1. Clean the metal skeleton, there should never be metal bending oil or acidic detergent and other chemical substances left on the skeleton.
2. Reserve space for expansion. Expansion value=linear expansion coefficient (6.5*10-5cm/cm/°C)*length*maximum temperature change value.
3. To apply neutral rubber ring, can not use PVC gaskets, because PVC gaskets in the plastic extrusion (DOP) and some of the chemicals in the rubber ring will be migrated to the surface of the gasket, and the installation of the PC board will damage the PC board.
4. double-sided waterproof tape in addition to waterproof agent, can also be used for PC board skeleton, as a backing material, most of the surface of the tape on the glue on the PC board are destructive, so you need to choose not to damage the PC board double-sided waterproof tape, the current butyl tape will not be destroyed on the PC board.
5. Cutting must be done with power tools, the saw blade should be made of tungsten carbide, and the plate should be fixed to avoid vibration when cutting.
6. PC board is easy to scratch. Therefore, do not tear the protective film when cutting, cutting before the line must be marked, as far as possible to mark the protective film, such as must be directly marked on the plate, please use crayon, should avoid using sharp tools marking, installation is completed before tearing off the protective film.
7. When the cement floor of a new building is not completely dry, the PC board should not be directly contacted with it, otherwise the salt content in the cement will damage the PC board.
8. If the PC board has to be bent, its construction radius needs to be larger than the permissible radius of curvature (the radius of curvature needs to be more than 180 times the thickness of the board).
9. radius of curvature is less than 180 times the thickness of the plate, bending construction first reserved for processing, such as vacuum forming (one of the ways of heat treatment molding) and its heat treatment temperature is higher than 150 ° C, pay attention to the drying of the PC board itself and the protective film needs to be torn off first.
10. PC board surface dust, dirt generally first soft cloth or sponge with neutral detergent wipe, then rinse thoroughly with water, and finally dry with a soft cloth.
11. If you need to use solvents to clean, remember that most of the solvents. Such as toluene, acetone, gasoline, carbon tetrachloride, etc. on the PC board are destructive, must not be used, it is recommended to use in PC solvents alcohol: such as alcohol or isopropyl acetone.
Installation method:
1. Embedded installation method:
A. The protective film on the PC board will affect the adhesion with the seal, so the protective film on the embedded part should be removed before the PC is embedded.
B. When PC board is embedded, proper embedding amount and expansion space are required. If the embedding amount is too little, the PC board may fall off due to wind pressure or other heavy pressure; if the expansion space is not enough, the PC board may also be damaged due to stress caused by expansion.
Screw mounting method:
A. Screw spacing, according to the thickness of the board, do the appropriate configuration, spacing too small and too large are not good. If the spacing is too small, sometimes it will be too tight and cause stress, resulting in damage; if the spacing is too large, and may make the PC board fixed instability. Appropriate spacing is as follows:
(1) plate thickness of 3.0mm or less, the spacing is 10~20cm; (2) plate thickness of 3.0mm or more, the spacing is 20~30cm; (3) if the pressure strip fixed, the spacing is 20~30cm
Note: If you use self-tapping screws to fix the PC board directly, the larger the screw spacing is, the better it is to prevent the board from being damaged.
(2) The size of the screw holes should take into account the different thermal expansion and contraction of the PC board in summer and winter and day and night. Generally speaking, the screw hole diameter is 2~4mm larger than the diameter of the screw, in order to reserve space for expansion.
(3) When the location of the screw holes is too close to the edge of the PC board, it is very easy to break the board. In general, the location of the screw holes from the edge of the board, at least 2.5 times the diameter of the screw holes.
(4) Do not lock the screws too tightly, otherwise deformation will occur and stress will be induced.
