Machin guards

[Jonathon BywaterParticipant @jonathonbywater45041]

Wondering what clear plastic to use as machine guards. Acrylic shatters I believe so something bendable ! Thanks.

[Jonathon BywaterParticipant @jonathonbywater45041]

Material

[Russell EberhardtParticipant @russelleberhardt48058]

Polycarbonate.

Russell

[Jonathon BywaterParticipant @jonathonbywater45041]

Thank you Russel

[Rod RenshawParticipant @rodrenshaw28584]

Acrylic is said to go opaque after some years of contact with cutting fluids.

[Jonathon BywaterParticipant @jonathonbywater45041]

I think acrylic shatters to . Nice!

[Bill PudneyParticipant @billpudney37759]

Polycarbonate a.k.a. Lexan is what you want. Acrylic a.k.a. Perspex or Plexiglass does shatter, Polycarbonate doesn't.

Polycarbonate is used on industrial machines when a cheap transparent guard is required. Armoured glass is possibly more resistant to impact but more expensive.

cheers

Bill

[Jeff DaymanParticipant @jeffdayman43397]

Lexan is Sabic's brand of polycarbonate ( Used to be GE Lexan, but General Electric Plastics was bought by Sabic in about 2007 as I recall)

Makrolon is Covestro's brand of polycarbonate (Used to be BASF Makrolon, but BASF became Covestro in about 2011 as I recall)

Local to me, Makrolon sheet is much cheaper to buy than Lexan. May be wise to shop a bit where you are, when buying polycarbonate sheet.

[old martParticipant @oldmart]

I made some guards out of 6mm polycarbonate sheet for the museum's mills simply because it was available laying around. Slightly overkill, as 3mm would have been easier to work. The arm holding the screens is a cheap adjustable arm stand for flat screen monitors up to about 19".

[Jonathon BywaterParticipant @jonathonbywater45041]

Interesting. Thank you

[not done it yetParticipant @notdoneityet]

Doesn’t it depend on what one is guarding against? Guarding against splashes, physical contact with moving parts, or prevention of projectiles escaping into the main workshop need different approaches.

[David JuppParticipant @davidjupp51506]

If using Polycarbonate for guards, never use acetone for cleaning. It leads to severe stress cracking.

[Ex contributorParticipant @mgnbuk]

Doesn’t it depend on what one is guarding against?

No, not really.

The OP requirement was for a clear plastic material & for a machine tool application polycarbonate sheet covers all bases, so why consider anything else ?

The only real disadvantage to it is that it scratches if you are not careful cleaning it. Some polycarbonate is available with a scratch resistant coating & industrial machines sometimes use a safety glass / polycarbonate / safety glass sandwich to give more resistance to scratching, but the downside to that solution is that an impact from a broken tool or job coming out on a lathe cracks the glass & replacements are expensive. And heavy.

Nigel B.

[noel shelleyParticipant @noelshelley55608]

A good cheap sorce would be to try a sign maker , I once came home with a large amount for a £5 in colours as well, some was 12mm thick. For off cuts try AMARI PLASTICS, in the UK. Good Luck, Noel.

[old martParticipant @oldmart]

To bend polycarbonate, a hot air gun will do, my efforts with the 6mm were not very good, but thinner material should be easier. I tended to overheat the bend line, the picture of the guard with bent ends does not really show the poor bends. Practice with a small offcut would help a lot.

[Jonathon BywaterParticipant @jonathonbywater45041]

Sorry ,had no signal for 2 days!msinly to stop oil and swarf flying at me. Most things I do a pretty small so polycarbonate would probably stop it. Never happened yet.I still wear face protection too,!

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