/Blown Asphalt
Blown Asphalt

Blown Asphalt

What is Blown Asphalt?

Blown Asphalt produced by Blowing Process. Penetration Bitumen heated up to 300C under controlled environment. What`s Oxidized Bitumen most popular grades? Oxidized Bitumen 95/25, 85/25, 90/40, and 115/15. We are also produce other grades upon request by customers.? Oxidized Bitumen 95/25, 85/25, 90/40, and 115/15. We are also produce other grades upon request by customers.

Oxidized Bitumen grades are produced by passing air via soft bitumen under controlled temperature conditions. This process gives bitumen more rubbery properties than penetration or hard grade bitumen. Also enables product to serve a variety of uses in industrial uses. These are proper for sealing saw cuts and joints because it`s minimum moving in joint. Their wide temperature range prevents bleeding in high temperature usages. They can also used for industrial applications such as pipe coating, roofing, waterproofing, flooring, mastics, sound damping, carpet backing, adhesive and electrical use.

Hard bitumen under controlled temperature conditions is widely used as an anti-slip layer compound in the piling industry, for manufacture of roofing felts, the roofing and waterproofing industries, for sound dampening felts and under carriage sealant in the automotive industry, electric cable joint protection, joint filling compound, sealant compound and many others. Also used in sealing saw cuts and joints where expected movements are minimum. It is also used in the manufacturing of bituminous marine mastic for oil & gas pipeline joints.

Blown Asphalt grades?

The most popular grades are; grades 95/25, 85/25, 90/40, and 115/15. We are also capable of producing other grades of Blown Bitumen upon request by our customers. Oxidized Bitumen high softening temperatures qualify them as excellent sealant for prevention from bleeding in high temperature applications.Blown Bitumen maybe broken to small pieces and heated slowly to application temperature 220ºC-230ºC. It used also in automobile industry. Also used in roofing felts and sound dampening felts.

Further, Oxidized Bitumen is used in the manufacture of bituminous marine mastic, which is required for the oil and gas pipeline joints. This Oxidized Bitumen is available in different grades like 95/25, 85/25, 75/25, 90/40 and 115/15. Oxidized is also capable of producing other grades of Oxidized Bitumen according to the specifications of individual clients.

What is Blown Asphalt advantages?

It is completely water resistant, highly flexible and durable. Further, it is chemically very stable. Oxidized bitumen is a very flexible compound that is not only chemically stable but also a very durable compound apart from being completely water resistant. Lastly, Oxidized Bitumen has some very prominent technical advantages that makes it a very sought after compound in various applications.


Blown Asphalt

How to produce Oxidized Bitumen?

Production process of hard bitumen by blowning bitumen penetration:

  • Bitumen 60/70 heating to 265-270 °C.
  • Transferring melted bitumen to blowing towers
  • Blowing air to bitumen penetration 60/70
  • Cooling melted bitumen with water
  • Packing

Production process of hard bitumen:

Producing operation of Blown Asphalt mainly includes tank loading different steps, bitumen blowing, condenser external gases and packing. So in beginning loose bitumen shipped, transferred to raw material store tanker. For easy transfer to blowing tower, burner contrived at bottom of store tanker for heating. If blowing towers are empty, hot bitumen can uploaded directly and blowing operation start.

Since the volume of bitumen increases as a result of blowing and it may overflow. Blowing tower filled up to 70%.
Air injection usually done when temperature of material reach to 190-230 °C.
For gradual heating, air pipes entered from tower`s top. Bitumen oxidation done At bottom. Also light molecule, volatile gases and steam emitted from top of tower.
Blowing operation done in temperature 215-290 °C. Suitable temperature is between 265 to 270 °C.

Burner contrived provides necessery heat at bottom of the tower. Bitumen reaction is calorific so in order to prevent explosion danger resulted from temperature increasing. Temperature controlled by water injection, burner extinguisher and air amount reducing. Blowing end point is usually signified by sampling from tower and bitumen properties testing. The blowing operation stops when oxidized bitumen reaches to specified properties. After this in order to fix final point and de-polymerization bitumen got in high temperature.


Blown Asphalt Feature:

One of most meaningful properties of air-blowned asphalt is its temperature at which asphalt becomes soft is raised. This usually called the softening point of asphalt. Even at this temperature asphalt still retains its waterproofs and durability. However, there is some decline in -ductility as compared with asphalt cement for paving purposes.

Transferring Blown Asphalt:

It`s necessary to transfer to store after packing and presented to sale. The produced gas and steam entered condenser through pipe fixed at top of the blowing tower. As a result, bad smelling gases and oily and volatile parts separated. Then shifting to sewage accompanied with water. Other un-separated gas parts emitted from top of condenser, transfer to furnace and burned. After cooling blowing oven to 150-160 °C, all content of blowing oven able to loading and packing. Because of liquid height in blowing tower, it’s transferr by gravity so no need to pumping.


Uses of hard Asphalt:

Blown bitumen has a wider range of uses due to its water resistance, added durability and chemical stability. Approximately 90% of the asphalt, use in paving and 10% goes into roofing products such as shingles and rolled roofing products.

There are many other special applications that include:

  • Waterproof lining for reservoirs and canals
  • Pipe coating enamels
  • Concrete joints
  • Anti-slip coatings
  • Sound dampening felts
  • Roof coating

Two types of blown asphalt coated roofing materials are available; Built up roofs
Roofing shingles made.
Built up roofing is typically commercial or apartment type buildings.
Roofing shingles are another type of roofing material coated with blown asphalt. Bitumen is cross linked or blown.