Embed Size (px)
Citation preview
POLYUREA SPRAY
EQUIPMENT
Prerequisite to make your Polyurea job
Successful
Presenter: Stephan Rindfleisch
Authors: C.Royo, S. Rindfleisch, H. Mann
• 2 Component System
• Spray Pressure between 150 and 240 Bar
• Temperatures between 65 and 80 C°
• Flow Rates between 2 and 10 liter/minute*
*for typical coating applications
APPLICATION REQUIREMENTS
• Meter and Mix the chemicals at the right mixing
ratio
• Capability to produce and maintain the required
operating pressure
• Achieve enough Delta T (Temperature Rise) to heat
up the chemicals to the application temperature at
required pressure and flow rate
• Deliver the desired flow rate at required pressure
EQUIPMENT REQUIREMENTS
EQUIPMENT OVERVIEW
Feed system for
200 liter drums
Proportioning and
Heating unit
Heated hose
Spray gun
FEED SYSTEMS
Feed pumps are required to bring enough material at the right
pressure to the dosing unit
Double acting piston pumps
Double Diaphragm pumps
Available
technologies:
FEED SYSTEMS
The feed systems is a key component of the system setup to
transfer the chemicals from the drums to the machine.
Special attention is required to select the proper pump for
the application to meet the viscosity and storage temperature
of the chemicals.
Agitation is required on the Resin side to avoid
sedimentation of material (color pigments, fillers)
A wrong selected feed pump can cause major issues with the
application by not delivering the chemicals at the right
pressure or the right flow rate to the machine
PROPORTIONING SYSTEMS
There are 3 different technologies for fixed
ratio proportining systems available:
• Air operated systems
• Direct electrical driven systems
• Electro-Hydraulic driven systems
PROPORTIONING SYSTEMS
Air operated systems:
• One air motor drives 2
(or more) positive
displacement pumps
which meter the
chemicals and create
the necessary spray
pressure
PROPORTIONING SYSTEMS
PROPORTIONING SYSTEMS
Direct Electric operated systems:
• One electric motor with drive
shafts on either end, drives 2
positive displacement pumps
which meter the chemicals and
create the necessary spray
pressure
PROPORTIONING SYSTEMS
PROPORTIONING SYSTEMS
Electro Hydraulic Driven systems:
• One electric motor drives a
hydraulic pump to operate a
hydraulic motor with 2
displacement pumps which meter
the chemicals and create the
necessary spray pressure
PROPORTIONING SYSTEMS
Hydraulic pump operation
PROPORTIONING SYSTEMS
variable ratio
There are different technologies for variable
ratio proportining systems available:
• Mechanical
• Electronic
PROPORTIONING SYSTEMS
variable ratio, mechanical
The Air driven and hydraulic driven
proportioning systems can be modified to
operate at mixing ratios other than 1:1
• The dosing pumps on these units can
be changed to different sizes to match
the desired ratio up to 10:1
PROPORTIONING SYSTEMS
variable ratio, electronic
An electronically variable ratio system also
available:
By using two independant hydraulic
circuits and a control system, the machine
can achieve mixing ratios from 1:1 up to
10:1
Fluid Heaters
To achieve the necessary Delta T (Temperature rise)
at the desired flow rate, the fluid heaters are key
element of the application.
There are 3 main versions of heating systems:
• Mass heater
• Immersion (Direct contact heating)
• Hybrid
All of these types work fine, as long as the Delta T is
achieved
Heater schematics
Pressure gauge
Temperature sensor
Heating element Fluid outlet
Fluid Inlet
Mass Block
Pressure switch
Pressure switch
Heated Hoses
Heated hoses are needed to maintain the temperature of
the chemicals coming from the heater. With the
exception of the start up, heated hose are not used to
heat up material but to maintain temperature.
Hoses are typically low voltage types and are
temperature controlled with a sensor inside one of the
lines of the 2 components.
Impingement Mix guns
Due to the extreme short reaction time of Polyurea,
only impingement mix guns can be used
There are different Technologies available
• Air Purge gun
• Mechanical Purge gun (aka Needle gun)
Impingement Mix guns – Air Purge
• An Air Purge gun uses a metal mixing chamber with 2 orifices
for the chemicals and an outlet to exit the mixing chamber.
• At each of the orifices a valve (side seal) is used to open or close
the fluid flow to the mixing chamber.
• When the gun is triggered, the 2 components will flow through
the mixing chamber and Polyurea is sprayed to the surface.
• When the gun is de-triggered, fluid flow stops and pressurized
air will flow through the orifices and clean out the mixing
chamber = Air Purge
Impingement Mix guns – Air Purge
AIR PURGE GUN OPERATION:
Impingement Mix guns – Mechanical Purge
• A Mechanical Purge gun uses a mixing module with 2 orifices
for the chemicals and an outlet to exit the mixing module to
an atomizing tip.
• A needle is used to open or close the two orifices of the
mixing module.
• When the gun is triggered, the 2 components will flow
through the mixing module and Polyurea is sprayed to the
surface.
• When the gun is de-triggered, fluid flow stops and the needle
will push out all mixed material from the module =
Mechanical Purge
Impingement Mix guns – Mechanical Purge
Impingement Mix guns – Air Purge
Impingement Mix guns – Mechanical Purge
Conclusion
Application of Polyurea requires a complete system setup
to match the chemicals specification.
• Feed System
• Proportioning and Heating System
• Heated Hoses
• Spray gun
All components need to be selected properly to fit the
needed application requirements on flow, temperature and
pressure.
Conclusion
Training is another key element for a successful
Polyurea application
• Training on how to use the equipment
• Provided by the machine manufacturer (or its
distributor)
• Application training
• See Applicator training from PDA-Europe
(www.pda-europe.org)
Disclaimer Credits
This presentation contains
materials and copyright content
from the following companies:
GAMA, Spain
Graco, Belgium
WiWa, Germany
Thank you for
your attention!
