Handling pretreatment of nylon & spandex

GOLLER Spun Oil Washing Range is designed for pre-treatment processing and production of fabrics from elastic knitted weft nylon and spandex blended microfibre.

The application of microfibre (unifilar fibre density is less than 0.5 dtex) and fine denier fibre (unifilar fibre density is less than 1.0 dtex.) is the rapidly-developed and much numerous one among the distinct fibres. The microfibre is featured by its large specific surface area, small bending rigidity and high light reflectivity. It owns both the wearing comfort of natural fibre (eg. silk) and the versatility of chemical fibre. Among the different type of microfibres, the nylon microfibre products possess good permeability, abrasion resistance, suspension property, antistatic property, water resistance and temperature compensation etc. So, the nylon microfibre is often used in the production of outdoor clothing and top-grade underwear. Combined the disadvantages of weft fabric – easy exfoliation, curling, silk hooking and loop-size instability with the additive oiling agent used during the production process and the residual internal stress caused by the elongation of nylon silk, it is difficult for the weft-knitted microfibre fabric to handle the pretreatment processing.

GOLLER Spun Oil Washing Range

According to the features of elastic knitted weft nylon and spandex blending microfibre, at present, GOLLER Spun Oil Washing Range is particularly designed for this kind of fabric for pre-treatment processing and production and the range has the following characteristics: low tension, low energy consumption, even spun oil washing effect, high reproducibility, etc.

The configuration of GOLLER Spun Oil Washing Range has the following key points:

• Low water consumption: The range is controlled by PLC system and it replenishes water according to the fabric weight and the mechanical speed of the fabric, which results in consuming less water.
• Automatically-controlled system: Perfect and automatic dosing system enables the highly precise dosing. The recipes can be saved and outputted automatically, and the relative parameters can be pre-set on PLC system, which is very convenient to operate. Trouble-shooting and reference for tendency chart of some important parameters enhance and strengthen the visualisation of the range.
• Vacuum suction device (Vacuset): When the fabric passes the microscler gaps that are covered densely on the working surface of the vacuum water absorption tubes, the negative pressure inside the tubes will remove the moisture and impurities of the fabric. On both ends of water absorption tubes, there are seal belts, that its length can be adjusted to adapt to the width change of fabric.
• E+L tension-controlling system: During production, we should monitor the tension variables of machine by controlling the motors with the frequency inverter.
• It allows the application run normally and avoids the corrugation and shrinkage rate becoming higher.
• High efficiency washing compartment (Sintensa): This compartment combines power spray washing with turbulent washing into one system, which enjoys the benefits of large circulation capacity and effective washing effect.

Production case

The kind of fabric for processing: Microfibre weft nylon and spandex blending series (No.CNF390, CNF011s2, CNF002)

Technology application process during production: Tidying up the fabricfabric inlet with J-boxcentering devicedyestuff soaking(85o)vacuum suction devicewashing by hot water (75o)washing by hot water (65o)washing by cold water (30o)vacuum suction devicefabric outlet (winder).

Recipe for technology application process:

Machine speed: 25m/min

Temperature: 85deg. 75deg. 60deg. 30deg.

Washing agent: 2ml/l

Soda ash solution: 5.3ml/l PH: 7

Extracting agent: 2.0ml/l

Dispersing agent: 1.0ml/l acid

Osmosis agent: 0.5ml/l

Water supply for production technology application: 2.5 l/kg 1l/kg

Tension: 30N

Capacity of vacuum suction: 30mbar~50mbar

Remarks

• Water supply for production application is counted by the fabric weight, and kg means the fabric weight.
• The statistics after spun oil processing
• Above fabric is the typical fabric processed by GOLLER ranges, whose final width, water shrinkage rate change and the fabric quality have been constantly satisfied the needs of our customers.

Common problems and solutions

• The problem of “snagging” on the fabric surface

Reason: Snagging is a defective quality that the fibre and yarn are snagged out on the fabric surface. Since snagging can affect the fabric quality of the appearance, so it should be avoided.

Solutions

• When the fabric is dwelled in J-box and its nips are sewed, touching the fabric with hands directly is prohibited (one should wear gloves when touching it.). In addition, dragging the fabric is not allowed either at this time, which can prevent the sharp articles touching the fabric surface and causing silk hooking.
• The impurities should be cleaned up in time inside the range. Impurities, such as filthy water, spot of auxiliary, nips of yarn can attach or twine on the surface of the rollers and expanders. During the washing processing of fabric, touching these impurities will lead to silk hooking and “scratch”.
• The problem of “stained with impurities ”during the fabric processing

Reason: During the production, there are impurities staining on the fabric inversely, which can affect the fabric’s finishing.

Solutions

• The power sprays before the squeezers should be on to facilitate the effective washing-off of impurities from fabric.
• Clean up the machine and the power spray pipes in time and moderately according to the production.
• Pay attention to the auxiliaries chosen and try to choose those washing agents and dispersing agents that are suitable for the continuous open-width machine technology applications. It would prevent auxiliaries to demulsify inside the range. The demulsification of the auxiliaries causes impurities staining during processing.
• The problem of ‘crease’ of fabric surface and ‘rolling crinkle on fabric sides’

Reason: The “rolling crinkle” on fabric sides and the “crease” of the fabric surface are caused by the exfoliation and curling of superfine weft fabric.

• The expanders before the squeezers can be controlled by frequency inverter, so when there is any curling, we can speed up the expanders and expand the sides of the fabric.
• Moderately increase the expansion of the fabric before it goes into the squeezers with the help of the expanders to make the curling open.
• When coming across the fabric which curls easily (the effect is not so obvious by regulating the speed of expanders and by raising the expansion), all the squeezers have to be opened and we could use the suction capacity of the vacuum suction device to finish the spun oil washing process.
• The dwelling amount of fabric in the J-box should not be too much. If dwelled a lot, the crease of the fabric surface may occur because of the squeezing of the fabric. Generally, dwelling 120 m, that is about half of one bolt of fabric works.
• The problem of higher shrinkage rate for fabric after spun oil processing Reason: Usually, due to the tension of continuous open-width washing range during washing process, there are always problems of weft shrinkage and larger warp stretching.

Solutions

• The detection of loadcells and the amendment of tension control values: During production, we should detect the loadcells regularly, for example, we have to detect their rotation flexibility and their accuracy of resuming null point. Besides, from favourable production point of view, we ought to adjust the tension control value daily to make it accurate during production. Choosing the tension control value reasonably and adjusting it flexibly: Choosing appropriate recipe and summarising the technology application suitable for each fabric gradually in production to store the statistics for future use. It is avoided to use one recipe for all processing. In addition, there are diminutive differences among different batches of the same kind of fabric. So, we should also adjust the tension control value slightly.
• The problem of the “uniformity” for spun oil washing effect of fabric.
• Reason: The effect of spun oil uniformity for fabric mainly reflects in the effect of fabric surface after dyeing and heat setting of the finished product. If there is not any printing, stain and chromatic aberration on the fabric surface, it shows that the effect of the spun oil washing on the fabric is preferable, or it is dissatisfactory (After the factors of dyeing and heat setting excluded)

Solutions

For the fabric with higher spandex content, we have to appropriately enhance the washing force of power sprays and speed up the rotors to improve the effect of flushing and turbulent washing, since this kind of fabric itself contains much oiling agent. Adjusting the pick-up of every squeezer to get left, middle and right balanced.

Epilogue

In these years, micro-denier elastic weft nylon and spandex blending fibre is used widely in the production of high value-added fabric, eg underwear, etc. and it has promising market. As for the features and characters of this kind of fabric, using GOLLER spun oil washing range for pretreatment process can meet the demand for low water consumption, good size stability, good spun oil washing result and high reproducibility.