Loss Of Breaking Strength Research Articles

Low temperature reactive dyeing of silk: An investigation into dyeing conditions, and strength loss and friction damage of fabric

The low temperature dyeing of textiles has obvious energy-saving effect. Silk fabric suffers from friction damage in the rope dyeing process, and additionally silk is complained about unsatisfactory color fastness. To address the aforementioned issues, the reactive dyeing of silk fabric at low temperatures was studied in terms of dyeing conditions, dye selection, alkali resistance of silk, and strength loss and friction damageoffabric. Reactive dyes exhibited higher fixation to silk in alkaline bath than acidic and neutral baths. The breaking strength and whiteness of silk fabric was less affected by sodium bicarbonate, but greatly affected by sodium carbonate. Silk fabric treated with sodium carbonate at 50–60 ℃ had acceptable loss of breaking strength (<10 %). Silk fabric dyed at 60–80 ℃ using sodium bicarbonate exhibited higher color depth than that dyed at 50–60 ℃ using sodium carbonate. The high temperature dyeing in alkaline bath caused the friction damage and fuzz appearance of silk fabric, which did not occur in low temperature and alkaline conditions. The reactive dyes selected from commercial products could be applied at 50 ℃ and met requirements for high fixation, high color fastness and a variety of colors.

Developing the functional cotton fabric with N-halamine antibacterial structure based on DA/PEI

In this study, functional coatings with N-halamine structure were formed on cotton fabrics by dopamine (DA) auto-deposition and DA/Polyethyleneimine (PEI) covalent co-deposition, respectively. SEM、UV-Vis and XPS had confirmed the deposition of DA and DA/ polydopamine (PDA) on the cotton fabrics. When the mass ratio of DA/PEI was 1:1.5, a uniform functional coating was formed. XRD had indicated that the coating and the oxidative sodium hypochlorite solution did not affect the crystal structure of cellulose. The DA/PEI co-deposited modified cotton fabric had excellent antibacterial property after chlorination, and the inactivation rate against E coli and S aureus could reach 100% with a contact time of 30 min. In vitro cell cytocompatibility studies demonstrated that the DA/PEI co-deposited modified cotton fabric has good biocompatibility. The functional coating on the cotton fabric remained stable after 50 washing cycles. The UPF values and the wrinkle recovery angle (WRA) tests showed that the DA/PEI co-deposited coating imparted great durable press and UV protective properties to the cotton fabric. The breaking strength loss rate of the modified cotton fabrics after chlorination was about 20%, which had little effect on the wearing property.

Anti-wrinkle finishing of Tencel fabric with glyoxal using response surface methodology

In this study, formaldehyde-free anti-wrinkle finishing agent glyoxal was applied on Tencel fabrics. Box Behnken experimental design in conjunction with response surface analysis and regression methods were used to study the effects of process parameters on their wrinkle resistant angle (WRA) as well as tensile strength. It was found that WRA increased with the increase of glyoxal and catalyst MgCl2 concentration and curing temperature, along with the increase of breaking strength loss. Variance analysis showed glyoxal concentration and curing temperature played significant role on the recovery angle and tensile strength of the treated fabrics. The established regression model was reliable and can predict the response value accurately. The Tencel fabric obtained good WRA and tensile strength retention when treated with optimum finishing recipe: glyoxal 49.35 g/L, MgCl2 18.64g/L and curing temperature 136.38 °C. FTIR confirmed the crosslinking reaction between Tencel fibre and glyoxal. SEM observation revealed the treatment produced no damage to the Tencel fibre. The treated Tencel fabrics kept high whiteness retention and glyoxal finishing resulted in no yellowing of Tencel fabrics.

Effect of montmorillonite on the oxidative stability of polyphenylene sulfide fibers prepared by melt spinning

Masterbatches of polyphenylene sulfide (PPS)/organic montmorillonite (MMT) composites were produced via melt blending. A self-made spinning equipment was then used to produce the PPS/organic MMT composite fibers by melt spinning directly from the masterbatches. X-ray diffractometer and transmission electron microscope were used to examine the dispersibility of organic MMT. The morphology, tensile property, crystallization behavior, and oxidative stability of PPS fibers were investigated. The results indicated that organic MMT could be uniformly distributed in the PPS matrix to form a mixed dispersion of intercalated and exfoliated structure and influence the longitudinal surface morphology of fibers to become rough. The roughness of composite fibers surface was proportional to the content of organic MMT. The organic MMT nanolayers could act as the heterogeneous nucleating agents to improve the crystallization, and the crystallity of composite fibers increased with the increase of organic MMT content. The breaking strength of composite fibers first increased and then decreased by increasing the amount of organic MMT. After the oxidation treatment, the breaking strength of neat PPS fibers and composite fibers declined, but the degree of breaking strength loss for composite fibers is lower than that of neat PPS fibers. The dynamic oxidation induction temperature of composite fibers also showed a significant increase by adding organic MMT. Moreover, the addition of organic MMT could limit the chemical combination of element sulfur and oxygen, retard the generation of sulfoxide groups, and induce the conversion of sulfur atoms from C-S bond to sulfone for improving oxidative stability.

Study on wettability improvement of raw cotton yarns pretreated with snailase

Raw cotton fibers were water repellent due to the existence of the cuticle layer. This study was designed to systematically investigate how snailase pretreatments influenced the wettability of cotton yarns. For comparison, sodium hydroxide (NaOH) solution which was commonly used to pretreat raw cotton yarns was also conducted to obtain control sample. Raw cotton and pretreated yarns were analyzed by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). Then, effects of snailase pretreatment on pectin removal percentage, wettability and breaking strength loss of cotton yarns were studied respectively and wicking height was used to evaluate the improvement of wettability. Observation of the surface morphology revealed that the snailase-pretreated fibers presented a smooth surface. By FTIR, it was found that the pectin in the raw cotton yarns was completely removed. XRD results suggested that snailase pretreatment was prone to remove pectin without damaging crystalline region. The snailase pretreatment had positive effects on enhancing the wettability of cotton yarns with barely affecting breaking strength.

Antibacterial modification of PET with quaternary ammonium salt and silver particles via electron-beam irradiation

Quaternary ammonium compound 2-dimethyl-2-hexadecyl-1-methacryloxyethyl ammonium bromide (DEHMA) was synthesized and grafted onto polyester (PET) fibers with acrylic acid (AA) via electron-beam (EB) irradiation process. The grafted fibers were soaked in AgNO3 solution for further improving antibacterial efficiency. SEM, FTIR, EDX, and XPS were used to characterize the treated PET samples. The antibacterial efficacy testing showed the grafted PET samples inactivated all Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli O157:H7) in 10min. After coated with silver ions, the antibacterial efficacy of the grafted PET with silver against S. aureus improved significantly. The EB irradiation process only caused a small degree of the breaking strength loss of the grafted PET fabrics which is acceptable in practical application.

Antimicrobial modification of cotton by reactive triclosan derivative

4-(4-chloro-6-(5-chloro-2-(2,4-dichloro-phenoxy)phenoxy)-1,3,5-triazin-2-ylamino)-benzenesulfonic acid sodium (CPTB), an antimicrobial agent, was synthesized from cyanuric chloride, sulfanilic acid and triclosan. The synthesized compound was coated on cotton fabrics by covalent bonds through a reactive dyeing process. The cotton fabrics coated with CPTB were characterized by FTIR and SEM. The antimicrobial properties against S. aureus and E. coli O157:H7 and the breaking strength of the treated cotton fabrics were examined before and after chlorination. The unchlorinated coated fabrics containing triclosan inactivated 95.88 % of S. aureus and 79.65 % of E. coli O157:H7 within 30 min, while the chlorinated coated samples enhanced the efficacy significantly and inactivated all S. aureus and E. coli O157:H7 within 10 min. The novel coating process in this study only caused a small degree of breaking strength loss compared with traditional pad-dry-cure coating. Washing tests and UV light tests showed that CPTB attached to cotton fabrics was very stable toward repeated washing and UVA irradiation.

Preparation of quaternary ammonium salt of chitosan nanoparticles and their textile properties onAntheraea pernyisilk modification

A novel eco-friendly finishing agent of quaternary chitosan nanoparticles was prepared in two steps from a chitosan with low molecular weight. The water-soluble quaternary ammonium salt of chitosan, N-[(2-hydroxy-3-trimethylammonium)propyl] chitosan chloride (HTCC), was first synthesized in heterogeneous system by quaternization, and then HTCC was further prepared to nanoparticles via ionotropic gelation reaction in the presence of 1, 2, 3, 4-butane tetracarboxylic acid and sodium hypophosphite. The size distribution and morphology of the HTCC particles were characterized using a laser particle size analyzer and transmission electron microscope (TEM). When Antheraea pernyi ( A. pernyi) silk fabric was treated with HTCC nanoparticles by using a conventional dip-pad-dry-cure process, the modified A. pernyi silk fabric demonstrated durable wrinkle-resistant property, shrinkage-resistant property and antimicrobial activities against Staphylococcus aureus and Escherichia coli, even after being exposed to 50 consecutive home-laundering conditions. However, the modification of A. pernyi silk fabric caused breaking strength loss, breaking elongation reduction and initial modulus rise to some extent.

Application of Ultrasonic Treatment on the Stripping of Cellulose Sponge

Cellulose sponge has the characteristic of porous and spongy. It’s difficult to strip in conventional processing. This paper describes a process using ultrasonic aided in solution of thiourea dioxide and sodium hydroxide. The cellulose sponge can be faster and better handled in this process. It will have a better stripping effect. And the optimization parameter of ultrasonic process is described for: thiourea dioxide 30 g/l, sodium hydroxide 40 g/l, the time of 10 min, the temperature of 70 °C. Under the condition of this operation, cellulose sponge stripping rate was 98.8%, the breaking strength loss rate was 27.6%.

Hydrolytic degradation of poly(1,4-butylene terephthalate-co-tetramethylene oxalate) copolymer

Experimentally synthesized poly(1,4-butylene terephthalate-co-tetramethylene oxalate) (PBT–PTMO) monofilaments were evaluated for hydrolytic stability in salt water (SW) and distilled water (DW) at temperature below and above glass transition temperature (Tg), along with commercially available poly(hexamethylene adipamide) (NY), poly(ethylene terephthalate) (PET), and polypropylene (PP) monofilaments. There was no decrease in mechanical properties in case of NY, PET, and PP in either DW or SW below their Tg. The breaking strength, ultimate elongation, and thermal shrinkage of the PBT–PTMO, however, decreased as the ageing time increased. Total strength loss occurred after approximately 300 days at 25°C in either DW and SW. This can be attributed to the chain scission that occurs in the PBT–PTMO copolymer chain. The poor hydrolytic stability of the PBT–PTMO may be attributed to the higher moisture regain. The salinity of water did not have a significant effect on the breaking strength loss of the materials. The mode of hydrolytic degradation of aged PBT–PTMO polymer was confirmed by the increasing generation of the acid carbonyl and hydroxyl groups with concomitant increasing consumption of ester groups, regardless of ageing conditions. Above Tg, the hydrolytic rate constant (k′H, day−1) of the PBT–PTMO, estimated by the rate of formation of acid carbonyl groups, is greater at a higher ageing temperature. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 921–936, 1999

Color Change as a Predictor of Strength Loss in PFD Cover Fabrics

Abstract The fabric covers of many wearable personal flotation devices (PFDs) currently on the market are subject to rapid fading and loss of strength when exposed to light. The result of this rapid degradation may be loss of flotation protection for the wearer. This research evaluates the relationship between color change and loss of breaking strength in six PFD cover fabrics and explores the possibility of using color change to predict strength loss of selected PFD covers. Regression models were developed for each fabric and the models were used to predict the level of color change at which the fabric would fail to meet the U. S. Coast Guard minimum strength requirement for covers of wearable PFDs.

Dyeability of Artificially Aged Cotton Fabrics

A cotton fabric has been artificially aged by dry heat at 150°C with or without initial exposure to ultraviolet light. The observed property changes in the aged cotton samples include a loss of breaking strength, a decrease in moisture regain, yellowing, and an increase in carbonyl or carboxyl content. Dyeability is examined to characterize the physical and chemical changes in the aged samples. Dye uptake with direct dyes decreases as heating time increases, which can be attributed to increased crystallinity and the formation of carbonyl and carboxyl groups. The decrease in dye uptake is more remarkable with the larger molecular sized dye than with the smaller dye, in dicating that some changes have occurred in the size of the pores that accept dyes. From the adsorption isotherms, we see that the dye adsorption mechanism is not similar for untreated and aged samples, due to chemical structural changes such as the formation of carbonyl and carboxyl groups. The slight increase in basic dye uptake is also attributable to carboxyl group formation.

The effect of inflammatory synovial fluid on the breaking strength of new “long lasting” absorbable sutures

The effect of inflammatory synovial fluid upon several absorbable sutures potentially useful for arthroscopic procedures, e.g., meniscus repair and shoulder stabilization, was studied by implanting lengths of these sutures into unstable, arthritic rabbit knees and testing their breaking strength after varying time periods (up to 18 weeks). Polyglyconate (Maxon) sutures retained no significant strength at 6 weeks. Polydioxanone (PDS) sutures began to lose breaking strength at 3 weeks, retained only 40% of their original strength 6 weeks after implantation, and had no measurable strength at 9 weeks. Polycaprolactone (LTS) sutures showed a slow reduction in strength and retained ∼90% of their original breaking strength after 18 weeks of implantation. Green braided polyester (Mersiline) sutures showed no loss of breaking strength over the testing period. Measurements of inherent viscosity were made to give an indirect indication of the decline in molecular weight of these sutures. These data paralleled the breaking strength decline in every case. The surgeon selecting an absorbable suture must consider the length of time the suture will hold the target tissue. This information should be helpful to surgeons considering an absorbable suture for procedures such as meniscus repair and shoulder stabilization.

ナイロン網糸の紫外線劣化の機構

Photodegradation of nylon netting twine exposed in the carbon arc Fade meter was investigated from the relation between mechanical and chemical properties. The progress of photodegradation of the samples after u.v. irradiation was evaluated by measuring breaking strength, molecular weight (viscometeric method) and density. With increasing of irradiation, a continuous decrease in molecular weight and also an increase in density were observed in proportion to a significant loss of breaking strength. Form these results, the mechanism of the photodegradation of nylon was estimated as follows. The loss of molecular weight during irradiation suggested the occurrence of photochemical degradation causing the scission of chemical bonds in polymer chain. And also the occurence of reorientation of polymer chain and/or the formation of crosslinking were suggested by the results of the increase in density of nylon fiber with progressive degradation. The results on breaking strength, molecular weight and density of nylon samples treated with additive (702) showed that this additive acted as a good retardant to photodegradiation of nylon.

Inflammatory synovial fluid and absorbable suture strength

The effect of inflammatory synovial fluid upon several absorbable sutures commonly used for meniscus repair was studied by implanting lengths of these sutures into unstable, arthritic rabbit knees and, after varying lengths of time (1-6 weeks), testing their breaking strength. Both polyglactin-910 (Vicryl) and polyglycolic-acid (Dexon) sutures retained only minimal breaking strength 3 weeks after implantation. Chromic gut sutures demonstrated a steady reduction in breaking strength until they retained only 6% of their original strength at 5 weeks and none at 6 weeks. Polydioxanone (PDS) sutures began to lose breaking strength at 2 weeks and retained only 40% of their original strength 5 weeks after implantation. The rate of loss in polydioxanone breaking strength was faster in inflammatory synovial fluid than previously reported in the normal synovial joint. Braided polyester sutures (Mersiline) showed no loss of breaking strength over the duration of this test. While the choice of suture is only one variable influencing the outcome of a meniscus repair, this study demonstrates that only polydioxanone and green braided polyester sutures retain any strength 6 weeks after implantation (the time of immobilization commonly recommended for meniscal repairs). Complete meniscal healing can require several months. In the absence of compelling evidence to the contrary, the use of nonabsorbable suture materials for meniscal repair seems the most appropriate choice.

The effect of pH on the in vitro degradation of poly(glycolide lactide) copolymer absorbable sutures.

The pH effect on the hydrolytic degradation of Polyglactin 910 copolymer was studied in terms of the tensile properties of the suture specimens. The use of a cord/yarn grip, newly designed specifically for fibrous materials, eliminated the grip-induced failure. Different degrees of hydrolytic degradation of this copolymer at 3 different pH levels were observed. The suture specimens exhibited the best retentions of breaking strength at the physiological pH of 7.44, while the specimens at pH = 10.09 showed the fastest loss of breaking strength. Thus, a maximum retention of tensile properties occurred around the pH level of 7.0, whereas smaller percentages of retention of tensile properties were observed at both acidic and strong alkaline solutions. This synthetic absorbable suture material exhibits the basic characteristic of hydrolysis which is catalyzed by both acid and base.

Performance Properties of Cottons at Two Levels of Durable-Press and Conditioned Wrinkle-Recovery Angles

Polymerization-crosslinking reagents such as N-methylolacrylamide, N-methylol- methacrylamide, and N-methylolpolyethyleneurea (dp = 3) (NMP-2) and conven tional crosslinking agents such as dimethylolethyleneurea, dimethyloldihydroxyethyl eneurea, and formaldehyde were used to treat cotton twill fabrics. A concentration study with these reagents was carried out, and physical and chemical properties of the finished fabrics were compared. Strength and abrasion properties of treated fabrics at two levels of DP and conditioned WRA were also determined. The results indicated that the experimental reagents capable of undergoing polymerization as well as crosslinking within the cellulose substrate afford a superior balance of strength and abrasion properties. NMP-2 appears to be most stable to loss of formaldehyde among the polymer-forming reagents studied and most sensitive to loss of breaking strength from scorching following treatment with chlorine bleach.

Further study of polyglycolic acid suture

Implantation studies were carried out in rats, rabbits, and dogs to compare the rate of loss of breaking strength of polyglycolic acid and chromic catgut sutures. The rate of loss was about the same during the first five to ten days. Thereafter, the rates of loss were variable for both suture materials.

Emulsifier choice in design of spin finishes for man‐made fibers

AbstractSpin finishes for diverse, polymeric textiles are necessary for efficient processability and maximum conversion to functional fiber. Such finishes should provide lubricity, cohesion and increased resistance to static development on the fiber. The emulsifiers, lubricants and antistats used in fiber processing differ in reactivity with such polymers. Finish components rely extensively upon derivatives of fats and oils, particularly the numerous emulsifiers used. Certain deficiencies of these finish components, with particular emphasis upon their reactivity with process equipment having polyurethane surfacing, are discussed. Susceptibility of polypropylene to degradation in the presence of conventional finish components is examined. Unique properties of polyglycerol esters and glycerido‐ester ethoxylates, which overcome these processing difficulties, are considered. The relationship of chemical structure to plasticising activity appears as the key to polymeric fiber resistance to loss of breaking strength.

Chemical and Mechanical Wear of Cotton Fabric in Laundering*

International organisations are studying the standardisation of unsoiled cotton test pieces and methods of using them for the determination of chemical damage and mechanical wear in laundering. Of particular importance is the relation between chemical attack, as measured by viscosity or fluidity changes, and the corresponding strength loss. Study of the literature reveals that the available experimental data are far from complete and that published curves differ. In order to clarify the position, loads of test pieces of two different plain–weave cotton fabrics were laundered up to 35 times, without and with hypochlorite bleach, under different conditions, and an attempt was made to find the breaking strength loss corresponding to a given fluidity increase under identical mechanical conditions.It is concluded that, up to a 20 % strength loss, the relation between strength loss and fluidity increase is a linear one, provided that the severity of the chemical attack remains constant; above this value a curve similar to that of Clibbens and Ridge is found. In practice, however, test pieces are examined after a constant number of launderings, usually 25; consequently, low fluidity values correspond to a slow chemical attack, and high values to a rapid chemical attack. Under these conditions a curve is found that is similar to the Delft curve now under consideration for international standardisation, up toa 20% strength loss; above this value it remains similar to the curve of Clibbens and R idge.