Experimental study of laser–cheese interaction for making of thin cheese slices with complex shapes

Current cheese-handling machines are not flexible to cut thin cheese into complex shapes. It is desirable to have a single versatile and inexpensive tool that is capable of shaping thin cheese slices into customer-designed shapes for dairy industry. Ultraviolet (UV) laser photo-ablation (a low-temperature cutting process) could offer an advantageous solution. This paper studies the wavelength and energy fluence dependence of UV laser drilling and cutting of cheese with a pulsed Nd:YAG laser at wavelengths of 355 and 266 nm. While damages and burns occurred around and inside the cutting cross-section with the laser beam of 355 nm, the laser beam of 266 nm produced high quality cutting and drilling and much larger cutting depth. Complex patterns, transported from computer aided design (CAD), were fabricated on cheese with the laser beam of 266 nm. The cutting speed was still low since the repetition rate of the laser used in this study is only 20 Hz. With ultraviolet (UV) laser sources of higher repetition rate and higher power, the process can be improved significantly to become cost-effective.