Arconic – Kawneer, Alberta

Location: Lethbridge, Alberta
Owner/Operator: Arconic – Kawneer

How HGC Addressed Workplace Noise Control for CNC Manufacturing Operations in Lethbridge, Alberta

The Kawneer manufacturing facility in Lethbridge, Alberta is the Canadian manufacturing hub of Arconic’s Building and Construction Systems business, producing aluminum extrusions, building products, and OEM extrusions for architectural and commercial construction markets across North America. Kawneer, an Arconic company, is a global supplier of architectural aluminum systems including storefronts, entrances, curtain walls, windows, and framing used on schools, offices, healthcare facilities, and other non-residential buildings. The Lethbridge plant is one of Kawneer’s major North American manufacturing sites and supports both Kawneer’s own architectural product lines and external OEM extrusion customers.

HGC Noise Vibration Acoustics was retained by Arconic – Kawneer to assess workplace noise conditions associated with two Tekna CNC machining centres located in the door manufacturing area at the Lethbridge facility. The machines are used in the production of metal door frames and generate varying sound levels depending on the machining activity, product series and material being processed. Workers near the CNC area had identified sound levels that could affect communication and comfort during certain production activities, particularly where extended use of hearing protection may be required.

The purpose of the assessment was not simply to document existing noise conditions, but to identify practical engineering noise control options that could support a safer, more functional workplace. Arconic wanted to understand whether acoustic treatments, barriers, curtains or more complete enclosure strategies could reduce noise exposure around the CNC machines while preserving access for loading, unloading, maintenance and visual supervision of equipment.

HGC’s Workplace Noise Assessment Approach

HGC began with a detailed site investigation at the Lethbridge manufacturing facility. During the visit, HGC personnel observed CNC operations, reviewed the surrounding production layout, identified typical worker and operator positions, and completed sound level measurements during representative machining activities. The measurement campaign was designed to capture the character of the sound produced during milling, cutting and drilling, and to distinguish direct machine noise from the contribution of the surrounding industrial space.

The assessment was conducted with reference to the Occupational Health and Safety Code, Alberta Regulation 191/2021, as amended by Alberta Regulation 210/2024, Part 16 – Noise. This regulation establishes employer duties for reducing worker noise exposure, requires noise exposure assessment where workers may be exposed above prescribed thresholds, and identifies noise exposure limits for Alberta workplaces. It also references accepted measurement procedures and instrumentation requirements, including CSA, ANSI and IEC standards for occupational noise measurement.

Modelling CNC Noise Propagation and Workplace Acoustics

Following the site measurements, HGC developed a computational acoustic model of the CNC area and adjacent door department. The model incorporated the facility layout, machine locations, worker positions, surrounding wall conditions, floor and roof surfaces, and the partial enclosure conditions already present in the area. By combining site-measured sound data with a three-dimensional noise model, HGC was able to evaluate how CNC noise travelled through the workspace and how various mitigation concepts could influence the sound environment at operator and nearby worker locations.

This modelling process helped distinguish between strategies that would provide meaningful improvement and those that would have limited effect. For example, adding absorptive treatment to surrounding surfaces can help reduce reverberant build-up in some industrial spaces, but it does not always address the direct sound path between a high-noise machine and the worker. In this case, HGC’s analysis indicated that acoustic absorption alone would not provide a sufficient or readily noticeable reduction for CNC operators.

Recommended Noise Mitigation Strategies for CNC Machine Operations

HGC evaluated barrier-based approaches that could interrupt the direct path of sound from the CNC machines to workers. One option involved a heavy acoustic curtain system positioned around the perimeter of the CNC work area. This approach would combine absorptive facing with barrier mass, helping both to absorb sound energy and block line-of-sight noise propagation. The curtain concept was considered especially relevant because it could potentially be mounted on movable track systems, allowing the operating area to remain accessible for loading, unloading and maintenance.

HGC also assessed the potential benefit of a more complete acoustic enclosure around the CNC machining centres. The report noted that a custom enclosure would need to be coordinated with the equipment manufacturer to confirm that machine operation, access, ventilation, visibility and safety systems would not be compromised. Where visibility is required, glazed components could be considered, provided the enclosure remains continuous and well-sealed. HGC recommended that the inside of any enclosure incorporate absorptive finishes to reduce sound build-up within the enclosed space.

Enhancing Worker Communication, Safety and Operational Functionality

The recommended mitigation concepts were intended to support a more manageable acoustic environment while recognizing the realities of an active manufacturing facility. In industrial settings, noise control measures must be technically effective, but they must also preserve workflow, equipment access, safety-zone integrity and operator visibility. HGC’s assessment therefore focused on options that could reduce exposure from the CNC operations while remaining compatible with day-to-day production requirements.

Acoustical Services Provided by HGC Noise Vibration Acoustics

• Workplace noise assessment for CNC machining operations

• Review of Alberta OHS Code Part 16 – Noise requirements

• On-site sound level measurements and operational observations

• Assessment of worker/operator noise exposure conditions

• Computational acoustic modelling of CNC equipment and surrounding work areas

• Evaluation of acoustic absorption, curtain barrier and enclosure concepts

• Conceptual recommendations for practical industrial noise mitigation measures