Home

Automated Universal Deflasher for Blow Molded Product

Background

GAMMA2, Inc., currently headquartered in Carlsbad, CA, is a plastics manufacturer specialized in producing a wide variety of pet food containers. The majority of the products are produced using a blow molding process, see Fig. 1. Melted plastic is extruded into a hollow cylinder shape, or parison, and is dropped and clamped into the mold. Compressed air is then used to blow and shape the plastic within the mold. At the end of the blow molding cycle, excessive materials adhered to the product, or flash, need to be trimmed (de- flashed) before assembly (Fig. 2).

Objectives

The objective of this project is to design, build and test an automated deflasher that trims the excessive materials(flash) on the finished plastic pet food container. For the result, the deflasher has to be easy-to-use, reliable, safe and stable. As for now, the products are trimmed manually by operators. The process is expensive and time-consuming. The success of this MAE156 project can significantly decrease the time of the deflashing and optimize the efficiency of the production process. As a result, the cost of production of the container will be dropped so that it would be more profitable for the sponsor.

Description of the Final Design

The final design solution incorporates four major parts including the pneumatic driven clamp, pneumatic driven cutters, a PLC control system and an aluminum frame. The aluminum clamp was shaped to match the contour of the container so that the container can be clamped tightly and stably during the process of trimming. The stainless steel cutters included a top cutter and a bottom cutter with different shapes. Stable compressed air is also required to power both the clamp and the cutters. The whole system was controlled by a PLC system called WindLDR which is designated to pneumatic driven system like this deflashing machine To ensure safety, during the process of exchanging trimmed container and to-be-trimmed container, the power of the entire system would be shut off. The operator can only start powering the machine until the protection case is closed.

Fig 3: CAD Assembly (no safety case)

CAD Animation

           Total Cycle Time: 20 s

The speed and the pressure of the pneumatics were chosen regarding the safety concern and to maximize the cutting pressure. The air pressure at the factory of GAMMA2 may be bigger than the available one at the machine shop of UC San Diego. Higher air pressure may be used for the pneumatic driven cutters to optimize the cutting. Below are a few pictures of containers before and after being deflashed by the deflashing machine.

Safety Features:

                  Door Switch                                                         E-STOP

Movie of the Final Machine

Manual Demo                                    

Programed Demo

Executive Summary

https://drive.google.com/open?id=0ByLVjppuH0g6bEFMWWlMT21nZFU