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The current challenges faced by the development of polyurethane adhesives
The polyurethane ink binder currently faces multiple technical challenges, mainly concentrated on performance balance, environmental compliance, and cost control. Firstly, the contradiction between adhesion and flexibility is the core difficulty. When printing on low surface energy films such as BOPP and PET, the adhesive needs to provide a strong anchoring effect, but this often reduces the molecular chain segment mobility of the resin, resulting in the ink film becoming brittle after...
Cautionary Notes for the Use of Polyurethane Ink Binders
When using polyurethane ink binders (especially alcohol-soluble/ester-soluble types), the key points to control are moisture, solvents, compatibility, curing, substrate and storage. This is to avoid problems such as composite delamination, non-drying and poor adhesion. 1. Strict control of moisture and active impurities: The binder contains hydroxyl groups. When exposed to active hydrogen substances such as water, alcohols, and amines, it will consume the curing agent - NCO, resulting in...
Can polyurethane ink binders be mixed and used at will?
Polyurethane ink binders must not be mixed or used randomly. Otherwise, it may cause system conflicts, performance degradation, or even product failure. It is necessary to strictly follow the three principles of the same system, the same type, and small-scale confirmation. Why can't they be mixed randomly? 1. Conflict between structure and cross-linking: Different binders have different resin hardness, Tg, molecular weight, OH/NCO ratio, etc. Mixing them will disrupt the cross-linking...
Analysis of raw materials and cost of polyurethane adhesive
The cost core of polyurethane adhesive is dominated by the fluctuation of upstream raw materials, in which the total proportion of isocyanate and polyol exceeds 70%, and the cost of additives and energy is superimposed to form its complete cost system. The fluctuation of raw material price directly affects the profit of enterprises and product pricing. 1.Composition of core raw materials (cost-oriented) (1)Isocyanate: the core raw material, which determines the strength and curing...
The Properties of Polyurethane Adhesive
1. Polyurethane adhesive contains isocyanate group (-NCO) and carbamate group (-NHCOO-) with strong polarity and chemical activity, and has excellent chemical adhesion with materials containing active hydrogen. However, the hydrogen bond between polyurethane and the bonded material will enhance the internal force of molecules and make the bonding stronger. 2. The proportion and structure of soft segment and hard segment in molecular chain can be controlled by adjusting the formula of...
The solid content of polyurethane adhesives: Definition, significance and influencing factors
The solid content of polyurethane adhesive, in simple terms, refers to the percentage by mass of non-volatile substances in the adhesive. These non-volatile substances mainly include polyurethane resin, curing agent, fillers, and other functional additives, while the volatile part is usually organic solvents or water. Solid content is one of the key technical indicators for evaluating the performance of polyurethane adhesives. The solid content directly affects the coating amount, drying...
The viscosity of polyurethane adhesives: A key factor influencing and applying them
The viscosity of polyurethane adhesives is the core indicator for evaluating their flowability and construction performance, directly determining the coating method, operational convenience, and final bonding quality. In simple terms, viscosity reflects the adhesive's ability to resist flow - the lower the viscosity, the better the flowability; the higher the viscosity, the thicker it becomes. In practical applications, the viscosity needs to be precisely adjusted according to the process...
How to clean polyurethane adhesive?
During the application of polyurethane adhesive, there may be situations where the polyurethane adhesive leaks and contaminates the items. In general, properly cleaning the polyurethane adhesive can solve the problem. 1.Cleaning un-solidified polyurethane adhesive ①Skin contamination: Immediately wipe off the excess glue with a dry tissue, then apply alcohol (concentration above 75%) and rub for about 30 seconds, followed by rinsing with water. If no alcohol is available, you can use hand...
What kind of material is polyurethane adhesive?
Polyurethane adhesive is a high-performance adhesive with polyurethane resin as its main base material. From a chemical composition perspective, it is mainly formed by the chemical reaction polymerization of isocyanates (such as MDI, TDI) and polyols (such as polyester, polyether). The core feature of this type of adhesive lies in the presence of strong polar amine carbamate groups in its molecular chain. By adjusting the ratio of the soft segment (polyol) to the hard segment (isocyanate) in...
Polyurethane Adhesive and Its Application in the Processing of Food Packaging Composite Films
Polyurethane adhesives are a type of high-molecular material with amino carboxylic acid groups in its molecular chain. Due to their excellent bonding performance, good flexibility, low-temperature resistance, and controllable curing speed, they have become an indispensable key material in the processing of food packaging composite films. In the production of food packaging composite films, polyurethane adhesives are mainly used for interlayer bonding between multi-layer structural...
Introduction to the Components of Polyurethane Adhesive Materials
The core components of polyurethane adhesives consist of isocyanate and polyol, forming the main framework, and are supplemented by various functional additives, jointly determining the bonding performance. Isocyanate is the active core, containing highly reactive - NCO groups, which dominate the curing and bonding strength. TDI (toluene diisocyanate) is commonly used for general scenarios; MDI (methylene diphenyl diisocyanate) has high activity and high strength, suitable for structural...
Current Overview of the Polyurethane Adhesive Market in China
The polyurethane adhesive market in China has maintained a steady growth trend in recent years. By 2025, the market size is expected to be around 47 billion yuan, with a compound annual growth rate of over 10%. The industry has strong resilience in development. The downstream demand shows a diversified driving pattern. Construction, automobiles, and packaging are traditional core application fields that support the basic demand of the market; new energy vehicles, photovoltaic packaging, and...
The flexible packaging polyurethane adhesive
Flexible packaging polyurethane adhesive is a kind of special adhesive widely used in packaging field. It takes polyurethane as the main component and forms an adhesive layer with excellent bonding performance through specific chemical reaction. Because of its unique chemical structure and physical properties, this adhesive occupies a decisive position in the flexible packaging industry. Technically speaking, flexible packaging polyurethane adhesives react with hydroxyl groups in polyols...
The bonding construction matters of polyurethane adhesives
1.Gluing: The methods of applying glue include spraying, brushing, dipping, and roller coating, etc. The choice depends on the type of glue, its viscosity, and production requirements. The key is to ensure that the glue layer is uniform, free of bubbles, and without any missing areas. 2. Air-drying: For solvent-based polyurethane adhesives, after applying the adhesive, it is necessary to let it air-dry for several minutes to several tens of minutes to allow most of the solvents in the...
Waterborne polyurethane adhesive is a new type of environmentally friendly adhesive material with water as dispersion medium, which has sprung up in the field of adhesives in recent years. Compared with traditional solvent-based polyurethane adhesive, its biggest advantage lies in replacing organic solvent with water, which eliminates the emission of volatile organic compounds from the source, not only ensures the health of producers and users, but also reduces the pollution to the atmospheric...
The compatibility of polyurethane adhesives with flexible packaging
The reason why soft packaging widely uses polyurethane adhesives is mainly due to their excellent molecular design flexibility and broad adaptability to complex substrates. The specific reasons can be understood from the following four aspects: 1.Wide substrate compatibility Soft packaging often involves the composite of various materials with distinct properties (such as plastic films, aluminum foil, paper, etc.). Polyurethane molecules contain isocyanate groups (-NCO) and amide groups...
Can the expired polyurethane adhesive still be used?
The answer is no. Polyurethane adhesives that have exceeded their shelf life have undergone irreversible chemical changes. Using them forcefully will pose significant risks and performance hazards. The specific reasons are as follows: 1.The curing effect does not meet expectations. The curing of polyurethane adhesive relies on the cross-linking reaction between the isocyanate component in the adhesive and moisture in the air or curing agent. After expiration, there may already be a small...
Polyurethane Adhesive: The Invisible Hero Empowering the Soft Packaging Industry
In the rapid development of the flexible packaging industry, polyurethane adhesives play an indispensable and crucial role. As the "glue soul" of composite packaging materials, they firmly bond different types of substrates - such as plastic films, aluminum foil, paper, etc. - giving flexible packaging outstanding composite strength and functionality. The reason why polyurethane adhesives dominate the soft packaging industry lies in their unique molecular structure advantages. By adjusting...
The multifunctional material: Polyurethane adhesive
Polyurethane adhesives refer to adhesives whose molecular chains contain amine carbamate groups or isocyanate groups. Since researchers first discovered their application in the bonding of metals and rubber in the 1940s, due to their outstanding comprehensive performance, they have become an important type among the eight major synthetic adhesives. Its core advantage stems from its unique chemical structure: the polar groups in the molecular chain can react with the active hydrogen on...
The main function of the ink binder
The ink vehicle is the core component of the ink, playing a crucial role as the carrier for pigments and the material for film formation. Its main functions can be summarized as follows: 1. Dispersed and stable pigments The binder is the carrier of the pigments. During the ink manufacturing process, it wets the pigments and evenly disperses the solid pigment particles to prevent them from re-aggregating, ensuring that the ink has good fluidity and stability. Only in this way can the ink...
How to Use Polyurethane Adhesives in a Standardized Manner
Polyurethane adhesives have excellent performance, but if used improperly, it is difficult to achieve their best results. Standardized operation is the key to ensuring the quality of the bonding. 1.Surface treatment is fundamental. The substrate to be bonded must be clean, dry, free of oil and dust. For smooth surfaces such as metals and glass, it is recommended to perform grinding or chemical treatment to increase the roughness; for plastics, sometimes corona or flame treatment is required...
Characteristics of Polyurethane Resin for Ink
1.Excellent resistance to yellowing The polyurethane resin used in ink is mainly synthesized from aliphatic polyesters and aliphatic isocyanates during the preparation process. Compared with aromatic polyurethanes, it has excellent optical stability and the formed film has excellent resistance to yellowing. 2. For the excellent adhesion of the film substrate The molecular chain segments of the polyurethane resin used for ink contain polar groups such as amine carbamate, urea carbamate, ester...
Curing of Polyurethane Adhesives: Principles, Types and Key Points
The bonding strength of polyurethane adhesives is achieved through the curing reaction. Unlike the physical evaporation and drying of ordinary adhesives, PU adhesives mostly undergo chemical reaction curing. Once the cross-linking process is completed, the bonding force and durability will significantly improve, which is the core advantage that makes it suitable for various scenarios. 1.The mainstream methods of solidification have their respective applicable scenarios. (1)Humidity curing...
Classify polyurethane adhesives by their form
1.Solvent-based polyurethane adhesive The most classic liquid form, with moderate viscosity and uniform application, it cures quickly and has strong initial adhesion. It has excellent compatibility with difficult-to-adhere materials such as leather, plastic, and fabric. However, it contains a small amount of organic solvents, and construction requires ventilation. It is mainly used in fields like shoe manufacturing, soft packaging laminating, and leather covering, and is a commonly used product...
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Privacy statement: Your privacy is very important to Us. Our company promises not to disclose your personal information to any external company with out your explicit permission.