Keywords: Adhesive; Transparency; Process I. Why Transparency Is Required for Adhesives Application Requirements In certain specific fields, such as the manufacturing of optical components, electronic displays, transparent packaging materials, etc., adhesives with high transparency are required. Performance Requirements Transparency is one of the important indicators for evaluating the optical properties of adhesives. High-transparency adhesives can reduce light scattering and reflection losses, which is critical for applications requiring high light transmittance. Visual Appearance In many consumer products such as mobile phones, tablets, and monitors, the use of transparent adhesives delivers a better visual effect. It makes the product look neater and more aesthetically pleasing, while enhancing the overall texture. Processing and Manufacturing Requirements During the lamination of transparent materials, transparent adhesives eliminate the need for additional grinding and polishing, thereby reducing costs and improving production efficiency. Long-Term Stability High-transparency adhesives generally exhibit better weather resistance and aging resistance. II. Test Methods for Adhesive Transparency A comprehensive test method is generally adopted: preliminary screening is first carried out by visual inspection, followed by accurate evaluation using light transmittance measurement and haze measurement. Visual Inspection Method: Direct Observation: Observe the appearance characteristics of the adhesive such as color and transparency directly with naked eyes or a magnifying glass. This method is simple and easy to operate but with low precision, suitable for preliminary screening and rapid judgment. Instrumental Measurement: Use special instruments such as colorimeter, turbidimeter and gloss meter to accurately measure the transparency of the adhesive. These instruments can provide more accurate data and are suitable for applications with high transparency requirements. Spectrophotometer Measurement: Measure the light transmittance of the adhesive at specific wavelengths using a spectrophotometer. This method can accurately reflect the ability of the adhesive to transmit light of different wavelengths. Light Transmittance Tester Measurement: Measure the light transmittance of the adhesive directly with a light transmittance tester. This method is easy to operate and can obtain results quickly, suitable for the detection of large quantities of samples. Haze Meter Measurement: Measure the haze value of the adhesive with a haze meter, which refers to the degree of turbidity caused by light scattering when passing through the adhesive. The lower the haze value, the higher the transparency of the adhesive. III. Three Methods to Improve Adhesive Transparency 1. Dehydrate the solvent to prevent moisture from affecting the transparency of the adhesive, and perform defoaming during preparation to remove air bubbles in the adhesive. 2. Ensure that all raw materials are fully and uniformly mixed, and avoid excessive heating that may cause decomposition, oxidation or yellowing of raw materials. 3. Select tackifying resins with low color number and low wax cloud point. For SIS raw materials, ensure no discoloration or impurities are present.