Is a used slitting machine worth buying? Reliability Testing and Pit Avoidance Guide

Whether it is worth buying a used slitter depends on the condition of the equipment, the price, the need to use it, and your risk tolerance. The following is a detailed guide to reliability detection and pit avoidance to help you make informed decisions:

1. The advantages and disadvantages of second-hand slitting machine

Merit:

1. Low cost: The price is usually 30%-50% of the new machine, which is suitable for enterprises with limited budget.

2. Fast delivery: no need to wait for the production cycle, it can be put into use quickly.

3. Slow depreciation: Second-hand equipment has passed the period of substantial depreciation, and the loss is small when it changes hands.

Shortcoming:

1. Hidden faults: There may be wear and tear, aging, or historical repair issues.

2. Backward technology: Older models may be inefficient, consume energy, or have poor compatibility.

3. No warranty: Most second-hand equipment does not provide after-sales service.

2. The key reliability testing steps

1. Device Background Check

• Service life: The life of the slitter is usually 8-15 years, and equipment more than 10 years needs to be cautious.

• Original use: Ask the previous owner if it was used for high-load production (e.g. 24-hour continuous operation).

• Maintenance records: Check whether there are overhaul records (e.g. spindle and servo system replacement).

2. Inspection of core components

• Slitting Knife Holder & Blades:

◦ Check whether the cutter shaft is deformed and the degree of wear of the blade edge (obvious notches need to be replaced).

◦ Test the flexibility of the blade adjustment mechanism with or without jamming.

• Drivetrain:

◦ The belt/gear transmission should be free of cracks and looseness; Whether the chain is overstretched.

◦ The servo motor or inverter needs to be powered on to observe whether it is abnormal noise or overheating.

• Electrical system:

◦ Open the control cabinet and check the aging of the circuit and the status of the PLC module.

◦ Test whether the touch screen or keys are responsive.

• Roller & Tension Control:

◦ The surface of the roller should be free of dents and rust (affecting the flatness of the material).

◦ Whether the tension sensor is sensitive, and whether the unwinding/winding is uniform.

3. Test verification

• No-load operation: observe whether the vibration and noise of the equipment are abnormal (can be detected by decibel meter, and more than 75dB needs to be vigilant).

• Strip Test:

◦ Test cutting with actual production materials to check the slitting accuracy (such as ± within 0.1mm is better).

◦ Check whether the scrap rate is reasonable (generally ≤ 3%).

4. Technical adaptability

• Material compatibility: Confirm that the device can handle your materials (e.g. film, paper, metal foil thickness range).

• Speed matching: The speed of the second-hand slitting machine may be lower than that of the new machine, and the capacity demand needs should be compared (such as 300m/min for the new machine and 200m/min for the old machine).

3. Pit avoidance guide

1. Common pitfalls

• Refurbished machines pass off as second-hand: Paint to cover up rust and replace inferior parts. Focus on checking the traces of screw disassembly and internal oil stains.

• Concealing faults: Sellers may run briefly to cover up problems. Requires a cold start-up test.

• Model elimination: It is difficult to find accessories for old models (such as specific PLC models), so it is necessary to check the market supply in advance.

2. Purchase channel selection

• Priority Channels:

◦ Original refurbished machine (with warranty).

◦ Well-known used equipment platforms (e.g. Ritchie Bros., Equipment Trader).

• Prudent Channels:

◦ Individual sellers (lack of after-sales protection).

◦ Online stores without physical stores (to avoid "mismatching").

3. Price negotiation skills

• Reference basis: according to the age of the equipment, the average market price (such as about 40% of the new machine for 5 years), and the maintenance cost (such as about 20,000 yuan for the replacement of servo motors).

• Additional terms: Require the seller to bear the cost of test materials or a short-term (e.g. 1 month) failure warranty.

4. The comparison of alternatives

5. Decision-making suggestions

• Worth buying: If the following conditions are met:

◦ The equipment has been professionally tested and has no major hidden dangers.

◦ The price is 40% lower than that of a new machine and the remaining life ≥ 5 years.

◦ You have a technical team available to handle minor glitches.

• Not recommended to buy: If:

◦ Critical components of the equipment (e.g., spindle, control system) are damaged.

◦ Extremely high slitting accuracy requirements (e.g. medical grade materials).

◦ There are no test conditions or the seller refuses to inspect the goods.

Final Steps:

1. Hire a third-party testing agency (cost about 2,000-5,000 yuan) to issue a report.

2. Sign the contract to clarify the status of the equipment, payment terms and terms of default.

Through systematic evaluation, second-hand slitting machines can become a cost-effective choice, but they must be strictly inspected to avoid risks.