A spark generating tube includes a single tube and a pyrotechnical mixture. The single tube only has a single layer of plastic material, such as ethylene vinyl acetate (EVA) and polyethylene. The pyrotechnical mixture has formed a thin layer in contact with the single layer of the single tube. The pyrotechnical contains an oxidizer, a reducing agent, a substance with low temperature of Tammann and an agent for lubricating and adhering, wherein the agent for lubricating and adhering is either talc or graphite, and the reducing agent can be an aluminum powder in microscale. During the process for manufacturing a spark generating tube, the mixture of the oxidizers and additives is formed separately from the reducing agent. The final mixture is obtained only in the single tube formed with an extruder. In this way, only a very small amount of pyrotechnic mixture is formed at any instant.