Chapter 3
Description and Technical Specs
UFD Applicator, Manual 40-43, Rev. 6.16 Page 19
3.2 Description of UFD Spray Applicator
Description
ITW Dynatec’s UFD Spray Applicators are air-operated, single or multi-module hot melt
adhesive applicator assemblies with integrated basket filters, which prevent particulate
matter from obstructing flow through the heads.
The Applicator is heated by replaceable cartridge heating elements which are controlled
by an integrated sensor and electronic control. Each model can be configured for ITW
Dynatec’s DynaControl, MCV or Upgrade control schemes or for Allen-Bradley PLC
controls. Pressure transducer ports are standard features for all Applicators. A choice of
adhesive inlets and an angled filter nut allows either vertical or horizontal spray.
Four standard UFD models supporting up to six modules, are available, ranging in width
from 50mm to 150mm (2” to 6”). Their design is metric.
Theory of Operation
Each Applicator features one or more modules (adhesive valve) mounted to a single
service block. Each module is opened and closed by air pressure (solenoid valve).
Springs are used to keep the stem closed when no air pressure is supplied to the head.
The rate of adhesive flow from the applicator is determined by the adhesive pressure
applied by the Adhesive Supply Unit’s (ASU’s) pump, the nozzle type and the stem stroke
adjustment.
As shown in the illustration below, the heated adhesive supply hose may be connected at
the rear of the applicator or at the top. Adhesive flows from the hose into the service
block, through the filter and then to the module. Air pressure (Control Air) opens the
module, allowing adhesive to flow through the module’s nozzle.
Adapters are available to allow industry-standard pressure transducers (1/2-20 thread) to
be connected to monitor adhesive pressure within the service block.
On the UFD spray models, an air preheater is located below the service block. The
preheater supplies heated air (Process Air), used to fiberize the adhesive streams, to the
UFD modules. The air preheater is thermally isolated from the service block and its
temperature is controlled independently.
The adhesive pressure in the system is influenced by the following parameters:
• Temperature and viscosity of the adhesive
• Size and speed of the Adhesive Application Unit’s (ASU’s) pump
• Cross-section and length of the adhesive hoses
• Adjusted adhesive pressure at Applicator (if adjustable pressure relief valve)
• Nozzle type
See illustration typical parts of UFD Applicator on next page.
Nozzles compatible with UFD Applicator:
Two different UFD nozzles (Omega and Random) are available to fiberize the
adhesive streams:
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