JPS5810518B2 - doctor plaid - Google Patents

Description

Detailed Description of the Invention The present invention provides a doctor blade that removes slag and impurities that adhere to the rolls of machines used in paper making, printing, rubber manufacturing, textile processing and finishing, etc., and has excellent roll cleaning performance. More specifically, it relates to a doctor blade made by laminating a laminated assembly of various fibers impregnated with resin and hardening the hard plate-like felt, arranged between hard plastic sheets, stacked, and bonded together with an adhesive.

The doctor blades conventionally used for the above-mentioned rolls include metals such as phosphor bronze and molybdenum copper, Bakelite,
These blades were molded from synthetic resins such as urethane resin, nylon resin, and synthetic rubber, but these could damage the surface of the roll, break the blade itself, or deform it due to heat, or come in contact with it. There were drawbacks such as insufficient adhesion to the roll and poor ability to remove deposits and clean the roll.

Therefore, there is still no optimal doctor blade, and we have had to use a small roll coated with sandpaper or a blade whose cutting edge is coated with sandpaper, but slag and impurities get stuck between the abrasive grains of the sandpaper. It became smooth and had no abrasive properties, so its lifespan was extremely short, and replacement work was complicated.

The doctor blade of the present invention improves these drawbacks, has good adhesion to the roll, has excellent sludge scraping and cleaning properties, has a long life, and is easy to maintain, and will be explained below with reference to the drawings.

The doctor blade of the present invention is composed of three layers: a hard plate-like felt 1 and hard plastic sheets 2, 2 disposed on both the front and back surfaces of the felt, and these are firmly bonded together with an adhesive 3.

The hard plastic sheet is made of heat-resistant and abrasion-resistant materials such as epoxy resin, polyester resin, phenol resin, etc., and fiber-reinforced plastics containing synthetic fibers, glass fibers, etc. are used to increase the strength against breakage. A sheet is used, and the thickness is preferably about 0.1 to 2.0 mm.

The material and thickness of the hard plastic sheet are determined depending on the material of the rolls in contact with it, the temperature, and the difficulty of removing slag and impurities.

The hard plate-like felt can be made from chemical fibers alone or mixed with natural fibers to form threads or batts, which can be woven, compressed, or kneaded.
The woven felt, compressed felt, or needle felt produced with a high density by a drifter is treated with a resin and cured, and the details are as follows.

In other words, chemical fibers used as raw materials include synthetic fibers such as polyamide, polyester, polyacrylonitrile, and polyolefin, and inorganic fibers such as glass fiber, ceramic fiber, carbon fiber, and metal fiber, and natural fibers include wool and cotton. , hemp, and asbestos fibers, and these are used alone or in combination.

When wear resistance and durability are required, it is preferable to use polyamide-based or polyester-based synthetic fibers.
When heat resistance is strongly required, it is preferable to mainly use aromatic polyamide synthetic fibers or inorganic fibers such as glass fibers and carbon fibers.

Yarns made from such raw materials are woven, and if necessary, the yarn is shrinked, the web laminate is compressed, or the web alone or the fiber laminate with a base fabric is subjected to needling treatment. This material is impregnated with synthetic resin, heated to a temperature of 130 to 200°C to harden it, and is made into felt.
It is made to have an IS hardness of 70 to 100 degrees and a thickness of 1 to 40 mm.

The synthetic resins include synthetic rubbers such as styrene-butadiene rubber, nitrile rubber, and chloroprene rubber, epoxy resins,
polyester resin, acrylic resin, polyurethane resin,
It is used as a solution or dispersion of silicone resin, fluororesin, or a resin blended with phenol resin, melamine resin, or isocyanate resin, and the amount of resin attached is 10 to 50% of the felt weight (hardness) depending on the desired hardness. It is preferable to change it within the range of (type conversion).

The hard plate-shaped felt produced in this way can be easily split into a uniform sheet with a predetermined thickness (approximately 1 mm or more), and in order to make the surface smooth and increase the hardness, After splitting, the felt is further dipped in an epoxy resin liquid to impregnate the surface of the felt, and then dried to obtain a hard plate-shaped felt with an extremely smooth and dense surface.

In this case, the concentration of the epoxy resin is preferably 10 to 30%, and the solvent is preferably triethane.

Next, a hard plate-shaped felt like the one described above is placed in the center, and hard plastic sheets are placed on both sides, and a thermosetting adhesive such as epoxy resin, phenol resin, or isocyanate resin is applied to each adhesive surface. , temperature 70 with a pressure machine
~180°C and a pressure of 1~15/9/cm2 for 1~30 minutes to bond and form a laminate with a thickness of 2~20 mm.

This structure is particularly preferable when used in high-temperature locations because it does not cause any curvature due to heating.

The hot pressing conditions are determined depending on the ratio of the thicknesses of each layer and the desired thickness, elasticity, or hardness of the blade.

The laminated board made in this way is strong, has high wear resistance, and has elasticity, making it an excellent substrate for doctor blades.

Next, cut the tip of the laminate diagonally to provide a taper 4,
Complete Doctor Blade.

To use the doctor blade of the present invention, attach it to a support device (not shown) and align it as shown in FIG. It is most effective to arrange the surface so that it is in close contact with the roll.

In other words, at first the tapered surface does not come into close contact with the curved surface of the roll, but soon (as the hard plate-like felt deforms and adapts to the curved surface, the tapered surface comes into close contact with the roll, and the slag attached to the roll is removed). Since impurities are scraped off by the hard plastic layer and brought into contact with the hard plate-like felt layer, the roll can be easily cleaned.

It can also be used with the tip of the tapered surface facing upward and in contact with the roll as shown in FIG.

As described above, the doctor blade of the present invention is strong and has good adaptability to the rolls in contact with it (scrapes and impurities).
It has many advantages such as not breaking and being easy to clean.

In addition, it has excellent ability to remove deposits, so the blade pressure can be reduced.
Therefore, power costs can be reduced.

[Brief explanation of drawings]

FIG. 1 is a side view of the doctor blade of the present invention, FIG. 2 is a side view showing its use condition, and FIG. 3 is a side view showing another use condition. 1... Hard plate felt, 2... Hard plastic sheet, 3... Adhesive, 4... Taper, 5... Roll.

Claims (1)

[Scope of Claims] 1. A doctor blade made by laminating a laminated assembly of various fibers impregnated with resin and hardening the hard plate-like felt, arranged between hard plastic sheets, stacked, and bonded together with an adhesive. 2. The doctor blade according to claim 1, wherein the hard plastic sheet contains synthetic fiber or glass fiber. 3. The doctor blade according to claim 1 or 2, wherein the hard plate-like felt is a woven felt. 4. The doctor blade according to claim 1 or 2, wherein the hard plate-like felt is a compressed felt. 5. The doctor blade according to claim 1 or 2, wherein the hard plate-like felt is needle felt.