Most coatings are composed of a base material (one or more resin mixtures), pigments (including physical pigments and functional pigments), solvents and some small amounts of additives and other coating raw materials. In the production of coatings, after the selection of various coating raw materials necessary for coating components, the next is how to make reasonable use of the technical and economic properties of coating raw materials to produce high-quality coatings. As we all know, the selection of various coating raw materials has a great impact on the performance of the coating. If one component is not selected properly, the entire paint formulation may fail. Therefore, in the overall composition arrangement of the coating formula, in addition to fully considering the role of each component, there is also consideration of compatibility and synergy between various components. After selecting the appropriate component, the volume concentration of the pigment must also be taken into account. In addition, the influence of the solvent on the construction process of the coating and the coating performance, as well as the role of the solvent on the control of the fluidity, viscosity, and drying time of the coating are all issues that must be considered in the correct selection of the coating raw materials and the overall raw material formulation design. Alkyd resin is the most used resin in coating production, its raw materials are easy to obtain and the manufacturing process is simple. Alkyd resin contains a large number of ester groups, so the way of modification is very wide. Thixotropic coatings can be prepared with polyamide modified alkyd resin, and amino resin can be used as excellent coating materials for coil and home appliance coatings. Varnish requires no pigment ratio. But color paint must be added to increase color and coverage. The varnish is colorless and transparent, and has no covering power, so the color paint with color and covering power accounts for the highest proportion of paint varieties. Pigment is one of the most important paint raw materials. Before the use of paint pigments, it is necessary to focus on the color, hiding power and coloring power performance. Color is the color that the coating product needs to achieve, which is correctly selected when selecting pigments after it is clearly defined in the overall plan of coating production; The covering power of pigment is related to its refractive index, crystal type and particle size. Among the known pigments, rutile TiO2 has the largest refractive index and the largest refractive index difference between it and the polymer, so it is the white pigment with the best hiding power. The hiding power of the pigment depends not only on the amount of light scattered by the paint, but also on the absorption capacity of the light irradiated on it. For example, carbon black does not reflect light at all, but can absorb all the light irradiated on it, so its hiding power is the st...

1.Touch optimization: the pursuit of softness and fullness In view of the frequent skin-to-skin contact of fabrics, the primary goal of the design of waterborne polyurethane coatings is to achieve soft touch and full form. This requires us to carefully balance the ratio of hard and soft segments in the formulation adjustment, while carefully selecting the types of both to ensure that the coating retains the necessary support without losing its fineness and comfort. 2.Heat stable: stick to high temperature Considering the high temperature environment that fabrics may encounter during processing, transportation and use, waterborne polyurethane coatings require excellent heat stability. This means that under high temperature closed conditions, the coating can maintain its original form and function, non-adhesion, non-deformation, to ensure product quality. 3.Strong adhesion: tight combination of coating and substrate As a functional coating and adhesive, the adhesion between the waterborne polyurethane coating and the substrate fabric is very important. Only by ensuring that the coating can be firmly attached to the substrate can it give full play to its various performance advantages. 4.Solvent resistance: The ability to resist erosion In the face of potential threats from solvents such as daily washing and alcohol, waterborne polyurethane coatings need to have excellent solvent resistance. Through the use of advanced technical means, such as sealing hydrophilic groups, the introduction of curing agent crosslinking, improve the water resistance and solvent resistance of the coating to ensure that the coating remains stable in complex environments. 5.Color persistence: The performance of color fixation When the waterborne polyurethane coating is combined with the color paste to give rich color to the fabric, its color fixing performance becomes an important index to measure the coating quality. The high-quality coating ensures that the color is firmly locked to the fabric, making the fabric colorful and long-lasting. 6.Waterproof and moisture-permeable: dual function of balance Although the coating treatment has a certain impact on the moisture and air permeability of the fabric, the water-based polyurethane coating can improve the moisture permeability of the fabric while maintaining the waterproof performance, and achieve a good balance between waterproof and air permeability by introducing innovative technologies such as hydrophilic groups. 7.Superhydrophobic exploration: Implications for nature Inspired by the superhydrophobic phenomenon of lotus leaves, waterborne polyurethane coatings are gradually moving into the field of superhydrophobic. By imitating the special structure of the surface of the lotus leaf, a coating with super hydrophobic properties has been developed to bring unprecedented protection to the fabric. 8.Efficient preparation: Advantages of high solid content and low viscosity coatings The development of water based polyurethan...

Pigment is the main component of ink, is a fine powder-like solid colored substance, can show ball, flake and other irregular shape. Generally, the diameter of pigment particles is in the range of several hundred nanometers to tens of microns (10-7~10-5m). The pigment can be evenly dispersed in the medium, but it is insoluble in the medium and does not react with the medium. Pigment is a colored body, it gives the ink color, at the same time, its dispersion, aggregation and directly affect the fluidity of the ink, chemical stability and dryness. Ink factory pigment selection error or improper use of ink, will cause a lot of quality problems, pigment caused by quality problems, do the following analysis, for the reference of peers. First, classification of pigments Pigments can be divided into inorganic pigments and organic pigments according to the characteristics of compounds. In organic pigments, they can be divided into lake pigments, color pigments and pigment dyes according to different molecular aggregation states. According to the different molecular structure, it can be divided into azo pigments and phthalocyanine pigments. According to the color characteristics, it can be divided into color pigments (such as yellow, magenta, green, etc.) and achromatic pigments (such as black, white, gray). Quality problems caused by pigment problems 1. Knife line problems caused by pigments 1)The pigment of the ink itself is badly ground, resulting in hard particles. (General ink fineness requirements ≤15μm). 2)When the ink is used for a long time, the resin wrapped in the pigment is missing, and the coarse particles produced by the pigment particles are clumped, condensed, and returned. In addition, the ink factory uses a carrier of color lake pigments, such pigments are soluble dyes precipitated with a precipitant, and then dyed on the high dispersion of aluminum hydroxide, barium sulfate, aluminum barium white and other carriers. This kind of ink will be used for a long time will wash away the dye, carrier separation, carrier clumping. Solution 1)Turn upside down and shake the new ink before opening the bucket. 2)The new and old ink is filtered with more than 100 mesh filters before entering the ink plate. 3)The ink that has been used for a long time is found to have floating pigments on the surface of the ink plate, indicating that the resin is not enough, and the ink mixing oil should be added for sufficient mixing and dispersion. It is best to mix the old ink with a dispersion mixer, and the printing plant can prepare a simple dispersion mixer. 2.Pigment caused by poor ink temperature resistance, high temperature cooking or bag hot press after discoloration Cause analysis The ink factory used the wrong pigment, the use of non-temperature resistant pigment. The printing factory used the wrong ink, and the ink that did not withstand temperature was used on the products of high temperature cooking bags. Solution When purchasing ink, we should check t...

Paper aluminum-plastic composite film in the actual application of medical packaging powder, granule packaging products compared to the plastic aluminum-plastic packaging commonly used in the market now has the following advantages: (1)The mechanical strength of the paper is high, the rigidity is good, and the ability to maintain the bag after forming is strong, which improves the cleanliness of the product appearance; (2)Automatic packaging does not need to be easy to tear, with good easy to tear effect; (3)Due to the high mechanical strength of the paper, when filling and sealing on the automatic packaging machine, it has a good resistance to the shear external force damage when sealing, and protects the aluminum foil from thermal sealing compression and compression break, which further ensures that the barrier performance of the middle layer aluminum foil is guaranteed. In front of the market, the main application of paper aluminum-plastic structure of drug packaging with composite film paper, aluminum, plastic, its main technical indicators are: 1.Appearance There shall be no perforation, foreign body, odor, adhesion, separation between composite layers and obvious damage, bubbles, wrinkles, dirt and other defects. The heat sealing part of the composite bag should be smooth and without virtual sealing. 2.Water vapor transmission The test temperature was 38℃±0.6℃, the relative humidity was 90%±2%, and the water vapor transmission was less than 1.5g/ (m²·24h). 3.Oxygen transmission The heat surface is towards the oxygen low pressure side, and the test temperature is 23℃±2℃, and the oxygen permeability is ≤3.0cm³/ (m²·24h·0.1MPa). 4.Peeling strength of inner layer and sub-inner layer: ≥ 2.5N / 15mm 5.Heat sealing strength: ≥ 12N / 15mm 6.Residual solvent The total amount of residual solvent shall not exceed 5.0mg/m², of which the residual benzene solvent shall not be detected, and the detection limit of a single benzene solvent is 0.01mg/m². First, roughness test of printing surface On the packaging of finished products, will be printed with a clear pattern and logo. However, we will also find that the printing on some materials (especially paper or paper film) packaging is fuzzy, some is related to the quality of the ink, the color process, but a large part is related to the roughness of the printing surface. Since the general printing ink layer is only tens of microns thick, if the printing surface roughness is too large, then the printed ink layer will be embedded into the deep layer of the material, so that the ink layer thickness on the surface is not uniform, which will produce the phenomenon of paste and white. We should be printed surface roughness test, by simulating the conditions of the printing press to measure the surface roughness, from the microscopic point of view to examine the smoothness of the material on the printability, according to the results of the roughness, according to 2 to 2.5 times to adjust the thickness of the ink...