Raising and sanding
Raising and sanding of knitted fabrics is a post-finishing method. The pile-type fabrics include pure cotton terry, pure cotton terry, and T-shirts. /C terry and terry cloth, 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 sandpaper to produce uniform short fluff on the surface of the fabric.
Influencing factors and precautions
The fabrics that have a greater impact are mainly low weight and weaving structure. T/C fabrics that are loose and have high elasticity in both the horizontal and vertical directions are not soft enough. They either don’t have 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.
Fuzzing agent: A well-known method in the industry is to mix low-yellowing soft tablets with less than 10% dimethyl silicone emulsion (also called raising oil). This raising agent The formula can only provide a smooth and soft feel, and has no effect on this type of buttoned fleece fabric.
For pure cotton terry and terry cloth with heavy weight and tight weaving structure, soft sheets with good fluffiness, add a little high ammonia value silicone oil and dimethyl silicone oil emulsion (linting oil) , the hairiness will be rich in one pass.
Do not use amino silicone oil on T/C fabrics. The resilience and viscosity of amino silicone oil will have a counterproductive effect on pile fabrics. It will increase the softness, smoothness and elasticity of the fabrics, and increase the hooking and tearing of the pile fabrics. The probability is that sometimes the fabric feels very soft, but does not have lint or buckles.
The correct way to soften T/C fabrics is to use soft sheets mixed with dimethyl silicone emulsion, and then add a little multi-functional finishing agent (also called moisture-absorbing and sweat-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 increase the looseness and elasticity of the fabric. Easy to hang and buckle; just add some fluffy and smooth feel; thick fabric can be made soft and smooth, which can reduce the number of fluffing.
Due to various reasons, the weaving factory did not use pile yarn to weave fabrics, resulting in the phenomenon of nap or buckle. However, the nap caused by the looseness of the weaving structure or the increase in elasticity of the fabric due to inappropriate softness solutions. The phenomena of velvet and hanging buttons are different and cannot be confused.
Thin, short, dense pile raising process
The raising process is to expose the surface fibers of the fabric to increase the thickness of the fabric , using softeners to improve its feel and enhance its thermal insulation 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 practicality of the fabric can be improved.
This project improved the tension control and shearing device by selecting the appropriate fabric structure, and conducted in-depth research on factors such as plucking intensity, plucking sequence and number of plucking, and developed a short, dense and application-friendly fabric. Good thin velvet fabric.
Raw material selection
The fabrics of this project include base fabric layer and wool Loop layer, in which the base fabric layer is woven from ordinary polyester filament whose fiber cross-section is usually 0.22~0.33 tex; the terry layer is woven from ultra-fine denier, fine denier or functional polyester filament. The base layer completely covers the base fabric layer, showing a reverse-wrapped structure. The fabric structure is tight, which increases the difficulty of drawing, combing and shearing, and overcomes the problems of light and thin fabrics that are prone to straight strips, holes and poor bursting during drawing. problem.
Device optimization
Improve 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 may cause fluffing and breakage of the fabric, affecting the nap of the fabric. The fabric feeding tension control device and the cloth exit roller tension control device of the raising machine have been improved. . Through equipment improvement and process optimization, a thin velvet fabric has been developed. The fabric has short and dense pile, fewer holes in the fabric surface, and excellent hand feel and application performance.
a. Fabric feeding tension control device
△ Improvements Cloth tension control device
The improved cloth 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 operates, thereby generating tension, which is controlled by the 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. Discharge roller tension control device
△Improved cloth outlet roller tension control device
The improved cloth outlet roller tension control device measures the fabric tension through a tension sensor installed on the cloth outlet roller, and The measured tension is fed back to the PLC at the same time. The motor speed of the cloth outlet roller can be controlled by setting the tension value on the PLC, thereby accurately controlling the force exerted on the fabric on the cloth outlet roller.�strength. 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
△The expansion device of the shearing machine head
The expansion device of the shearing machine head
A new shearing machine blade expansion device has two advantages: with the help of this device, the curled edge of the fabric can be peeled off smoothly, so that the shearing effect on the edge of the fabric is also stable and the amount of waste fabric is reduced; It can reduce the probability of holes during shearing.
Fabric development process
The process flow is: raising→combing→shearing. ” The sequence of plucking is “Back → Front → Back → Front → Back → Front”.
Carding 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, , optimize the shearing tension, brush distance, shearing knife distance and other process parameters, and finally determine the front shearing process parameters as wool direction: smooth hair, shearing tension: 2.5 kgf, cloth delivery speed 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.
Related knowledge
Sanding, pulling, grabbing and brushing?
1. Sanding
refers to rubbing the cloth surface with an abrasive roller or metal roller;
Different fabrics are combined with different sanding mesh numbers to achieve the desired sanding effect.
The general principle is that high-count yarns use high-mesh sand leather, and low-count yarns use low-mesh sand leather.
The abrasive rollers are used for forward and reverse rotation. Generally, an odd number of abrasive rollers are used.
[Influencing factors]
Sanding roller speed, vehicle speed, cloth body moisture content, covering angle, tension, etc.
2. Fleece grabbing
uses a steel wire bent needle at a certain angle to insert into the yarn. Hooking out fibers to form hairiness;
It means the same thing as pulling hair, but it’s just a different term;
Different fabrics use different Steel needles can be divided into round heads and pointed heads. Generally speaking, cotton needles use pointed heads, and wool needles use round heads.
[Influencing factors]
Car speed, card clothing roller speed, number of card clothing rollers, moisture content, tension, card clothing density, steel needle bending angle , yarn twist, additives used in pre-treatment, etc.
3. Brushing
Using a brush-like bristle roller to sweep over the cloth surface;
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 treatment, such as brushing cloth before singeing; wire brushes are generally used for fabrics that require severe fluffing, such as knitted flannel; carbon wire brushes are used for High-grade cotton fabrics require fine surface treatment; ceramic fibers are used for finer processing requirements.
[Influencing factors]
The number of brush rollers, rotation speed, stiffness of brush filament, fineness of brush filament, brush filament Density etc.
The difference between the three
Capturing 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 a fuzz effect on the surface. , compared with brushed products, the brushed fluff is short and dense, and the hairy feel is very delicate. Specific products include brushed yarn card, brushed poplin, peach skin, etc., and some sanded products do not look obvious. , but the 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 is a bristle machine, which is generally equipped with 8 to 10 hard brushes and 6 to 8 soft track brushes. Thick corduroy strips also need to be brushed afterward. In addition to hard and soft brushes, the rear brushing machine is also equipped with a wax plate. During the process, the velvet is waxed at the same time to make the corduroy velvet strips shiny, so the rear brushing machine is also called a waxing machine. </p
