Custom equipment guards, assembly display stands, and wall-mounted signs all require hole and slot drilling, and acrylic material has high brittleness, making drilling and slotting edges prone to chipping and cracking. Especially for thin sheets of 2-3mm and thick sheets over 15mm, the processing difficulty is higher. Dongguan Shangsheng Acrylic has developed layered processing standards for different thicknesses of board materials and hole sizes, covering tools, rotation speeds, feed methods, and clamping fixtures to completely avoid cracking defects. Below is a detailed explanation of the practical control plan.
Tool selection is the foundation for preventing chipping. Ordinary woodworking drills and metal helical drills must not be used for acrylic processing. Special acrylic drills have chamfered and dullened tips, reducing cutting resistance and preventing edge tearing of the board. For small holes with diameters of 3-8mm, use single-edged acrylic drills, and for large holes over 10mm, use expansion drills to enlarge holes in layers. For long rectangular slots, use narrow-blade flat-bottom milling cutters to avoid wide tools pulling the board in one cut. Tools must be kept sharp; dull tools will squeeze the board during cutting, resulting in radial fine cracks around the hole. The workshop replaces all tools with new ones every 200 pieces of board to eliminate dull tool processing.
Rotation speed and feed speed are adapted to the thickness of the board in layers: for 2-5mm thin boards, the main shaft rotation speed for drilling is set to low 8000 rpm, with slow and uniform feed, with a maximum depth of cut not exceeding 1mm per pass, and lifting the tool in segments to remove chips, preventing high temperatures from melting and cracking due to continuous cutting; for 6-10mm conventional boards, the rotation speed is 10000-12000 rpm with uniform continuous feed; for boards over 12mm, use a sloped progressive downward cutting method, not inserting vertically with force, drilling in 3-4 layers in steps, lifting the tool to cool after each layer to avoid heat accumulation and internal stress cracking. During slotting, cooling air is used throughout to promptly remove cutting dust and heat, as dust accumulation and friction against the inner wall of the board can cause scratches and discoloration.
Board fixing and pad protection are equally critical. Workstations for drilling and slotting are equipped with whole high-density rubber pads on the workbench, and the board is placed on the pad. When drilling, the drill penetrates the board and directly enters the pad, preventing bottom chipping caused by impact on a hard surface. Thin boards are fixed with full vacuum adsorption, leaving no suspended areas; thick boards are clamped evenly with multiple points, with clamping points avoiding the locations of holes and slots to prevent the board from warping during processing. When processing in batches, gaps are left between boards to avoid stacking, preventing lower boards from cracking due to pressure.
High-risk processes such as grooving for alien shapes and small corner holes require additional pre-processing steps. For edge and corner drilling, micro-guiding holes are drilled at the center of the points first, then expanded to standard dimensions to eliminate stress concentration at the corners; for long internal grooves, rounded holes are drilled at each corner before connecting the grooves to avoid cracks caused by straight-angle cutting. After processing, the plates should not be quickly pulled or bent, and should be placed in a normal temperature environment to release stress. The hole-bearing plates should be left static for more than 12 hours before bonding or printing.
Many small workshops directly use ordinary drills and no support plates for processing, resulting in large-scale edge chipping on the bottom of the holes, which can only be scrapped and redone. Shangsheng workshop uniformly implements three standards for all drilling and grooving processes: layered cutting, specialized tools, and support plate protection. The finished hole edges are smooth and free of cracks, requiring no additional grinding or repair. When designing drawings, customers can communicate for optimization in advance, leaving a safety distance of more than 3mm from the edge of the plates for holes to reduce the probability of cracking during processing, while also reducing scrap losses in custom processing and reasonably controlling the final product quotation.
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