Napped and brushed
Raising and sanding of knitted fabrics is a post-finishing processing method. Raising fabrics include pure cotton terry, pure cotton terry, T/C terry and terry, CVC terry, etc.
The customary distinction is: terry cloth has small loops, and terry cloth has large loops. The raising of this type of loop structure fabric uses steel needle rollers to mechanically cut the loop structure to produce fluff. There are many woven structures of sanded fabrics. They use the mechanical friction between the carbon fiber of the sanding machine and the sandpaper to produce uniform short fluff on the surface of the fabric.
Influencing factors and precautions
Fabrics with a large impact are mainly low weight and weaving T/C fabrics with a loose structure and high elasticity in the transverse and longitudinal directions are not soft enough. They either cannot get rid of lint or are stuck (the loops are picked up but not cut). The auxiliary factory will only sell a single raising agent, and they don’t know the root cause of the poor raising.
Raising agent: A well-known practice in the industry is to mix low-yellowing soft tablets with less than 10% dimethyl silicone emulsion (also known as raising oil). This fluffing agent formula can only provide a smooth and soft feel, and has no effect on this type of buckle fleece fabric.
For heavy-gram woven pure cotton terry and terry cloth with tight structure, soft sheets with good fluffiness, and a little high ammonia value silicone oil and dimethyl silicone oil emulsion (hair raising oil), the hairiness will be rich in one application.
Do not use amino silicone oil on T/C fabrics. The resilience and viscosity of amino silicone oil will have a counterproductive effect on fluffing and increase the softness and smoothness of the fabric. And elasticity, increase the probability of the fleece fabric to catch the buckle and tear the fabric. Sometimes the fabric feels very soft, but it cannot catch the velvet or catch the buckle.
The correct way to soften T/C fabrics is to use soft sheets mixed with dimethyl silicone emulsion, and then use a multi-functional finishing agent (also known as moisture wicking) finishing agent).
Low weight fleece fabrics must not be soft and slippery, as this will greatly reduce the strength of the fabric, tear the fabric during fleece, and cause the fabric to tear. The looseness and elasticity are increased, making it easy to hang the buckle; just add some fluffy and smooth feel; the heavy fabric can be made soft and smooth, which can reduce the weight.Less linting.
Weaving factories do not use pile yarn to weave fabrics for various reasons, resulting in the phenomenon of no pile or hanging buttons, but it is loose with the weaving structure or due to inconsistency. The lint-free and buckling phenomena caused by the loosening and elasticity of the fabric caused by the appropriate softness solution are different and cannot be confused.
Thin, short, dense pile raising process
Raising process is to remove the fibers on the surface of the fabric Exposed to add thickness to the fabric, improve its feel through softeners and enhance its insulating properties.
The raising process directly determines the style and quality of the fabric. By raising the fabric, the appearance and feel of the fabric can be significantly improved, and the warmth retention and quality of the fabric can be improved. Practicality.
This project improved the tension control and shearing device by selecting appropriate fabric structure, and conducted in-depth research on factors such as pulling intensity, pulling sequence and number of pulls. , developed thin velvet fabrics that are short, dense and have good application performance.
Raw material selection
The fabric of this project includes a base fabric layer and a terry layer. The base fabric layer is made of ordinary polyester filament with fiber cross-section, and the yarn density is wei 0.22 ~0.33 tex; the terry layer is woven from ultra-fine denier, fine denier or functional polyester filament. The terry layer completely wraps the base fabric layer, showing a turn-up structure. The fabric structure is tight, which increases the difficulty of carding and shearing. It overcomes the problems that light and thin fabrics are prone to straight strips, holes and poor bursting during brushing.
Device optimization
Improved tension control device
The tension control of the raising machine is unstable, which can easily lead to unstable fabric raising quality. In serious cases, it can cause fluffing and breakage of the fabric, which affects the raising of the fabric. The tension control device of the raising machine and the cloth exit roller tension control device must be inspected. improved. Through device improvement and process optimization, a thin velvet fabric has been developed. The fabric has short and dense pile, fewer holes on the fabric surface, and good hand feel and applicability.Excellent performance.
a. Fabric feeding tension control device
△Improved fabric feeding tension control device
The improved fabric feeding tension control device holds the bearing tightly through the oil pressure control washer 2 to produce a damping tension effect. The fabric rotates on the passive tension roller 1, driving the passive tension roller 1 to operate, thereby generating tension. This tension Damping force controlled by oil pressure. In order to prevent the fabric from slipping on the passive tension roller, the passive tension roller can be wrapped with anti-slip rubber.
b. Output roller tension control device
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△Improved cloth delivery roller tension control device
The improved cloth outlet roller tension control device measures the fabric tension through the tension sensor installed on the cloth outlet roller, and feeds back the measured tension to the PLC at the same time. The output can be controlled by setting the tension value on the PLC. The motor speed of the cloth roller can accurately control the tension of the fabric on the cloth roller. Among them, the PLC has speed control and tension control options, which can solve the tension control methods of different elastic fabrics to achieve stable quality of fabric production.
Shearing machine blade expansion device
△Expansion device of the shearing machine head
Expansion device for shearing machine blades
A new shearing machine blade expansion device has two advantages: with the help of this device , can peel off the curled edge of the fabric smoothly, so that the shearing effect on the edge of the fabric is also stable, reducing the amount of waste fabric; it can also reduce the probability of holes during the shearing process.
Fabric development process
The process flow is: raising→combing→shearing.
Brushing process
Choose 2% fluffing agent and determine three times of light plucking, the plucking sequence of “reverse side→front side→reverse side→front side→reverse side→front side”.
Combing process
This project chooses moderate reverse combing process.
Shearing
The shearing blade distance is the main factor that controls the shearing height. After many tests, the shearing tension, The process parameters such as brush distance and shearing knife distance were optimized, and the front shearing process parameters were finally determined as hair direction: smooth hair, shearing tension: 2.5 kgf, cloth delivery speed and tension: 1.5 kgf, knife distance: 0.8/0.15 inch, knife speed: 850 r/min, brush distance: 2.5 inch, brush speed: 50 r/min
Sanding, pulling, and scratching. Hair and bristles?
1. Sanding
It refers to using an abrasive roller or a metal roller to rub on the cloth surface;
Different fabrics use different abrasive mesh numbers to combine. To achieve the desired sanding effect
The general principle is to use high-mesh sanding leather for high-count yarns and low-mesh sanding leather for low-count yarns.
The sanding roller has forward and reverse rotation. Generally, an odd number of sanding rollers are used.
【Factors affecting the sanding effect of the sanding roller Yes]
Sanding roller speed, vehicle speed, fabric body moisture content, covering angle, tension, etc.
2. Catching
It uses a steel wire bent needle at a certain angle to insert the yarn Inside, fibers are hooked out to form hairiness;
It means the same thing as pulling hair, but it is just a different term;
Different fabrics use different steel needles, which are divided into round heads and pointed heads. Generally speaking, cotton-type needles use pointed needles, and wool-type needles use round heads.
【Influencing factors】
Vehicle speed, card roller speed, number of card rollers, Moisture content, tension, card clothing density, steel needle bending angle, yarn twist, additives used in pre-treatment, etc.
3. Brushing
It uses a bristle roller like a brush to sweep on the cloth. Over;
Different fabrics and treatments use different bristle rollers, including bristle brushes, steel wire brushes, carbon wire brushes, and ceramic fiber brushes.
Use a bristle brush for simple processing, such as brushing cloth before singeing; wire brushes are generally used for fabrics that require severe fluffing, such as knitted flannel; carbon wire The brush is used for high-grade cotton fabrics, which require fine surface treatment; ceramic fibers are used for finer processing requirements.
【Influencing factors】
Number of brush rollers, rotation speed, stiffness of brush filaments, brush The fineness of the wire, the density of the brush wire, etc.
Differences between the three
Catching and pulling are the same concept, that is, the same process , the equipment used is a brushing machine, which uses a steel needle roller to pull out the microfibers in the fabric yarn to form a fluffy effect on the surface. The specific products include flannel, silver hydroxyl cloth, etc. The brushing process is also called “napping” .
The equipment used in the sanding process is a sanding machine, which uses sand leather, carbon, ceramic and other rollers to grind out the microfibers in the fabric yarn to form The surface fuzz effect is shorter and denser than that of brushed products.The wool feel is very delicate. Specific products include brushed gauze card, brushed poplin, peach skin velvet, etc. There are also some brushed products that do not seem to have obvious wool feel, but the hand feel is greatly improved.
Brushing is mainly a special process for corduroy, because the velvet of corduroy is cut from the weft yarn of the surface tissue, and the yarn is broken up by brushing to form a cohesive velvet strip. The equipment used is a bristle machine, which is generally equipped with 8 ~10 yuan Hard brushes and soft brushes with 6 to 8 tracks. Thick corduroy strips also need to be brushed after the hair. In addition to the hard and soft brushes, the back brushing machine is also equipped with a wax plate. During the brushing process, the hair is waxed at the same time. It is the corduroy velvet. The strips are shiny, so the rear brushing machine is also called a waxing machine.
Source: printing and dyeing people, knitting industry
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