Production process of shake grain velvet dyeing and finishing

01.polar fleece

The fleece fabric is soft, lightweight, fast drying, easy to wash, and can still keep warm when damp. Under the same conditions, it has twice the cold resistance of Merino wool and four times that of cotton. Lightweight fleece is easy to move and comfortable to wear.

The main component of fleece is polyester fiber (polyester), which has the advantages of high strength, good elasticity, good heat resistance, good wear resistance, good sunlight resistance, corrosion resistance, light weight, good insulation, and is not afraid of enzyme damage. Another outstanding advantage is that it is easy to maintain and can be washed with water.

In addition, fleece can also be combined with any other fabric for better insulation effect (fleece and fleece composite, fleece and denim composite, fleece and lamb fleece composite, fleece and mesh fabric composite with waterproof and breathable film in between, etc.).

02.Machining Process

technological process:

Weaving → dyeing → adding fuzzing agent to dyeing vat → dehydration → drying → cutting → brushing → combing → shearing → shaking → finished product shaping → inspection → packaging → storage.

precautions

1. The design of dyeing and finishing process flow and parameters should consider maintaining the shape of hollow fibers as much as possible, avoiding shrinkage of fiber cavities, otherwise it is difficult to reflect the differences between irregular hollow fibers and conventional fibers.

2. When designing the process parameters for each process, it is necessary to ensure that the fleece has a thick and fluffy effect, increase the static air layer between fibers, and enhance the warmth, lightweight, and softness of the fabric.

03.Production process

Production process of shake grain velvet dyeing and finishing

1. Dyeing

The irregular hollow polyester fiber fabric is dyed under high temperature and high pressure, with a dyeing temperature of generally 120-130 ℃. While ensuring color fastness requirements, it is recommended to use 120 ℃ dyeing as much as possible, and the insulation time should not exceed 30 minutes to reduce the phenomenon of fiber shrinkage caused by high dyeing temperature and long time. During dyeing operations, the cylinder capacity should not be too large and should not exceed 80% of the cylinder capacity as much as possible to avoid prolonged stacking of fabrics in the dyeing cylinder.

2. Add fuzzing agent

The methods of adding fuzz agents include setting fuzz agents and dyeing vat fuzz agents. The addition of fuzzing agent to the dyeing vat is achieved by impregnating the fuzzing agent at room temperature. The advantage of adding fuzzing agent is that the tension on the fabric is small, it relaxes, and does not change the shape of the irregular hollow fibers. In addition, the auxiliary agent has a long and uniform effect on the fibers, resulting in high production efficiency. Therefore, the dyeing vat with fuzzing agent is used.

3. Brush bristles

Brushing is the use of mechanical straight needles to support the flat surface of the fabric, and bent needles (starting needles) to gradually break the fiber layers on the loop, and continuously hook and tear the loop yarn, making the loop yarn loose and loose, forming independent fluff, feathering, and covering the surface of the fabric. Due to the continuous hooking and pulling of the loop yarn by the curved needle, the fabric shrinks longitudinally and laterally, resulting in a thick and sturdy body that is not easily shedding hair. The fluff is fluffy, and the added value of the fabric is increased. The bristle conditioner should pay attention to tension and fuzzing rate (i.e. bending needle speed). The tension determines the length of the bristles, while the fuzzing rate determines the density of the fluff.

The faster the needle covering speed, the looser the tension, the faster the needle lifting speed, and the higher the fuzzing rate. On the contrary, the tighter the tension, the lower the fuzzing rate. The gap between the pre shaped hollow polyester fibers is large, and the tension during brushing is looser than that of conventional fleece. Light brushing is sufficient. The bristle needle cloth uses curved bristles with low density and good elasticity to easily hook and feather the hollow fibers, reducing the probability of elongation and breakage of the hollow fibers and minimizing losses.

4. Combing hair

After brushing, the semi-finished product is processed by a carding machine using a needle roller to comb and straighten the messy hair. The hair is then stood upside down to remove any broken hair from the fluff, making it fluffy and straight after combing. This ensures that the hair length is consistent after shearing, and the grains are easy to form when shaken.

Process parameters for carding of irregular hollow polyester fibers and conventional polyester fibers with fleece

picture

A. The adjustment of tension in sections B and C is to ensure that the fabric is evenly applied to the large plate of the carding machine, and the tension is generally only slightly adjusted. The combing rate is the main factor in combing regulation. The higher the combing rate, the heavier the combing, and vice versa, the lighter the combing.

The gap between the irregular hollow polyester fibers is large, and light combing can meet the requirements, reducing the degree of elongation and breakage of the hollow fibers. The hollow fibers can be straightened and fluffy.

5. Trimming hair

After weaving, untwisting, or brushing, the plush fibers on the surface of velvet fabrics vary in length, and it is necessary to cut the fuzz short into upright and neat short hairs; Or trim the long hair evenly to make the velvet surface flat. The length of the shearing directly determines the size of the shaking particles. The longer the hair, the larger the particles, and the fluffiness of the shaking particle style. The more static air content in the irregular hollow polyester fiber, the better the insulation.

Therefore, in the production of ultra fluffy shaped hollow polyester fiber fleece, it is necessary to have long shearing and trimming to reduce the amount of floating hair and minimize shearing losses. However, shearing and leaving hair should not be too long, otherwise there will be too much floating hair on the fabric surface, and the hair surface will be uneven, which will cause the particles formed after shaking to be blurry and uneven, affecting the beauty. When shearing, adjust the angle between the triangular knife and the circular knife according to the thickness of the fabric, so that the sheared fluff is upright and not prone to lodging. This allows for free space for the fluff to wrap and contract with each other during shaking, forming full and fluffy particles. Otherwise, the resulting particles will be flat and not fluffy.

6. Shake granules

Shaking granules are made by mechanically flipping and blowing with hot air in a shaking machine, causing the fluff to entangle, aggregate, and shrink with each other.

There are currently two types of granulators: tension-free granulator buckets and jet type continuous granulator anti shrink machines.

The tension-free shaking drum is a traditional shaking method, which requires cutting the fabric head after shearing. The shaking drum relies entirely on manual lifting and pulling of the fabric, resulting in high losses and labor costs. The tension-free shaking drum is heated by steam, dried by hot air, and cooled by cold air.

The jet type continuous shaking anti shrink machine is heated by hot air and cooled by cold air. After shearing, there is no need to cut the fabric head. The fabric is directly fed into the jet type continuous shaking anti shrinking machine through the guide wheel. The fabric rotates in the shaking machine, and the hot air blows, oscillates, and rubs to form particles.

The shaking drum uses direct steam to heat the shaking wool, and the temperature cannot be set according to the process requirements. High temperature will cause the irregular hollow polyester fibers to shrink greatly, reduce the hollow volume, and affect the hollow structure and the fluffiness of the shaking wool. Hollow fibers are suitable for production using a temperature adjustable jet type continuous shaking anti shrinking machine.

7. Finished product shaping

When shaping irregular hollow polyester fibers, the stretching tension should be small to reduce the probability of narrow hollow pipelines and hollow walls sticking due to stretching, and to avoid the phenomenon of backcombing caused by excessive stretching, which can reduce the fluffiness of the shaking style. The finished product of the shaking cloth should not be shaped by rollers, otherwise it will affect the fluffiness of the shaking style.