In order to improve the bending properties of softening of wood, plastic deformation increases, the need to be softened prior to bending

The softening treatment methods are as follows: hydrothermal treatment, high frequency heating treatment and chemical treatment.

The main components that make up the wood cell wall are: cellulose, hemicellulose and natural pigment. After the wood is hydrothermally treated, a part of hemicellulose is easily decomposed and dissolved into a liquid state, and the free hydroxyl group on the molecular chain of the amorphous region of cellulose adsorbs water, so that the water film in the cellulose gap is thickened, the distance between molecules is increased, and the attraction force is reduced. It is easy to produce relative slip under the action of external force.

There are two kinds of hydrothermal treatment methods: steaming and boiling. The boiling method will increase the moisture content of the wood, and the drying time will be delayed after bending.

Long, in addition to the presence of free water in the cell cavity, during the bending process, it is easy to generate static pressure and cause waste. Steaming is often used in production today, mainly with saturated steam. ”

The steaming time is related to the thickness of the curved square, the moisture content, the tree species and the required degree of plasticization.

The cooking time required for the elm and ash squares before bending.

species	Curved square material thickness ( Mm )	Different temperature Required cooking time (in degrees Celsius) ( min )
		110	120	130	140
elm wood	15 25 35 45	40 50 70 80	30 40 60 70	20 30 50 60	15 20 40 50
water Rhynchophylla	15 25 35 45	- - - -	80 90 100 110	60 70 80 90	40 50 60 70

Note: The table shows "

U ” Steaming time of curved parts in different tree species and thicknesses.

If the cooking is insufficient, the plasticization is not good, and it is easy to cause damage under the degree of severe bending; if the cooking is excessive, the tensile strength and the compressive strength are reduced.

Kontnan has tested in the temperature range of -191 °C -200 °C to prove the compressive strength of wood along the temperature

Decrease and rise

Since the compressive strength parallel to grain overcooked it decreases, the Fangcai bear end surfaces of compressive deformation during bending and damage.

The cooking pot used should be close to the curved wood equipment. The amount of wool to be cooked should not be too much, and the surface of the rabbit should be excessively cooled and overcooked. Leave a gap between the sides in the cooking pot

6 - 8 mm to make the temperature uniform and shorten the cooking time.

Guarantee the quality of the bend. Steamer diameter is generally

250 - 400mm , not too big. The length of the pot is slightly larger than the bend

Part length.

The high-frequency medium heat treatment is to place the bending wool between two electrode plates in a high-frequency electric field, and repeatedly polarized, intermolecular

Rubbing against each other produces heat, which softens the wood. This is an effective softening method that can be directly inserted after the square is bent.

Into the drying and shaping process.

Microwave heating at higher frequencies

300MHZ electromagnetic wave radiation field irradiation, bending wool placed on the waveguide harmonic

The radiation field of the vibration chamber is illuminated. Currently used

9l5MHZ apparatus and 2450MHz two frequencies, in the microwave heating of 2450MHz 20 X 10mm (cross-section) may be bent to a radius of curvature of the timber is 150mm, such as a smaller radius of curvature of the curved shape and then bending to be heated by microwaves.

High-frequency and microwave heating is fast and uniform, which makes bending and shaping continuous, and has received much attention.

The chemical softening treatment methods include: ammonia plasticization treatment and urea plastic treatment.

Ammonia plasticizing is done with liquid ammonia (-

33 ° C), ammonia or gaseous nitrogen treatment of wood, mainly ammonia and wood have good

Affinity, it spreads much more in wood than water vapor, and it can occur with all three major components of the cell wall.

With, for example, liquid ammonia can not only enter the amorphous region of cellulose, but also enter the crystallization zone, destroy the hydrogen chain, form ammoniated cellulose, play a role of relaxation and swelling, and make the hemicellulose change direction; It can plasticize lignin and achieve excellent plasticization. Liquid ammonia treatment time is short (tens of minutes to several hours), but the equipment is complicated. Another type of hydrazine (肼)

The treatment method, the ammonia water and ammonia treatment time is longer than the liquid ammonia method, and the ammonia water needs to be immersed for more than ten days.

Urea plasticizing is to soak the wood in

40 % - 50 % of the urea solution for several days, then dried to a moisture content of 8 % - 12 %, and then bent at 100-105 degrees, can improve the bending performance.

In addition, sodium thiosulfate, or a sulfonate or the like may be used as a softening agent, sprinkled on steamed wood or immersed in wood.

Lanyard

Lanyard

1.What is lanyard:

A lanyard is a cord or strap that is worn around the neck to hold an identification badge, whistle, keys or other small object. You can see lanyards in use everywhere by businesses, schools, hospitals, at special events, conventions, reunions, and in many recreationall activities.

2.Lanyard Category:

Based on different material used for lanyard production, here are five kinds of Zipper: Heat Transfer Lanyard , Silk-Screen Lanyard , Silicone Lanyard, Zipper Lanyard and Jacquard Lanyard.

2.1. Heat Transfer Lanyard

Sublimation Lanyard is designed in the pattern, production copperplate, electric carving through the mechanical sub-color pattern engraved on copperplate. Copperplate printing machine and then get on the pattern printed on the PET film, and then through the mechanical heat transfer lanyard pattern is transferred to the product.

Sublimation lanyard content can be product brands, publicity posters, slogans, may also be sporting events, concerts, commercial activities, the name and other gatherings LOGO. Nylon, cotton, bamboo fiber can not withstand high temperatures, and high cost to go through a special process to heat transfer lanyard.Such as custom printed lanyard,double hook lanyard.

2.2. Silk-Screen Lanyard

Silk webbing lanyard is the production process LOGO traditional common expression, LOGO is printing ink by screen printing on the surface of the webbing. Printing out of LOGO texture clear, strong sense of three-dimensional, high definition, good adhesion.

Generally can be divided into screen printing lanyard phone lanyard, U disk lanyard, MP3 lanyard, working lanyard, lanyard exhibition, documents cards sling, brand badge lanyard, badge lanyard, lanyard visit visitors Wait. Product brands, publicity posters, slogans, may also be sporting events, concerts, commercial activities, the name and other gatherings LOGO.

2.3. Silicone Lanyard

Silica gel is silica gel mSiO2 · nH2O made of a suitable dehydrating porous materials of different particle sizes. Has an open porous structure, specific surface area (surface area per unit mass) is large, can absorb many substances, it is a good desiccant, adsorbent and catalyst supports.

Silica gel lanyard using silica gel as a material made of, but not limited to mobile phone ornaments, can be widely used in MP3, MP4, digital cameras, small flashlights and other products of the match.

2.4. Zipper Lanyard

Zipper lanyard and zipper is shaped the same,It is the perfect companion for the mobile phone, brand certificate, key ring. Beautiful and practical zipper manufacturing plating with laser engraving and other advanced technology refined elegance applicable Peigua digital cameras MP3 U disk, PU rope, PVC rope, zipper cell phone rope, rope, harnesses, hand Wan belt.In addition to metal beads, other materials can be printed corporate LOGO logo, and in different parts and assembly methods, play publicity, promotional purposes. According to customer needs, design and manufacture many styles, diverse fashion lanyard!

2.5. Jacquard Lanyard

Jacquard Ribbon Ribbon is a high-grade varieties.

Jacquard Ribbon generally used for high profile clothing materials or decoration materials (such as curtains, sand release material). Jacquard manufacturing process complicated. Warp and weft interwoven ups and downs, to form different patterns, convex, more weave flowers, birds, fish, insects, animals and other beautiful patterns.

Jacquard Ribbon soft, delicate, unique and smooth texture, good gloss, good drape and breathability, color fastness (yarn dyeing). Weft jacquard pattern amplitude with large and beautiful, color structured three-dimensional sense, and by the Jacquard pattern is relatively simple, relatively simple.

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