Basic quality requirements:
1. Board quality and color difference: The block material must be the fine quality of the stone pier which is cut off at least 5 cm of the oxidized skin. The designated material of the tile mining site is divided into blocks and stone piers of different mining periods. Slate can not be mixed.
2. The surface of the board is required to be flat, and there must be no curved plates or rocking plates. There must be no platinum wire, sand wire, water ripple and penetrating pyrite.
3. There shall be no internal cracks and penetrating cracks;
4. Angle tolerance: four angles of 90°, the angle error on the long side is within 1°, and the angle error on the wide side is within 0.5°;
5. Size error: length and width error: +1mm – 0mm,
6. Thickness: between 5-7mm:
Large panels 650×533, 650×350, 650×355, 600×300, 500×250, 500×375, 450×300, 450×250 shall not have slate below 5mm thickness; small panels 400×250, 400×200, 300×200 shall not have a thickness of less than 4.5mm (5-4.5) And cannot exceed 5%;
7. Complete corners: 4 corners are required. If there is a corner, the corners should not be larger than the long face 20mm x 10mm wide, and the number of notched tiles should not exceed 5%. (When punching, try to make a corner Stay in the small head of the slate.) If there are two corners and the corners are at one end of the board, try to keep the two corners in the small head and leave the hole in the hole. If the missing corners are at the two ends of the board and the missing angle is greater than 20x10mm, it is a waste product and needs to be picked out.
8. Hole position: The large surface is the back side and the small surface is the front side. Two holes are drilled from the back side of the slate to the front side. The hole diameter is 4mm. The distance between the center of the hole and the left and right sides is 30mm, and the distance from the head is 245mm. Not more than 1mm;
Wooden box size：
1. The inner diameter of the package is 1040mm, the inner diameter is 605mm, the inner diameter is 605mm, and the outer diameter is not greater than 1140mm.
2. The middle column of the outer wooden strip must be strong, the width of the wooden strip shall not be less than 70mm, and the thickness of the wooden strip shall not be less than 25mm.
The width of the cross strip and the border strip shall not be less than 60mm, and the thickness shall not be less than 20mm; and the angles of the two ends of the cross strip shall be respectively resisted on the wooden strip of the column and the wooden strip of the frame, and there shall be no gap; the number of nails at the intersection Not less than 3, and the triangle is staggered into the wooden strip to ensure stability and strength;
3. The width of the iron wrap angle shall not be less than 45mm, and at least 3 nails shall be nailed at each end. Two of the nails shall be straightened into the inner wooden strip of the frame; the other nail shall be directly nailed into the top of the wooden strip outside the frame.
4. The height of the bottom sleeper is not less than 60mm;
5. Wood crate wood should be selected as hard material as the material, and the surface must not have insect eyes and bark;
Packing method：
Large facets are loaded in one direction;
Two 3 mm thin wooden strips should be placed in parallel between each layer of slate floor to reduce damage. Each row of slabs should be placed with 3 mm thin wooden strips up and down to avoid bumps and corners during transportation.
Depending on the size of the board, some are vertically stacked with 3 rows, and some sizes of the board are placed upside down with 3 layers.
Taro brush system：
1. The surface of the wooden box can be brushed on one side; the number of the wooden box, the size and the number of pieces are respectively printed on the outer horizontal strip from the left to the right;
2. Brushed on the skewed wood strip.