Engraving on a CNC milling machine

Engraving by removing material with a milling cutter is widely used to make key rings, sign plates, advertising signs, logos, POS products, decorative relief patterns on frames and door leaves, gifts, promotional items and more. Metal engraving, for example, is so fine that it rivals the best work of professional engravers, and it is far more precise than any hand work. The technology is widely used for office sign plates, and a wide range of materials can be used. The usual requirement is that the material is soft, like aluminium, brass or plastic.

High-quality machining and precise control of the groove depth and engraving profile make it possible to create advertising signs, lamps and other edge-lit products.

 

Complex engraving for edge-lit light panels

Clear plastic with lettering or a design engraved on one side creates the illusion of floating, self-luminous letters or elements when lit from the edge. Clear acrylic sheets such as cast ALTUGLAS CN are a perfectly clean and transparent material designed for edge-lit illuminated advertising. Polystyrene, PVC, SAN, PET and other transparent materials are not clear enough for edge-lit products.

Engraving is done on clear cast acrylic, Altuglas CN, 3 to 25 mm thick. The customer can set any engraving depth from a fraction of a millimetre up to 5 mm. Bear in mind that a deeper cut makes the engraved groove wider (fig. 1). The groove width (L) relates to the depth (h) as follows:

• for a 36° tool: L = 0.64 h
• for a 60° tool: L = 1.15 h
• for a 90° tool: L = 2 h
  
  
  
  
  
  When using engraved plastic as the face of an edge-lit panel (acrylic light panel), follow these recommendations:
  
  
• To avoid shadows in the corners of the acrylic light panel, choose the length of the lit side from this series: 165; 240; 320; 470; 620; 930; 1230; 1530; … mm (standard lamp length + 30 mm).
• The other dimension must allow for the depth to which the plastic sits in the profile. For standard profiles this is 12 mm.
• Use the table to choose the plastic thickness:
  
  

  Cross dimension (mm)	Recommended plastic thickness (mm)
  up to 300	6.0
  300–500 mm	8.0
  500–800 mm	10.0
  Over 800 mm	12.0

  
  
  
• For sizes over 1 m, use lighting on two sides.
• All plastic edges must be polished. Edges without lighting must be covered with Oracal 352-01 mirror film.