I. Differences in Physical Forms

Liquid silicone exhibits the characteristics of a liquid and has good fluidity. It can flow freely like water and can easily fill the cavities of molds with complex shapes before vulcanization, so as to meet the diverse product modeling requirements. For example, in the packaging process of some precision electronic components, liquid silicone can perfectly conform to the fine contours of electronic elements by virtue of its excellent fluidity, achieving a tight and precise wrap and ensuring good sealing performance and protection effect.
Solid silicone, on the other hand, is in the form of solid blocks or granules. It has no fluidity, has a fixed shape and structure, and is relatively hard and stable in texture. In industrial production, common solid silicone products such as silicone sealing rings and silicone keys are all processed by molding processes such as mold pressing with solid silicone as the raw material. These products can stably play roles in sealing, cushioning, and insulating in various mechanical and electronic equipment and are not easily changed in shape by external forces.

II. Differences in Vulcanization Characteristics

The vulcanization speed of liquid silicone is usually relatively fast, thanks to its special chemical formula and molecular structure. Under the action of appropriate temperature and catalysts, liquid silicone can complete the transformation from a liquid to a solid state in a relatively short time to form silicone products with elasticity and various properties. This characteristic of rapid vulcanization gives liquid silicone a significant advantage in large-scale industrial production, enabling it to effectively improve production efficiency and reduce production costs. For example, on the production line of silicone products for mothers and babies, liquid silicone can be quickly vulcanized and formed to quickly meet the large market demand for such products.
The vulcanization process of solid silicone is relatively complex and slow. Generally, it needs to undergo a relatively long vulcanization reaction under high temperature and high pressure conditions to form a stable cross-linked structure among silicone molecules, so as to obtain the required physical and chemical properties. Although this vulcanization method takes a long time, it can endow solid silicone with higher strength, hardness, and wear resistance and other properties, making it widely used in some fields with demanding product performance requirements, such as engine seals in the automotive industry and shock-absorbing pads in industrial machinery.

III. Differences in Chemical Properties

There are certain differences in chemical properties between liquid silicone and solid silicone. Due to its relatively loose molecular structure, liquid silicone may be slightly inferior in tolerance to some chemical substances. For example, when facing some strong oxidizing acids or strong alkali solutions, liquid silicone may undergo a certain degree of swelling or chemical reactions, thus affecting its performance and service life. However, liquid silicone performs excellently in water resistance and moisture resistance and can effectively prevent the penetration and erosion of water, which makes it have important application value in some fields that are sensitive to humidity, such as the packaging of electronic equipment and outdoor waterproof sealing.
Solid silicone has relatively high chemical stability and can tolerate a wider range of chemical substances. It has good resistance to most acid, alkali, salt solutions and organic solvents and is not prone to chemical reactions or physical changes. This enables solid silicone to be widely used as pipeline seals, reactor linings, food molds, etc. in industries such as chemical engineering, pharmaceuticals, and food processing, and it can work reliably in complex chemical environments to ensure the safety and stability of the production process.

IV. Differences in Application Fields

Based on the above various differences, liquid silicone and solid silicone each show their own advantages in different application fields.
Liquid silicone, by virtue of its excellent fluidity, rapid vulcanization characteristics, good transparency, and soft touch, has been widely used in fields such as medical care, mother and baby products, food contact, and electronic packaging. For example, liquid silicone is widely used to make baby pacifiers, medical silicone tubes, waterproof seals for high-end electronic products, etc. These products have extremely high requirements for the safety, softness, and precision of materials, and liquid silicone can just meet these requirements, providing consumers with high-quality, safe, and reliable product experiences.
Solid silicone is mainly applied in fields such as industrial manufacturing, the automotive industry, and construction engineering. In industrial manufacturing, solid silicone is used to make various seals, molds, shock-absorbing pads, etc. By virtue of its high strength, high wear resistance, and temperature resistance, it can ensure the stable operation and long-term reliability of mechanical equipment. In the automotive industry, solid silicone is used for engine seals, door and window sealing strips of automobiles and other key components, effectively preventing oil leakage, air leakage, and water leakage and improving the overall performance and safety of automobiles. In the construction engineering field, solid silicone is used as a sealant and waterproof material, which can effectively fill the gaps and cracks in buildings, prevent rainwater leakage and air infiltration, and improve the thermal insulation, heat insulation, and waterproof performance of buildings.

V. Differences in Processing Technologies

The processing technology of liquid silicone is relatively simple and flexible. It usually adopts processing methods such as injection molding, extrusion molding, or potting. During the injection molding process, liquid silicone is injected into the heated mold cavity and can be formed into the required product after rapid vulcanization. This processing method can achieve efficient and high-precision production and is suitable for the manufacturing of large-scale and complex-shaped products. Extrusion molding is suitable for producing continuous-shaped products such as various silicone tubes and sealing strips. Liquid silicone is extruded into shape by an extruder and then solidified in the subsequent vulcanization process. The potting process is mainly used for the packaging protection of electronic components. Liquid silicone is poured into the shell of electronic components or packaging molds, and after vulcanization, a tight protective layer is formed to protect electronic components from the influence of the external environment.
The processing technology of solid silicone is relatively complex and mainly includes multiple steps such as mixing, molding, and vulcanization. First, the solid silicone raw material is fully mixed with various additives (such as vulcanizing agents, reinforcing agents, pigments, etc.) in a mixing machine to make them evenly distributed. Then, the mixed silicone material is made into the required shape through molding processes such as mold pressing, calendering, and extrusion. Finally, the molded product is placed in vulcanization equipment for high-temperature and high-pressure vulcanization to make the silicone molecules cross-linked and solidified to obtain the final product performance. This processing technology requires professional equipment and technicians, and has relatively high requirements for the control of the production process, but it can produce high-quality and high-performance solid silicone products.