One of the issues I have been facing is that the laser cut flaps cut quite well but the black finish is damaged by the high temprature gases that are formed under the cut material.
When the laser point hits the polypropylene it rapidly heats and vaporises the plastic, creating hot gas which pools under the material in the honey comb grill. This leaves a white smokey debris that can be cleaned off but also leaves heat damage.
For many materials this isn’t really a problem because the melting temperature is higher and many materials come with protective plastic stops scratching but also offers protection against this gas. Polypropylene however doesn’t come with this protection as 0.8mm thicknesses, additionally polypropylene has a particularly low melting temperature of only 150ºC which means at anything over 100ºC it can easily begin to effect the finish of the plastic.
The solution to this is to use die cutting, which would have been the method of choice for Solari, Kone and other manufacturers as it allows hundreds of flaps to be produced per minute and the cost of tooling a cutting die reduced the more you use it, while the laser cutter costs remain constant.
With this in mind I asked around some graphic designer friends who they used for die cutting and one came back and suggested Medway Cutters I asked them for a quote for a die cutter for personal use with my design as well as some small runs having them do the work, prices include VAT, exclude postage:
- 1 up cutter = £90
- 100 flaps = £96 (96p per flap)
- 500 flaps = £222 (44p per flap)
I have asked them for a sample of the quality and how many flaps they expect the 1 up cutter would last, looking at these costs it is pretty expensive and doesn’t seem to run with what the cost’s I would have expected, additionally it doesn’t match the laser cutting costs:
Cutting time: 10p per flap (5 minutes x 75p = £3.75 for 36 flaps per sheet)
Material: 5p per flap (£1.63 per sheet ÷ 36 flaps)
Total: 15p per flap (£7.50 per module)
The flap design is probably going to remain the same now so here is the pattern: