The main inorganic fillers used in polyurethane foam are various after fine crushing natural inorganic minerals such as calcium carbonate,barium sulfate,the purpose is to improve some of the physical properties of foam and reduce the cost.
Most of these fillings are between 300 and 1500 and must be fully mixed with polyethers to be used for production.
The use of inorganic filler is difficult to obtain a stable suspension dispersal,which is usually deposited after hours of rest.
The stuffing itself has a certain nucleation effect,and if the filling portion increases during production,the amount of air injected will also have to be reduced properly.
In mechanical foaming it will also accelerate the wear of the metering machine,and the resulting foam products will be soft after prolonged bending fatigue,and the enhancement effect of the packing will be lost.
This is because for calcium carbonate particle size is larger,particles and the combination of the basic materials,substrate material by external force when the particles away from the basic material and formation of cavitation effect,produce stress concentration,causing the crack causes the destruction of the whole material.
Therefore,the solution is to make the calcium carbonate particles reach micron level,improving the structure of the table interface(e.g.,the use of coupling agent),improve the effective combination of particles and the polymer molecules.
The addition of packing has some effect on the dosage of each component in the soft foam production,and it needs to be adjusted.
Experiments at the same time of adding filler barium sulfate,adjust the other components,the soft foam foam product(30 kg/m3 density)of 50%,tear strength,compression load test data
With the increase of filler,the compression of foam products bearing performance increase,but can be seen from the above data,both the organic filler and inorganic filler but opposite to the effect of foam tear strength,increase organic filler,the foam properties on the rise,and the intensity of inorganic fillers added to tear down a lot.
The addition of inorganic filler improves the physical performance of one aspect,but it tends to affect other physical performance and mechanical foaming properties.
And organic fillers and polyether graft copolymer chemical combination between the two,stable structure,can be adjusted according to the needs of its product performance and organic filler content,to improve the properties of foam at the same time,keep good processing performance,and in most applications has been gradually replaced by inorganic fillers.
source：未知
time :2017-06-12 23:36
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