Introduced the dyeing and finishing process of recycled polyester knitted fabrics. It is pointed out that the performance of recycled polyester itself has a certain impact on the dyeing effect, so each batch of recycled polyester needs to be re-sampled before dyeing; the temperature rise curve of recycled polyester knitted fabrics should be designed slower, with a dyeing temperature of 125°C, a dyeing time of 20 minutes, and a dyeing pH of The value is 4.0~5.0; when restoring and cleaning, the pH value should be controlled not to exceed 11.0; the color fastness to washing, acid perspiration and light of the recycled polyester dyed in this way is comparable to that of ordinary polyester, and can reach level 4 above. In addition, it was pointed out that the oil content of recycled polyester is higher than that of ordinary polyester. In the pre-treatment stage, pre-treatment additives should be selected, the amount of degreaser should be increased, and the pre-treatment temperature should be increased. For knitted velvet fabrics made of recycled polyester, padding and anti-stripping should be performed before napping. Static agent, and rationally design the production processes and process parameters between pulling, combing, and shearing to achieve a good suede effect.
Foreword
The so-called recycled polyester is to use complete cycle chemical recycling technology to centrally recycle discarded polyester fabrics, clothing or polyester waste, crush it into granules, and then decompose it into polyester through chemical treatment The raw material is finally spun into polyester. According to statistics, 1.00t of waste polyester bottles can be used to produce about 0.98t of recycled polyester, saving 6.00t of oil and 3m3 of landfill space. For this reason, the recycling of waste plastics and the production and use of recycled polyester are inevitable choices for developing a circular economy and building a resource-saving society.
Compared with ordinary polyester, recycled polyester has better hygroscopicity and air permeability, and can be widely used in the production of sportswear. However, recycled polyester has a high oil content, high rigidity, and is not as strong and heat-resistant as ordinary polyester. Each batch of recycled polyester produced by the manufacturer has certain differences in performance and color, which increases the difficulty of subsequent processing.
At present, there are many studies on the spinning and weaving of recycled polyester. This article focuses on the dyeing and finishing of recycled polyester knitted fabrics. Discuss the process.
1 Test
1.1 Fabric
Recycled polyester knitted fabric: 22.22tex (200 D) /100f Yihua Yuhui recycled FDY polyester filament as terry yarn, 8.33tex (75D) /36f DTY polyester low elastic yarn as connecting yarn towel.
Ordinary polyester knitted fabrics: 22.22tex (200 D) /100f Yihua Yuhui FDY polyester filament as terry yarn, 8.33tex (75D) /36f DTY polyester Low stretch yarn is a terry cloth with attached yarn.
1.2 Reagents and instruments
Reagent: Disperse dye Rubine S- 2GFL [Clais Chemical Group (China)], high temperature leveling agent 3620 (Shanghai Hansong Textile Technology Co., Ltd.), acetic acid (industrial grade), sodium acetate (industrial grade), chelating dispersant YH-56 (Shanghai Yiyi Hua Industrial Chemicals Co., Ltd.), etc.
Instruments: Datacolor 650 color measuring and matching instrument (Datacolor Company of the United States), Burst Tester (Mullen RTesters Company of the United States), Color Fastness to Washing Tester (James H.heal&Co. .Ltd.Halifax England), light fastness testing machine (James H.heal Co., Ltd., UK), perspiration color fastness oven (Nantong Hongda Company), etc.
1.3 Dyeing process prescription and curve
1.3.1 Process prescription
Rubine S-2GFL 1%
HAC 0.8g/L
Warm leveling agent 36200.8 g/L
NaAc1.0 g/L
Chelating dispersant YH-56 0.3 g/ L
1.3.2 Process curve
1.4 Test method
1.4.1 Test of color difference
Use Datacolor 650 color measuring and matching instrument to test the dyeing of different batches of fabrics The final color difference is △Ecmc.
1.4.2 Test of relative dye uptake rate
Relatively high Dyeing rate – A/B×1000/ (1) In the formula: A is the K/S value dyed under certain conditions; B is the K/S value of the fabric dyed under 135°C and 30 minutes. The K/S value is measured by Datacolor650 color measurement and matching instrument.
1.4.3 Force score test
The force score passes Datacolor The 650 color measuring and matching instrument directly measures and reads out. The meaning of its value is the percentage of staining depth of the test sample and the standard sample. The dyeing sample of recycled polyester fabric at 125°C and 30 minutes was used as the standard sample.
1.4.4 Test of Burst Strength Retention Rate
Bulking The breaking strength test was conducted in accordance with the American Society for Testing and Materials standard ASTM D 3786-2001 “Standard Test Method for Hydraulic Bursting Strength of Fabrics, Thin Film Bursting Strength Tester Method”. The calculation of the strength retention rate P is as shown in formula (2):
P- (Po-Pl) /PO×100% (2) where: Po is the fabric before treatment The bursting strength; Pl is the bursting strength of the treated fabric.
1.4.5 Test of color fastness to washing
Color fastness to washing is tested in accordance with the provisions of IS0 105C06-2010 “Tests on Color Fastness of Textiles Part C06: Color Fastness to Domestic and Commercial Laundering”.
1.4.6 Test of color fastness to acid and perspiration
According to The color fastness to acid and perspiration in IS0 105 E04-2009 “Testing on Color Fastness of Textiles Part E04: Color Fastness to Perspiration” was tested.
1.4.7 Test of light fastness
Light fastness The fastness test is carried out in accordance with the provisions of IS0105802-1994 “Textiles Color Fastness Test Part B02: Color Fastness to Artificial Light: Xenon Arc Lamp Test”.
1.4.8 Color fastness rating
Color fastness rating Analyze�, so in the pre-treatment stage, according to the depth of the dyed color, pre-treatment additives should be preferred and the treatment intensity should be increased; and the amount of degreaser should be increased; the pre-treatment temperature should be higher than that of ordinary polyester. , to ensure that the final cloth surface effect is good.
3.2 Heat setting process of recycled polyester knitted fabrics
Due to regeneration The difference in dry heat shrinkage or boiling water shrinkage of polyester is too large, which will cause different shrinkage during heat treatment in printing and dyeing processes, causing the width of the fabric to vary and the formation of irregular strip wrinkles. Therefore, the heat setting process of recycled polyester knitted fabrics is more strictly controlled than that of ordinary polyester knitted fabrics. The specific control methods are shown in Table 6.
3.3 Brushing, carding and shearing processes of recycled polyester knitted fabrics
Table 6 Comparison of heat-setting surface temperature of recycled polyester and ordinary polyester fabrics
Recycled polyester knitted fabrics should be padded before napping Preferred antistatic agent to reduce lint, control fabric feeding tension, straight needle and curved needle speed during the shearing process, optimize knife distance, brush distance, speed and other process parameters during the shearing process, for example, ordinary polyester knitting in the napping process The speed difference between the straight needle and the curved needle is 15r/min, while the speed difference between the straight needle and the curved needle of the recycled polyester knitted fabric is 19r/min, which can ensure that the tension of the recycled polyester fabric is small during the napping process, which can effectively solve the problem of recycled polyester knitting Velvet fabrics have the problem of easy hair removal during the tufting process, so as to achieve a good suede effect.
4 Conclusion
4.1 The influence of the properties of recycled polyester knitted fabrics on dyeing There is a certain impact on the effect. The performance of recycled polyester is unstable, and each batch of recycled polyester needs to be re-sampled before dyeing.
4.2 The temperature rise curve of recycled polyester knitted fabrics should be designed slower, with a dyeing temperature of 125°C, a dyeing time of 20 minutes, and a dyeing pH value of 4.0 to 5.0; the recycled polyester knitted fabrics should be restored and cleaned When using, try to control the pH value not to exceed 11.0.
4.3 For recycled polyester, attention should be paid to the adjustment and control of process conditions during the pre-treatment, shaping and napping stages. </p
