Western hemlock

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West Coast Hemlock (Tsuga heterophylla)

Description

A strong, tall hemlock, Tsuga heterophylla, native to the northwestern Pacific coast of Canada and the U.S. The western hemlock produces a soft, lightweight wood with a straight, fine grain. Peak production was in 1927. The lumber was used for millwork, construction, boxes, fences, and boats.

Synonyms and Related Terms

Tsuga heterophylla; Pacific hemlock; west coast hemlock; werstern hemlock-spruce; hemlock fir; Prince Albert's hemlock

Western Hemlock fiber stained with Graff "C" Stain

Physical and Chemical Properties

  • Height = 50-70 m, diameter up to 3m; branches are drooping
  • Bark = thin, brown with furrows
  • Leaves = needles are 5-23 mm long and 1.5-2 mm wide
  • Density = 28 pcf
  • Cones = small, cylindrical (14-20 mm long)
  • Density = 28 pcf

Paper fiber type: softwood. Using transmitted light microscopy, fibers are identified by the presence of small piceoid and cupressiod ray parenchyma pits. Ray tracheids are non-dentate and usually collapsed. Appearance with Graff "C" stain: varies with pulping method. Average dimensions of fibers: length, 4.2mm; width, 30-40 μm. Common pulping method: kraft (sulfate) and sulfite.

Resources and Citations

  • G.S.Brady, Materials Handbook, McGraw-Hill Book Co., New York, 1971 Comment: p. 394
  • Dictionary of Building Preservation, Ward Bucher, ed., John Wiley & Sons, Inc., New York City, 1996
  • External source or communication Comment: West Coast Lumbermen's Association, Seattle, Wash.: air-dry weight = 28 pcf
  • Marja-Sisko Ilvessalo-Pfäffli. Fiber Atlas: Identification of Papermaking Fibers (Springer Series in Wood Science). Springer, 1995.
  • Walter Rantanen. 'Fiber ID Course.' Integrated Paper Services. June 2013. Lecture.