Classification and characteristics of screen-printable pressure sensitive adhesives Ⅱ Classification of screen-printable pressure sensitive adhesives Because of the simple screen printing equipment, convenient operation, simple printing, plate making and low cost, for the application of coating pressure sensitive adhesive, also often consider the use of screen printing process to coating.The commonly used screen-printing pressure sensitive adhesives on the market can be divided into: Water-based pressure sensitive adhesive: Currently the more common water-based screen printing pressure sensitive adhesive is represented by 3M company SP-7533, SP-7533 has higher peel strength and better high temperature resistance, and occupies an important position in the market.This product is based on acrylic emulsion as the main body, solid content of 65%, viscosity of 35000cps, mainly used in various industrial label applications. Solvent-based screen printing pressure sensitive adhesive: Although the heat curing solvent-based screen printing pressure sensitive adhesive has a higher balance of peeling strength and shear strength than water-based pressure sensitive adhesive, and the water resistance and silkscreen operation are better than water-based screen printing pressure sensitive adhesive, due to the requirements of environmental protection in various countries, the restriction of VOC emission is more and more strict, and the solvent is harmful to the body of the operator. Currently, solvent - based pressure - sensitive adhesives are rarely used in screen printing.UV curing type screen printing pressure sensitive adhesive: As a concept that contains neither water nor organic solvents, UV solidified pressure-sensitive adhesive is environmentally friendly. Over the years, many world-renowned chemical companies, such as BASF, Hankel and 3M, have invested more research and development efforts to develop UV solidified pressure-sensitive adhesive. Universities and other scientific research institutes have also invested in a large number of basic researches. At present, the more mature application is mainly UV curing hot melt pressure sensitive adhesive, such as used in the printing of trademark labels. As a UV curing pressure sensitive adhesive suitable for screen printing, it needs to maintain a state suitable for printing at room temperature, so it needs lower viscosity, requiring the addition of a large number of UV monomers as active diluent in the formula.Generally, it is difficult to obtain both high peel strength and high shear strength in a short UV curing time, thus limiting the application of UV pressure sensitive adhesive in high performance industrial tapes. High performance UV pressure sensitive adhesive, should have high peel strength and high shear strength, and can meet the requirements of low UV energy and fast curing, and has good water resistance, temperature resistance and weather resistance and other physical properties. EcoPSA-1125 as a UV...

Classification and characteristics of screen-printable pressure sensitive adhesives I.Characteristics and performance requirements of screen printing process Screen printing is through a certain pressure to make the printing base material through the holes of the plate to the substrate, the formation of an image or text. In order to achieve good printing adaptability, the physical properties of screen printing base material are required: 1.Viscosity of printing base material: Viscosity has a great influence on the printing effect. General screen printing viscosity requirements between 1000cps to 100,000cps. Too much viscosity will cause problems such as wire drawing or plugging; Viscosity is too small, will make the impression definition is poor or sticky screen version of the problem. 2. Viscoelasticity of printing base material:Pressure sensitive adhesive polymer Viscoelasticity refers to the mechanical properties of a substance with the elasticity of a solid and the viscosity of a liquid under the action of external forces. Polymers are almost always viscoelastic. Viscoelasticity has a close relationship with the splitting and drawing of the printing base material and the smoothness of the printed surface. There is no viscosity only elastic printing base material, printing is difficult to transfer; No elasticity only viscous printing base material, or serious drawing, or rheology is out of control, can not obtain good printing. 3. Surface tension of printing base material:Acrylic pressure sensitive adhesive When the surface tension of the printing base material is greater than the surface tension of the printing surface, the printing will shrink, and even appear fisheye holes. In this case, the surface tension of the printing base material can be equal to or less than the surface tension of the printing surface with the help of silicone or fluorine-containing surface additives, so as to obtain good printing effect.Pressure sensitive acrylic adhesive

New environmental protection water-based laminated adhesive 1.This new environmental protection water-based laminated adhesive does not contain any organic solvent, has passed the international certification SGS, so it is non-toxic, there is no flammable, explosive danger, please rest assured that the manufacturers in the industry use. 2.Water-based laminated adhesive does not contain toxic heavy metals, in line with the international trade in the relevant packaging laws and regulations. Therefore, the relevant manufacturers do not have to worry about the use of this kind of laminating glue, pollution of the environment, in violation of packaging laws and regulations. 3.For the original use of solvent-based adhesive manufacturers, do not need to replace the laminating machine, water-based laminating glue can be used on the solvent-based laminating machine, so that the relevant manufacturers have no worries, can not replace the adhesive and replace the laminating machine, and in addition to invest a sum of money and worry. 4.For difficult to stick ink, such as black, brick red printed matter, can be used dry coating, general color printing matter, can be used wet coating, coating speed is fast and save electricity, that is to improve efficiency, but also a good way to save cost. 5.We recommend the new adhesive adhesion and durability, moisture resistance, heat resistance, cold resistance are far more than solvent coated adhesive, belongs to high efficiency, energy saving, environmental protection, economic innovation products, fill the domestic gap, the international leading level. 6.Water-based laminating adhesive can also be used for BOPP, PET, coating and other plastic film and paper printing bonding, the application range is also wider. The use of new water-based adhesive film is the general trend, but also has huge social benefits. Water-based film adhesive in the process of use, no solvent volatilization, safety, environmental protection, do not cause harm to the health of production personnel. The use of water-based laminating adhesive for laminating processing, the comprehensive cost is reduced, has good economic benefits. For such an advanced water-based adhesive value we recommend, also hope that the relevant manufacturers use this kind of laminating adhesive as soon as possible.

Existing water-based adhesives are not 100% solvent-free and may contain limited volatile organic compounds as additives to their water-based media in order to control viscosity or fluidity.The advantages are mainly non-toxic, no pollution, no combustion, safe use, easy to achieve clean production technology, etc., disadvantages include slow drying speed, poor water resistance, poor frost resistance. PART 01 Classify 1.Classification by material Polyvinyl alcohol water-based adhesives, vinyl acetate water-based adhesives, acrylic acid water-based adhesives, polyurethane water-based adhesives, epoxy water-based adhesives, phenolic water-based adhesives, silicone water-based adhesives, rubber water-based adhesives. 2.Classification by application Water-based adhesive for construction, packaging, automobile, shoemaking, daily use, water-based adhesive. 3.according to the solvent classification Water soluble and emulsion adhesive two kinds. PART 02 Properties and modification of water-based adhesives Waterborne polyurethane (APU) adhesive APU is a new type of polyurethane system in which water replaces organic solvent as dispersion medium, also known as water-dispersed polyurethane, water-based polyurethane or water-based polyurethane. Waterborne polyurethane with water as solvent, no pollution, safe and reliable, excellent mechanical properties, good compatibility, easy to modify. APU adhesive is non-toxic and pollution-free, and its high molecular weight enables it to form an excellent adhesive film. It has the advantages of low temperature resistance, flexibility, good bonding performance and wide adjustable range of the physical property of the adhesive film. Its molecular structure has flexible molecular chain, showing excellent impact resistance, fatigue resistance, low temperature resistance, but also has the performance of designability, the adhesive layer from flexible to rigid arbitrary adjustable, can meet the bonding needs between different materials; At present, the synthesis method of waterborne polyurethane adhesive has been relatively mature. There are mainly the following methods: (1)Introduce some hydrophilic groups into the structure of polyurethane resin to make it self-emulsifying.  (2)Acetone method: the high viscosity prepolymer is prepared first, and then acetone is added to reduce the viscosity, and then the hydrophilic monomer is added to the water under high speed stirring, and it is dispersed in the water through strong shear. After emulsification, the decompressive distillation to recover the solvent is prepared PU water dispersion system. (3)End-sealing isocyanate method: select an appropriate sealer, protect the end-NCO group of the water-sensitive isocyanate, make it lose its activity, and then add chain extender and crosslinking agent co-emulsion to make emulsion use, through a certain temperature and special catalyst, regenerated into -NCO end-group, chain extension to prepare waterborne polyurethane. (4)End-sea...