METAL 2007 22. – 24. 5. 2007 Hradec nad Moravicí INFLUENCE OF SURFACE TREATMENTS MECHANICAL SEWING NEEDLES ON QUALITY OF THE STITCHES JANA ZOUHAROVÁ Departament of Engineering Technology, Section of Engineering Metallurgy, Technical university of Libere, Hálkova 6, 461 17 Liberec 1, [email protected] Abstract This article engages the surface finishes of the sewing machine needles and their hold on lifetime. These needles are important a construction and a function element sewing machines. First of all they influence an expensive way a quality sewn seam over the synthetic material which they are using for seats and airbags upholstery car‘s. The effect of temperature which she originates over a period of sewing smelt on the sewing machine needles a synthetic sewn material. The information search is devoted characteristic and surface finishes sewing machine needles which they are resisting warmer temperatures. The experimental part is dedicated on the mechanical tests sewing machine needles with different surface finish and on the interpretation their applicability for thermal load let us say for sewing synthetic materials. 1. Inroduction All the time in the sewing industry inscribe to great attention to machine equipment. The sewing machine lived to see assorted betterment with techniques and electronics development. In this departure is great attention to dedication to quality and durability apportionable parts and functional components. Sewing machine needles range among these components. All the time they are looking for apt of the surface finishes which they are given abrasion resistance in motion sewing machine needle by the technical textile. Some textile pigments include soft microscope erosive elements which they wear down and heat sewing machine needle and they lower her lifetime. This article deals with the influence of the surface treatments of the sewing machine needles on the sewing capacity of the sewing thread from native and synthetic materials. 2. The surface finishes of the sewing machine needles The surface finishes of the sewing machine needles have significant influence for decrement thermal stress sewing machine needle’s. In this time surfaces of the sewing machine needles finish polishing, chrome plating, nickel plating and then lay on coating of the titanium nitride, teflon and we know sewing needles with ceramic coating of the needle point. Polishing is simplest surface finish. It is process polishing by means of the polishing medium. It withheld corrosion protection by the sewing machine needle. Chrome plating saves of the sewing machine needle corrosion protection, especially so called hard chromium plating give to the sewing machine needles high abrasion resistance. Nickel plating saves of the sewing machine needle corrosion protection and heating. Titanium nitride lay on to the sewing machine needle surface for attainment homogenous, hard and smooth surface. As a result is extreme hard and flexible rate of the sewing machine needle. The needle point is abrasion resistance and decomposition. Sewing machine needle with titanium nitride surface has essentially higher lifetime.
1 METAL 2007 22. – 24. 5. 2007 Hradec nad Moravicí Teflon is non metallic surface which it is thermoplastic compact, chemical and thermal extensively resistant. Ceramic coating is using for the sewing needle intended for the special sewing machines. Heating decreased by 20 25 % and stop from creation to static electricity. 3. Experiment The purpose experiment was develop to the influence of the surface finishes by the sewing machine needles on the sewing capacity sewing thread and change loop strength of the sewing thread from native and synthetic materials for making sewn line. Sewing machine Sewing capacity was testing on the sewing machine Minerva Properties of the sewing machine: • Maximal speed 2800 stitches per minute (s.p.m.) • Needle system 135 x 5 • Stitch length 2 Sewing machine needles Sewing machine needles were chose for experiment with different of the surface finish with the same fineness metric count 90. 1. Sewing machine needle with chrome plating • Gebedur trade mane 2. Surface finish titanium nirtide • Gebelub trade mane 3. Surface finish – teflon 4. Sewing machine needle with ceramic coating Test sewing thread Three types of the sewing threades were chose for their test of the sewing capaticy. These sewing threads are best used types in the process. They are two types polyester threads which they have different construction and one type cottone theard. 1. TRIANA trade mane from the manufacturer AMANN Sponit Trading Ltd. • Cottone theard with line weight 12,4 x 3 2. BELFIL S trade mane from the manufacturer AMANN Sponit Trading Ltd. • Polyester thread with line weight 13,8 x 2 3. SABA C trade mane from the manufacturer AMANN Sponit Trading Ltd. • Core thread type poly/poly with line weight 13,5 x 2 Sewn material • Material structure CO/PL • plain weave • basis specific weight 120 g/m 2 • warp sett/ pickage 350/230 on 10 cm • thickness 0,15 mm 3.1 Measure of the loop strength Change of the loop strength the sewing threads was detected comparison of the loop strenght of the sewing needles undamaged and involved. Involved sewing theards were unsewn from continuous belt intended for detection of the sewing capacity. Stage unsewn length was defined on 30 cm for clamping sample to the shredding machine.
2 METAL 2007 22. – 24. 5. 2007 Hradec nad Moravicí Experiment was made on the shredding machine Lab Test 2.050. Properties of the shredding machine • test length 250 mm • prestress 0,2 N • test speed 250 mm/min • measurement range 0 100 N • clamps yarn Climatic conditions • Temperature 20 22 °C • Humidity 45 50 % 3.2 Methodology of measure and data processing For test of the thread breakage in the loop is no norm therefore I got on the norm ČSN EN ISO 2062 (80 0700) Strenght and elongation detection of the indvidual thread by the breakage. Test threads were unused and used for sewn used needles. Measuring values are introduced in Fig. 1 4. In these graphes are arithmetic means from five measure.
16 14 12 10 Chrome plating Teflon 8 Titanuium nitride 6 Ceramic coating Strenght /N/ 4 2 0 0 1 3 5 Workshift count Fig. 1 Loop strenght of the TRIANA
16 14 12 Chrome plating 10 Teflon 8 Titanuium nitride 6 Ceramic coating Strenght/N/ 4 2 0 0 1 3 5 Workshift count Fig. 2 Loop strenght of the BELFIL S
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20 Chrome plating 15 Teflon Titanuium nitride 10
Strenght/N/ Ceramic coating 5
0 0 1 3 5 Workshift count Fig. 3 Loop strenght of the SABA
15,7 15,6 15,5 15,4 15,3 unused shreaad 15,2 unused thread 15,1 Streght /N/ Streght 15 14,9 14,8 14,7 Triana Belfil S SABA S Thread type Fig. 4 Loop strenght of the unused thread 3.3 Measure of the sewing capacity This exteriment issued from methodology of the rating sewing capacity of the sewing threads from VÚO Prostějov. Used threads were weared after 1, 3 and 5 workshifts. 3.3.1 Methodology of VÚO Prostějov This test was practised of the sewing on the two layer belt with 0,5 m long. There were made out 50 fields which they were practised at the maximum running speed. Data processing were appraised by breakage rate n on the 50 sewing fields. Measuring values are introduced in Fig. 5 7.
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9 8 7 workshift count N 6 5 workshift count 1
n /1/ 4 workshift count 3 3 workshift count 5 2 1 0 Chrome Teflon Titanium Ceramic plating nitride coating sewing needle plating Fig. 5 Sewing capacity of the TRIANA
8 7 6 workshift count N 5 workshift count 1 4
n/1/ workshift count 3 3 workshift count 5 2 1 0 Chrome Teflon Titanium Ceramic plating nitride coating sewing needle plating Fig. 6 Sewing capacity of the BELFIL S
8 7 6 workshift count N 5 workshift count 1 4
n/1/ workshift count 3 3 workshift count 5 2 1 0 Chrome Teflon Titanium Ceramic plating nitride coating sewing needle plating Fig. 7 Sewing capacity of the SABA S 3.4 Surface of the sewing machine needled after weared Next photos are showing of the surface of the sewing machine needles after abrasion which they were got at the electronic microscope VEGA TS 5130.
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Fig. 8 Chrome plating 1 workshift, needle point
Fig. 9 Chrome plating 3 workshifts, needle point
Fig. 10 Chrome plating 5 workshifts, needle point
Fig.11 Titanium nitride 1 workshift, needle point
Fig. 12 Titanium nitride 3 workshifts, needle point
Fig. 13 Titanium nitride 5 workshifts, needle point
Fig. 14 Teflon 1 workshift, needle point
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Fig. 15 Teflon 3 workshifts, needle point
Fig. 16 Teflon 5 workshifts, needle point 4. Summary Sufrace finishes of the sewing machine needles are by one of the crucial factors which they influence not only lifetime of the sewing needles but even quality of the sewing process and then lifetime of the sewn products (airbag, seat, upholstery car’s). These experiments have showen that the loop strenght of the sewing thread varies owing to surface wear of the sewing machine needle. This negative effect shows itself as late as process use of the product. From experiment is evident that changes sewing capacity of the sewing machine needles are dependent on combination to the surface finish of the sewing machine needle and the sewing thread. According to classification photos of the surface finish of the sewing machine needles after abrasion it is safe to say the best sewing machine needles are needled with surface finish from titanium nitride and chrome plating. On the contrary the sewing machine needle with teflon surface finish is making big abrasion of the layer by sort term using (for about one workshift) which it is visible to the naked eye. This abrasion of the sewing machine needle is decreasing the sewing capacity of the sewing threads and it has an influence on decreasing of the productivity of labour too. This article was elaborate with support of research plan MSM 4674788501. 5. Literature [1.] DAUBNEROVÁ, K. Vliv povrchových úprav strojních šicích jehel na šicí schopnost šicí nitě z přírodních a syntetických materiálů . [Diplomová práce] Liberec: TU v Liberci, 2004. [2.] Firemní prospekty katalogy firmy Groz Beckert a Schmetz. [3.] JECH, J. Tepelné zpracování oceli . [Metalografická příručka]. 2. vyd. Praha: , 1977. [4.] MOTEJL, V. Průzkum příčin zvyšování teploty strojové šicí jehly při šití . [Kandidátská disertační práce] Liberec: VŠST, 1973. [5.] NASIROV, K. Tepelná analýza strojní šicí jehly. [Diplomová práce] Liberec: VŠST, 1997. [6.] PAULIOVÁ, P. Vliv povrchových úprav strojních šicích jehel na jejich životnost. [Diplomová práce] Liberec: TU v Liberci, 2002 [7.] STŘÍŽ, B. Pružnost a pevnost. I.díl . [Skripta], Liberec: VŠST FS, 1979. [8.] VRZAL, B a kol. Strojnické tabulky, svazek II. 1. vyd., Praha ,1971. [9.] www.tescan.cz/cz_main.html.
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