Meaning, work of foaming done at original place(at site). The pouring / Injection of twin pack chemicals MDI & Polyol in specified ratio into Pipelines, Storage Tanks, Reactors, Wall Cavities etc. It finds application in process house of Pharmaceutical & Chemical processing units, Beer storage tanks in Breweries, Brine & Chiller water plants, where the temperature of material stored/processed is to be maintained at a temperature ranging from -35 to +10 degrees.
To avoid heat losses in transit from the point of generating certain temperature up to the point of its application/usage, this is the most preferred technique. The thickness of Puf insulation is directly proportional to the difference of outside temperature (T1) & inside temperature (T2); (T1-T2)
The concept of GREEN BUILDING effect is essentially for the conservation of energy, finds application on the top/outer surface of RCC building rooftop where PUF sandwiched panel cannot be installed.
To maintain Ideal/Ambient temperature & relative humidity inside the working arena of office buildings, PUF in chemical state is sprayed over the freshly laid RCC surface. The material in chemical state reaches all the joints & corners of surface effectively sealing them. An Endothermic reaction takes place & the material solidifies to form a joint less & seamless solid layer of rigid PUF of desired thickness varying from 30 to 75 mm.
Since PUF is not UV (Ultraviolet) resistant, the top surface is covered with a solid Polymeric membrane/PCC coating. If not tempered with, this surface has a long lifespan of 10 years & more.
This insulated surface deflects/reflects 80-85% of sun’s heat & absorbs only 15-25% thus lowering the energy bills n cooling the interiors at reasonably low cost.
As maximum heat (Approx. 75 %) is transferred thru the roof, it is imperative to insulate the RCC roof top surface. Since it is in liquid state when sprayed with the machine, it manages to reach all the corners to plug any cracks & joints thus forming a seamless & jointless surface having more than 95 % closed cell structure resulting in least heat transfer putting less load on Air-Conditioning plant.
It thus supersedes & is a preferred choice of insulation material for its fire retarding properties as compared to EPS, XPS or Styrofoam which has many surface joints while laying.
Since PUF is not UV (Ultraviolet) resistant, it needs to be covered with any Polymeric membrane like APP, EMA, EMB (Elastomeric membranes). Due to its Excellent Strength (Compressive, Tensile & Shearing), it can easily take load of Concrete, Tiling or any other conventional material required as finishing surface of roof top.
Providing & laying roof insulation with 40 mm thick Impervious Sprayed, closed cell free rigid Polyurethane foam over deck insulation conforming to IS:12432 part III (density of foam being 40-45 kg/cum), over a coat of Polyurethane primer applied @ 6-8 sqm/litre, laying 400 G thick polyurethane sheet over PUF spray and providing a wearing course of 40 mm thick cement screed 1:2:4 (1 Cement : 2 Coarse sand : 4 Stone aggregate 20 mm nominal size) in chequered rugh finish, in panels of 2.5 M X 2.5 M and embedding with 24 G wire netting and sealing the joints with polymerised mastic all complete as per the direction of engineer-in-charge.
The same treatment of PUF spray foaming done on the Inner/Lower side of metallic roofing shall achieve the best results to repulse heat transfer from outside to the inner/working area of shed. PUF also can be injected in cavity of outer walls of buildings preferably in East & Southwest direction walls where the sun rays have maximum impact during the day thus lowering the energy bills.
This process is prevalent & preferred in Industrial sheds with metallic (Profiled / Corrugated) roofing sheets. Since it is difficult to spray PUF on outside surface (Which is to be made UV resistant with some polymer), the same is done from below after the sheets are fixed on Trusses, Purlins, Rafters.
The objective is to stop heat transfer from outside where the body temperature of roofing sheet is 5-7 degrees more than the atmospheric temperature & achieve optimum temperature of working arena.
It also find utility & application in Studios & other sensitive work places where it helps in minimizing the Resonance, Reverberations & Noise effect caused by incessant rain falling on roofing sheets to maintain required acoustic levels of less than 80 db (Decibels).
Vertical walls are another potent source of heat transfer other than the roof. It finds application on the walls of Cold Stores, Banquet Halls, Studios, Laboratories & site offices among other structures. Not only it helps transfer of heat thru the walls, it also imparts acoustical value to the walls & help reduce high decibel noise crossing from one chamber to the other.
For existing walls / Structures, the modus operandi is to create a cavity of 50 – 80 mm by erecting another wall & pour PUF into the cavity / gap of two walls.
Main area of application is Pharmaceutical units, Breweries, Milk plants, Cold store
Pipe line carrying Chilled water, Milk, Nitrogen, Ammonia & Brine where sub zero / Low temperature is to be maintained throughout from source of generation to the end point (Process house), PUF INSITU POURING (Pouring at site) is done to stop the drop in temperature of carrier Fluid & retain its quality.
Tanks storing Material (Raw, In-process or Finished) which is quite expensive & whose temperature cannot be compromised like Beer before being packed is stored in huge low temperature insulated tanks to maintain its quality & avoid huge losses in rejection.
Refrigerated Trucks & Vans to transport perishable Food products like Milk over long distance have the cavity between the outer & inner surfaces with high density PUF to retain the quality of foodstuff at optimal low temperature.
Metallic Containers are extensively used as site offices with thick sheet exterior and nicely done interiors have their jacketed cavity filled with PUF to maintain ambient air conditioned temperature inside the work stations.
| Compressive Strength | Horizontal - 70 PSI ; Vertical - 68 PSI | |
|---|---|---|
| Tensile Strength | Horizontal – 84 PSI ; Vertical – 65 PSI | |
| Shearing Strength | Vertical – 50 PSI | |
| Moisture/Water Absorption | 0.025 LB / Sq ft (Which means almost Zero Porosity) | |
| Physical Change/Distortion Test | Nett change in volume & Linear change is almost 1.5% in first 30 Days of installation. | |
| Fire Resistance (FR grade) | Fire retarding grade PUF resists propagation of fire & does not Emits poisonous/toxic gases like Styrene or Carbon monoxide on Burning as in the case of XPS, EPS, Styrofoam. | |
Copyright @ Globe International All Rights Reserved
Designed and Promoted by Web Expert India ( Web Designing Company in Delhi )