What matters should be paid attention to in the production and processing of laser knife die carving equipment?

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Laser precision carving equipment for knife dies has unique advantages in the machining of knife dies because of its high energy density and precise controllability. However, due to the high temperature, radiation and precise mechanical operation involved in laser machining, many matters should be paid attention to in the production process to ensure safety, accuracy and efficiency. The following are specific considerations:

First, safety protection: avoid laser injury and accident risk.

Laser belongs to high-energy radiation, and the processing process is accompanied by high temperature and potential combustion risks, so safety is the primary prerequisite.

Operator protection

You must wear laser protective glasses (choose the corresponding model according to the laser wavelength) to prevent the eyes from being damaged by direct laser or reflection.

Wear flame-retardant overalls and gloves to avoid direct skin contact with high-temperature workpieces or laser paths.

It is forbidden to extend the body parts into the processing area (such as under the laser head and inside the workbench) when the equipment is running.

Equipment safety settings

Ensure that the safety interlock device of the equipment works normally (for example, the laser can only be started when the protective cover is closed, and stopped immediately when it is opened), so as to prevent the laser from leaking due to misoperation.

Equipped with emergency stop button, and ensure that the operator is familiar with the location, and can stop immediately in case of emergency (such as material fire and abnormal sound).

High-voltage components such as laser power supply and cooling system should be insulated to avoid electric shock.

environmental safety

It is forbidden to store inflammable and explosive articles (such as alcohol, gasoline and paper accumulation) in the processing area. Especially when processing wood and paper knife dies, the high temperature of laser may cause combustion, so a fire extinguisher (dry powder or carbon dioxide type) is required.

Keep the processing area well ventilated, install a smoke exhaust system, and exhaust the smoke generated by laser cutting in time (such as lampblack from wood burning and waste gas from metal oxidation) to avoid the operators from inhaling harmful gases.

Second, material adaptation and pretreatment: to ensure processing stability.

There are many kinds of materials (wood, metal, composite materials, etc.) processed by laser die, and the physical characteristics of different materials have great differences in response to laser, so it is necessary to adapt them in advance.

Material selection and inspection

Confirm whether the material is suitable for laser processing: for example, some chlorine-containing and fluorine-containing composite materials (such as some plastics) will produce toxic gases when laser cutting, which should be avoided; The thickness of metal die (such as steel plate) should be suitable for laser cutting (usually ≤3mm, too thick may lead to incomplete cutting).

The surface of the material should be smooth and free of impurities: the surface burrs and nails of wood/plywood should be removed to avoid sparks during laser reflection or cutting; Metal materials need to be cleaned of oil stains and rust to prevent the laser energy absorption from being affected.

Material fixation

Fix the material firmly on the workbench with a fixture or vacuum adsorption device to prevent the material from shifting due to laser impact or thermal deformation during processing, which will lead to cutting deviation (such as dislocation of the cutting edge of the die).

For thin materials (such as steel sheet and multi-layer cardboard), it is necessary to ensure uniform fixing strength to avoid material deformation.

Third, processing parameter setting: guarantee accuracy and quality.

The core parameters of laser machining (power, speed, focal length, etc.) directly affect the precision (such as the depth and smoothness of the cutting edge) and machining efficiency, and need to be accurately adjusted according to the material characteristics and the requirements of the die.

Debugging of core parameters

Laser power: too low power may lead to incomplete cutting (such as the cutting edge of wooden knife die is not cut through); If the power is too high, the material will be burnt (the wood will be black) and the metal edge will be melted and deformed, which needs to be tested according to the material thickness (for example, the power of 3mm plywood is usually set to 80-120W, and that of 1mm steel plate is set to 150-200W).

Cutting speed: the speed is matched with the power. If the speed is too fast, it is easy to appear "tailing" (uneven cutting edge). If it is too slow, it may burn the material excessively. The best speed needs to be determined through trial cutting (for example, wood is usually 50-100mm/s and metal is 20-50mm/s).

Focus calibration: The laser focus should accurately fall on the surface (or inside, according to the cutting requirements) of the material. The focus deviation will lead to energy dispersion, which will affect the cutting depth and accuracy. It needs to be checked regularly with a calibration tool (such as using a focusing block).

Path optimization

The cutting path is planned by software to avoid frequent turning back of the laser head (reducing the idle time), and at the same time, the path of complex graphics (such as irregular cutting edge) is ensured to be continuous, so as to prevent cutting edge defects caused by "breakpoints".

For multi-layer die (such as ladder structure), parameters should be set in layers to ensure that the cutting depth of each layer accurately matches the design requirements.

Fourth, equipment maintenance: to ensure long-term stable operation.

The core components of laser equipment (laser tube, lens, cooling system, etc.) require extremely high cleanliness and state, and regular maintenance is the key to avoid failures and maintain accuracy.

Cleaning of optical components

Laser lens (focusing lens, reflector): It needs to be gently wiped with special lens paper dipped in absolute ethanol every week to remove oil and dust (dust will absorb laser energy, which will cause overheating damage to the lens and weaken the laser intensity). If the lens is found to have scratches or cracks, it needs to be replaced immediately (to avoid affecting laser focusing).

Laser tube: keep the inside of the laser tube clean to avoid scale deposition (water-cooled equipment), change the cooling water regularly (once a month is recommended), and use deionized water or distilled water (to prevent scale formation).

Maintenance of mechanical parts

Guide rail and lead screw: check the lubrication condition of the guide rail before processing every day, and add special guide rail oil regularly to prevent the movement accuracy from decreasing due to wear (excessive clearance of the guide rail will lead to positioning deviation of the laser head).

Drive belt/gear: check the tightness. Too loose will lead to drive lag, and too tight will increase the motor load, which needs to be adjusted according to the equipment manual.

Cooling system maintenance

Water-cooled equipment needs to ensure that the cooler works normally, the water temperature is controlled at 20-25℃ (the efficiency of the laser tube will decrease at high temperature, or even shorten its life), and the filter in the water tank should be cleaned regularly to prevent blockage.

Air-cooled equipment should ensure smooth ventilation of fans to avoid dust blocking the cooling holes.

5. Processing flow control: check the whole process from prenatal to postpartum.

Prenatal preparation

Review the design drawings of the die: confirm whether the graphic size, cutting edge angle and indentation line position meet the requirements of laser processing (for example, the minimum radius of fillet should be ≥ the diameter of laser spot to avoid being unable to process).

Trial cutting verification: when processing or replacing materials/parameters for the first time, first carry out small-size trial cutting, check whether the depth, flatness and dimensional tolerance of the cutting edge meet the standards, and then adjust the parameters before mass production.

Monitoring of machining process

Real-time observation of machining status: pay attention to whether the laser spot is stable, whether the material has abnormal combustion (especially wood material) and whether there is abnormal sound (possibly mechanical parts failure).

Avoid long-term continuous processing: the laser tube and motor will overheat after working for a long time. It is recommended to stop for 10 minutes every 2-3 hours, or stop automatically through the overheat protection function of the equipment.

postpartum examination

Measure the key dimensions (such as the distance between cutting edges and the position of locating holes) of the die with calipers and micrometers to ensure that the tolerance is within ±0.05mm (usually required for packaging die).

Check the quality of the cutting edge: the wooden knife die should be free of burr and scorch; The metal die should be free of curling and oxide layer, and polished if necessary.

VI. Environment and personnel management: reducing external interference