Design and Development of an Almond Kernel Sizing Unit Using Visual Sizing Function and Biomechanical Properties

Document Type : Research Paper


1 Associate Professor, Department of Mechanical Engineering of Biosystems, Shahrekord University, Shahrekord, Iran

2 MSc of Mechanical Engineering of Biosystems, Office of Agricultural Mechanized Technologies, Organization of Chaharmahal and Bakhtiari Province, Shahrekord, Iran


The most important part of the agricultural products sizing machines, is sizing unit. The main purpose of this research was to determination some engineering properties of almond kernel and design and manufacturing of sizing unit for use in a sizing machine. To choose the best sizing mechanism, the concept of visual sizing parameter function was used. The results showed that the thickness and length dimensions, with coefficients of 0.647 and 0.353 respectively, play the most important role in the sizing of almond kernels. In addition, statistical studies showed that the thickness dimension, in terms of having the lowest dispersion and standard deviation of data, is also the best dimension to design the device. To determine design parameters, some physical and mechanical properties of three varieties of almond kernel namely Sefid, Sangi and Mamaei, at three moisture levels (3, 9 and 15%), on three surface textures including polished steel, Teflon and wood were evaluated. The results showed that with increasing levels of humidity, the friction coefficient in all three varieties and on all three surface textures, showing an increasing trend while the force needed to break almond kernels showing a decreasing trend. Based on the obtained results, sizing unit using a pair of diverging polished steel rollers, was chosen as the best option and after determination of other attributes such as appropriate length and diameter for rollers, was used in special device for sizing almond kernels.


Main Subjects

Altuntas, E., Gercekcioglu, R. & Kaya, C. (2010). Selected mechanical & geometric properties of different almond cultivars. Journal of Food Properties, 13, 282–293.
Aydin, C. (2003). Physical properties of almond nut and kernel. Journal of Food Engineering, 60, 315-320.
Bart-Plange, A. & Baryeh, E. (2003). The physical properties of category B cocoa beans. Journal of Food Engineering, 60, 219-227.
Borges, A. & Peleg, M. (1997). Effect of water activity on the mechanical properties of selected legumes and nuts. Journal of the Sciences of Food and Agriculture, 75, 463–471.
Food and Agriculture Organization. (2010). Faostat. Crops Production. Retrieved April, 14, 2010, from
Ghanbarian, D., Kolchin, N.N., Hasan Beygi S.R. & Ebrahimi R. (2008). Design and development of a small potato-grading machine using capron net. Journal of Food Process Engineering 33, 1148–1158.
Islamic Republic of Iran Ministry of Agriculture. (2011). Iran's Agricultural Statistics. May 6, 2011, from (In Farsi)
Jarimopas, B., Toomsaengtong, S. & Inprasit, C. (2007). Design and testing of a mangosteen fruit sizing machine. Journal of Food Engineering, 79, 745–751.
Khazaei, J., Borghei, A.M. & Rasekh, M. (2003). Determination of some physical and mechanical properties of almonds. In: Iranian journal of agriculture science, 9 (3), 11-33. (In Farsi)
Khazaei, J., Rasekh, M. & Borghei, A.M. (2002). Physical and mechanical properties of almond and its kernel related to cracking and peeling. In: Proceedings of ASAE Annual International Meeting, 28-31 July, Chicago, Illinois, Usa.
Kolchin, N.N. (1982). Complex machine and implements for postharvest operations of potatoes and vegetables, Machinestroienie, Moscow.
Mohammadi Dehcheshmeh, A. (2009). Evaluation of physical and mechanical properties of almonds (Shahrood 12 & Mamaei Varieties). MS.c of Farm Machinery Thesis, University of Shahrekord, Shahrekord. (In Farsi)
Mohsenin, N. N. (1986). Physical properties of plant and animal materials (2nd Ed.). New York: Gordon & Breach Science Publisher
Peleg, K. (1985). Produce Handling, Packing and Distribution. Westport: Avi Publishing Company, Inc
Sacilik, K., Ozturk R. & Keskin, R. (2003). Some physical properties of hemp seed. Biosystems Engineering, 86 (2), 191–198.
Stroshine, R., Hamann, D. (1995). Physical properties of agricultural materials and food products. Purdue University, West Lafayette, Indiana.