Polycarbonate in Manufacturing

Polycarbonate is bought for two properties and both are destroyed by the process that shapes it, which makes the post-machining step the whole of the capability. The programme argument is in manufacturing SEO.

What the material is chosen for

Polycarbonate carries the highest impact strength of the common machinable transparents, which is why guards, covers, and lenses are specified in it rather than in acrylic.

Optical clarity is the second requirement, and it is the one a machined surface immediately compromises. Where a part must be seen through, the surface is polished or flame treated after machining rather than left as cut.

Grades differ in additives rather than in the polymer. UV-stabilised stock exists for outdoor service, and flame-rated grades exist for enclosures.

What drives the quote

Machining introduces stress and stress becomes crazing, a network of fine surface cracks that appears days or weeks later, often triggered by contact with a cleaning solvent.

Annealing is what prevents it, and it is a scheduled oven cycle rather than a finishing touch. A shop that has run polycarbonate has an annealing schedule; one that has not discovers the requirement through a warranty claim.

Coolant compatibility matters for the same reason it does with polyetherimide. Some fluids attack the polymer and initiate cracking, so fluid selection is a capability question rather than a preference.

An achievable surface finish is a polishing capability rather than a machining one where the part is optical, which is the same relationship tool steel has with grinding.

What a capability page should state

A capability page must state process, materials, tolerances, capacity, certifications, and industries served, and polycarbonate belongs there with the post-processing named.

State whether annealing is performed in-house and to what schedule, whether polishing or flame treatment is available, and which grades are stocked. Say what stock thicknesses are held, since sheet availability drives lead time.

The structure is at capability page structure and the cluster reasoning at materials.

Common questions

Why do polycarbonate parts crack after delivery?

Machining stress that was never annealed out, usually triggered by a solvent. It is the defining failure of this material.

Is acrylic a substitute?

For clarity, often. For impact, no. Acrylic is stiffer and far more brittle, and the two are specified for different reasons.

Can a machined surface be made optical?

By polishing or flame treatment after machining, not by cutting alone. That is a separate capability and belongs on the page.

Does annealing change dimensions?

Slightly, which is why it sits before final measurement rather than after. The sequence matters as much as the step.