Brief introduction
Seal strip, is a product that seals something so that it cannot be easily opened, and plays the role of shock absorption, waterproof, sound insulation, heat insulation, dustproof, and fixing. Seals are available in rubber, paper, metal, plastic and other materials.
Classification of seal strip
Seal strip can be classified according to several methods such as section shape, vulcanization method, use part and application, and use material.
Classification by section shape
It can be divided into solid core products (round, square, flat section shape), hollow products and metal-rubber composite products and other types.
Among them, metal-rubber composite seals account for more than 60%. For the rubber sealing strip section design is crucial.
First of all, the seal lip shape, size design, both sides of the seal lip should be the same, the size of the appropriate force from both sides of the window glass contact glass. Lip length, thin and thick should be appropriate, too thick, too long will make the glass lifting resistance is large, too thin, too short will lead to the glass is not well guided and sealed, resulting in vibration, noise, rain leakage phenomenon;.
Secondly, the shape and size of the bottom of the section design, the window steel groove section has a projection, its role is to assemble the guide groove, therefore, the bottom of the guide groove section should be designed with the appropriate structure, both easy to install, but also the use of their own elasticity of the seal attached to the steel guide groove to prevent it from coming out;.
Finally, the shape and size of the outer lap edge, in order to improve the appearance, the outer surface of the guide groove should fit closely with the body.
Classification by vulcanization
(1) Discontinuous vulcanization method (the extruded rubber strip is cut to a certain length and put into the vulcanization tank, and the semi-finished products of the extruded rubber strip are put into the model for vulcanization).
(2) Continuous vulcanization method (microwave continuous vulcanization method, salt bath continuous vulcanization method, hot air continuous vulcanization method and several other methods).
A. Microwave continuous vulcanization of composite seals: microwave vulcanization technology is a production technology applied and widely promoted after the energy crisis in foreign countries in the 1970s. The use of microwave continuous vulcanization technology can not only produce a variety of materials from metal core, solid core rubber and sponge rubber composite rubber strips, but also, in energy saving, improve efficiency and other aspects of continuous vulcanization method device superior. This technology is recognized worldwide as the best process for producing extruded products. The characteristic of microwave heating is that the heat is generated directly in the heated object instead of being input from outside as conventional, which not only generates heat quickly, but also distributes it evenly, which is conducive to improving product quality and greatly shortening the time used for heating.
B. Salt bath continuous vulcanization seal: salt bath vulcanization using a salt bath system containing nitrite, environmental pollution, has been gradually eliminated.
C. Hot air vulcanization seal: hot air sulfur has been developed to strong wind type vulcanization, that is, the use of high temperature, high-speed hot air vulcanization (Tmax: 450 ° C and Vmax: 60m / s) can also achieve the role of flame pretreatment, and safety greatly improved.
Classification by part and use
(1) Window glass sealing strip.
(2) car door sealing strip.
(3) decorative strips, inserts.
(4) other seals (luggage compartment lid seal, hood seal, water tank seal, emergency door seal, etc.).
According to the material classification
There are three kinds of rubber materials for automotive seals: dense rubber, sponge rubber and hard rubber. Hard rubber hardness up to Shore A95. sealing strip rubber more use aging resistance, low temperature resistance, moisture resistance, chemical corrosion resistance, especially ozone aging EPDM rubber (EPDM).
EPDM can be compounded with steel tape, steel wire woven tape, TPE, fleece, flocking, PU coating, silicone coating, etc., to ensure that the interior and exterior of the car and its own waterproof, dustproof, sound insulation, heat insulation, vibration damping, anti-wear and decorative role. In general, EPDM seal can be stable for more than ten years.
Can also choose to have good ozone resistance and good aging resistance of neoprene (CR). Considering the common rubber process performance, sometimes also need to choose and rubber, such as natural rubber (NR) and CR and styrene-butadiene rubber (SBR) three kinds of rubber and or polyethylene (PE), EPDM and NR rubber and plastic type to improve ozone resistance. As thermoplastic elastomer (TPE) technology continues to develop and mature, applications continue to expand.
In the manufacture of raw materials for sealing strips, the main raw material used in the past EPDM rubber is also constantly updated and developed. The new EPDM with excellent physical properties and good processing properties can control the long chain branching in the molecule, making it better vulcanization performance, and can improve the extrusion speed and product yield.
New thermoplastic elastomers such as TPO and TPV materials are also increasingly used in automotive seals. These materials have both the excellent engineering properties of elastomers, but also has the excellent characteristics of plastics, both convenient processing, but also recyclable and reusable, these materials are gradually replacing EPDM products.
Classification by type
D-type seals are divided into large D-type, small D-type seals, P-type seals and E-type seals.
The car sound insulation bumper strip is divided into 3M backing small D type seal, 3M backing large D type seal and 3M backing large P type seal.
But with the development of the automotive industry in recent years, a domestic WAND double-sided adhesive occupies an increasingly large market share, which overcomes the shortcomings of 3M adhesive construction is not cold-resistant, simple construction, durable adhesion, overcoming the previous temperature on the life of the seal!
Classification by application
Seal market is mainly based on EPDM (EPDM) rubber, rubber and plastic materials, according to its use can be divided into several categories such as automotive seals, mechanical seals, door and window seals.
It has better corrosion resistance, weather resistance, noise reduction and heat insulation effect than ordinary door and window seals. The surface of plastic window and door sealing strip is smooth, not only has excellent sealing and waterproof performance, but also plays a beautiful decorative role. In the selection of materials, the general requirements of higher manufacturers are selected EPDM rubber or thermoplastic
EPDM (EPDM) product main performance: the product is non-toxic, environmental protection, aging resistance, high temperature resistance, stable performance, summer and winter can maintain good performance.
1, steel skeleton three composite, not easy to deformation shrinkage, assembly solid, good sealing
2, doors, windows, curtain walls with sealing strips, the product has good elasticity, migration resistance, can effectively block noise, dust, weatherproof.
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