Indian Journal of Fibre & Textile Research Vol. 33, March 2008, pp. 93-96 Design of an automatic parallel type jute bag making machine Abhijit Mahapatra a , Umesh S Patkar & Rajesh W Lanjewar Central Mechanical Engineering Research Institute, Durgapur 713 209, India and Shibendu Shekhar Roy National Institute of Technology, Durgapur 713 209, India Revised received 3 July 2007; accepted 20 September 2007 An attempt has been made to design a jute bag making machine in which all operations, like fabric cutting, hemming, mid-folding and herackle stitching, are carried out automatically in a single setup to produce parallel type jute bags of industrial standards. The salient design features of indigenously developed first prototype of an automatic jute bag making machine have been described. The proposed machine comprises four major units, like fabric cutting and conveying unit, simultaneous mouth edge folding and stitching unit, mid folding and material guidance unit, and simultaneous parallel side stitching unit. The motor drives, sensors and actuators are synchronized and automated by programmable logic controller. The proposed machine can produce bags of uniform quality with mouth edge folded, hemmed and parallel side stitched in one single integrated setup at higher productivity compared to present manual system. Keywords: Actuator, Jute bag, Parallel type bag, Programmable logic controller, Sensor IPC Code: Int. Cl. 8 D05B Jute bags are being preferred to replace plastic bags for packaging of agricultural products, like sugar, vegetable and fruits, because of growing awareness about the harmful effects of plastic bags. The present demand of jute bags cannot be met with the existing state-of-the-art followed in jute industries for bag making because the bags are manufactured by stand- alone cutting and sewing machine with the help of number of operators and helpers. An industrial survey reveals that a balanced setup for making parallel type jute bags consists of one shear cutting machine, twelve numbers of single needle double thread chain stitching machines and six machines for single needle double thread overlock stitching. All operation, such as material movement, edge folding or mouth hemming, feeding to stitching machines, mid-folding of bags and herackle stitching are carried out manually. Hence, the existing system cannot avoid the drawbacks in the manufacturing of jute bags. Firstly, the quality production rate depends on the efficiency and willingness of the operators. Secondly, the above- mentioned operations are labour intensive. Thirdly, the manufacturing plant occupies large floor area. To overcome these drawbacks, fully automated bag making machines have been a long felt need. However, from prior art details, it is found that there is no exclusive machine of this type specified for bag making which is capable of doing all operations right from mouth hemming with edge folding to parallel side stitching in a single set up automatically in a synchronized manner. However, there are few designs of semi-automatic or partly automatic machine for making bags from plastic mesh, fabric, cloth, etc. One US patent 1 discloses a bag making machine wherein bag is made from flat tubular web of plastic. Another US patent 2 describes a bag stitching machine wherein a fabric material is transported to a fixed sewing machine. Here, one seam of the bag is sewn followed by transportation at 90° for sewing of next seam. Such types of bags are commonly known as ‘L’ type bags. This machine is not suitable for parallel sides stitched and mouth hemmed bag that is commonly known as parallel type bag. Other related patents 3,4 show an apparatus for producing pillowcases, bags and the like wherein continuous material is cut into individual sections before folding. The bags are sewn by moving sewing machines. This system may be suitable for manufacturing pillowcases and bag made of stiffer fabric but not suitable for manufacture of jute bags of the intended specifications from coarse and less stiff jute fabric. The machine does not have any provision for mouth edge folding which is essential for the parallel type jute bag. Another patent 5 shows the bag making machine in which the fabric material is unwound and folded before being taken to other operations, such as cutting and two side stitching. In this machine, simultaneous hemming and parallel sides stitching are not possible. Hence, this machine is not suitable for producing parallel type bags. ___________ a To whom all the correspondence should be addressed. E-mail: abhi_mahapatra@yahoo.co.in Therefore, in the present work, an indigenous parallel type jute bag making machine has been