Products - Safety Glass                                      

Glass is a noble material. It is durable, timeless, spacious and transparent, and especially beautiful. Zijlstra uses only Safety Glass for the manufacture of its glass furniture. Your safety is our priority.

Safety Glass must be cut to size and undergo a certain polishing treatment prior to the toughening process. If required, openings such as drilling holes and/or cut-outs must be carried out prior to the toughening process, as this is no longer possible after toughening of the glass.

What is Safety Glass?

Safety Glass is thermally toughened glass, which is manufactured through heating it horizontally in a hot oven (transported on rollers) to approximately 700°C and then cooling it rapidly with a controlled blast of air. This process creates a permanent uniform tension, making Safety Glass approximately 5 times stronger than untoughened glass. Safety Glass can also withstand a much greater mechanical shock, impact or bending load, and difference in temperature. The risk of damage to Safety Glass in general, including during transport, is many times smaller than with untoughened glass.

If, for any reason, a glass fracture should occur, the glass will break into small cubic fragments rather than shards, which are less likely to cause harm. Fractures in products made of untoughened glass will cause the product to break into large, sharp shards, which are dangerous. These shards can cause life-threatening injuries. This danger is non-existent with Safety Glass, which is why Zijlstra recommends products manufactured exclusively of Safety Glass.

Untoughened glass		Toughened glass

Safety Glass – Unprecedentedly strong!

To show you just how strong the products from our glass product range are, we have taken a snapshot of a motorcycle with an approximate weight of 300 kilograms on top of one of our dining room tables (art. 3871). This is possible because this glass table is made of Safety Glass, which is much stronger than normal glass.

The photo alongside shows that enormous pressure is applied to one of the stainless steel legs through someone sitting on the leg. This leg is attached to the leaf of the table through the application of UV glue to a stainless steel disc. In this way, we demonstrate that the adhesive compound is capable of bearing such a weight.

Points to bear in mind when using glass furniture

• Do not use sharp pointed objects on or against the glass.
• Do not stand or sit on the glass.
• Do not use the glass surface as a workbench or chopping board.
• When moving glass furniture, make sure that you do not bump up against anything.
• Always move the furniture with two people; do not slide it.
• Do not place glass on a hard surface without protection.

   

Damage

When furniture made of normal glass is damaged through a knock, a fall or a heavy object, this will directly lead to a fracture. Because Safety Glass is much stronger than normal glass, the chances are relatively small that it will fracture and break (into small, cubic fragments). In spite of the fact that the furniture is still in one piece, it could still be damaged. The strength of Safety Glass furniture is negatively affected by damage to the edges or the surface.

In a later stage, this damage could still lead to fracture. This can also occur days later and, in exceptional cases, much later. Influences that normally have no effect on glass furniture, such as a light touch, radiation from the sun or a change in temperature during the night as a result of switching on the night thermostat, could be the proverbial last drop.

To some people, furniture appears to "spontaneously" break; cause and effect are sometimes not immediately apparent.

Temperature differences

Safety Glass can withstand temperature fluctuations of more than 200°C. If the glass volume is not evenly heated, it can lead to internal tension in the glass and ultimately lead to glass breakage. Do not place hot objects – without a place mat – directly on glass furniture.

Load capacity

The load capacity of furniture made from Safety Glass is shown (where necessary) on the information sticker on the article.

How do you recognise Safety Glass?

Using two pieces of polarizing material (for example, two glasses from a pair of sunglasses), a clear tension line along the edge of the glass is visible in Safety Glass. This line is not visible in untoughened glass. Your retailer will be happy to demonstrate this upon request. We are informing you about this test because we stand behind our products. We invite you to apply this method to glass products of other suppliers. It could sometimes lead to surprising results! 

Untoughened glass		Toughened glass