Full FAQ of 15 Core Shoe-Making Machines for Complete Production Line
list of shoe-making machinery
1. Swing Arm Hydraulic Cutting Machine (Material Cutting)
2. Gantry Heavy-Duty Cutting Machine (Large Panel Cutting)
3. Computerized Vibration Knife Cutting Machine (Intelligent Cutting)
4. Band Knife Splitting Machine (Upper Preparation)
5. Fully Automatic Hot Melt Cement Folding Machine (Edge Treatment)
6. Roller Feed Sewing Machine / Post Bed Sewing Machine (Upper Stitching)
7. High-Speed Computerized Pattern Sewing Machine (Automatic Stitching)
8. Fully Automatic Toe Lasting Machine (Toe Molding)
9. Fully Automatic Heel Lasting Machine (Heel Molding)
10. Infrared Multi-Zone Drying Conveyor Line (Assembly Line Drying)
11. Universal Air Bag Sole Pressing Machine (Sole Bonding & Molding)
12. High-Speed Quick Freezing Setting Machine (Setting & Last Stripping)
13. Fully Automatic Injection Sole Molding Machine (Outsole Manufacturing)
14. Intelligent 3D Vision Glue Spraying Robot (Intelligent Molding Spraying)
15. Automatic Last Stripping Robot (Intelligent Post-Processing)
12. Fully Automatic Heel Lasting Machine
Q: The rubber tightening band shifts left and right when wrapping the heel.
A: The heel positioning support platform is skewed, or air pressure of tightening cylinders on both sides is unbalanced. Re-calibrate the central line and balance cylinder pressure on both sides.
Q: The glue area on upper leather turns white and loses adhesion after heel lasting.
A: The built-in heating sheet of the tightening band is burnt out, failing to activate hot melt glue instantly. Inspect and replace heating components.
Q: The manipulator frequently drops shoe lasts during gripping.
A: Anti-slip rubber pads on clamping jaws are worn and slippery; magnetic proximity switches of clamping cylinders shift position, triggering the next action before full clamping. Replace rubber pads and readjust sensor positions.
Infrared Multi-Zone Drying Conveyor Line
Q: Glue remains sticky and bubbles form on shoe surfaces after passing through the oven.
A: Oven temperature is excessively high with poor exhaust and dehumidification. Solvents inside glue boil instantly and form bubbles. Reduce heating tube power and boost exhaust fan airflow on top of the oven.
Q: The drive motor buzzes, while the conveyor belt slips and moves intermittently.
A: The belt stretches loose after long service; key grooves of drive rollers wear and slip. Adjust the tension screw at the tail to re-tighten the conveyor belt and repair worn rollers.
Q: Infrared heating tubes burn out frequently with short service life.
A: Unstable factory voltage generates surge voltage; poor circulation of oven fans leads to local heat accumulation and over-temperature operation of heating tubes. Install voltage stabilizers and overhaul circulating fans.
Universal Air Bag Sole Pressing Machine
Q: Air bag pressure drops gradually during pressure holding and cannot maintain the set value.
A: Internal air circuit leakage. Check if sealing gaskets at the joint between air bag and metal base are aging; inspect if the one-way sealing of intake/exhaust solenoid valves fails. Replace aged seals and repair solenoid valves.
Q: The heel part of high heels or special grooved outsoles is dented with uneven stress during pressing.
A: Install special heel supporting ejectors to balance upward supporting force of the air bag and ensure uniform stress distribution.
Q: Daily protection tips to prevent air bags from being pierced by sharp edges of soles.
A: Cover the air bag surface with high-elastic wear-resistant rubber protective film during operation; clear nails and hard burrs on soles before feeding.
High-Speed Quick Freezing Setting Machine
Q: The internal temperature of the freezer cannot drop below minus 10°C.
A: Refrigerant leaks – perform leak detection and refill refrigerant; excessive frost blocks air ducts on the evaporator. Start the forced defrost program manually.
Q: Heavy condensation dew covers uppers and lasts after taking shoes out of the freezer, dampening leather.
A: Damaged or missing thermal insulation wind curtains at freezer inlets and outlets allow hot humid external air to enter and condense instantly. Replace airtight wind curtains.
Q: Drive chains jam or skip teeth frequently.
A: Ordinary lubricating grease solidifies under ultra-low temperature and increases friction resistance. Remove old grease completely and fill with special low-temperature aviation lubricant.
13. Fully Automatic Injection Sole Molding Machine (Disc Outsole Machine)
Q: Harsh metal friction noise occurs during screw feeding, and black scorch spots form on molded outsoles.
A: Noise: Heating tubes of certain temperature zones burn out, plastic fails to melt fully and the screw grinds hard material dryly. Scorch spots: Over-temperature of partial zones carbonizes plastic. Inspect heating tubes of each zone and lower temperature of overheated sections.
Q: Large flash overflow occurs at mold closing surfaces and causes waste soles.
A: Insufficient mold clamping force or internal leakage of clamping hydraulic cylinders; excessive injection metering stroke exceeding mold cavity volume. Reduce injection volume and overhaul mold clamping hydraulic system.
Q: EVA/rubber outsoles shrink severely and become undersized after demolding.
A: Insufficient mold cooling time, too short pressure holding time and pressure. Internal thermal stress of outsoles cannot be fully released before mold opening. Optimize molding parameters by extending cooling and pressure holding duration.
14. Intelligent 3D Vision Glue Spraying Robot
Q: The 3D camera scans outsoles normally, but the overall glue spraying track shifts 2–3 mm.
A: Hand-Eye Calibration data between the vision system and industrial robot is lost or slightly shifted (caused by minor collision of the robot head). Re-run the calibration program with a calibration block.
Q: The glue line sprayed by the gun diverges, splits or flows intermittently.
A: Residual glue semi-clogs the nozzle. Remove and soak the nozzle in gun cleaning solvent; check solvent liquid level of the automatic cleaning station and refill timely.
Q: The robot emergency stops suddenly and the teach pendant reports "Axis Limit / Hardware Limit Exception".
A: The programmed spraying track exceeds the physical motion limit of robot joints. Readjust the placement angle of outsoles on assembly line fixtures and re-plan spraying paths.
15. Automatic Last Stripping Robot
Q: Gripping jaws often pinch and tear heel leather during last stripping.
A: Excessive clamping pressure of jaws; polyurethane soft protective pads on jaws wear off and expose hard metal edges. Replace protective pads and lower the proportional valve pressure.
Q: The machine frequently reports "Last Stripping Torque Over Limit" and fails to pull out shoe lasts.
A: Insufficient drying and freezing setting in previous processes; unhardened glue sticks uppers tightly to lasts. Optimize parameters of the freezing setting machine, and spray proper release agent before lasting.
Q: The vision camera repeatedly fails to recognize positioning holes/gripping points on shoe lasts and shuts down frequently.
A: Fluctuating workshop lighting (strong direct sunlight or dim night light) leads to overexposure or underexposure of the camera. Install industrial light shielding hoods and constant LED strip light sources.
Summary & Suggestions
This complete FAQ covers mechanical, hydraulic, pneumatic, thermal control, servo automation and machine vision faults of all 15 full-production-line shoe machines. It can be compiled into workshop Standard Operating Procedures (SOP) and used for mechanic training and daily equipment inspection, greatly improving Overall Equipment Efficiency (OEE) and reducing production defect rates.
