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ASSAY |
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Purity (assay %) is only one of the measures for quality. It is likely that a product with high assay is non- stabilized or improperly stabilized, since the assay decreases due to addition of stabilizers. Product with high assay due to above reasons may adversely affect acidity of the product.
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Yellow / White Phosphorus content. |
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The White Phosphorus content in Red Phosphorus is more susceptible to moisture attack as compared to Red Phosphorus which is a much more stable compound. The White Phosphorus in the presence of moisture forms Phosphoric Acids resulting in increase in acidity which is detrimental to the life of the striking surface.
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ACIDITY |
Acidity is basically controlled by effective stabilization of the product. Stabilized Red Phosphorus keeps the pH neutral when dispersed in water for longer time. On storage, Red Phosphorus gradually starts releasing toxic phosphine gas & also starts forming different types of phosphoric acids. The phenomenon shown in the diagram below is accelerated in improperly stabilized Red Phosphorus.
If the properly stabilized Red phosphorus is not used then the Phosphoric acids, which are formed, will start eating away the striking surface & thereby lower the life of matchboxes. The strike surface does not withstand the repeated impact of matchsticks & does not live up to the expectation of lighting the number of matches it is expected to do.
Higher acidic Red phosphorus when used over a period of time will also badly affect the printing drums by eroding the surface. In view of this, it is necessary to use red phosphorus with lower acidity levels.
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MESH SIZE |
| A coarse product
does not always pass through the printing screen resulting in starvation
problem on the striking surface. Moreover, because of coarseness,
the friction compound does not form a cohesive emulsion since proper
binding does not take place. This results in the surface getting peeled
off & leading to spurting problems. Coarser material can cause pre-ignition
problem as against finer material, which also gives a better yield.
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