Bad Characteristics And Causes Of Popular Science Silicone Products!

- Nov 20, 2019-

             Silicone products are mainly made of H4 silicone rubber made of D4, DCM and other different materials. It is well known that the role and popularity of silicone rubber has occupied our life and industry. Silicone products are used as auxiliary parts and main components are not counted. The number, and the line has a difficult practice, that is, the quality of the guarantee, silicone products are no exception, it also has inevitable quality problems in the process, Xiaobian has concluded that the common defects of silicone products Features and phenomena are common to everyone.


Serial number


Scrap type


Waste characteristics


Causes


1


Inaccurate size


The thickness of the product is uneven, the outer shape is out of tolerance, and the size does not meet the requirements of the pattern.


1. Poor parallelism of equipment and mold


2. Silicone shrinkage calculation is not allowed


3. Poor mold processing


2


Lack of glue


The product has no obvious outline and its shape does not meet the requirements of the pattern.


The product has a clear outline, but there are local depressions and defects.


1. Insufficient weight of the loaded compound


2. When it is pressed, it rises too fast, and the rubber does not fill the cavity and overflows the mold.


3. Poor exhaust conditions


3


Flash edge thickening


Silicone rubber products have thickening at the mold parting surface


1. Excessive amount of rubber loaded


2. The mold does not have the necessary residual trough or the residual trough is too small


3. Not enough pressure


4


bubble


Silicone rubber products have bubbling on the surface and inside


1. The air in the cavity is not completely discharged when pressed


2. The rubber contains a lot of water or volatile substances.


3. Die exhaust conditions are not good


4. The loaded compound is not heavy enough


5


Concave and concave defects


Silicone rubber products have convex and concave marks on the surface


1. Machining traces left during mold processing


2. The rubber itself is defective (such as high viscosity or overdue)


3. Die exhaust conditions are not good


6


gap


Cracking on silicone products


1. The product is scratched when the product is removed during mold opening


2. Layering of rubber due to excessive coating agent in the cavity


3. The mold structure is unreasonable


4. The molding method of the rubber compound is unreasonable (especially fluorine rubber and high hardness nitrile rubber)


7


Wrinkle crack, separation


Wrinkle on the surface of the product


Cracks and separations on the surface and inside of the product


1. The cavity is filled with dirty rubber


2. Excessive release agent in the cavity


3. Mixed with different rubber compounds


4. Process operation (forming, feeding method) is incorrect


5. Rubber overdue


8


Impurity


Impurities on the surface and inside of the product


1. The rubber compound is mixed with impurities in plasticating, mixing, storage and transportation.


2. The mold is not cleaned (including flash, scrap is not cleaned)


9


Partition surface misalignment


The product has a large misalignment at the parting surface


1. Mold manufacturing precision error and processing accuracy are not enough


2.45 degree splitting apron thickened by flash


3. Poor mold positioning


10


crimping


The product has obvious inward shrinkage at the parting


1. Poor rubber processing performance (such as fluororubber)


2. The mold structure is unreasonable (thick products should adopt closed structure molds and reasonable open residual tanks)