157.

The delaminating test serves for evaluation of laminates adherence or for gauging the way in which the facings adhere to the substratum (DIN53357,1982). The delaminating force is the force determined for the evaluation, according to the standards.

Flammability (safety characteristic of automotive industry) was tested using an ATLAS-HMV burning room by means of a horizontal burning method. The automobile constructors establish the specific requirements regarding composite flammability inside the automobile.

The used standards for car seat covers are TSM 0500G for the Japanese client, and TL1010 for the German client and D45 1333 for the French client.

For the material tested by means of these three testing methods, the burning rate is calculated (mm/min) as a fraction between burning distance (mm) and burning time (sec) (TSM0500G, 2002).

3. RESULTS AND DISCUSSIONS

The results obtained for the adherence of textile material--foam of textile composites are shown in the following table.

Table 1 shows that the testing methods are different according to the testing speed and the distance between the catching trappers (which imply differences to method DIN 53357), therefore we note the possibility of using standards and replacing them according to the client's requirements only by means of TSL2100/4.39.1 and D41 1157 .

The material test results of car seat covers obtained for flammability are given in Table 4.

All sample test results are in accordance with the required specifications, that is, values less than 100mm/min. For the test of flammability, even if the standards are different, the described methods are identical (identical sizes of the specimen, identical devices used, identical testing parameters).

The high demand for textile composites used for car seats calls for a change in the currently used methods.

The standards for the technical textile products are essential in the automotive industry as compared to the level and time period requirements associated with a traditional product, which can be replaced by a technical textile product.

4. CONCLUSIONS

The results obtained by way of experimenting are included in the required specifications, although they have been tested by means of 2 or 3 different methods.

There are circumstances when the method specified by the customer cannot be replaced with a similar one resulting from the adherence test of the complex materials.

Although the methods are different for the characteristcs under review, the results can be considered similar in certain circumstances: they should be expressed through the same size and should be determined by using the same principles and devices with a comparable accuracy degree.

The next necessary step would be the unification of the testing methods which would mean the use of a common language in the analysis of different characteristic products.

5. REFERENCES

Brad, R.; Coman, D. (2006). Techniques and methods for testing automotive industry textiles, Acta Universitatis Cibiniensis, vol. (LIII), Technical series, Sibiu, 2006, pp.140-149, ISSN 1583-7149.

Dorogan, A. (2005). Textile tehnice-solutii pentru domeniul mijloacelor de transport (Technical textiles--solutions for the automotive industry), Industria textila, 56, (No.2), pp.106-111, ISSN 1222-5347.

DIN 53357 (1982).Testing of plastics sheets; adhesion test, Available from:http://www.auto.ihs.com/products/standards, accessed:http://store.ihs.com/URXVCAAAAAAAAAA

TSM 0500G (2002). Flammability test method for interior non-metallic materials, Available from:http://his automotive standards collections

Visileanu, E., Niculescu M., Dumitrescu, I. (2005). Dezvoltarea sistemului national de standarde pentru domeniul textil (Developing the national system of standards in the textile domain), Industria textila, 56, pp.77-79, ISSN 1222-5347.

Table 1. Testing Parameters for Knitted fabric-foam Adherence

 Specific TSL2100 DIN D41 1157
No. parameters /4.39.1 53357 200 x 50

1 Size of 150 x 25.4 mm 200 x 50 mm 200 x 50 mm
 specimen

2 Testing speed 200 mm/min 100 mm/min 100 mm/min

3 Distance 10mm 60mm 100mm
 between the
 catching
 trappers

4 Displacement 80mm 40mm 50mm
 of specimen

5 Number of 3 length 5 length 5 length
 samples direction direction direction
 specimens specimens specimens
 3 transverse 5 transverse 5 transverse
 direction direction direction
 specimens specimens specimens

6 Ways of Minimum Fpeaks Delaminating Delaminating
 results (N/mm)/Average force (N) force (N)
 reference/ of 3 specimens /Average of /Average of
 evaluation 5 specimens 5 specimens

Table 2. Testing Parameters for Flammability

 Specific TSM D45
No. parameters 0500G TL1010 1333

1 Size of 350 x 100 x 350 x 100 x 350 x 100 x
 specimen 12 mm 12 mm 12 mm

2 Number of 3 length 3 length 3 length
 samples direction direction direction
 specimens specimens specimens
 3 transverse 3 transverse 3 transverse
 direction direction direction
 specimens specimens specimens

3 Ways of Burning rate Burning rate Burning rate
 results (mm/min) mm/min (mm/
 reference/ /Average of /Average min)
 evaluation 3 specimens of 3 specimens /Average
 of 3 specimens

Table 3. Results of Delaminating Resistance

No. Method Specimen Adherence (N/mm)

1 TSL2100 length 2.209
 /4.39.1 direction
 transverse 2.527
 direction

2 DIN length 12.26
 53357 direction
 transverse 10.33
 direction

3 D41 length 14.68
 1157 direction
 transverse 13.94
 direction

Table 4. Results of Flammability Testing

 Burning
 rate
 Distance Burning mm/
No. Method Specimen mm time's min

1 TSM length 254 310 49.17
 0500G direction
 transverse 254 255.4 59.87
 direction
2 TL1010 length 254 308 49.48
 direction
 transverse 254 249 61.2
 direction
3 D45 length 254 311 49
 1333 direction
 transverse 254 241 63.23
 direction