A New Chapter in TPE Material Applications: A Success Story of ES70A-YJT in Hanger Accessories
Time of issue:2026-01-19
I. Background Requirements
The customer reported that the existing hanger accessories (PP-coated stickers) exhibit issues such as friction-induced whitening and powder shedding during use, and they strictly require that no oiling on the surface whatsoever is allowed. The development goal must simultaneously meet the following requirements:
- Completely solve the powder-shedding issue (core indicator of scratch resistance)
- 100% dry and oil-free (mandatory requirement)
- Suitable for 190℃ injection molding process
- Stable coating on PP/PE substrates
II. Candidate Material Screening
Four TPE grades were selected for comparative testing: ES70A-YJT, ES65A-ZH, C65CT03, and ES60A-MW.
III. Analysis of Key Issues in the Import Process
1. ES70A-YJT Testing Status
- Advantage ：
- The scratch resistance test fully meets the standards, effectively addressing the issue of powder shedding.
- Remains surface-dry even in high-temperature environments, with zero oil seepage.
- Initial issues ：
- Cold material layering occurs at the gate point (due to the medium flowability of the material and the original mold gate design, which results in an excessively low temperature at the front of the melt flow).
- Solution ：
Redesign the gate dimensions, raise the hot runner temperature to 195–200℃, and increase the holding pressure—ultimately achieving perfect molding.
2. Test Status of ES65A-ZH
- Failure manifestation ：
- Scratch-resistant pass, but the surface is severely oily.
- There is also delamination at the gate location.
- Root cause analysis ：
The material formulation contains small-molecule migratory plasticizers that continuously leach out at high temperatures; mismatched flowability exacerbates cold-flow layering.
3. Test Status of C65CT03
- Failure manifestation ：
- Scratch resistance meets the standard.
- Slight oiliness
- The cold glue shows obvious delamination.
- Root cause analysis ：
Insufficient melt strength causes the leading edge of the material flow to cool too rapidly; lubricant components in the formulation separate out, forming oil stains.
4. Test Status of ES60A-MW
- Failure manifestation ：
- Meets scratch resistance standards but exhibits noticeable oiling.
- The hierarchical issue is the most serious.
- Root cause analysis ：
Excessive fluidity causes a sudden drop in the temperature of the melt front during injection molding, resulting in a cold slug; the plasticizing system lacks sufficient stability.
IV. Breakthrough Solutions
- Material lock Only the ES70A-YJT meets the core requirement of “no oil leakage.” Its special polymer toughening system prevents the migration of small molecules, and its medium-flow characteristics, after being adjusted via mold design, are transformed into molding advantages.
- Mold Process Collaborative Optimization Increasing the gate diameter by 15% reduces shear-induced heat generation. The hot runner is heated to 195℃ to maintain the melt temperature, and the holding pressure is increased by 20% to eliminate interfacial delamination.
- Ultimate verification result ：
Coating adhesion: Adheres to the PP/PE substrate with satisfactory peel strength.
Weather Resistance: No chalking or cracking after 500 hours of accelerated UV aging.
Dryness: No oil stains appear after 30 days of storage at 60℃.
Mass-production yield: Jumped from an initial 62% to 98%.
V. Conclusion
This case through Precise selection of material formulations + deep collaboration in mold technology Successfully addressing industry pain points:
- Final material ES70A-YJT
- Core Values Original molecular structure design achieves a breakthrough in the industry by realizing “zero oil leakage”; its scratch resistance completely eliminates the issue of powder shedding caused by hanger friction; and its weather resistance ensures long-term outdoor use.
- Customer Feedback The non-performing rate has dropped below 2%, and the project has passed acceptance inspection.
Technical Insights
- The essence of the oil leakage issue Avoid using small-molecule plasticizers and instead adopt a polyolefin-based toughening system.
- Hierarchical resolution of key issues Medium-flow materials require a flared gating system.
- Systems Development Thinking Materials, molds, and processes must be optimized through three-dimensional coordinated optimization.
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ADD: Huangxi Industrial Park, Shiwan Town, Boluo County, Huizhou City, Guangdong Province，China