A Novel Automated System for the Handling of Car Seat Wires on Plastic Over-Injection Molding Machines

Abstract

The structure of car seats is becoming increasingly complex, with mixing of wire conformation and plastic injection. The plastic over-molding process implies some labor, which can be reduced if novel solutions are applied in this manufacturing area. The handling of the wires used in car seats is the main problem identified in the process, wasting time both in the feeding and in the extraction of the molds used in the wire over-molding process. However, these machines are usually extremely compact and the free space around them is too short. In classic molding injection machines, there are just two half-molds, the female, and the male. In the over-molding process of wires used in car seats, three half-molds are used in order to increase the cycle time. Thus, to solve this problem, the classic robotic solutions are not appliable due to lack of space and elevated cost. This work describes the development of an automated solution able to handle the wires in both the feeding and the extracting phases of the production cycle, avoiding the traditional labor costs associated with this type of machine. Departing from an industrial need, the developed novel solution is described in detail and can be successfully adapted to other situations of low added-value products where it is needed to increase the productivity and competitiveness of the product. The system developed uses mechanical and pneumatic solutions which, combined, can be used to solve the identified problem, occupying a restricted space and requiring a small budget. This solution can be translated into guidelines that will allow the analysis of situations where the same system can be applied.

A new approach to increase the environmental sustainability of the discharging process in the over-injection of conduits for bowden cables using automation

“…This work presents a solution, based on automation, to reduce energy consumption and increase productivity of polymer injection machines. Indeed, this method of employing automation to solve quality and production, without the need for robotics and complex/expensive solutions is quite beneficial, [41][42][43] being applied to a wide variety of manufacturing processes. 44,45 In the present work, the employment of the developed concept, using automation, produced very satisfactory results.…”

Increasing the Sustainability of Manufacturing Processes in Plastic Injection: Recovering Out-Of-Service Robots to Eliminate Manual Assembly Operations

“…Furthermore, the complexity of this concept is more modest than that performed in this work. On the other hand, Silva et al [8] presented a ROI of 5 months for the automation of a process linked to the over-moulding of metallic wires with plastic, which automation involved the orderly arrangement of wires for collection with a gripper, and a dedicated gripper design for feeding and collecting the product. However, the value of the ROI obtained through this work (12 months) is lower than several other works where automation also aimed to increase the productivity and competitiveness of products, although without environmental concerns.…”

“…However, the plastic injection process is not confined to the injection operation itself, especially in more complex parts commonly supplied to the automotive industry, requiring its extraction from the mould and interconnected operations, such as the inspection and assembly of other components. In this perspective, the help of automation and robotics has been proven to be fundamental [8].…”

“…Seeber et al [11] studied the physical interactions between the different resources existing in a workstation, trying to establish methodologies that help Process Engineers in the design of these workstations. Silva et al [8] developed an automatic solution for inserting previously shaped wires into a mould, where plastic over-injection was performed on the ends of these wires. In this case, the authors opted for automation without robotics, as the setup time needed to change production from one reference to another was small, and changes in the product to be manufactured were infrequent.…”

“…In this case, the developed system could be manufactured at a significantly lower cost than an industrial robot. Furthermore, the system occupied less space, allowed for a faster cycle time than a robot, could be perfectly adjustable to the cycle time of the equipment responsible for forming the wire, and sorted the bent wires, placing them in the supply position for the next process, developed in [8]. Regarding the savings achieved by this solution, the return-on-investment calculated for the new equipment was less than 9 months, which clearly shows the advantages provided by the carried-out study.…”