What are the advantages of silicone waterproof sealing strips
What are the advantages of silicone waterproof sealing strips:
1. Because the main production material of silicone sealing strips is Silicone rubber material, so compared to sealing strips made of other materials, silicone rubber sealing strips have better sealing performance, and can also be widely used in some high-temperature working environments. They also have good weather resistance and can be effectively It is resistant to the invasion of some natural factors, such as rain and snow; even if the silicone rubber sealing strip is used for a long time, there will be no aging damage. At the same time, because the silicone rubber sealing strip has good earthquake resistance and waterproof functions, no matter how smooth the surface of the material to be bonded is, the silicone rubber sealing strip can fit the material very densely.
2. Because there is tape on the back of the silicone rubber sealing strip, there is no need to use any adhesive. The silicone rubber sealing strip can be bonded very effectively and has a good seal. Performance; no matter whether the silicone rubber sealing strip is used for many times in a high-temperature environment, it will not fall off, making it the first choice of sealing material.
3. Because the main production material of silicone rubber sealing strips is silicone rubber, it has good insulation properties and will not cause certain pollution to the environment because it is an environmentally friendly material. At the same time, the silicone rubber sealing strip will not produce any odor or toxins.
4. The surface of the silicone rubber sealing strip is very smooth. Observing its surface, we will also find that its surface has a very uniform foaming density and good resilience.
5. The silicone sealing strip has good sealing performance, high temperature and weather resistance, anti-aging and impact resistance, shockproof and waterproof, and can fit all kinds of smooth surface materials.
6. It can be self-adhesive with adhesive tape and has better sealing performance. The high-temperature resistant adhesive will not fall off after long-term use. Environmentally friendly and safe, with good insulation, high temperature resistance, small compression deformation, strong resilience and non-toxic.
7. Heat resistance: Silicone rubber has much better heat resistance than ordinary rubber. It can be used almost forever at 150 degrees without performance change; it can be used continuously at 200 degrees for 10,000 times. hours; it can also be used for a period of time at 350 degrees.
8. Weather resistance: Ordinary rubber degrades rapidly under the action of ozone generated by corona discharge, while silicone rubber is not affected by ozone. And its physical properties only change slightly when exposed to ultraviolet rays and other climatic conditions for a long time.
Uses of silicone strips:
Used for supporting electrical appliances, electronics, furniture equipment, toys, hardware, medical equipment, sporting goods, audio, lighting, machinery, automobiles, and bottle sealing , building curtain wall sealing and other industries
Dongguan Mingzhen Rubber and Plastic Products will give you the answer, I hope it will be helpful to you
How to calculate the compression amount of silicone strips?
Generally, it varies between 10--40 depending on the formula, material, and hardness.
For example, general Shore 70-degree silicone has a compression amount of 20, which can meet normal sealing requirements.
Silicone rubber strip is a sealing strip produced from silicone rubber. Mainly used in industry, medicine, food and other fields, it plays the role of dustproof, insectproof, waterproof, fixation, sound insulation, shock absorption, sealing and other functions.
The sealing strip produced by silicone rubber has a transparent and smooth appearance, is soft, elastic, non-toxic and odorless. It has good elasticity, high and low temperature resistance, is not easy to age, does not deform, and is resistant to slight acid and alkali. In addition, it also has good performance in ozone resistance, solvent resistance, and electrical insulation. It is the first choice for seals in the chemical, pharmaceutical, food, electronics, and machinery industries.
Introduction to silicone rubber strips
As we all know, silicone rubber is also called silica gel and is an excellent product among synthetic rubbers. Not only is it odorless and non-toxic, it can withstand severe cold and high temperatures, and remains unscathed even in environments of 300°C and -90°C. The silicone rubber strip we are going to introduce today is a sealing strip made of silicone rubber.
Seals made of silicone rubber are very popular among people, which is determined by its characteristics.
The silicone rubber sealing strip is transparent and smooth in appearance, soft and elastic to the touch, and what people love most is that it is non-toxic, odorless, and environmentally friendly. Its elasticity is 35-75 degrees Shore, and it is resistant to high temperatures. If you have used it, you will fall in love with its durability and resistance to slight acid and alkali. It is commonly used as seals in the medical, industrial, electronic industry, and machinery fields.
The following are its index parameters:
The sheet resistance is 1014 ohms
The dielectric loss factor is less than or equal to one percent
Bullshit Elongation at break is greater than or equal to 200
Volume resistivity is greater than or equal to 1014 ohms_
Shore hardness is 30-80 5
Long-term temperature resistance can reach minus 70 degrees Celsius to 250 degrees Celsius, short-term to 300 degrees Celsius for several hours
Tear strength can reach 4.0 to 8.0Mpa
Tear strength is 15-KN/M
Dielectric The dielectric strength is 20KV/MM
After this brief introduction, you may still be a little unfamiliar with silicone rubber strips. However, we often use it in life. Due to its good performance, it is often used to prevent small insects from crawling in, dustproof, soundproof, and fixed. For example, in daily life, it is needed for the gaps between doors and windows. Sealed sealing strips can preserve heat, save energy and prevent wind. Therefore, many people use silicone rubber on the installation of doors and windows.
Silicone rubber strips may be used in some fields such as industry and medical treatment. Because it has very good performance in both high temperature resistance and low temperature resistance, it is used in lighter tubes, medical diversions, wires and cables and other products that require excellent sealing strips in daily life. Some manufacturers produce colorful silicone rubber strips to make them more aesthetically pleasing.
So how do we distinguish between high-grade silicone rubber strips and inferior PVC sealing strips?
Generally speaking, the ones with a pungent odor are cheaper and will burn when burned. What bubbles and shrinks is the PVC sealing strip, while the high-grade silicone rubber strip only has a little mellow smell, which is almost invisible, and is almost smokeless and odorless when burned. The silicone rubber strip burns fully and produces The substance is in the form of white powder.
How long is the service life of silicone rubber sealing strips
Its main feature is that it is resistant to both high and low temperatures. It is currently the most high-temperature resistant rubber; at the same time, it has excellent electrical insulation. It has high stability to thermal oxidation and ozone, and is chemically inert. The disadvantages are low mechanical strength, poor oil resistance, solvent resistance, acid and alkali resistance, difficulty in vulcanization, and higher price. Operating temperature: -60℃~+250℃. According to these surfaces, the service life of general silicone sealing strips is more than 10 years.
Performance characteristics of silicone sealing strips:
1. Environmentally friendly and safe, good insulation, high temperature resistance, small compression deformation, strong resilience;
2. The surface is smooth and the foaming density is uniform;
3. Acid and alkali resistance, anti-aging, and non-toxic;
4. Silicone product manufacturers have good surface non-stickiness and good air permeability;
5. Junyi uses 100% high-quality silica gel raw materials and has undergone strict testing to meet environmental protection requirements.
Does anyone know why the silicone rubber strip ages?
During the processing, storage and use of rubber and its products, the physical and chemical properties and mechanical properties of rubber gradually deteriorate due to the combined effects of internal and external factors, and finally lose their use value. This change is called Rubber aging.
The surface appears to be cracked, sticky, hardened, softened, powdered, discolored, moldy, etc.
2. The factors that cause rubber aging are:
A) Oxygen and oxygen react with rubber molecules in the rubber by free radical chain reactions, and the molecular chains are broken or over-cross-linked. Cause changes in rubber properties. Oxidation is one of the important causes of rubber aging.
B) Ozone and ozone's chemically active oxygen are much higher and more destructive. It also breaks the molecular chain, but the effect of ozone on rubber varies depending on whether the rubber is deformed or not.
When used on deformed rubber, cracks will appear in the direction of the stress, which is the so-called "ozone crack"; when used on deformed rubber, only an oxide film will be formed on the surface without cracks.
Basic structure of rubber and resistance to ozone aging
Molecular structure
The resistance to ozone aging of NBR and HNBR is determined by their structures.
Basic molecular structure
Double bonds
Ozone will react with the double bonds of NBR and break the chemical chain, thereby degrading NBR.
On the other hand, HNBR is becoming more and more common, and it removes the double bonds of NBR through hydrogenation. Although there are still a small number of double bonds in the structure of HNBR, which are used to maintain the properties of rubber, its structure has excellent ozone aging resistance.
C) Heat: Increasing the temperature can cause thermal cracking or thermal cross-linking of rubber. But the basic function of heat is activation. Increase the oxygen diffusion rate and activate the oxidation reaction, thereby accelerating the rubber oxidation reaction rate. This is a common aging phenomenon - thermal oxygen aging.
D) Light: The shorter the light wave, the greater the energy. It is ultraviolet rays with higher energy that cause damage to rubber. In addition to directly causing the breakage and cross-linking of rubber molecular chains, ultraviolet rays also produce free radicals due to the absorption of light energy, initiating and accelerating the oxidation chain reaction process. External light plays a heating role. Another characteristic of light action is that it mainly develops on the surface of rubber. Samples with high glue content will have network cracks on both sides, which are so-called "light outer cracks".
E) Mechanical stress: Under the repeated action of mechanical stress, the rubber molecular chain will break to generate free water, triggering an oxidative chain reaction and forming a mechanochemical process. Mechanical breaking of molecular chains and mechanical activation of oxidation processes. Which one has the upper hand depends on the conditions. In addition, ozone cracking is easily caused under stress.
F) Moisture: The role of moisture has two aspects: rubber is easily damaged when it is exposed to rain in humid air or soaked in water. This is because the water-soluble substances and water-soluble substances in the rubber are destroyed. Water extracts and dissolves. Caused by hydrolysis or absorption. Especially under the alternating action of water immersion and atmospheric exposure, the damage of rubber will be accelerated. However, under certain circumstances, moisture has no damaging effect on rubber and may even delay aging.
G) Others: Factors that affect rubber include chemical media, variable-price metal ions, high-energy radiation, electricity and biology, etc.
3. There are two ways to prevent rubber from aging:
1) Natural aging test method: It is divided into atmospheric aging test, atmospheric accelerated aging test, natural storage aging test, natural medium and biological aging test, etc.
2) Artificially accelerated aging test method. For thermal aging, ozone aging, photo aging, artificial climate aging, photo-ozone aging, biological aging, high-energy radiation and electrical aging, and chemical media aging, etc.
For natural rubber, the test temperature is usually 50~100℃, and for synthetic rubber, it is usually 50~150℃. The test temperature for some special rubber is higher. For example, nitrile rubber is used at 70~150℃, and silicone fluorine rubber is generally used at 200~300℃. In short, it should be determined specifically based on the test.
4. Rubber anti-aging material: rubber protective wax
1. The protection principle of rubber protective wax
Rubber protective wax, as the name suggests, is a special wax specially formulated and processed to protect rubber products from the erosion and aging of light, oxygen, and ozone. Its main protective principle is to add a certain amount of rubber protective wax when preparing the rubber to make it dissolve in the rubber and reach a certain degree of saturation. When the rubber product is affected by the outside temperature, the rubber protective wax in the rubber product is also affected by the outside temperature and migrates to the surface of the rubber product, forming a smooth surface, uniform thickness, good sealing and structure on the surface of the rubber product. A wax film that is tight, has strong toughness, elasticity and strong adhesion and is not easy to fall off. The formation of wax film on the surface of rubber products effectively curbs the erosion and aging of the surface of rubber products by light, oxygen, and ozone, and prevents surface cracks of rubber products, thereby extending their service life.
At the same time, it must be pointed out that in order to have this ability, appropriate chemical antioxidants should be added to the rubber compound to achieve the same performance
Which one is better, silicone rubber or EPDM sealing strip?
EPDM rubber is a polymer of ethylene, propylene and a small amount of the third monomer non-conjugated diene. The international name is EthyienePropyeneDieneMethyiene, which is abbreviated as EPDM. UV rays, weather resistance, heat aging resistance, low temperature resistance, ozone resistance, chemical resistance, water resistance
Good electrical insulation, elasticity and other physical and mechanical properties. These advantages are that EPDM rubber strips, which cannot be replaced by other materials such as PVC, are formed in one step using a microwave vulcanization process. They have a smooth and beautiful surface, good elasticity and resistance to compression deformation, and are weather-aging and resistant.
Due to its excellent properties such as ozone resistance, chemical resistance and wide operating temperature range, it has been widely used in manufacturing industries such as automobile doors, windows and curtain walls. For products with different shapes, different materials, or products with requirements such as cold resistance, heat resistance, foaming, solid body, and special properties.
Both can meet the needs of design and use