Measuring the Mechanical Properties of Black Ash (Fraxinus nigra M.) grown in Northwestern Ontario

for use in Value Added Forest Products

Lakehead University, Thunder Bay, Ontario

Brent Forbes

Dr. Mathew Leitch

Dr. Chander Shahi

Black Ash

• Fraxinus nigra Marsh.

• Slow growing hardwood

– Wetland or mesic Sites

• .4% of provincial growing stock

– 20 million cu/m3 across the province

• Flooring, mouldings, furniture, handles, novelties

Ontario’s Forest Sector

• Vital component of the Canadian economy

– Province’s largest industry; $15 billion

• Economic downturn over the last decade

– 40 manufacturing facilities closed

• Worldwide demand for forest products is steadily increasing

• Become more competitive, capitalize on emerging markets and utilize Northwestern Ontario's vast wood supply

Research Objective

• Identification of underutilized species with potential for development and increased marketing potential

• Complete understanding of the variation in physical and mechanical properties of these species in Northwestern Ontario

• How this knowledge can be applied to end use attributes in valued added manufacturing

Methodology

Sample Preparation

Property Testing

• Modulus of Elasticity

• Modulus of Rupture

• Specific Gravity

• Janka Ball Hardness

• Compression Parallel to Grain

• X-Ray Densitometry

• Growth Rate

Methodology

Zones of

longitudinal

similarity

Zones of

mature &

juvenile wood

Wood

property

mapping

Zones of

radial

similarity

25

50

75

100

1 2 3 4

1. Juvenile core

2. Juvenile and

mature transition

3. Heartwood and

sapwood

4. Outer sapwood

juve

nile

wo

od

Results – Modulus of Elasticity

1 2 3 4

• 4,912 to 11,899 Mpa

• 8,307 Mpa average

• 3 distinct sites

• Longitudinal subsets

2

3

4

1

Results – Modulus of Rupture

1

2

3

4

• 48 to 114 Mpa

• 87 Mpa average

• 3 distinct sites

• Little variation in either direction

Results – Relative Density 12%

1

2

3

4

1 2 3 4

• 546 to 753

• 650 average

• 2 subsets of sites

• Consistent trends

Results – Janka Ball Side Hardness

1 2 3 4

• 1,544 N to 7677 N; 5410 N Average

• 2 subsets of sites

• Insignificant radial variation

• Homogenous subsets within stem

• Consistent longitudinal trends

2

3

4

1

1 2 3 4

Key Findings

• Site was significant for each of the selected properties– 3 distinct sites or 2 subsets– Prediction of properties based on site characteristics

• Consistent radial trends with little variation – No change from heartwood to sapwood, juvenile to

mature– Large heartwood area with consistent properties

• Little variation in longitudinal bolts– Consistent properties from stump to crown– First bolt shows potential for increased properties

• Homogenous wood properties with potential for predictive models

Utilization Potential

• Inherent properties and underutilized nature of black ash make it desirable for many products

• Growth rate plays a significant role in the inherent properties– Earlywood to latewood ratio

– Faster growth results in higher wood properties

– Potential for increased utilization in shorter time frames

• Higher hardness values then any species in the region provides potential for value added flooring

Future Research

• Completion of detailed property maps for black ash stems

• Stand attribute data

• Provide the value and quality of black ash stands, not just volume

• Understanding of potential yields, products and markets with a focus on smaller, value adding businesses in Northwestern Ontario

I would like to acknowledge the following:

• Lakehead University Wood Science and Testing Facility

• Ontario Ministry of Natural Resources

• Northern Ontario Heritage Fund Corporation

• FedNor and the Northern Ontario Development Program