The characteristics of imported sealing strips are summarized. The performance of ethylene propylene rubber is also good, but it is closely related to all curing systems. TMTD is ethylene propylene rubber of vulcanization system. After soaking in 125 ℃ superheated water for 15 months, the mechanical properties change little, and the volume expansion rate is only 0.3%. 6. Under the condition of 30% stretching, it can reach 150 hours without cracking. 3. Corrosion resistance due to the lack of polarity and low unsaturation of EPR, it has good resistance to various polar chemicals, such as alcohol, acid, alkali, oxidant, refrigerant, detergent, animal and vegetable oil, ketone and grease, but it has poor stability in aliphatic and aromatic solvents (such as gasoline, benzene, etc.) and mineral oil. Under the long-term action of concentrated acid, the performance will also decline. In ISO / to 7620, nearly 400 kinds of corrosive gaseous and liquid chemicals are collected, and the level 1-4 is specified to indicate the degree of action. Therefore, it can reduce the cost of rubber products, make up for the shortcomings of high price of EPDM raw rubber, and for EPDM with high Mooney value, the physical and mechanical energy reduction after high filling is not significant.
PU foam imported sealing strip is often used in many luxury cars. What kind of performance does PU foam imported sealing strip have in actual use? First of all, its scalability is relatively large, which is very important. Only by reaching this point, can you keep good performance when using it, and at the same time, it can not achieve deformation in long-term use. Another point is that it does not absorb water, so it is also a substitute for the traditional asphalt material, and it is not precisely because of its water resistance, so it will not form a saturated under high water pressure. Another point is that it is more environmentally friendly on the whole material, and will not cause any harm to the human body. Moreover, the design of the imported EPDM sealing strip is often more advanced. It has an independent bubble structure, so it can form a good sealing combination ratio. All the bubbles also reach a uniform distribution, which can play a good expansion and contraction performance. It is precisely because of this, so it can not flow or deform in use Crack and other excellent performance, it in the use of contact materials in addition to the plane, can not be combined with many uneven materials.
Classification of PU foaming imported sealing strip materials: there are three kinds of rubber materials for PU foaming imported sealing strip, i.e. dense rubber, sponge rubber and hard rubber. The hardness of hard rubber can reach shore A95. The imported sealing strips are mainly made of EPDM, which is resistant to aging, low temperature, moisture and chemical corrosion, especially ozone aging. EPDM can be compounded with steel belt, steel wire braided belt, TPE, flannelette, flocking, PU coating, organic silicon coating, etc., to ensure the waterproof, dustproof, sound insulation, heat insulation, vibration damping, wear resistance and decoration functions of the car interior and the outside as well as its own. In general, EPDM imported sealing strip can be used stably for more than ten years. CR with good ozone resistance and aging resistance can also be selected. Considering the process properties of common rubber compounds, it is sometimes necessary to select and use rubber, such as natural rubber (NR), Cr and SBR, or polyethylene (PE), EPDM and NR rubber plastic to improve ozone resistance. According to the use parts, it can be divided into three categories: Automobile inlet sealing strip, door and window inlet sealing strip, ship inlet sealing strip, machinery inlet sealing strip, etc.; among them, machinery inlet sealing strip includes cabinet inlet sealing strip, container inlet sealing strip, etc.
PU foam imported sealing strip products mainly use the elasticity of the lip, cavity, flange and other parts of the body structure and the contact pressure generated by the surface of the assembled coupling parts (glass, metal parts, etc.) to seal and decorate. It is generally used in the range of - 50 ~ 70 ℃. The technology is divided into dense rubber strip, sponge rubber strip, two compound rubber strip and three compound imported sealing strip. According to their use parts and conditions, different cross-section structures can be designed. In consideration of the performance requirements of aging resistance, oil resistance, heat resistance, fire resistance, sunlight resistance, ozone resistance, acid and alkali resistance, chemical reagent resistance, fire resistance, etc., it is generally made of chloroprene rubber, ethylene propylene rubber, silicone rubber, natural neoprene butadiene rubber, rubber and plastic compound with excellent aging resistance. The manufacturing methods of PU foaming imported sealing strip are extrusion molding continuous vulcanization, extrusion molding vulcanization tank vulcanization or molding vulcanization. It consists of sealing and installation. This kind of product mainly uses the elasticity of the lip, cavity, flange and other parts of the body structure and the contact pressure generated by the surface of the assembled coupling parts (glass, metal parts, etc.) to seal and decorate
Preparation method of fuel resistant EPDM formula
Background technology:
EPDM is short for EPDM, which belongs to non-polar rubber. It has no resistance to general non-polar mineral oil and fuel oil, and can be seriously dissolved by such oil and fail, which is also the * defect of EPDM rubber in performance. At present, EPDM or NBR PVC blends are mostly used as the materials of air intake hose for automobiles, and AEM and eco are also used for some models. Because the air intake hose is connected with the engine connecting pipe, there must be incomplete combustion of oil and gas back to the hose, so the air intake hose is required to have a certain degree of oil resistance; at the same time, because the automobile air intake hose is arranged near the engine, that is, the high temperature area, it is also required that the hose has excellent heat and temperature resistance performance. The oil resistance of EPDM is poor, the temperature resistance of NBR PVC blend is insufficient, AEM and eco are expensive. All of the above materials have certain use limitations and limitations. Therefore, improving the oil resistance of EPDM is of great significance to solve the problem of manufacturing automobile intake hose materials.
The curing system has little effect on improving the oil resistance, but increasing the crosslinking density can slow down the swelling of fuel oil to a certain extent and reduce the swelling degree. EPDM is unsaturated rubber, which can be effectively vulcanized by common sulfur curing system and peroxide curing system. The characteristics of EPDM peroxide curing system are fast curing speed, high temperature resistance and small compression deformation. Although the properties of peroxide vulcanized material are good, it is not suitable for the injection molding process to manufacture the air inlet hose because of its poor thermal tearing. The common vulcanization system of ethylene propylene rubber has been used earlier, and its characteristics in the injection molding process are high temperature and short time vulcanization, and the products are prone to frost spray. In recent years, Shanghai Keyi Chemical Co., Ltd. has launched a new type of composite accelerator GA developed and produced by itself with foreign advanced technology. It is a special accelerator for EPDM rubber, which is composed of a variety of raw materials and uses only one accelerator. It works well with a small amount of sulfur and does not spray frost. It can be used for vulcanization of injection process. The vulcanization speed of this system is faster, the physical properties of vulcanizate are better, and the heat-resistant oxygen, ozone aging and oil resistance are better.
EPDM product features: product features: heat preservation, low water absorption, buffering, temperature resistance, sound absorption
According to the performance characteristics of ethylene propylene rubber, it is mainly used in the fields of aging resistance, water resistance, corrosion resistance and electrical insulation, such as light colored sidewall, heat-resistant transport belt, cable, wire, anticorrosive lining, sealing gasket, building waterproof sheet, door and window import sealing strip, household electrical appliances accessories, plastic modification, etc. Properties and uses of EPDM.
Ethylene propylene rubber is synthesized with ethylene and propylene as the main raw materials, with outstanding aging resistance, electrical insulation performance and ozone resistance. EPDM can be filled with oil and filled with carbon black in large quantity, the product price is lower, EPDM has good chemical stability, and its wear resistance, elasticity and oil resistance are close to that of SBR. EPDM has a wide range of applications. It can be used as tire sidewall, rubber strip, inner tube and auto parts. It can also be used as wire, cable sheath and high-voltage and ultra-high-voltage insulation materials. It can also manufacture light colored products such as shoes and sanitary products.
Brief introduction of self-adhesive imported sealing strip for electric cabinet door
The self-adhesive imported sealing strip of the electrical cabinet door is made of EPDM rubber with good elasticity, compression deformation resistance, aging resistance, ozone, chemical action and wide use temperature range (- 40 ℃ ~ + 120 ℃), which contains unique metal clamp and tongue shaped buckle, which is solid and durable, and plays a key role in various electrical cabinets.
The framework import sealing strip is made of dense rubber, foamed rubber and steel wire / steel sheet. EPDM, also known as EPDM, is suitable for the special environment of - 40 ℃ - + 160 ℃, with superior ozone resistance, UV resistance, chemical solvent resistance, and various physical and chemical performance indexes far beyond the same products.
It is widely used in box sealing, building sealing and other fields. The cold resistance, heat resistance, foaming, solid and special performance developed and designed by our company can meet the application needs. Installation method of inlaid wood door import sealing strip: because the width of saw blade or slotting knife used by each manufacturer in slotting is different, usually 4mm, 3mm , 2.5mm, 2.0mm, most of which use 3mm. When choosing imported sealing strips, you must be optimistic.
It is better to directly install the imported sealing strip into the groove opened in advance by the door stop line. It must be about 15mm long, so as to prevent the rubber strip from shortening. The water-proof imported sealing strip of electrical distribution cabinet is mainly used for filling, sealing and bonding of edge joints, component expansion joints and holes of building doors and windows. It is a kind of polyurethane elastic sealing foaming material solidified by moisture. It can be divided into two types: gun type and tube type. The gun type requires a special polyurethane foam gun to use. The tube type is equipped with a rubber tube. It is a one component, moisture curing, multi-purpose polyurethane foam filled elastic sealing material. As for the installation of the sealing strip at the inlet of the electric cabinet, the styrofoam strip is a special polyurethane product which is filled with polyurethane prepolymer, foaming agent, catalyst and other components in the pressure resistant aerosol tank.
When the material is ejected from the aerosol tank, the foamed polyurethane material expands rapidly and solidified with the moisture in the air or the contact matrix to form a foam. The foam foam has the following functions: joint sealing, sealing, heat insulation, sound absorption, etc. it is an environmental friendly, energy saving and convenient building material. It can be applied to sealing and plugging, filling and sewing, fixing bonding, heat insulation and noise insulation, especially for sealing and sealing of plastic steel or aluminum alloy doors and windows and walls.
The self-adhesive imported sealing strip of the electrical cabinet door is made of EPDM rubber with good elasticity, compression deformation resistance, aging resistance, ozone, chemical action and wide use temperature range (- 40 ℃ ~ + 120 ℃), which contains unique metal clamp and tongue shaped buckle, which is solid and durable, and plays a key role in various electrical cabinets.
The difference between EPDM compound imported sealing strip and rubber plastic imported sealing strip
Sanyuan EPDM composite imported sealing strip
Performance features: excellent comprehensive performance, outstanding ozone resistance, excellent weather resistance, high temperature and low temperature resistance, outstanding chemical resistance, resistance to a variety of polar solutes, low relative density,
Disadvantages: generally in mineral oil and lubricating oil, the expansion is large, generally dark products.
Applicable range: operating temperature range-