Raising and sanding
Raising and sanding of knitted fabrics is a post-finishing method. 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 sandpaper to produce uniform short fluff on the surface of the fabric.
Influencing factors and precautions
The fabrics that have a great impact are mainly T/C fabrics with low weight, loose weaving structure, and high elasticity in the transverse and longitudinal directions are not soft enough. They either do not 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 and dense velvet raising process
Raising process It exposes the fibers on the surface of the fabric to increase the thickness of the fabric, improves its feel and enhances its thermal insulation performance through softeners.
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 fabric of this project includes a base fabric layer and a terry layer, where the base fabric layer is made of fiber cross-section usually Weaved from ordinary polyester filament, the yarn density is 0.22~0.33 tex; the terry layer is woven from ultra-fine denier, fine denier or functional polyester filament, and the terry layer completely wraps the base fabric layer, showing a reverse wrapping The structure of the fabric is tight, which increases the difficulty of drawing, carding and shearing, and overcomes the problems of light and thin fabrics that are prone to straight strips, holes and poor bursting during drawing.
Device optimization
Improve tension control device
The tension control of the raising machine is unstable, which can easily cause the fabric raising quality to be unstable. In severe cases, it can cause fluffing and break the fabric, which affects the raising of the fabric. It will also affect the fabric feeding tension control device and the cloth exit roller of the raising machine. The tension control device has 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
△Improvedfabricfeedingtensioncontroldevice
Theimprovedfabricfeedingtensioncontroldeviceholdsthebearingtightlythroughtheoilpressurecontrolwasher2togeneratedampingtensionAsaresult,thefabricrotatesonthepassivetensionroller1,drivingthepassivetensionroller1tooperate,thusgeneratingtension.Thistensioniscontrolledbythedampingforcecontrolledbyoilpressure.Inordertopreventthefabricfromslippingonthepassivetensionroller,thepassivetensionrollercanbewrappedwithanti-sliprubber.
b.Distributionrollertensioncontroldevice
△Improved cloth outlet roller tension control device
The improved cloth outlet roller tension control device uses a tension sensor installed on the cloth outlet roller To measure the fabric tension, and feed the measured tension back to the PLC at the same time. The motor speed of the cloth output roller can be controlled by setting the tension value on the PLC, so as to�Accurately control the tension of the fabric on the cloth delivery 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
△Theexpansiondeviceoftheshearingmachinehead
TheexpansiondeviceoftheshearingmachineheadWidthdevice
Anewshearingmachinebladeexpansiondevicehastwoadvantages:withthehelpofthisdevice,thecurlingedgeofthefabriccanbepeeledoffsmoothly,sothattheedgeofthefabriccanbeTheshearingeffectisalsostable,reducingtheamountofwastecloth;itcanalsoreducetheprobabilityofholesduringtheshearingprocess.
Fabricdevelopmentprocess
Theprocessflowis:raising→combing→shearing.
Nuffingprocess
Selected2%raisingagent,determined3Secondlylightplucking,thepluckingsequenceis”Back→Front→Back→Front→Back→Front”.
Cardingprocess
ThisprojectchoosesmoderatereversecombingCraftsmanship.
Shearing
Theshearingbladedistanceisthemainfactorincontrollingtheshearingheight.Factors,aftermanytests,theshearingtension,brushdistance,shearingknifedistanceandotherprocessparameterswereoptimized,andthefrontshearingprocessparameterswerefinallydeterminedaswooldirection:smoothhair,shearingtension:2.5kgf,clothdeliveryspeedtension:1.5kgf,knifedistance:0.8/0.15inch,knifespeed:850r/min,brushdistance:2.5inch,brushspeed:50r/min.
Sanding, pulling, scratching 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.
The factors that affect the sanding effect include: sanding roller speed, vehicle speed, cloth body moisture content, covering angle, tension, etc.
2. Catching hair
uses a steel wire at a certain angle The curved needle is inserted into the yarn to hook out the fibers and 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 types use pointed heads, and wool types use round heads.
Influencing factors: vehicle speed, card clothing roller speed, number of card clothing rollers, moisture content, tension, card clothing density, steel needle bending angle, yarn twist, pre-treatment Additives used, etc.
3. Brushing
Using a bristle roller like a brush Sweep across the cloth;
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: number of brush rollers, rotation speed, stiffness of brush filaments, fineness of brush filaments, density of brush filaments, etc.
The difference between the three
Catching and pulling are the same concept. It 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 It’s called “fluffing”.
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 brushing 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
