Project: Three screw caps with slightly deviated, non-unified thread dimensions needed to fit a single glass bottle body. Our master craftsmen demonstrated peerless craftsmanship—from design drafting to mold adjustment, coordinating with production supervisors to closely monitor the assembly line, minimizing thermal shrinkage, and ensuring seamless front-backend communication—ultimately delivering a near-perfect product that flawlessly fit three cap types and a gasket.
Limitations of traditional molds: Conventional thread engagement requires an error <0.2mm, but the three caps had a 0.55mm thread discrepancy. Master Wang led the mold team in 72 consecutive hours of surveying:
▶ Scanned cap threads with a three-coordinate measuring instrument, generating 2,000+ point data (with measurement cloud diagram attached)
▶ Innovated a “layered nested core” structure: embedded three fine-tunable thread inserts in the main core, adjusting insert spacing to 0.01mm via micrometer (1/6 the diameter of a human hair)
Mold trial history: First two trials failed—
▶ 1st trial: Cap #1 was over-tightened with uneven thread edges
▶ 2nd trial: Cap #2 had thread over-engagement (standard required ≥0.2mm)
▶ 3rd trial: Leveraging our backend experience, we modified mold dimensions, controlled temperature, and thickened thread crests, finally minimizing torque difference for perfect engagement
Precision temperature control: With strict control over glass bottle ejection and cooling temperatures, the shrinkage rate reached 1.2%. To offset the difference:
▶ Front-end engineers used Moldflow to simulate different cooling layouts, finalizing a design that improved cooling efficiency by 40%
▶ Veteran production master Zhang monitored molding temperatures with an infrared thermometer every minute: “The bottle mouth temperature must be controlled at 55±2℃—too high expands threads, too low makes the bottle body brittle.”
Data-driven management: Established the Three-Cap-One-Bottle Adaptation Production Manual, specifying:
- Indicator: Melt Temperature, Standard Value: 230±5℃, Control Measure: Segmented intelligent temperature control
- Indicator: Cooling Time, Standard Value: 18-22 seconds, Control Measure: Real-time monitoring of inlet-outlet temperature difference
- Indicator: Thread Concentricity, Standard Value: ≤0.08mm, Control Measure: Central positioning column + secondary correction mechanism
Cross-departmental workflow:
▶ Front-end development actively communicated with clients, ensuring every request was recorded and responded to
▶ Design team (Master Shao): Synchronized mold adjustment data to the production department daily at 17:00
▶ Production team (Master Zhang): Sampled 50 bottle bodies per batch, comparing thread profiles with instruments and conducting physical trials
▶ Quality team: Developed “three-cap adaptation testing” to simulate 1,000 cap presses and 500 screwing operations for durability
Our Response speed:
▶ Retrieved gasket supplier’s material report (hardness 55±5 Shore A) within 10 minutes
▶ Collaborated with the design team to modify the bottle mouth seal groove depth from 1.8mm to 2.1mm within 2 hours
▶ Successfully trial-produced within 4 hours, increasing gasket compression from 15% to 22% to meet leak-proof standards
Adaptation accuracy of industry benchmarks:
▶ Air leakage rate after screwing three caps: ≤1% (industry standard for one cap-one bottle: ≤3%)
▶ Torque consistency: ±0.2N·m (peers typically have ±0.8N·m)
▶ Thermal cycle test (-20℃~60℃, 100 cycles): No cracking or loosening
Value to customers:
▶ Mold cost savings: $60,000 saved compared to three sets of molds
▶ Lead time compressed: From 35 days to 18 days, meeting peak-season stocking needs
▶ Follow-up cooperation: Customer received an additional $1.5 million order from the principal
Customer says:
“Their project coordinator Xiao Zhu sent production videos three times a day, even filming the mold numbers. Most shockingly, during the 5th mold trial, Master Shao disassembled the threaded insert and hand polished it with fine sandpaper for 2 hours for a special angle that the machine was difficult to form—now this bottle has become our best-selling packaging, and a competitor asked us about the supplier last month.”
The core challenge of “three caps-one bottle” lies not in single-point technical breakthroughs, but in end-to-end precision control:
- Design end: Using an “elastic compensation structure” to transform static threads into a dynamic adaptation system, adjusting the thickness and shape of thread segments
- Mold end: Breaking through the “one mold-one specification” convention to achieve “millimeter-level collaboration of multi-specification threads”
- Production end: Establishing a real-time mapping model of “temperature-shrinkage-precision”
- Collaboration end: Transforming “departmental barriers” into a “data sharing hub”
This capability has formed a replicable “Non universal product adaptation solutions”, which has helped over 50+ customers solve similar problems. While the industry is still using “increasing the number of molds” to solve problems, we choose to do “subtraction innovation” with a precision of 0.1mm, breaking down every “impossible” link into verifiable technical nodes.
