Structural characteristics and wood characteristics of Douglas fir

Douglas fir (Yellow cedar) is Canada's largest tree and contains two major species: Coastal Douglas Fir and Inland Douglas Fir. The sapwood is light in color and narrow in width. Heartwood varies from yellow to reddish brown. The colors of early wood and late wood are distinct, and the latter has a deeper, sharper ribbon. This color difference causes the shape of the wood grain to be different when the flat saw is used. The wood material is fine to medium, and the texture is straight and non-permeable. Douglas fir is one of Canada's strongest commercial softwoods. It has high hardness and high abrasion resistance. It is suitable for places where wear is a factor, such as brackets, bridge components, wooden houses and commercial buildings.

 

1. Structural characteristics of Douglas Fir: Douglas fir is world-renowned for its excellent strength-to-weight ratio. Its high specific gravity provides good nail holding and fixing force. It is suitable for the production of residential houses, small commercial buildings, multi-storey buildings and industrial buildings. Wooden frame used.

 

   Among the softwood species in North America, Douglas fir not only has a high modulus of elasticity, but also the outermost bending fiber stress, the tensile force, the transverse shear force, the horizontal grain pressure and the grain pressure are also extremely good. Because of the physical properties of Douglas fir, the durability of the heartwood and the outstanding physical stability, many construction companies around the world use Douglas Fir as a standard for judging all framed wood.

 

   Douglas fir is known for its structural properties and its appearance is beautiful. Douglas fir is the most commonly used type of wood when design structures require large wooden beams, long spans or specially shaped arches (eg churches, bridges, stadiums, etc.). In the construction of residential buildings, commercial buildings, public buildings, tower buildings and water facilities, the structurally laminated beams made by Douglas Fir are commonly used as horizontal load-bearing frames for roofs, floors and pillars. Glued beams are also reliable building materials in the construction of industrial plants, warehouses, garages, and even architectural structures that require a beautiful appearance.

 

2 , appearance grade characteristics of Douglas fir wood: Douglas fir has a light rose color and beautiful straight texture, the color becomes dark after sun exposure. Douglas fir's ductile fibers are not easy to cut or sculpt by hand, but smooth cutting surfaces can be obtained with sharp power tools and machine tools. This kind of wood can be processed into the shape of the grain A wide range of products, the surface is easy to paint, and can maintain a variety of dyes and varnishes.

 

   The bark of the tree is thick and deep scaly. The leaves are strip-shaped, about 1.5-3 cm long, the ends are blunt or slightly pointed, the top is dark green, the lower color is lighter, and there are two gray-green stomata bands. The fruit of the tree ( cone ) is oval-ovate, about 8 cm long, brown and shiny. The scales are rhomboid or nearly rhomboid, the scales are longer than the scales, the middle lobes are narrow and long, and the lobes on both sides are wider and shorter.

 

   Douglas fir hi-light, like warm and humid climate and well-drained acidic soil, can withstand the drought in winter and spring. The bark is in the shape of a leopard, the heartwood is reddish, the sapwood is pale yellow and has a resin. The material is tough, elastic and has a long shelf life. Wood can be divided into coastal and inland types. Douglas fir is a good building and appliance material.

 

3 , Douglas fir surface treatment: Douglas fir can accept various types of dyeing treatment, the surface treatment materials include transparent paint, clear paint, varnish, paint or wax, and even a variety of dyeing and bright or soft color paint. In order to obtain the best surface treatment, the moisture content of the wood should be between 12% and 15% , or the closer to the normal humidity, the better. The outdoor building structure should be coated with a primer first, because Douglas fir is a relatively dense heavy wood.

 

4 , non-defective materials, processing materials, construction materials and custom wood and other grades: Douglas fir in the construction and secondary processing industry is widely used due to its good physical properties and numerous wood grades. All Douglas fir wood is processed, graded and classified according to relevant domestic or foreign grade standards. According to the Canadian classification, Douglas fir wood is divided into:

   1) Non-defective materials ( no thrift ) : Class II and above non-defective materials, Class III non-defective materials and Class 4 non-defective materials.

   2) processing timber (reprocessed into defect-free material): Top plate material processing, secondary processing of the top plate, and one or more processing materials, materials Moldings A and B.

   3) Architectural use: light frame material, light structural frame material, structural shelf and board.

 

5 , a wide range of structural materials: Douglas fir has a variety of uses, is a widely used structural materials, favored by engineers and builders, especially suitable for structural parts and heavy wood structures, is also widely Used in wood piles, railway sleepers, sawmills, warehouses and many other areas where structural performance is important. Douglas fir is a hard and stable wood that can be used to build wood frames for light and heavy construction.

 

Due to its high strength and good gluing properties, Douglas fir is often used to make glulam beams of various structures, including indoor sports fields, swimming pools, churches and supermarkets.

 

Douglas fir has a good appearance and is easy to process. It is suitable for processing window frames and door frames, mouldings, cabinets and other joinery products. The hardness and strength of Douglas fir also increase durability.

 

Douglas fir has high corrosion resistance and excellent structural properties, so it is also the main wood for industrial tanks, vats and other storage containers. Its stability and ease of processing also make it a material for manufacturing industrial parts.

 

6. Use of the Douglas Fir construction project: Due to its high bearing weight and high weight ratio, Douglas fir is mainly used in gluing beams and building wood. The most extensive of these is the use of building wood. The wooden building is called the mouth material. Mainly based on 35*85 specifications. There are also different specifications depending on the geographical location. Among them, Hangzhou is mostly 39*89 , and there are also 5*10 specifications.

 

7. Distribution pattern of Douglas fir market: The current Douglas fir is mainly imported from logs and processed by various wood processing plants. Common Douglas fir specifications are mainly 3 or 4 meters long.

Back to school Stationery

Due to the different objects of Back to School Stationery, the style of stationery for students of different ages is also very different. The School Stationery for primary school students is mostly cartoon stationery series, while the stationery for middle school students and college students is mainly practical, and has been inclined to office stationery series.
Student Stationery Set covers a wide range. According to the characteristics of stationery itself, it can be roughly divided into the following four categories:
1. Writing stationery for students. For example:
Pencils, automatic pencils, pencil refill, watercolor pens, whiteboard pens, neutral pens, ballpoint pens, oil pens, pens, crayons, etc.
2. Modified stationery for students. For example:
Correction tape, correction fluid, eraser, etc
3. Storage stationery for students. For example:
Pencil bag, pencil case, file folder, excersice book,document file, etc.
4. Tool stationery for students.
Pencil sharpener, liquid glue, glue stick, ruler, compass, utility knife, scissors, book cover, etc.

School Stationery,School Stationery Wholesalers,Stationery Set,School Supplies

NINGBO MACEY EDUCATION PRODUCT CO.,LTD , https://www.maceytoys.com