Sand application technology

2 main properties of sand

2.1 sand asphalt shingles

2.l.1 frost resistance

Sand particles if there are cracks, water will enter, volume expansion caused when frozen, crack further expansion, and so freeze-thaw cycles, leading to split on sand. Mineral particles in the production process is difficult to avoid the cracks, but as long as the ceramic coating layer can prevent the full impact of water and ice.

Sand is usually freeze-thaw cycle test to determine the frost resistance, is frozen -25 ℃, 50 ℃ melt to 15 or 25 times as a test, with the screening and low-power microscope to determine whether damage .

2.1.2 Color Consistency

The sand color with a color is uniform, is the asphalt shingles is very concerned about the indicators users, because asphalt shingles in the course of irradiation by light of different intensity, it is easy to see the color difference. And this difference is often difficult to find in production, especially in batches manufactured products but also to note the color consistency.

2.1.3 Membrane strength

High film strength to be able to avoid the sand in the transport process, the asphalt waterproof material production or use of the impact of the process (such as hail.)

Test method 2:

Shooting method: sand into the air guns in private, to 2 m far from the ceramic target shooting, shooting before and after the determination of screening results.

Gravity method: sand to a certain height (1 m or 2 m) free fall impact in the metal plate or ceramic plate, the same judge to screening results as a basis.

Determination of shooting a short time, but requires special equipment; gravity method more often, the number of free fall of 50 times, 100 times, 200 times, 500 second class, measured a long time.

2.1.4 UV

In the long term (decades) can not use the fade, this is a basic requirement of sand, the international community has done a lot of 1970. The earliest use of the instrument is accelerated aging instrument, and eventually found sand in the artificial accelerated aging and natural aging can not afford to establish relevance. After extensive research, clearly the main factor is the fading effects of UV and UV on the color change reaction is extremely sensitive.