Why does insulating glass “cry”?

Silicone sealant has high and low temperature resistance, aging resistance, UV protection and other properties. It has good bonding properties and the waterproof sealing layer formed after curing has both elasticity and bonding properties. Therefore, it has been widely favored in the construction industry. It is also an important sealing material for doors, windows and curtain walls.

Since the market price of dimethicone contained in silicone sealants fluctuates greatly, some manufacturers use cheap white oil instead of dimethyl silicone in order to reduce costs. As a result, the tensile strength of the sealant containing white oil gradually decreases and the hardness gradually increases over time, and the sealant will become hard and brittle. Sealants failed prematurely, curtain walls leaked, and insulated glass also "shed tears."

Glass "tears"

What is "white oil"?

          White oil, commonly known as paraffin oil and mineral oil, is a mixture of n-isoparaffins extracted from crude oil. It is flammable and volatile. As a plasticizer, white oil can increase the gloss of silicone sealant, increase the extrusion speed, and can reduce the cost by about 10% compared with dimethyl silicone oil. Therefore, in order to reduce costs, some manufacturers use white oil instead of dimethyl silicone as a plasticizer.

Wall cracks

However, white oil has a smaller molecular weight, lower viscosity, and particularly strong permeability. Therefore, silicone sealants using white oil as plasticizer often cause various problems. Therefore, if white oil is mixed in, it will cause the sealant to age prematurely, crack, leak, etc.

How to distinguish "white oil glue"

1. "Thin Film Method"

Take a slightly thick piece of polyethylene plastic film, apply silicone sealant on the film, and scrape it flat. Wait for a while and then open it. If the film becomes uneven, the sealant contains white oil.

2. Look at the appearance

The brighter the colloid, the more white oil is added.

3. Ask about the price

Be especially wary of silicone sealants priced below the market price. Of course, high-priced products do not necessarily mean high-quality products, so several other methods must be used to determine them.

4. "Butyl sealant" contact method

White oil can dissolve butyl sealant. Take butyl glue and put it into silicone-based paste. If the butyl glue dissolves, the sealant contains white oil.

White glue not only destroys the beauty of the building and reduces the service life of the silicone glue, but more seriously endangers the safety of doors and windows, causing unnecessary losses and trouble to the owners.

Here, it is recommended to choose sealant with guaranteed quality and good brand reputation, especially from brand door and window manufacturers and decoration companies. For the sake of customers and brand image, we must check from the source and choose high-quality silicone glue.