CNC machining polycarbonate and water jet cutting polycarbonate

The ultra-thick polycarbonate sheet is compatible with various cutting methods like electronic cutting machines, plate cutting machines, CNC milling, and water jet cutting. Among these, CNC milling and ultra-high-pressure water jet cutting are highly recommended for thick polycarbonate.

Waterjet cutting come in two types: Abrasive Water Jet and Pure Water Jet Cutting. Pure waterjet cutting helps maintain the physical and chemical properties of the ultra-thick polycarbonate sheet and provides a superior, polished surface. For polycarbonate sheets thicker than 200mm, abrasive waterjet cutting offers high speed and pressure, aiding in efficient cutting. Finer abrasive particle sizes result in a better polishing effect and improved cutting surface finish. With waterjet technology surpassing ultra-high pressures of 520MPa, it can effectively cut ultra-thick polycarbonate sheets exceeding 300mm in thickness.

When drilling holes in thick polycarbonate sheets, use a twist drill with a spiral angle between 12 to 16 degrees for easy chip removal. Keep the drill bit and surface cool, and ensure the groove is smooth and clean. For larger holes, try distributed drilling or hollow drills. Use sharp bits to prevent damage. Keep holes away from the sheet edge and space them apart. Consider bolt holes with a slightly larger diameter than the bolt for thermal expansion.

To make thick-walled polycarbonate cylindrical transparent parts, excavating holes, semi-perforated parts, or internally hollow polycarbonate transparent components, boring is a typical CNC cutting for internal processing of transparent materials. By utilizing CNC boring processes along with polycarbonate milling, drilling, and grinding methods, suitable tools can be used for thick polycarbonate sheet machining. Boring can be divided into through-holes, tapered holes, and non-through-holes based on polycarbonate sheeting thickness , enabling the creation of arbitrary internal diameters and wall thicknesses for tubular components.

Polishing can be carried out using traditional machining methods like milling, grinding, coarse polishing, and fine polishing. The process includes grinding depths of 0.06-0.2mm and 0.01-0.05mm for coarse and fine polishing, respectively. During grinding, monitor grinding wheel speeds and cooling of contact surfaces. For Excelite thick polycarbonate sheeting, mechanical polishing can attain 610-750r/min or use wool pad polishing. When dealing with smaller areas, manual polishing can be done using polishing paste and cotton with uniform pressure. If it’s your first-time do ultra-thick polycarbonate machining, try some offcut material out first to understand material and tools and reliable machining techniques.

Annealing is a standard procedure to make thick polycarbonate sheet and general purpose polycarbonate sheet. Yet, in high-end or ultra-precise applications, further annealing might be needed. This process involves slowly heating the thick polycarbonate sheet to 100±3℃ at 1℃/min and maintaining this for 10min per 1mm thickness. Then, it cools slowly at a rate of 10℃/h back to room.