【LUCK GLASS】Popularization of Toughened Glass Knowledge

Tempered glass processed by controlled thermal or chemical treatments to increase its strength compared with ordinary glass.

Advantages:

The tempered glass is generally used to describe fully tempered glass but is sometimes used to describe heat strengthened glass as both types undergo a thermal 'toughening' process. There are two main types of heat treated glass, heat strengthened and fully tempered. Heat strengthened glass is twice as strong as annealed glass whilst fully tempered glass is typically four to six times the strength of annealed glass and withstands heating in microwave ovens. The difference is the residual stress in the edge and sheet glass surface. Fully tempered glass in the US is generally above 65 MPa while Heat Strengthened glass is between 40 and 55 MPa. It is important to note that while the strength of the glass does not change the deflection, being stronger means that it can deflect more before breaking. Annealed glass deflects less than tempered float glass under the same load, all else being equal.

Disadvantages：

1.Tempered glass must be cut to size or pressed to shape before toughening and can’t be re-worked once toughened. Polishing the edges or drilling holes in the flat glass is carried out before the toughening process starts.

2.Due to the balanced stresses in the glass, damage to the glass will eventually result in the glass shattering into thumbnail sized pieces.

3.The glass is most susceptible to breakage due to damage to the edge of the glass where the tensile stress is the greatest, but shattering can also occur in the event of a hard impact in the middle of the glass pane or if the impact is concentrated.

4.Using toughened glass can pose a security risk in some situations due to the tendency of the glass to shatter completely upon hard impact rather than leaving shards in the windowsill.