When waterborne polyurethane is used as adhesive, it must be mixed generally. Based on waterborne polyurethane, crosslinking agent, thickening agent, filler, plasticizer, pigment and other additives can be added. Other types of waterborne resin and water can be added.In order to obtain higher resistance to water Heat resistance and bonding strength, at present a lot of waterborne polyurethane systems have been popular use of crosslinking agent, a two-component system, and this single component solvent (volatile) polyurethane adhesive system is similar to the sizing methods of waterborne polyurethane adhesive and solvent adhesive basic same, such as manual brush mechanical roller coating, etc.When spraying, the particle size and viscosity of emulsion should not be too large. Adhesive is the key factor affecting the quality and performance of composite film, adhesive composite packaging film using the base material has plastic aluminum foil, and plastic is divided into many types, to these different surface characteristics of the film together, adhesive must have the ability to bond two different film materials at the same time.The main reason for the popularity of plastic-based composites is their lightness and flexibility.This in addition to its own to be flexible and foldable, the adhesive itself should also have this property if the hard film is brittle and not foldable, it loses the meaning of packaging. Heat resistance Many food packages are subjected to high temperatures (180~220) during manufacturing operations ), for example, heat sealing bag, packaged food by high temperature sterilization and cooking food, which not only requires a variety of substrate film to withstand the test of high temperature, the adhesive used can also withstand the test of high temperature, otherwise, after high temperature treatment of the film layered peel, is not a composite packaging film.This must be carefully considered in the selection of adhesive cold resistance many food packaging to low temperature refrigeration or cryopreservation, which requires the packaging film itself can withstand low temperature.If the adhesive becomes hard and brittle under low temperature, it does not meet the requirements of the phenomenon of delamination and degumming, dielectric resistance food itself is a very complex substance, containing oil salt wine, spicy spices, and even acetic acid citric acid lactic acid sugar sulfide oxide.In the face of these complex ingredients, packaging and then to the high and low temperature test of processing and long-term storage, to maintain the packing film is perfect, in addition to the base material good medium erosion resistance of the film itself, the stability of the adhesive is very important also, need to be able to resist a variety of media, otherwise it will cause composite film layer stripping, lost package.The safety and health of food packaging compound film is to protect the packaging of the thing is direct entry, in order to...

Food packaging is divided into ordinary packaging and high-performance packaging, the corresponding waterborne polyurethane adhesive can be divided into four categories: general use, steaming boiling, transparent cooking, aluminum foil cooking.Usually such adhesives are two-component solvent-based polyurethane adhesives, the main agent is polyether or polyester polyol After the aromatic isocyanate modified with hydroxyl polyurethane polyol (called a component), curing agent is aromatic isocyanate and three hydroxymethyl propane admixtures (called b component), when used, the a component and b component are mixed in a certain proportion, and then diluted with ethyl acetate to a certain concentration after sizing coating.At present, such glue has been produced in China, mainly with poly adipic acid polyester polyol as raw material, and most of the foreign use epoxy propane polyether as raw material, the cost is low.Transparent cooking bag and aluminum foil cooking bag with composite film polyurethane adhesive generally includes 121 cooking sterilization with composite film adhesive, and 135 high temperature cooking sterilization with composite film adhesive, the so-called high temperature cooking refers to 121~145 high temperature and 0.18~0.40MPa steam pressure for food sterilization processing technology.This not only requires a variety of base material can withstand high temperature test, the adhesive used also should be able to withstand high temperature.The polyurethane adhesive used in ordinary packaging is easy to hydrolyze at this high temperature, the adhesive strength is reduced, and the film is easy to fall off.In order to improve the cooking resistance of polyurethane adhesives, the molecular structure of soft polyester and hard segment is usually changed, the chain segment resistant to humidity, heat and high temperature is introduced, the variety of crosslinking agent is changed, the density of crosslinking agent is adjusted, and even the blending of high polymer and the formation of interpenetrating polymer network (IPN) is adopted to solve the problem. The pressure sensitive adhesive drug compound packing materials, mainly use ester soluble polyurethane adhesive, the adhesive is a two-component resin soluble polyurethane adhesives, its main agent polyether or polyester polyol after aromatic isocyanate modified polyurethane polyol containing hydroxyl, curing agent is aromatic isocyanate with trimethylolpropane composite. This kind of adhesive has excellent performance, mature process and many varieties, but the toxicity is large and the cost is high, and a large number of solvents are discharged to pollute the environment.Composite materials for a long time, may hydrolyze, release a carcinogenic substance TDA(diacetic acid), serious harm to the health of operators with the enhancement of environmental awareness, the use of this kind of adhesive is declining.Now developed countries in Europe and the United States using this kind of ad...

With the development of The Times, many products in the production of nano coating, the coating can be very good protection from water and air substances invasion, the use of nano coating can obtain what characteristics, let us know about it. 1.Features The hardness of the coating is extremely high, which is more than 3 times that of tool and die steel, even more than 4000HV(ceramic characteristics) the coating is fine and smooth, and the friction coefficient between steel and steel is small (ceramic characteristics) the coating and metal are not sticky, which can prevent chip deposition and improve the surface quality of the workpiece (ceramic characteristics): good toughness, impact resistance, impact resistance, can be used for stamping die (metal characteristics) good thermal stability, some coating can even withstand more than 1000 C operating temperature (ceramic properties) coating grain is very small, the structure is very close, so it has good acid and alkali corrosion resistance Coating non-toxic environmental protection, can be used for medical equipment, used in artificial food processing tools (such as: juice machine, etc.) conductive, magnetic (metal characteristics) 2 Advantages The hardness of the coating is extremely high, which is more than 3 times that of tool and die steel, even more than 4000HV(ceramic characteristics). Wear resistance of tools and molds is greatly improved, service life is increased by 3 to 10 times or even higher, so that customers' costs are greatly reduced; Shorten the tool change time, improve the production efficiency during mold repair; The surface quality of products is improved and the defect rate is reduced; the coating thickness is very thin, only about 3μm(0.0003mm), so generally does not affect the tool, the size of the mold is very fine. Our company produces nano superhydrophobic, which is used for building and wooden surface, car body, car glass and so on. Welcome to contact us, our email is sales@sinogracechem.com.

PCL is a fully degradable polymer with good biocompatibility. When introduced into waterborne polyurethane, it can make waterborne polyurethane have shape memory.Shape memory waterborne polyurethane has attracted wide attention for its shape memory function, temperature sensitivity and moisture permeability. PCL3000 PCL4000 was used as the soft segment, and toluene diisocyanate was used as the hard segment to generate hydroxy terminated waterborne polyurethanes, which were crosslinked with water-disperable polyisocyanate to form a two-component waterborne shape memory polyurethane coating adhesive.The results show that the water-based polyurethane finish fabric with PCL4000 as the soft section has better waterproof performance, and the maximum hydrostatic pressure resistance of the coated fabric is 9.8kPa. Because of the crystallization property of PCL, the moisture permeability of coated textile is significantly improved between 35 ℃ and 50℃, which is increased by 4 ~ 8 times. The crystallization property of PCL4000 is stronger than that of PCL3000. The moisture permeability of the coated textile prepared in the former is stronger than that of the latter, and the moisture permeability is 5.95kg/(m2·d). In recent years, waterproof and moisture permeable coating has achieved rapid development in textile finishing industry. The technology has gradually changed from non-temperature-sensitive waterproof and moisture permeable textile coating to temperature-sensitive waterproof and moisture permeable textile coating.Experts also constantly perfect the method and technology of waterborne polyurethane modified, win min type of waterproof and moisture permeable fabric coating in the future to explore key should first focus on the improvement of waterborne polyurethane coated fabric touch Improve the water resistance and anticorrosive antibacterial properties of fabric coating, etc, this is very important to this kind of fabric coating applied to clothing market.With the improvement of people's awareness of environmental protection and the improvement of living standards, the market demand for waterproof and moisture permeable textile coating has a wider development prospect Sinograce Chemical company produces various types of polyurethane solutions for a variety of applications such as stripable coatings, water-based glues, etc