Date of Award

2019

Degree Type

Capstone Project

First Advisor

Bahram Nassersharif

Abstract

The Toray Plastics plant in Kingstown produces plastic films used for food packaging. The production process involves using high speed rollers to roll film to prepare for shipment of the product. However, there is a maximum speed that the rollers cannot exceed; higher speeds result in vibration between the film roller and the roller that supplies force to the film roller, known as the nip roller. The nip roller is used to force air out from between each layer of film. When vibrations occur, air pockets form in the rolls that cause the plastic to roll unevenly, ruining the product. The solution proposed by Toray is to redesign the nip roller mounting arm to eliminate vibrations at higher speeds.

The process of solving this problem began with background searching. Literature and patent researches were conducted to explore previous inventions and articles related to production rollers, and then ninety conceptual designs were created by the team. Of these ninety designs, three were chosen as the most effective. Through engineering analysis, the diagrams, and simulations, a final design was developed. The new design involves the use of torque to create added force at the point of contact between the nip roll and the customer roll. The redesigned arm utilizes a horizontal beam that is loaded with weight. Along with this weight, an air piston is mounted to the horizontal arm, which greatly increases torque at the pivot point. The added torque at the pivot point is translated vertically up to the point of contact, where nip force is maximized.

To prove that this design works, a prototype was built, made almost entirely out of 8020 Aluminum, excluding connecting pieces and a few bolts. The redesigned arm is simulated by two pieces of 8020 aluminum that are connected at a 90-degree angle. Five- and ten-pound barbell weights are loaded at the end of the horizontal piece, and a 2” compressive air piston is mounted to the bottom of the same piece. The combination of these two forces mimics the effects of heavier weights and a larger piston that will be used in the full-scale model. The prototype was built at half scale of the full-sized mounting arm and it is secured in a very stable cradle made of 8020 Aluminum. Prototype testing produced data that, when scaled up, exceeds the target nip force that Toray plastics requested to eliminate arm vibrations at higher roller speeds.

Comments

Sponsor: Toray Plastics Inc.

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