Design, Construction, and Characterization of a Novel Robotic Welding Fume Generator and Inhalation Exposure System for Laboratory Animals

Abstract

Respiratory effects observed in welders have included lung function changes, metal fume fever, bronchitis, and a possible increase in the incidence of lung cancer. Many questions remain unanswered regarding the causality and possible underlying mechanisms associated with the potential toxic effects of welding fume inhalation. The objective of the present study was to construct a completely automated, computer-controlled welding fume generation and inhalation exposure system to simulate real workplace exposures. The system comprised a programmable six-axis robotic welding arm, a water-cooled arc welding torch, and a wire feeder that supplied the wire to the torch at a programmed rate. For the initial studies, gas metal arc welding was performed using a stainless steel electrode. A flexible trunk was attached to the robotic arm of the welder and was used to collect and transport fume from the vicinity of the arc to the animal exposure chamber. Undiluted fume concentrations consistently ranged from 90-150 mg/m(3) in the animal chamber during welding. Temperature and humidity remained constant in the chamber during the welding operation. The welding particles were composed of (from highest to lowest concentration) iron, chromium, manganese, and nickel as measured by inductively coupled plasma atomic emission spectroscopy. Size distribution analysis indicated the mass median aerodynamic diameter of the generated particles to be approximately 0.24 microm with a geometric standard deviation (sigma(g)) of 1.39. As determined by transmission and scanning electron microscopy, the generated aerosols were mostly arranged as chain-like agglomerates of primary particles. Characterization of the laboratory-generated welding aerosol has indicated that particle morphology, size, and chemical composition are comparable to stainless steel welding fume generated in other studies. With the development of this novel system, it will be possible to establish an animal model using controlled welding exposures from automated gas metal arc and flux-cored arc welding processes to investigate how welding fumes affect health.

Immunotoxicology of arc welding fume: Worker and experimental animal studies

“…Electron microscopic analyses (Figure 1) have revealed that most particles generated during arc welding processes are arranged as chain-line agglomerates of smaller, spherical primary particles (Zimmer and Biswas, 2001;Antonini et al, 2006). Particle formation during arc welding first includes nucleation, a process by which high temperature metal vapors are transformed into primary particles, followed Stick welding Simplest and most widely used process, inexpensive, weld is produced by heating an arc between a flux-covered metal electrode (consumable) and the work, shielding is obtained from decomposition of the flux covering, can weld all ferrous metals in all positions.…”

Sustainable Technologies for Thick Metal Plate Welding

“…1 System boundary and inputs and outputs of welding processes (Sproesser et al 2015) Fume emissions are calculated according to emission rates of representative processes (power range and transfer mode) from literature (Pohlmann et al 2013;Rose et al 2012) and are displayed in Table 1. The chemical composition is assumed to be mainly from iron oxide (Antonini et al 2006;Jenkins and Eagar 2005).…”

“…Welding processes generate a complex mixture of fumes (respirable and ultrafine particles) as by-products composed of an array of metals volatilised from the welding electrode or the flux materials incorporated (Antonini et al 2006). Welders' exposure to welding fumes is often associated with acute and chronic lung damage, lung cancer and other potential harm on heart, kidneys and central nervous systems (Gonser and Hogan 2011;Canadian Centre for Occupational Health & Safety 2016).…”

Determination of Customer Requirement for Welding Fumes Index Development in Automotive Industries by using Quality Function Deployment Approach

“…However, welders are not a homogeneous group, and the potential adverse effects of welding fume exposure are often difficult to evaluate. Differences exist in welder populations, such as industrial setting, types of ventilation, type of welding processes and materials used (Antonini et al, 2006). Indexing exposure by job type or process is almost impossible to implement.…”