The Complete Handbook of Spray String

Chapter 1: Understanding Spray String

Spray string is a pressurized canister that discharges a thin, continuous stream of semi-solid polymer which expands and cools into a web-like string as it travels through the air. You have seen it at birthday parties, sporting events, and stage shows, but the mechanics of what is happening inside the can and how the polymer behaves in flight are not widely understood. That lack of understanding is where most practical problems begin: a can that sputters, a string that snaps mid-air, or a mess that dries into a film that is nearly impossible to remove. To use spray string well, you have to know what it is made of and how the delivery system works.

At its core, spray string is an aerosol product. The canister contains a liquid mixture, usually a polymer resin dissolved in a volatile solvent, along with a propellant. The propellant can be a compressed gas or a liquefied gas that boils at room temperature. When you press the actuator, the mixture is forced up the dip tube inside the can and out through the small orifice in the nozzle. As the liquid exits, the pressurized solvent and propellant flash into gas. This rapid expansion cools the polymer, which begins to cure and solidify, and the turbulent flow and expansion cause the stream to crinkle and split into the tangled, spaghetti-like structure that you recognize as spray string.

The polymer is the most important ingredient. It determines the mechanical properties of