Chemical FibersInternational

TextileTechnology

Fiber Polymers, Fibers, Texturing and Spunbonds

April 2020D 2047 E1

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BEYOND THE HORIZONPROCESS SOLUTIONS FOR POLYMER RECYCLING AND SOLID STATE POLYMER UPGRADING

Polymetrix, a Sanlian Buhler Company, provides process technology including EPCM services for the polymer recycling and manufacturing industry. Leading supplier of rPET systems and intergated rPET plants for single line capacities up to 70’000 tons per year.

www.polymetrix.com www.slhpcn.com

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Fiber Production

The results of the various spinning trials (seetable) demonstrate that the new VacuFiltechnology is so effective that the rPET pro-duced is of very good quality and compara-ble to that of virgin material. The granulation step can be dispensed with ifthe VacuFil is combined with BBE’s rPET-com-patible VarioFil* R+ compact spinning system(or other direct spinning systems capable ofprocessing rPET). The waste material is recy-cled and directly spun in a single seamlessprocess – in high quality thanks to optimummelt treatment.In the case of a Sri Lanka-based customer, aflexible VarioFil R+ compact spinning systemwas installed with upstream VacuFil inline recycling unit with a direct feed. It has beendesigned to manufacture using recycled bottle flakes, recycled chips and virgin chips.

BB Engineering

One-step recycling and inline spinningof PET waste into high-end fibers

BB Engineering GmbH (BBE), Remscheid/Germany, combines its VacuFilrecycling process with the directly connected VarioFil spinning system,hence creating a one-step process for recycling and inline spinning of post-consumer and post-production PET waste into POY or FDY.

(LSP) recycling system for further processingpost-production spinning waste and post-consumer bottle flakes, optimally aligned tothe textile further processing of the recycledmaterials in the spinning plant (patent cur-rently pending). The core component of thisprocess is the vacuum filter, with which theviscosity can be separately controlled andmonitored. To this end, the required meltproperties can be achieved inline in a reliableand reproducible manner and controlled during operation.

Manufacturing polyester (PET) fibers for de-manding textile applications from recycledpolyester (rPET) granulate – particularly usingthe inline spinning process – is an extremelychallenging task. It requires recycling know-how and spinning plant expertise. The start-ing material has to be continually processedinto a homogeneous, spinnable melt. All pro-cessing steps must ensure the required meltproperties and keep these stable throughoutthe entire process runtime. For numeroustextile applications, parameters such as vis-cosity and homogeneity are decisive andmust be subject to the only the minutest fluc-tuations. In other words: using rPET withinthe textile segment requires suitable pre-treatment processes in conjunction with pre-cise process management.BBE, a subsidiary of Oerlikon Textile, hasdecades of experience and know-how in thedevelopment of spinning plant componentsand systems. Furthermore, it was this spin-ning plant expertise that was decisive for thesuccessful development of the VacuFil PETrecycling system. On this basis, the companydeveloped a liquid-state polycondensation

Synergy of VacuFil andVarioFil

Result of the various spinning trials

Virgin PET Bottle flakes Bottle flakes Fiber waste POYreference Indian customer European origin

Input IV [dl/g] 0.66 0.81 0.80 0.624 Output IV VacuFil [dl/g] 0.646 0.66 (±0.06) 0.643 (±0.05)Quality No. 22.1 22.8 21.8 20.9Frays / 10,000 m 0.65 0 0.75 0.41Yarn breaks / 1 ton 0 0 0 0Dyeing uniformity (1: best – 6: worst) 1-2 1-2 1-2

> 4.5 (gray scale) AA

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Fiber Production

On the one hand, this is possible as a resultof the drying system that is suitable for bothflakes and chips. On the other hand, the vac-uum extruder can be operated without orwithout vacuum and is therefore able to meltrecycled and virgin starting materials. The ex-perience acquired from >20,000 sold unitshas influenced the extruder design. As a re-sult of the gentle melting, BBE extrudersform the basis for completely homogeneousmelt, as required by the spinning plant. Thesingle-screw technology ensures the robust-ness necessary in recycling. Moreover, thespecial metering system for several compo-

nents also provides producers with flexibility:either 2 additives can be fed into the melt simultaneously or the metering unit can beused for fast dye switches. With 6 positions,this VarioFil configuration achieves productthroughputs of up to 150 kg/h and offers abroad end-product range with final titers ofbetween 50 and 150 den (DTY) with a DPFrange of 0.7-4.0 dpf. In other set-ups, theVarioFil R+ covers a range of 20-600 den POYor 30-500 den FDY with recycled PET.With this, the VarioFil compact spinning sys-tem is not only a versatile spinning machinefor the most diverse applications, it also

caters to the constantly rising demand forrPET fibers. Textile-processing businesses andcorporations – be these fashion brands,sports apparel and furniture manufacturersor those operating within the automobile in-dustry – are increasingly focusing on sustain-able products and products made from recy-cled materials. Today, they are already tellingsuppliers of filaments, fibers and nonwovensthat they will be switching from exclusivelyvirgin polyester to recycled polyester – insome cases up to 100 % – for the manufac-ture of their textile products in the near fu-ture. ■

If D/Y ratio is low, the yarn tension beforetwisting unit will be low and the tension af-ter the twisting unit will be high. This situa-tion can cause yarn damages. The effect ofD/Y ratio and heater temperatures on DTYhas been investigated in this paper. The workwas done on the PET textured filaments tofind the effect of machine parameters on thefilament properties [2, 3].

Material and Methods

Materials 250 denier, 48 filaments, semi-dull, PET par-tially oriented yarn (POY) was draw-texturedon the lab-type Aalidhra AFT-11 texturingmachine with 2 heaters. Process speed was835 m/min. The first heater length and tem-perature were 2 m and 200 °C, respectively.The second heater length and temperaturewere 1.25 m and 165 °C, respectively. Disk-type friction texturing unit was used. The diskconfiguration was 1+6+1. The disk materialwas ceramic and the disk thickness was 9 mm.

Methods All the machine parameters were kept con-stant initially like D/Y ratio and draw ratiowere kept constant. D/Y values were 1.3,1.5.0, and 2 and the draw ratios were 1.50,1.60, and 1.70.

Impact of texturing machineparameters on the properties of PET textured yarn Polyester fiber is widely used for many applications due to its structural prop-erties. These properties are totally dependent on yarn types, filament, fine-ness and shapes etc. These properties could be considered for the extentsof deformations in the filament on the efficacy of heater temperature anddisc to yarn ratio. Here, the base raw material partially oriented yarn pack-age of 250/48 denier was used to process on the draw-texturing machinewith standard and adjusted settings, later the testing was carried out to knowthe effect of machine parameters on the denier, tenacity and broken fila-ments- tight spots. During project evaluation it was found that there is ahuge difference in twisting and de-twisting which causes an increase in thenumber of tight spots. Furthermore, tenacity and crimp contraction were in-creased where boiling water shrinkage was decreased, when the heatertemperature increased.

Ranjit Turukmane, Shubham Patil, Rahul Chaudhari Centre for Textile Functions, MPSTME, NMIMS,Shirpur/India

can therefore be applied to any continuousfilament yarn, including viscose, glass andnew high-performance fibers, as well aspoly amide (PA), polyester (PET) and poly -prop ylene (PP). The texturing method was developed toovercome the disadvantages of man-madefibers such as flat geometry and smooth sur-face, fiber waviness or crimp increases vol-ume, resilience, moisture absorption, etc.The properties of PET textured yarn can be altered by changing these parameters. Drawratio, D/Y ratio, and heater temperatures arethe main process parameters to change. Theratio of the disk surface speed to the yarnspeed is usually referred to as D/Y ratio. D/Yratio is calculated as follows:

This project was aimed to analyze the struc-tural properties of draw-textured yarn (DTY)made by considering same process parame-ters with post textured heat setting tempera-tures. The draw-texturing process is one ofthe significant texturing processes of currentage. It is a unique texturing method where itcan blend different filament yarns togetherduring processing, and it can thereby simu-late the desirable attributes of staple spunyarns [1]. This greater versatility offers a sub-stantial scope for product developments. It