The aim of this thesis is design and simulation of an automated system for separation of plastic resins from each other in municipal wastes. In order to do this, the existing methods of plastic resins separation have been reviewed and a proper system has been proposed for this task. The proposed separation system was simulated using Visual Nastran software. This system includes three units, namely identification, control and throw unit. The principle of operation of identification unit is based on NIR reflectance spectroscopy. The reflectance spectrum of several various plastic samples from PET, HDPE, PVC, PP and PS were taken in different wavelength domains. On the basis of these reflectance spectrums, two separate algorithms have been obtained for identification of plastic resins from each other. These two algorithms are called “Two Filters” and “Second Derivative”. In "Two Filters" method algorithm, two specific wavelengths of spectrum in the near infrared domain have been utilized. Also, in "Second Derivative" method, the majority of this wavelength domain has been used. By surveying the effect of various parameters such as surface pollution, sample thickness and existence of label and cap, it was shown that both algorithms have the high efficiency in identification of resins. The algorithms have been developed for identification of HDPE and PP resins based on their colors. The spectrum of visible domain has been used in them. Furthermore, an algorithm was developed for identification of plastic resins, glass and paper so called “Four Filters”. The LabVIEW software and data acquisition card are used in control unit. The main task of control unit is execution of identification and recognition algorithms of desired material, and then the transmission of suitable command to the throw unit. After the necessary surveys, the "Advantech PCI-1710" data acquisition card was selected for control unit. This card is very suitable in data reception from identification unit and its transmission to the computer, due to its properties. This card has been also utilized for transmission of command to throw unit. The method of card configuration for computer was surveyed. The programs of data reception via card and command transmission have been developed in LabVIEW software and by using the card driver software. In addition, the identification programs based on the obtained algorithms for identification unit were developed in LabVIEW. In throw unit, the possibility of utilization of electro pneumatic valve has been surveyed.Finally,it can be said that the proposed separation system is a fast,accurate,proper and ideal system for separation of plastic resins. KeyWords: Plastic,Separation,NIR reflectance spectroscopy,Visual Nastran,LabVIEW