Machine Guards and Chemical Resistance

Polycarbonate has traditionally been used to produce machine guards due to its virtually unbreakable properties. Its good optical properties, ability to form to shapes and its reasonable cost make it an almost perfect choice for the application.

One problem with Polycarbonate in some machine guard applications is that some cleaning chemicals, oils, fuels and greases can attack the surface of the sheet over time. While this chemical attack does not occur in all applications, it can be a severe problem in some industries. This attack of the sheet means that the guards need to be replaced frequently or the user will have to live with optically and sometimes structurally damaged machine guards. Coating the Polycarbonate can offer some degree of protection against chemical attack, but this is not the ideal solution as any scratches that occur in the coating provide sites for attack. Also, using a coating can be a problem if the guards need to be formed, as standard hard-coats will crack. Another problem with Polycarbonate is that over time the surface can become scratched.

Even though Polycarbonate is reasonably inexpensive, the cost of replacing a damaged machine guard can be expensive particularly once the cost of machining, forming, installing the guard and machine downtime is taken into account.

At HighLine Polycarbonate we have developed a new monolithic sheet product known as Grade 5500. This product has been developed especially for applications requiring exceptional chemical resistance. The sheet will not be damaged at all by the vast majority of cleaning chemicals, oils, fuels and greases. The sheet is also much more resistant to scratches than uncoated Polycarbonate, is virtually unbreakable and is lighter than Polycarbonate. The material has also been approved for contact with foodstuffs having an alcohol content of less than 8% according to the FDA specification 21CFR 177.1500 (11).

All of these properties make it the ideal replacement for Polycarbonate sheet in machine guard applications, even in the food processing industry, where Polycarbonate is becoming damaged and needs to be replaced.

For more information about Grade 5500 sheet, contact HighLine Polycarbonate LLC.