China Xiamen Juguangli Import & Export Co., Ltd Company News

Whether silicone rubber produces and releases toxic gases and carcinogenic substances during processes such as heat refining has sparked widespread public discussion and even caused panic among residents. After being explained by professionals, it is completely worry free and the rubber products are safe and non-toxic, so you can use them with confidence.   According to relevant professionals, the process of silicone mixing, which involves the uniform mixing and thermal refining of rubber and additives, belongs to the physical mixing process. The silica gel raw materials and ingredients are evenly dispersed, just like the "noodle" when steaming Mantou, which will not produce chemical reactions, carcinogens and toxic gases. Under normal circumstances, during the rubber mixing process, it is accompanied by the physical odor of the rubber material itself, which is not a toxic gas or carcinogenic substance, thus ensuring the safety of silicone products. Since the 1980s and 1990s, the European Union and other countries have issued a series of environmental laws and regulations. The raw materials used in silicone products have achieved green substitution and upgrading. Potential toxic and harmful raw materials have been discarded and replaced with non-toxic and harmless environmental additives and silicone raw materials, isolating toxic and harmful substances in the rubber mixing process from the source. Experts further pointed out that although the odor of silicone produced during the rubber mixing process is non-toxic to the human body, many people still feel uncomfortable. Therefore, in order to reduce the impact of odors, it is recommended to use advanced equipment such as enclosed mixers and relatively enclosed spaces for gas collection during the production process to purify the exhaust gas appropriately.   Moreover, the production of silicone products is a complex process that requires real-time monitoring and attention. Besides mechanical and human factors, they are two important aspects that affect product quality, and the intermediate inspection process is the node for discovering and solving major product quality problems. Therefore, maintaining normal machine operation, good mold quality status, continuously strengthening the operational skills of molding operators and quality inspectors, and improving quality awareness are effective measures to reduce production defects, and are also a major benefit for silicone product factories.

Sealing rubber rings have their presence in various industries, especially in our electronic products. As a sealing, dustproof, and waterproof material, it has become one of the irreplaceable materials. Therefore, more and more products will be customized according to their own product appearance. However, some complex and varied design structures still have a certain impact on the waterproof interference fit, deformation, and shrinkage of the product. So, what issues should we pay attention to when customizing sealing rings?   Firstly, the structure and size of the product are closely related. In the field of silicone sealing rings, due to the inability to control the dimensional tolerances of silicone products to be very precise, all products in the silicone ring field need to be appropriately reduced to ensure their assembly tightness. If the size of the product is relatively small, the interference fit required for its size and assembly position can be appropriately reduced. However, if the product is relatively large, both shrinkage and size need to be made larger during the manufacturing process. The inner diameter is designed to fit the sealing groove, which may loosen and fail to achieve a complete sealing effect. Therefore, it is necessary to ensure the normal tolerance range and expansion range of the size during design. When designing the mold, the overall inner diameter needs to be reduced to achieve a tight sealing effect by squeezing and shrinking under force. Secondly, there are issues related to the material of the product, such as the softness and hardness of the material. The softness and hardness of silicone seals under different forces can affect the sealing performance of the product. If the material hardness is too high, it may cause the sealing ring to deform under long-term stress, leading to leakage and loosening. If the hardness of the product is too low during assembly, it is due to the influence of force, back and forth friction, or problems such as flipping and displacement during assembly, resulting in poor fit or insufficient tightness during assembly, which affects the service life. So the material selection of the sealing ring is quite important, in addition to its softness and hardness, it also has a significant impact on its material, such as tensile strength, friction resistance, and deformation rebound strength, such as high tensile silicone, oil emitting silicone, high rebound silicone, and other different types of rubber.   The precision in the production and processing process also needs to be prevented and controlled, such as the precision of the mold and the thickness of the fractal line. For silicone rings that are relatively precise and small, strict control is required over their cloaking, self-healing, and processing dimensions.

Is it normal for silicone products to have an odor? Silicone products are widely used in the fields of mother and baby, medical, electronics, industry, etc. due to their high temperature resistance, corrosion resistance, biocompatibility, and other characteristics. However, newly purchased silicone products often come with a slight odor, causing consumers to doubt their safety and quality.   The source of odor in silicone products: Production residues Silicone products need to be formed through vulcanization process, with vulcanizing agents acting as catalysts to promote cross-linking and curing of silicone molecules at high temperatures. Although vulcanizing agents may evaporate after molding, some low-quality vulcanizing agents may still have a pungent odor and have a volatilization period of several weeks. In addition, additives such as release agents and colorants may also have residual odors due to improper process control. Raw material characteristics Industrial grade silicone may be mixed with recycled materials or non environmentally friendly catalysts to reduce costs, resulting in a strong odor. Food grade and medical grade silicone use platinum vulcanizing agent, with very little residue and a lighter odor. For example, a certain brand of silicone nipple has been tested and found to have only 1/5 of the residual sulfurizing agent of ordinary silicone, making the odor almost imperceptible. Packaging and storage environment Silicone products may absorb the odor of packaging materials such as plastic bags and cardboard boxes in sealed packaging, and are particularly prone to mold odor in humid environments. A comparative test in a certain laboratory showed that after being stored in a closed environment for 30 days, the odor intensity of the same batch of silicone products increased by 40%.   How to determine if the odor is normal: Odor intensity and duration The slight rubber smell of new silicone products is a normal phenomenon and can usually dissipate naturally after being placed in a ventilated environment for 3-7 days. If the odor is pungent and lasts for more than 15 days, or if the odor worsens after heating, there may be defects in the raw materials or processes. For example, a consumer purchased a silicone spatula that had a burnt smell during its first use, and upon testing, it was found that the vulcanizing agent exceeded the standard by three times. Usage scenarios and safety standards Food contact grade silicone must comply with relevant standards, and its odor threshold is much lower than that of industrial grade products. If silicone products are used to hold food or come into contact with infants and young children, caution should be exercised even if the odor is mild. In a certain case, a silicone placemat labeled as "food grade" caused allergies in children due to residual sulfurizing agents. After inspection, it was found that its heavy metal content exceeded the standard.

As for why silicone rubber products turn yellow, in fact, silicone yellowing is not its essence. Silicone rubber raw materials are composed of hundreds of thousands of molecular crystals, and adding different components can change their composition freely. Therefore, even if there are hundreds of thousands of molecular chains that have not undergone chemical reactions, they will still turn yellow due to external obstacles such as vulcanizing agents, raw materials, anti yellowing agents, etc.   As for silicone vulcanization, most silicone rubber product manufacturers use ordinary vulcanizing agents, which can be used in many products. When used as high transparency or semi transparent products, white often appears yellow when it is transparent. Therefore, many manufacturers will use anti yellowing vulcanizing agents and add anti yellowing agents for high transparency and semi transparency products, which will not cause discoloration. It can be guaranteed that there will be no color change during the secondary odor vulcanization process in high-temperature vulcanization production, and the product will not undergo color change after long-term use.   In addition, there are certain factors in terms of raw materials. Generally, transparent silicone rubber raw materials are mainly reinforced with white carbon black, and the amount of white carbon black used is lower in material cost and has different performance adjustments. Therefore, while improving other properties, the anti yellowing effect will also be affected. Therefore, as the material itself changes, it is more affected by the quality of the material itself.   Another reason is that transparent silicone rubber products are not preheated during use, resulting in yellowing of ordinary precipitation method silicone rubber. Therefore, transparent silicone rubber products may have some yellowing effects, and it is recommended not to expose them to prolonged sunlight or acidic or alkaline liquids.

With the improvement of modern living standards, people's requirements for daily tools, supplies, and materials are gradually increasing, such as environmental protection and safety, food grade, non-toxic and odorless, and so on. Food grade silicone materials are widely used in various fields, such as mother and baby products, children's toys, adult products, food molds, precision products, silicone products, potting and sealing, special printing, etc. Because food grade silicone is a synthetic material, it has undergone technological advancements and improvements. The food grade silicone products produced by food silicone manufacturer Kexin Silicone have weather resistance, aging resistance, low temperature resistance of -65 ° C, instant temperature resistance of 400 ° C, and certain acid alkali and corrosion resistance, which depends on the concentration of acid and alkali. Silicone does not produce harmful radiation during the process from liquid to solidification.

What are the major categories of molds in terms of molding? Molds are mainly divided into injection molding, compression molding, extrusion molding, injection molding, and hollow molding in terms of molding. In addition, there are foam plastic molding molds, glass fiber reinforced plastics, low-pressure molding molds, etc.   1. Injection molding First, add the plastic into the heating cylinder of the injection machine. The plastic is heated and melted, and under the push of the injection machine screw or plunger, it enters the mold cavity through the nozzle and mold pouring system. Due to physical and chemical effects, it hardens and shapes into injection molded products. Injection molding consists of a cyclic cycle consisting of injection, pressure holding (cooling), and plastic part demolding processes, thus injection molding has the characteristic of periodicity. Thermoplastic injection molding has a short molding cycle, high production efficiency, and minimal wear of the mold caused by the melt. It can produce large quantities of plastic parts with complex shapes, clear surface patterns and markings, and high dimensional accuracy; However, for plastic parts with large variations in wall thickness, it is difficult to avoid molding defects. The anisotropy of plastic parts is also one of the quality issues, and all possible measures should be taken to minimize it as much as possible. 2. Compression molding Commonly known as compression molding, compression molding, and compression molding, it is one of the earliest methods of forming plastic parts. Compression molding is the process of directly adding plastic into an open mold cavity at a certain temperature, then closing the mold and melting the plastic into a flowing state under the action of heat and pressure. Due to physical and chemical processes, plastic hardens into a shape and size that remains unchanged at room temperature. 3. Extrusion molding It is a molding method in which materials in a viscous flow state are molded into continuous profiles with the desired cross-sectional shape at a lower temperature through a die with a specific cross-sectional shape under high temperature and certain pressure. The production process of extrusion molding involves preparing molding materials, extruding shapes, cooling and shaping, pulling and cutting, and post-processing of extruded products (quenching or heat treatment). During the extrusion molding process, pay attention to adjusting the temperature, screw speed, traction speed, and other process parameters of each heating section of the extruder barrel and the die head in order to obtain qualified extruded profiles. Special attention should be paid to adjusting the extrusion rate of polymer melt from the die of the machine head. Because when the extrusion rate of molten material is low, the extruded material has a smooth surface and uniform cross-sectional shape; But when the extrusion rate of the molten material reaches a certain limit, the surface of the extruded material will become rough, lose luster, and exhibit phenomena such as shark skin, orange peel patterns, and shape distortion. As the extrusion rate further increases, the surface of the extruded material undergoes distortion, and may even detach and fracture into molten fragments or cylinders. Therefore, controlling the extrusion rate is crucial. 4. Injection molding Also known as casting and pressing molding. It is to add plastic raw materials into the preheated feeding chamber, then place the pressure column into the feeding chamber to lock the mold, and apply pressure to the plastic through the pressure column. The plastic melts into a flowing state under high temperature and pressure, and gradually solidifies into plastic parts through the pouring system into the mold cavity. This molding method is also known as transfer molding. Pressure injection molding is suitable for plastics that are lower than solid plastics and can be compressed and molded in principle. Pressure injection molding can also be used. But it is required that the formed material has good flowability in the molten state below the solidification temperature, and a larger solidification rate above the solidification temperature.

Regarding the hardness range of silicone products. Most silicone products use silicone rubber compound, and the molding process is mostly hydraulic molding. The lower the hardness, the more unfavorable the product is for material placement, and the more bubbles will be generated during high-temperature vulcanization due to its semi fluid internal structure. Therefore, we have very high requirements for selecting silicone materials for such products, and we must also use the best vulcanizing agent by increasing the power of the vacuum machine and improving the mold structure to solve the problem. Silicone products have good toughness and elasticity, and are not easily deformed by external forces. There is a layer of oily substance on the surface layer, so it feels smooth to the touch. It is mainly used in industries such as construction machinery, automobiles, electronic products, household appliances, toys, medical care, sports equipment, etc. It has the functions of shock absorption, sealing, anti-static, high and low temperature resistance, wear resistance, flame retardancy, acid and alkali corrosion resistance, etc.   The adsorption function of silica gel is mainly physical adsorption, which can be regenerated and reused. Add acid to alkali metal silicate (such as sodium silicate) solution to acidify it, and then add a certain amount of electrolyte for stirring to generate silicic acid gel. In general, the hardness of silicone products is 30-80 °, which is also a common silicone hardness and suitable for the production of most silicone products. Let's take silicone tubing as an example: Silicone tubing, also known as silicone tubing. Used as a carrier for the circulation and encapsulation of liquids, gases, and other materials. Hardness: 70 ± 5, tensile strength: ≥ 6.5

1. Whether the self-healing edge of the product feels rough or not, the size of the mold closing line determines the workmanship of the product mold, and the mold workmanship determines the overall effect of the product. Self healing is very important! 2. The vulcanization effect of the product and the uneven hardness and softness of the product feel; Poor stretch resilience and rebound effect; It is related to the manufacturer's vulcanization time and the issue of raw materials. 3. The color and odor of silicone products depend on the uniformity of the manufacturer's mixing process. The longer the time, the better the color saturation. 4. Silicone raw materials are non-toxic and odorless, but when sulfurizing agents are added to the raw materials and subjected to high-temperature hydraulic molding by silicone manufacturers, a glue smell may appear. However, after secondary sulfurization and prolonged storage, it will gradually disappear! So having no odor is normal! 5. When choosing silicone products, we first look at the color. High quality colors are more vibrant, with a smooth surface that feels good when touched by friends; Poor quality silicone products feel rough to the touch and have a cloudy color. 6. Smell the odor. When smelling silicone products, there may be a slight odor due to residual sulfurizing agents, but this is normal. Generally, after being left in the air for a few days, the odor will be completely eliminated; Poor quality silicone products have a foul odor and a pungent smell. 7. In terms of usage, good silicone products are not easily deformed or twisted when pulled, have elasticity, and have bright colors:; Poor quality silicone products are prone to fading, deformation, and insufficient explosion resistance, making them easy to age. 8. Wear resistance is the ability of silicone products to withstand wear and tear during production and molding. Good silicone products generally have a surface that is rarely rubbed off by external factors, and does not affect the appearance, appearance, or color of the product. And the surface characters of low-quality silicone products are prone to falling off. 9. Elasticity, silicone products have good elasticity because high elasticity mainly comes from the movement of silicone molecular segments. Therefore, when purchasing silicone products, first check the elasticity of the silicone product to determine its quality. 10. Fatigue resistance: The phenomenon in which the structure and properties of silicone products change when subjected to alternating stress (or strain) is called fatigue. The phenomenon of damage to silicone products during the fatigue process is called fatigue failure. So fatigue resistance is also a method of identifying the quality of silicone products. 11. Hardness and tensile stress are important indicators of the rigidity (stiffness) of silicone materials, which are the forces required for silicone products to undergo certain deformations. It is also a method of identifying the quality of silicone products. 12. In terms of characteristic and tactile feel, silicone products have good toughness and elasticity, and are not easily deformed by external forces. Moreover, the tactile feel is relatively smooth, while counterfeit silicone products are prone to deformation and feel rough. 13. In terms of characteristics, silicone products are non-toxic, odorless, colorless, with good texture and no harm to the human body. However, it is difficult for counterfeit silicone products to achieve these effects. Counterfeit silicone products are generally toxic, have a pungent odor, and are also relatively rough! 14. At the same time, it is also very useful to judge the authenticity of silicone products through the convenience of flame combustion. Counterfeit silicone products have excellent smoke residue as black powder when burned, while real silicone products emit white smoke and white powder residue no matter what color they are burned.

I believe most customers who have used O-rings have experienced deformation of O-rings. O-ring is a common silicone rubber product that is widely used and the production process is not difficult. The selection of purpose, material, and size may also vary. One thing that can be confirmed is that the majority of O-ring damage does not come from the design and pressure of the O-ring. If the design only unilaterally increases the pressure, it is impossible to cause damage to the O-ring seal. By exploring the reasons, we will find that if the working environment is high temperature and pressure, it may cause deformation of the O-ring seal or bite when it is squeezed into the gap. The typical sealing effect of O-ring deformation caused by compression is that it will generate contact pressure with the sealing surface during installation. When the pressure exceeds the pressure of the sealing medium, the sealing effect will occur, and vice versa, leakage will occur.   Here are some reasons that can cause O-ring deformation: 1. Compression and tension 2. Temperature 3. Medium working pressure So how can we better and effectively avoid O-ring deformation 1. When choosing O-rings, the friction coefficient should be low and lubrication should be done properly. 2. The contact surface should be smooth, without roughness or stains; 3. When installing, ensure coaxiality, avoid excessive eccentricity, and ensure the rationality of the sealing system to prevent excessive dimensional errors

The hardness of silicone products is an important physical parameter in the production of silicone products, which involves the final performance and application of silicone products. So, what is the general hardness range of silicone products? The hardness range of silicone is very wide, and the hardness of silicone is generally measured by a Shore hardness tester, ranging from 10 degrees to 80 degrees.   In general, the higher the hardness of silicone, the more wear-resistant and compressive it is, but the elasticity will correspondingly decrease. On the contrary, silicone with lower hardness has a soft and comfortable feel, and has good elasticity. The difference in hardness between liquid silicone and solid silicone: Liquid silicone typically has lower hardness and is suitable for applications that require flexibility and fluidity. Solid silicone has higher hardness and is more suitable for making durable finished products. Application areas of silicone products with different hardness: The difference in hardness brings about significant differences in the application scenarios and fields of silicone products: for example, low hardness silicone is commonly used in medical equipment and baby products to provide a soft and comfortable touch; High hardness silicone is commonly used in the automotive and electronics industries to manufacture various seals and protective components. The hardness of commonly used silicone products: In daily life, many silicone products have clear hardness requirements. For example, kitchen appliances such as silicone spatulas usually require a certain degree of hardness to ensure durability; And protective cases like phone cases require moderate hardness to provide good protection. The hardness range of silicone is 10 degrees to 80 degrees, and the hardness values within this range can meet the majority of silicone applications. When choosing silicone products, factors such as hardness, temperature tolerance, chemical stability, and processing methods should be comprehensively considered to ensure that the product can perform well in specific usage environments.