What are the storage requirements for imported paper machinery spare parts?

The storage conditions of imported spare parts for papermaking machinery need to be specified according to the characteristics of spare parts types (mechanical, electrical, vulnerable materials, etc.). The core goal is to prevent physical damage, chemical corrosion and performance degradation, and ensure that spare parts maintain their original accuracy and function during storage. The following is a classification description of specific storage requirements:

I. General storage basic conditions

No matter what type of spare parts, the storage environment should meet the following basic requirements as the premise of quality assurance:

Environmental temperature and humidity control

Temperature: It is recommended to keep it at 15-30℃ (fluctuation range ≤ 5℃/day). Too high temperature will accelerate the aging of rubber and plastics, and too low temperature may lead to cracking of brittle materials (such as some engineering plastics);

Humidity: the relative humidity is controlled at 40%-60%. Excessive humidity is easy to cause metal corrosion and electrical components to be affected with damp; Too low humidity (such as < 30%) may lead to embrittlement of some fiber or paper packaging materials.

Measures: The warehouse shall be equipped with an automatic temperature and humidity recorder (recording data daily), air conditioner, dehumidifier (high humidity area) or humidifier (extremely dry area).

Cleaning and protection

The warehouse shall be kept free of dust and corrosive gases (such as chlorine, ammonia and acid mist, which may come from the chemical area of the paper workshop and need to be kept away from storage);

The ground should be hardened and leveled to avoid water accumulation (non-slip rubber mat or epoxy floor can be laid);

Smoking and storage of inflammable and explosive materials (such as alcohol and paint) are prohibited in the warehouse, and fire extinguishers (such as dry powder or carbon dioxide) should be equipped in the electrical spare parts area.

Stacking specification

All spare parts should be stored off the ground (using metal shelves and wooden pallets, height ≥15cm) to avoid moisture erosion on the ground;

The stacking height shall not exceed the bearing limit of the shelf (heavy spare parts such as rollers and motors shall be placed separately, and stacking is prohibited), and precision parts (such as bearings and sensors) shall be stored separately in layers to avoid extrusion deformation;

Spare parts shall be labeled for external demand, indicating the model, warehousing date and shelf life (if any), following the principle of "first in, first out", and spare parts with short storage time shall be given priority.

Second, the special storage requirements for different types of spare parts

1. Mechanical spare parts (bearings, gears, grinding discs, rollers, etc.)

Metal precision parts (bearings, gears, couplings):

Before storage, it is necessary to check whether the original packaging is intact (such as anti-rust paper and sealing box of bearings). If the original packaging is damaged, it is necessary to re-coat anti-rust oil (such as lithium-based antirust grease), wrap it with vapor-phase anti-rust paper and seal it;

Direct contact with hand sweat is prohibited (cotton gloves are required for operation) to avoid local rust caused by fingerprint residue;

Bearing and other parts with rolling elements should be kept horizontally when stored, and vertical suspension or stacking is prohibited to prevent the deformation of inner ring from affecting accuracy.

Large metal parts (roller, press roller, motor housing):

If there is a coating on the surface (such as chrome-plated roller), it needs to be completely covered with plastic film to avoid scratches or oxidation of the coating;

Iron castings (such as pumps and valves) should be inspected regularly (every 3 months). If rust is found, it should be polished with fine sandpaper in time and then painted with antirust paint.

Roller spare parts should be placed on a special V-shaped frame to ensure that the roller surface is horizontal and avoid bending deformation caused by gravity (especially for rollers with a length of more than 3 meters).

Cutters (paper cutters, pulper blades):

The cutting edge needs to be coated with antirust oil, wrapped with cardboard and stored separately in the tool box to avoid the cutting edge from cracking due to collision with other parts;

Alloy tools (such as tungsten carbide grinding discs) should be far away from strong impact sources (such as forklift operation area) to prevent brittle materials from breaking.

2. Electrical spare parts (PLC modules, sensors, servo motors, cables, etc.)

Control module and electronic components (PLC, sensor, driver):

The original packaging must be sealed (anti-static bag+foam buffer), and it is forbidden to store it naked after unpacking;

Store in an anti-static shelf (grounding treatment), away from strong magnetic fields (such as transformers and welding machines) and high-voltage equipment, to avoid the drift of component parameters caused by electromagnetic interference;

Humidity sensitive components (such as chips and capacitors) need to be additionally placed with desiccant (replaced every 3 months) and marked with "Humidity Sensitive Grade" (for example, MSL Grade 3 should be used within 24 hours after opening).

Motors and electrical equipment (servo motors, encoders):

The extended end of motor shaft should be coated with antirust oil and covered with protective cover to prevent dust from entering the bearing;

For components with precision circuits such as encoders, it is necessary to disconnect the connecting wires (if any) during storage to avoid interface damage caused by cable stress;

For motors stored for a long time (more than 6 months), it is necessary to manually rotate the rotor regularly (every 3 months) to prevent the bearing grease from solidifying.

Cable category (hydraulic hose, encoder cable, cable):

It needs to be coiled into a circle (the radius is not less than 10 times the diameter of the cable) to avoid excessive bending (especially for hydraulic hoses, excessive bending will cause the inner steel wire to break);

Hydraulic hoses should be far away from ozone sources (such as high-voltage motors) to prevent rubber from aging; The interfaces at both ends of the cable should be sealed with dust caps to avoid water or impurities.

3. Spare parts of vulnerable materials (seals, rubber rollers, filters, etc.)

Rubber/plastic (sealing ring, rubber roller, gasket):

It needs to be stored in a dark environment (avoiding direct sunlight or ultraviolet radiation), and can be wrapped in a black shading bag to prevent the rubber molecular chain from breaking and causing hardening and cracking;

Contact with organic solvents (such as gasoline, alcohol and engine oil) is prohibited to avoid swelling or dissolution;

The storage temperature shall not exceed 25℃, and the humidity shall be about 50%. For long-term storage (more than one year), it is necessary to regularly check the elasticity (such as whether the sealing ring can rebound quickly after being pressed).

Screen/screen (pulp screen, filter cloth):

It needs to be hung flat or laid flat to avoid mesh deformation caused by folding and extrusion (for example, the mesh skew of metal screen will affect the screening accuracy);

Textile filter cloth should be moisture-proof and mildew-proof, and a small amount of mothballs can be placed (to avoid direct contact with the filter screen) to prevent insects from eating.

Chemical spare parts (sealant, lubricant, cleaning agent):

It should be stored separately in a well-ventilated chemical cabinet, away from fire sources, and marked with production date and shelf life;

Sealants, adhesives, etc. should be stored upside down (to prevent colloid from solidifying at the bottle mouth), and lubricants (such as gear oil) should be prevented from freezing at low temperature (the storage temperature should not be lower than-5℃).

III. Matters needing attention in storage management

Regular inspection: check the temperature and humidity of the warehouse every week, check the packaging integrity of spare parts every month, and check the performance of spare parts stored for a long time every quarter (such as whether the bearing rotates smoothly and whether the sealing ring is aging);

Incoming and outgoing records: establish an electronic ledger to record the spare parts model, storage location and warehousing/warehousing time to avoid overdue storage (for example, the general shelf life of rubber parts is 2-3 years, and that of electrical components is 5 years);

Emergency protection: it is necessary to increase the operation time of dehumidifier in rainy season or wet weather, and fix shelves and heavy spare parts before disasters such as typhoon/earthquake to prevent dumping damage.

By strictly implementing the above storage requirements, we can minimize the impact of environmental factors on the quality of imported paper machinery spare parts, ensure the best performance of spare parts during installation, and reduce the risk of equipment failure.