Electric Spray Foam Systems
There are three types of spray foam machines from which to choose – electric, air driven and hydraulic. Each has its advantages depending on your spray foam needs and how you plan to use your equipment. This article explains how electric spray foam machines work and some things to consider before buying one.
Electric spray foam machines provide good performance for a wide range of applications, particularly if high throughput is required for the job. These systems are designed for use with fast-setting polyurethane two-component foam and polyurea coatings.
Advantages of electric
Consistent stall pressure and dynamic pressure
These systems are based on electric motor and pump technology that has been used in the industry for many years. In high-quality electric spray foam systems, motor control technology precisely controls these motors, because they must maintain consistent pressures when the applicator trigger is pulled (dynamic pressure), and when it is not pulled (stall pressure).
The motor control technology monitors fluid pressure and regulates electrical current to the motor. Pressure monitoring also is used to ensure the two pumps maintain the proper ratio. Because the two pump pressures must be about the same in order for the proportioner to produce a 1:1 chemical ratio, the pumps and applicator orifices are equally sized. If the pump pressures go out of balance, state-of-the-art systems will automatically shut down in order to prevent the operator from spraying bad foam or coating. The operator also receives a message indicating the reason for the shutdown, so the problem can be corrected.
Electric spray foam systems are reliable, and under the right conditions and with proper maintenance contractors can achieve good results with these systems for up to 15 years or longer. In fact, they are as reliable as the electric motor pumps they are built on, and some electric motor pump technology has been used for more than 25 years.
Heating the chemicals
These systems employ primary heaters that heat the chemical to the operating temperature. High quality systems also feature heated hoses to maintain the temperature set point and ensure that good quality foam is applied.
The foam and polyurea chemicals used with spray foam systems must be heated to a range of 110˚F to 180˚F. Electric spray foam systems typically have large electric primary heaters to heat the chemicals to the desired temperature set point. In theory, the hoses could simply be insulated to maintain chemical temperature set points, but insulation is not enough when a contractor starts up in the morning or during an extended shutdown during the day.
Heated hoses raise the chemical temperatures in the hose to operating levels at start up and maintain the temperature set point throughout the day. While maintaining the temperature of the chemicals is key, heated hoses should not be used as a way to boost chemical temperatures above the temperature set point of the primary heaters. In addition, electrical power in 200-240 or 350-415 voltage is required for the proportioning pump, primary heaters and heated hose. Compressed air also is required for the applicator.
Understand your options
Because there are a variety of electric spray foam machines available today, buyers should take some time to understand the pros and cons of each type, and how each works. Manufacturers that have nationwide distributor partners have a long history of supporting contractors, and are willing and very able to help select the correct system for the buyer’s needs.