Full Automatic Jar Capping Machine Single Head Plastic Glass Metal Bottle Cap Equipment

Cap torque is the single most important variable in bottle capping — and the most frequently uncontrolled. Every closure type, from a simple continuous-thread plastic cap on a water bottle to a child-resistant metal lug cap on a pharmaceutical jar, has an optimal torque range. Below this range, the cap may loosen during transport, leading to leakage, contamination, and product loss. Above this range, the cap may be difficult for the end user to open, the bottle neck threads may strip, or — in the case of glass containers — the finish may crack entirely.

The challenge is that torque requirements vary dramatically by application. A 28mm beverage cap may require only 1.5-2.5 N·m of application torque. A 110mm industrial drum bung may require 25-35 N·m. A child-resistant pharmaceutical closure requires a specific push-and-turn motion profile rather than simple rotation. Traditional mechanical and pneumatic capping systems apply a fixed level of force regardless of the closure type, making them inherently imprecise.

The CM100's servo-driven capping head replaces the pneumatic cylinder or mechanical clutch found in conventional cappers with a precision servo motor coupled to a torque sensor in a closed-loop feedback configuration:

1. The Command: The operator sets the target torque value (in N·m) on the HMI touchscreen, along with parameters for rotation speed, downward force, and the number of turns. These values are saved as a named recipe.
2. The Pickup: The servo motor positions the capping head precisely above the cap pickup point. The head descends, grips the cap (using either vacuum suction or mechanical jaws depending on cap type), and lifts it into position above the waiting bottle.
3. The Engagement: The capping head descends onto the bottle neck. The servo motor begins rotating at the programmed engagement speed — typically a slower initial speed to ensure the cap thread engages correctly with the bottle thread without cross-threading.
4. The Tightening: Once thread engagement is confirmed, the servo accelerates to the programmed tightening speed. Throughout rotation, the torque sensor measures actual applied torque in real time and feeds this data back to the servo drive at microsecond intervals.
5. The Stop: When the measured torque reaches the target value, the servo drive commands an instantaneous stop. There is no mechanical clutch to slip, no pneumatic cylinder to bounce, no inertia overrun from a coasting motor. The cap stops at exactly the programmed torque — every time.
6. The Verification: The actual torque value achieved is logged. If the value falls outside the acceptable range (which can be configured, e.g., ±3% of target), the machine flags the bottle for rejection at the downstream inspection station.

The financial impact of imprecise capping cascades through the supply chain:

• Under-torqued caps leak in transit, contaminating secondary packaging, triggering retailer chargebacks ($150-500 per incident), and eroding consumer trust. One major beverage brand estimated that a 1% under-torque rate cost $2.4 million annually in product loss and chargebacks.

• Over-torqued caps frustrate consumers, particularly elderly users or those with reduced hand strength. Consumer complaint data consistently ranks "cap too tight" among the top 5 reasons for negative product reviews. Damaged threads from over-torquing also create a leak path for the next use, even if the initial seal holds.

• Inconsistent torque across a production run means some consumers struggle while others find their caps loose — an inconsistency that damages brand perception of quality control.

The CM100's servo torque control eliminates these problems at the source, delivering identical torque to every bottle in the run.

The CM100's touchscreen HMI provides:

• Torque Set Point Entry: Digital keypad input of target torque in N·m, in·lb, or kgf·cm
• Real-Time Torque Display: Live graphical display of torque during the capping cycle, with min/max/mean statistics
• Alarm Configuration: User-defined torque limits; bottles outside limits trigger an alarm and can actuate a reject mechanism
• Recipe Management: 1,000+ stored recipes with alphanumeric naming and search

Q: What is the torque range of the CM100?

A: The standard CM100 servo motor and gearbox configuration covers a torque range of approximately 0.5-30 N·m, suitable for caps from 20mm to 130mm diameter. For applications outside this range, the servo motor and gear reducer can be resized. Please provide your target torque specification for an accurate configuration recommendation.

Q: How often does the torque sensor need calibration?

A: We recommend annual torque sensor calibration as part of preventive maintenance, or more frequently in high-utilization (3-shift) operations. Calibration is performed using a calibrated torque transducer traceable to national standards. The calibration procedure is documented in the user manual and can be performed by your in-house metrology team or by our service engineers.

Q: Does the torque remain consistent as the servo motor ages?

A: Yes — this is a key advantage of closed-loop feedback control. The torque sensor measures actual applied torque, not motor current. As long as the sensor is within its calibration interval, the feedback loop compensates for any changes in motor efficiency, bearing friction, or mechanical wear. Torque at the cap is what the sensor measures and what the controller maintains.

Q: Who manufactures the servo motor used in the CM100?

A: The CM100 uses internationally recognized servo motor brands. The specific brand and model are specified in your quotation and are selected based on your regional service preferences and voltage requirements. All servo motors used are supported by local distributors for spare parts and service in major markets worldwide.

Q: Can your engineers help us determine the correct torque specification for a new product?

A: Yes. Our application engineering team provides torque development support as part of our pre-sales service. Send us your bottles, caps, and any seal liner or gasket material, and we will perform torque-to-failure testing and torque-to-seal testing to determine the optimal torque window. We provide a formal report with recommended set points and tolerances.

Q: What happens if the servo drive fails after the warranty period?

A: Servo drives from major manufacturers are widely available globally. We provide the exact part number and firmware version in your machine documentation so you can source locally if preferred. Alternatively, we stock replacement drives and can ship internationally within 3-7 business days. Our remote diagnostic service can often resolve servo-related issues through parameter adjustment without hardware replacement.

Q: Do you offer a torque validation service for existing lines considering an upgrade to servo capping?

A: Yes. If you are currently using pneumatic or mechanical clutch cappers and considering an upgrade, we can provide a torque audit — measuring the actual torque distribution on your current line across a statistically significant sample — and quantify the improvement a servo system would deliver. This data supports your capital expenditure justification.