What is the reason why the silicone dipped shoelaces cannot be cured?

What is the reason why the silicone dipped shoelaces cannot be cured?
The silicone dipped shoelaces cannot be cured due to the following reasons:
Wrong ratio: Two-component silicone needs to be mixed in a precise ratio to cure properly. For example, if the ratio of component A (base glue) and component B (curing agent) is not accurate, too little curing agent will not trigger enough chemical reaction to achieve curing; too much curing agent may cause other performance problems and may also affect the curing effect.
Uneven mixing: Even if the ratio is correct, if the A and B components are not fully stirred when mixing, the local silicone may not be able to cure. For example, the surface is simply stirred, and the silicone at the bottom and inside is not fully exposed to the curing agent.
Expired silicone: Silicone has a certain shelf life. After the shelf life, the active ingredients in the silicone may deteriorate or become ineffective. For example, the active ingredients in the curing agent may have decomposed and cannot react with the base glue, resulting in failure to cure.
Contaminated: If there are pollutants such as oil, moisture, and impurities on the surface of the shoelaces or the containers and tools that come into contact with them during the dipping process, they may inhibit the curing reaction of the silicone. For example, chemical substances such as grease and detergents left on the shoelaces may react with the silicone and interfere with the curing process.
Environmental factors: The curing reaction usually has certain requirements for environmental conditions. Too low a temperature will slow down the curing reaction and may even cause it to fail to cure; too high a humidity may affect the performance of the silicone and cause incomplete curing. For example, in a low temperature and humid environment, the curing time of the silicone will be significantly extended, and it may not even be able to reach a fully cured state.
Unsuitable silicone type: Different types of silicone have different curing characteristics and applicable ranges. If the selected silicone is not suitable for shoelace dipping, it may fail to cure or the curing effect may be poor. For example, some silicones may require specific conditions (such as heating and pressurization) to cure, which cannot be achieved under ordinary dipping conditions.