Analysis of Common Faults in Plywood Machine Hot Press

The hot press is the main machine for the production of wood-based panels, and its performance will directly affect the quality of the production of wood-based panels. Therefore, wood-based panel manufacturers must be cautious when choosing a hot press, otherwise the loss will be irreparable. The quality of the hot press is closely related to the pressure of the machine. The hot presses used today are generally hydraulic, so the hydraulic cylinder is the main part of the whole machine;

    During the use of the hot press, some faults are usually encountered, which directly affects the quality of normal production and wood-based panels. Then we will understand that when the hydraulic cylinder piston slips or crawls, the hydraulic cylinder will not work. When it is stable, what should the operator do? The first thing is to find out the cause of the accident. Let us analyze it.

    (1) Poor lubrication or excessive machining of the cylinder bore. Because the piston and the cylinder, the guide rail and the piston rod have relative movement, if the lubrication is poor or the hydraulic cylinder aperture is out of tolerance, the wear will be intensified and the linearity of the cylinder center line will be reduced. Thus, when the piston is operated in a hydraulic cylinder, the frictional resistance will be large and small, causing slippage or creeping. The solution is to first grind the hydraulic cylinder, then prepare the piston according to the requirements, repair the piston rod, and configure the guide sleeve.

    (2) The internal pressure of the hydraulic cylinder is stagnant. The internal parts of the hydraulic cylinder are improperly assembled, the parts are deformed, the wear or the geometrical tolerances are over-limit, and the action resistance is too large, so that the piston speed of the hydraulic cylinder changes with the stroke position, and slips or crawls. Most of the reasons are due to poor assembly quality of the parts, scratches on the surface or iron filings from sintering, which increase the resistance and decrease the speed. For example, the piston and the piston rod are not concentric or the piston rod is bent, the hydraulic cylinder or the piston rod is offset from the mounting position of the rail, and the sealing ring is too tight or too loose. The solution is to re-repair or adjust, replace damaged parts and remove iron filings.

    (3) The hydraulic pump or hydraulic cylinder enters the air. Compressing or expanding the air can cause the piston to slip or crawl. The precautions are to check the hydraulic pump, set up a special exhaust device, and quickly operate the exhaust for several round trips.

To solve the problem, you should first find the cause of the problem, so that the solution is targeted. Moreover, the hot press is the most important equipment for the production of wood-based panels. In case of failure, it is necessary to repair in time to avoid delay in production.