Acrylic sheet

Common holes can be done by common twist drills, the cutting dip angle of which shall be grinded to 0, the chisel dip ( chisel tip angle) shall be 130. Standard high speed twist drill can also be used, but it needs not grinding. Too much heat generated at the drilling heat will easilly cause stress cracks. It is suggested that non-chloridized cooling agent(e.g. water) should be used to reduce stress.

A kind of very useful fast processing mode, it uses model railing lather, associated with cutting tools suitable for wooden processing. The speed should be fast. The linear speed of cutting tools shall be 1500m/min and higher. The tools should be sharp. It can be kept dry in procesing because the cutting tools can take the scraps away. Double-edge cutting tools are easier installed and used than many-edge cutting tools.

Acrylic sheet can also tap screw thread but coarse thread is preferred, with brass screw. Steel screw cann’t be used. In spite of that, the stressed part should be bonded instead of using screw. Besides that, countersunk screw cann’t be used for the over stressed positions, or it will likely cause break of acrylic sheet. If dismounting happens frequently. It is proposed that ad screws should be used for fixing instead of common screws.

The lathe for metal proessing is suitable for acrylic sheet, the sanding and polishing of knives are very important, the sanding degree shall be suitable for brass. The knife tip shall be sharp and the edge shall be polished. High-speed steel cutting tools are more suitable than carbonized tungsten cutting tools. If higher surface finish required. Diamond cutting tools can be used. If the work piece can be always kept cooling, cutting speed is not a key factor.

Mechanical carving machine or laser carving machine are both suitable for aclylic sheet. On different sheet, the laser carving has different effects. The surface of extruded sheet is bright; cooling agent is not needed in carving when the surface of cast sheet surface is not bright. Spray compressed air to the knife head to cool it down and blow off scraps.

The effect is very good when wax or paint is used for color filling treatment on the carved patterns. If paint is used, it should be dried at least for 3 hours with circulating air under 50-60 0C. If it is used outdoors, annealing treatment shall be done before color filling or painting.

Standard high-speed carpenter special type milling machine can be used for acrylic sheet and the speed need not regulating. Diameter of knife6-12mm, ＞12mm, rotating speed of axle center: 24000rpm, 18000rpm; double-edge knife is preferred and the back clearance angle is burnished to 12 0 . New type numerically controlled milling machine has high automation level and wide speed control range. Generally the special type milling machine does not need water cooling, but compressed air flow can cool down knife and blow off scraps.

Machine sandinguse motorized grinding wheel (3000rpm, diameter250mm), belt sand mill(350m/min). No water is used in polishing and the force should be proper to avoid over hot. After sanding, if bonding or silk screen printing is needed, annealing treatment shall be done. Manual sanding shall be from rough to fine, from deep to shallow, from internal to external ; polish the edge in a ring shape. Before sanding, neaten edges vertically with sharp hard blade. File round file, flat file and semi round file.
Rougn polishingremove obvious flaws ; fine polishing resume the original luster of acrylic surface. Polishing with fabric dics-use polishing wheel ( 1500rpm) with diamond suitable for straight edge polishing with width less than 10mm, fast and good effect. The surface finish is subject to the diamond selected. Polishing with diamond does not generate stress on average. Manual polishing suitable for light scratch or other unobvious damages. If the scratch is deep, use sand paper for wet