When
working with Homalite H-100, H-101 or H-911 sheet stock, it's important
to use the proper methods for machining hard plastics. By following
these guidelines, you should get superior results:
- Protect the plastic surface with masking.
- Use fixtures and/or clamp down the plastic.
- Minimize vibration between tool and material.
- Keep tools sharp and accurately dressed.
- Use recommended machine speeds.
- Feed evenly at slow-to-moderate rates.
- Take shallow cuts.
The material should be cooled by using water or air to cool the area
contacting the cutting tool. While Homalite plastics don't drag, fuse
or gum like many thermoplastics, avoiding overheating during fabrication
reduces stress build-ups.
Machined surfaces, edges and drilled
holes having any chips or roughness should be smoothed by sanding
or filing. Useful tool life may be extended with acetone cleaning.
Here are a few other key considerations:
Cutting:
Use diamond-coated circular saw blades
to provide a smooth cut. Water is recommended for cooling and reducing
dust. Band saws of at least 12 teeth per inch can be used for rough-cutting
parts.
Drilling:
Carbide-tipped and high-speed steel
drills are suitable for drilling Homalite plastics. Points should
be properly ground, with a 59° angle; the rake should be heavy
with 10° to 15° clearance. Drill speeds can range from 1,000
to 2,500 RPM. Holes larger than 1" can be cut with a hole saw.
In all cases, edges should be smoothed with a file or tapered stone.
Routing, shaping
and edge trimming:
These can be done with rotary cutters,
end mills, jointers, files or abrasive wheels. Tools should be operated
in the 3,000 5,000 RPM range for best results.
Punching:
Due to the specific properties of H-100,
H-101 and H-911, punching is not recommended.
Cleaning:
As indicated above, finished parts may
be cleaned with soap and water, chlorinated solvents, standard glass
cleaning preparations, and other non-abrasive cleaning formulas. Soft,
clean paper tissues are best for cleaning and wiping.