Categories of Rubber Sealing Strips
Rubber Sealing Strips can be classified by its sectional form ,vulcanization methods,use purpose, used material etc.
Classified by different sectional form
It can be divided in solid product (circle , square , plat), hollow product, and metal-rubber composite product etc.
Of which ,metal-rubber composite rubber sealing strips can exceed 60%.
Sectional Form is crucial to rubber seal.
First of all , shape of sealing lip edge ,design size,and side sealing lip edge should fix window glass with same
and appropriate strength .So length and thickness of rubber sealing lip should be suitable, too thick or long will
increase drag coefficient , too thin or short will cause glass vibration, noise, and leakage of rain.
Second , bottom sectional form and design size.
The bulge on window steel tank is used to install guide slot. So, bottom sectional form of guide slot should be
designed in relevant structure, in this way, it helps rubber sealing strips attach the steel guide slot easily,
guarding against its taking off .
The last , shape and size of outer edge.
In order to keep good look, exterior facing of guide slot should be tightly fitted car body.
Classified by vulcanization methods
1. discontinuous vulcanization method
cut extrusion bars into certain length, then put into vulcanizer ,and put semi-extrusion products in vulcanizer .
2. continuous vulcanization method
microwave continuous vulcanization methods, salt bath continuous vulcanization,hot air continuous vulcanization
etc. methods.
A. microwave continuous vulcanized composite rubber seal :
Microwave vulcanization technology is widely promoted after abroad energy crisis erupted in 1970s.Not only can
make metal insert ,solid and sponge composite rubber seals , but also superior to other methods in energy-saving
and productivity improvement.This method is widely acknowledged as the best process to make extrusion product.
The feature of microwave heating is that heat is directly generated by its heated objects, not like regularly,input from
outside. In this way, heating fast and even .It helps improve products quality and shorten heating time .
B salt bath continuous vulcanized rubber seal
Salt bath adopts nitrite salt bath system, having a heavy pollution to environment,so has gradually been eliminated .
C hot air continuous vulcanized rubber seal
Hot air vulcanized method has been evolved to strong wind type sulfide, that is , using high temperature and top
speed hot air to vulcanize (Tmax:450°C and Vmax:60m/s). It also can achieve flame pretreatment ,then improve
security .
Classified by use position and purposes
1 car window glazing sealing strips
4 other seals
trunk lid rubber seal ,engine cover rubber seal ,water tank sealing strips ,emergency door seal etc.
Rubber materials for auto seal include dense ,sponge and hard rubber .
Hardness of hard rubber can be up to A95 shore.
The rubber of seal commonly use EPDM ,which has good properties of anti-age ,low temperature resistant ,anti-
steam,resistant to chemical attack, especially anti-ozone aging . EPDM can be compounded to steel strip,steel
wire braiding ,TPE,lint, flocking,PU coating, organosilicone coated,to keep cabinet inside away from water, dust,
noise, heat,vibration,and abrasion.Commonly,service life of EPDM can be more than decades.Another good choice
is CR,which has good anti-ozone aging.According to different process property,sometimes may choose blend
rubber,such as blend NR ,CR,SBR or blend PE ,EPDM and NR to improve anti-ozone property.
For the past few years,along with continuous development in TPE technology,its application area have been
extended steadily.Main raw material-EPDM also updates and develops constantly.With good processing
properties,new type of EPDM can control the branch of molecular long chain,so has better vulcanization property,
furthermore,it can enhance extruded velocity and yield.Applications of new type of TPE ,such as TPO and TPV etc.
materials are widely used in auto sealing strips. As these materials not only have good engineering properties of
elastomers,but also have excellent characteristics of plastic,and convenient for processing and recycling use again,
they will gradually replace EPDM products.