Superfine fiber synthetic leather dyeing process is introduced

Used in PA6 and polyurethane dyeing dye alone has multiple types, containing acid dye, neutral dye, dye, reactive dye, etc. To separate dyeing on PA6 and polyurethane, the single dye can have very good effect, but about sea island contains two components, hong jie superfine fiber leather case is much more complicated, especially when dyed dark, and even need to think fight to mix two or even three dye dyeing.


Distractions dyeing


Distractions before dye is a kind of strong hydrophobicity and small water soluble non-ionic dye, no water soluble groups in the structure but is rich in many larger groups, such as NO2, NH2, – CN, OG, etc. Points are scattered because of the different types of dyes and dye dyeing rate is different, color matching should choose as far as possible on dyeing rate near or in compatibility good dye, for example distractions dye and weak mixing, dyeing with reactive dye or neutral dye to adjust light and improve the leveling degree of color, to reach the intention of the foster strengths and circumvent weaknesses.


Wandering dye dyeing rate is bigger to the dependence of the temperature, especially when dyeing so should pay attention to the temperature control. Temperature rise and fall disintegrating agent adsorption of dye, the dye particles between knock against, agglutination time increases. On the other hand, the temperature, increase the solubility of small particles and large particles to make progress, these will make the stability of the distractions liquid drop. Thus make good dye solution temperature should be low, should prevent the long-term heat dyeing liquid before dyeing. Usually in 40 ~ 50 ℃ in dye, about 0.5 ℃ / min up to exult. According to the dye levelling driving life situation, heat preservation water to wash again.


Wandering dyes to dye on the polyamide fiber and polyurethane together. Dyed guess many amide in the active group and PA6 molecules and molecules at the end of the amino through hydrogen bonding, van der Waals force, and I strongly to dyeing and fixation. Besides, PA6 molecules contains a lot of non-polar hydrophobic chain of hydrogen, which is unraveling of hydrophobic dyes to dye the reason of jin birch. Unraveling the dye smaller molecular weight, good dispersion function and dyeing method briefly, good levelness and day Sun fastness good, good to cover shame left can prevent polyamide fiber for aggregation component intrusive and exclusive or spinning different tensile strength, constitute the uneven dyeing. But with distractions with dye PA6, its full value is very low and dyed dark comparison difficult.


Unraveling the dye of polyurethane has good color, the molecular structure and comparison with polyurethane itself closely associated foam structure. Polyurethane in hong jie leather base cloth table surface and internal imperfect connection of polymer film, its structure is composed of soft segment and hard segment. Soft chain segment some loose structure, is the first position of distractions dye dyeing. Pu large to distractions of dye uptake, dyeing in the residual liquid dye residue is less, the selects high strength of the dysfunctional dye dyed dark species is very necessary. , within the range must follow the progress of dyeing temperature, color quantity is larger. In addition, dysfunctional dye on polyurethane fastness is better also.


In sea island superfine fiber hong jie dyeing, the leather dyestuff is dyed polyurethane top type. In comparison, other types of dyes for polyurethane paint is poorer, opposite nylon color; Some despite of polyurethane has good color, but together with nylon color, this about evenly dyed light, colorless difference of products is very unlucky. , even wandering dye dosage on also want to pay attention to control, because it of nylon color not only affect the colored light, can also affect the nylon dyeing fastness.


Acid dyes dyeing


Is one of the important dye nylon dyeing, acid dyes first is ionic bond contact between fibers and dyes. If dyed when low PH (PH < 3 =, the molecular chain of the amino also is ionization (N + H2) and contact the anionic dyes. Else, weakly acidic or neutral bath dyeing with acid dyes, hydrogen bonding and van der Waals force also plays an important role, their dyeing full value is usually beyond the amino content of accounting to the full value. Because amino content than light music and polyamide fiber end, so when using two or more than two dye color matching, usually attack race question, therefore should pay attention to when you spell color choose good dye compatibility.


Nylon for linear molecules, not branched molecule chain and large side group, but there are a lot of to form hydrogen bonding group. Dye molecules brief and fiber molecular KaoRao with larger van der Waals force, breeds into hydrogen bonding between the dyes and fibers, thus, the affinity of acid dye on the polyamide is usually higher than wool. Strongly acidic dye dyeing polyamide 2.3% full porridge known, weak acid dye is 5% ~ 5.2%. So, weak acid dye dyeing polyamide commonly used material, with the van der Waals force and hydrogen bond dye dyeing rate of progress.


Polyamide acid dyes with strong, usually is not deep, this is because the gender groups share different (commonly used acetic acid and benzoic acid polyamide hong jie recuperates the molecular weight, there was the end of the macromolecular amino acylation, plague Po acyl press and benzamide base in the form of a large, amino content than the carboxyl content is low, also found ring amide group in PA6). Thus with typical acid dye dyeing levelness, namely only by coulomb force on dye, difficult to dye the deep color.


Acid dyes on polyurethane can dye, because Lou in polyurethane molecular knot off amide, urea, carbamate acid base, contact form for the van der Waals force, hydrogen bond and ionic bonds, but not dyed ambitions. Especially strong acid dyes, dye fixation on fiber it will appear on the appearance, rarely to the interior fiber, soaping fade, solid color fastness is very poor. Weak than strong acid dye dyeing with reactive dye centigrade is a bit high, washing fastness This, the soaping fastness are still not ambition, dye could not enter inside the fiber, the same poor light fastness.


Neutral dyeing


Contains acid mordant dyes, neutral dyes is 1:2 type metal atoms with dye molecules share contact 2-1. Don’t contain sulfonic group in the dye molecules such as water soluble groups, and is rich in water soluble low only hydrophilic groups, such as amino (- SO2NHR) sulfonyl and thiamphenicol (- SO2CH3), etc., they are usually in neutral or weak acid medium dyeing, this is a title.


Nylon molecules have a lot of amino carboxyl end group, to be able to use neutral dyeing, and get a deeper colour and lustre, good wet fastness and disposal sunlight fastness; Dye color matching between good functionality, and less competitive dye now like, high utilization rate of dye; Relatively brief dyeing technology. But neutral dye chromatography is not complete, because the dye molecules that are rich in metal from together? , colour and lustre is gorgeous, so the product is suitable for dyeing dark shade.


Neutral dye ions form disease deed amino positive ions into ionic bond ties with PA6, dye molecules together also can contact with fiber with ammonia and van der Waals force, so the neutral dyeing of polyamide fiber has good affinity. Because the number of dye molecules attached absorption exceeded the number of fiber end macromolecular amino, dye uptake percentage is high, so dyeing full value is bigger also. Slow for the manipulation of the dye evenly dyeing, dye bath PH value should be a little higher, in order to cut down on the number of ammonia base cations, coulomb force. Lower percentage of dyeing color, in the boiling dye after a period of time, can participate in appropriate glacial acetic acid (usually at the mercy of the component which is 1%), in order to promote further dye dyeing.


Neutral dyes can also be used to dye polyurethane, primarily through hydrogen bonding, van der Waals force and coulomb force. Choose appropriate neutral dye type on the pu dyeing, can satisfy the full value. Dyeing should be under the low tension, if necessary, pass heat styling. Neutral dye adsorption performance for binary on polyurethane adsorption characteristics, namely the Langmuir type and Nernst type adsorption exist together, and followed the dye IOB values fall low, namely hydrophobic, Nernst increases adsorption dedication, affinity, dyeing rate significantly increased. Neutral dye dyeing of pu is better than the usual of acid dye effect.


Reactive dyeing


Reactive dye is a kind of can and fiber macromolecule contact a covalent chemical reaction in the dye.


The mechanism of reactive dyes on the dyeing PA6 contrast complex. Because molecules are a must have number of sulfonic group, under acid condition can end with PA6 molecules ionized amino generate ionic bond, so the reactive dyes dyeing polyamide usually choose weak acid bath, at the moment of dye dyeing conditions are similar to acid dyes.


Under the condition of weak acid, X type and K type reactive dye and PA6 can also generate a covalent bond. KN type reactive dye, because can’t produce vinyl sulfone base in the acid bath, so under acid condition can’t contact the PA6 generate covalent bond.


Reactive dyes dyeing of polyamide fibre can be divided into the dye by polyamide adsorption, the adsorption of dye into the fiber crop she scattered and penetration and dye and fiber contact by three during fixation. The covalent bond connection of the two factors was very strong, mining with reactive dyes is has the very high wet treatment of fastness, its reason lies in here. And ionic bonds between dye with polyamide, dipole role, van der Waals force and hydrogen bond relation during the dyeing process of adsorption has very important meaning. About after dyeing products, this link is more harm than good, it will serious impact products wet fastness of disposal. Therefore, dye on non covalent bond connection must degree to root out, usually after treatment with ammonia to. In the process of disposal, on the one hand, under the condition of high PH promote dye with response to attack has not continued with polyamide attack, on the other hand made no response, especially in ionic bond contact dye desorption since the polyamide fiber, and then to ensure that the products of color fastness. Reactive dyes to dye PA6 with colour and lustre is gorgeous, washable and conflict have good color fastness, high sublimation fastness and dyeing is convenient wait for an advantage. But for PA6 molecules of amino amount less, color quantity is low, coupled with poor levelness, so will only be used for medium and light types.


Of reactive dyes in dyeing polyurethane be much, but in hydroxyl-terminated poly (amino acid macromolecular chain, makes the existence of dyeing with reactive dyes can 膹 嫞


Mixed dyeing


Type on the island superfine fiber hong jie leather dyeing process, a single type of dyes usually reach satisfactory ambition, especially when dyed dark species. At the moment to think about mixing technology, dyeing to two or more dye combination is applied, in order to reach the requirements. Through regulate different components in the mixed dye guess share survey target. Variety of dyeing, must think to dye the compatibility between the question. After investigating different dyeing function curve refers to target, as far as possible selecting dyes dyeing function near for compatibility, together to choose the suitable dyeing auxiliaries (including levelling agent, soaking agent, agent, dispersing agent, fixing agent, etc.), strengthen the similar compatibility between the dye 膹 嫞 on dyeing technology, the mixture of dyeing is different from the same single dyeing, demand for appropriate adjustments. Demand, for example, different kinds of dye dyeing PH value is not the same, not in the same dye bath For different dyes. Able to pass the red the following two way to deal with at the moment: staining method step by step, namely segmentation for different types of dyes, each of these dyes were within the scope of its habit of PH condition; PH sliding method, namely the sliding agent to attend in the dye bath PH (PH conditioner, PH control agent), make the dye bath PH value in the process of dyeing active sliding, then used different types of dyes. The PH conditioner for organic ester and amide compounds, usually with a halogen group of organic compounds, volatile organic acids, and aldehyde, hydroxyl or carboxyl was rich in alkaline oxidizing agents, these substances can be in at higher temperatures, release acid, drop in the PH of the solution, make its sliding to acid.