Pouring - EQUIPMENT for polyurethane
To run a PUF pouring process, one must
solve the following technical problems:
• High-quality mixing of components
• Achieving a tough even jet at the mixer outlet
• Sufficient output rate of the unit
• High-quality washing (cleaning) of all ducts
The problems of quality component mixing
and achieving an even jet should be considered as interrelated.
Two component mixing techniques can be used in the polyurethane
foam pouring process.
High Pressure Chamber Mixing
Components A and B are mixed in a dedicated high
pressure chamber at 5 to 20 MPa (50 to 200 kg/cm2). This technique
is considered to guarantee the best possible quality of component
mixing and, consequently, the highest possible quality of the resulting
Mechanical Mixing in a Low Pressure Chamber.
Components A and B are continuously and
separately fed into the common chamber, in which the agitator rotates,
pass through the mixing area and move out together. A low pressure
in the chamber provides a way to produce equipment which is less
complicated in terms of technology and process, small-sized, portable,
and several times cheaper than the big high-pressure pouring machines.
However, such units have a limited output rate (max. 30 liters/min)
and a short deviation-free horizontal jet range.
NST has developed and commercialized a
variety of low-pressure PU foam pouring equipment with output rates
varying from 2 to 6 L/min and from 8 to 24 L/min. The performance
characteristics of our models are identical to those of their foreign
counterparts, the only difference being the price.
NST Low Pressure Pouring Heads
Professional POURING equipment is complicated
stationary high-pressure (or sometimes low-pressure) machines. These
packages require time-consuming installation, special operating
conditions, and dedicated maintenance. In fact, such equipment constitutes
the main unit in a small or large-size production plant.
POURING machines, however, have one common attribute; it is the
price that may range from USD 40,000 to USD 100,000. This is the
reason why all the existing Russian companies that use PUF POURING
technologies can be clearly divided into two classes.
The first one comprises a relatively small
(in nationwide terms) number of producers that own expensive professional
pouring facilities. Such companies occupy up to 90% of the Russian
PUF product market.
other class is lots and lots of small and large enterprises that
manufacture PUF products using the so called “hand pouring” method,
which is characterized by a low efficiency, considerable feed losses
(up to 30%) and a low product quality. The only advantage of the
“manual” technology is that it requires no capital investment. Such
business units’ production is mostly aimed at meeting their own
demand for PUF products. It is difficult for them to compete with
companies operating professional pouring equipment.
Obviously, even a USD 40,000 barrier is
impassable for many would-be manufacturers of commercial poured
Situation may change dramatically now that since September 2003
we have started commercial production and supply of the NST LOW-PRESSURE
POURING HEAD (ZG-006), which can be integrated into PENA-98 type
Why PENA-98 is the only Russian-made low-pressure
unit capable of both SPRAYING and POURING Polyurethane Foam. The
PENA-98P20UM model is complete with ZG-006 and is designed to manufacture
small-diameter sectional insulation, small panels, features, and
parts of furniture.
The latest development of NST Research
& Production Company is the Low Pressure Pouring Machine capable
of smooth output adjustment from 8 L/min up to 24 L/min. The machine
is complete with a ZG-016 low-pressure pouring head.
The ZG-006 Head evenly mixes the components,
forms a tough jet, and feeds the compound into any given cavity.
The operation of this equipment is visualized in the Sectional
Thermal Insulation Pouring Process Animation (click here).
ZG is complete with a Hydropneumatic Tank
(HPT), which is used to thoroughly wash all ducts and working cavities
of the Pouring Head using a solvent sprayed with the air jet.
|Working mixture pressure inside Pouring Head, MPa (kg/cm2)
Pneumatic. Speed: 2000 rotations/min,
Working pressure: 6.3MPa
Electric. Speed: 3000 rotations/min
|Compressed air consumption providing normal operation of actuator,
|Minimum compressed air pressure providing normal operation
of Pneumatic Actuator, MPa (kg/cm2)
|Volume of solvent to be poured into HPT, liters
|Overall dimensions of HPT with support, mm
|Weight of unloaded HPT, kg
|Compressed air consumption providing normal operation of HPT,
|Compressed air pressure providing normal operation of HPT,
|Overall dimensions of Pouring Head, mm
Separate assembly of the ZG-006 and ZG-016 Heads
has its own functional purpose but contributes to the general task
of the design.
The set volume and design of the mixing chamber provides an even,
uninterrupted, tough, waveless and spatter-free jet.
is specially tailored for thorough mixing and ejection of the compound.
The design of
the mixing chamber with two inlet ducts for the components prevents
the formation of “dead zones” where the mixture is decelerated.
rotation speed is optimal for thorough mixing of the components.
structural concept of the rotor wheel-mixing chamber junction contributes
to the leak-proofness of the cavity where the rotor connects with
the drive shaft.
We have developed
a system for high-quality and reliable cleaning of working cavities
and all ducts of ZG with airborne solvent.
We have designed
an offline system to feed pulverized solvent into the ZG head. The
additional air flushing can also serve as emergency cleaning.
NST’s ZG Pouring Head has the following GUARANTEED
The Pouring Head produces an even tough jet that has a stable diameter
of 4 or 5 or 6mm (depending on the nozzle) and has no outflowing
jet pulsation (provided the components are supplied steadily).
The mixing chamber
provides a thorough stirring of the components, thus ensuring a
proper chemical reaction and a high-quality foamed plastic.
When the service
regulations are observed, the cleaning system guarantees a dependable
However, the design and the structural concept of ZG’s mixer place
certain RESTRICTIONS on its use.
The best way
to use ZG-006 and ZG-016 is top pouring.
ZG-006 is designed
for a maximum output of 6L/min; therefore the end product weight
for single casting into one mold is limited to 2,5kg (provided the
starting time is 20 to 25 seconds).
ZG-016 is designed
for a maximum output of 24L/min; therefore the end product weight
for single casting into one mold is limited to 10kg (provided the
starting time is 20 to 25 seconds).
The ZG-006 and
ZG-016 solvent washing system has an open-cycle design.