Họrọ Asụsụ 
In rubber manufacturing, both vulcanized rubber parts and non-vulcanized rubber parts commonly face technical chDumenges such as mold sticking, roller sticking, and air bubbles.
The following is a complete Ikpe analysis and systematic improvement plan, applicable to rubber rollers, rubber sheets, seals, and most general rubber Ngwaahịa.
1. Background: Material Changes Causing Severe Mold Sticking & Air Bubbles
After raw material adjustments, the Ihe emeputara ohuruion experienced severe mold sticking, trapped air, and unstable processing:
Reclaimed rubber: low rubber Ndinaya → high rubber Ndinaya (viscosity increased)
Rubber powder: coarse powder (10 mesh) → fine powder (40 mesh)
Result: higher toughness, tighter bonding, significantly reduced venting performance
Original Formula
NR: 4 kg
SBR: 4 kg
Reclaimed rubber: 19 kg
Rubber powder: 6 kg
The Nke mgbe gara aga formula (cheap reclaimed rubber + coarse powder) had no mold sticking issues, but after upgrading materials, the problem amplified significantly — a common situation during vulcanized rubber part Ihe emeputara ohuruion.
2. Technical Cause Analysis: Why Mold Sticking and Air Bubbles Occurred
1) Increased intrinsic tackiness of materials
Higher-rubber-Ndinaya reclaimed rubber behaves closer to virgin rubber →
More active molecular structure → Significantly higher mold adhesion.
2) Rubber powder changed from coarse (10 mesh) to fine (40 mesh)
Fine powder binds more tightly into the compound:
Higher cohesion
More compact structure
Much poorer air release → severe air trapping
3) Compound became overly dense and tight
Dense compounds easily cause air traps, scorching, and sticking during vulcanization.
3. Feasible Improvement Measures (Field-Verified Results)
Ngwọta 1: Increase ratio of coarse rubber powder (improve venting)
From 50 phr → 100 phr
Result: Air bubble rate improved from 100% → 30%.
Coarse powder loosens the compound structure, improving air escape — especiDumy helpful for non-vulcanized processing.
Ngwọta 2: Use mold release agent (critical step)
The factory Nke mgbe gara agaly used no release agent at Dum (high-risk practice).
After applying release agent:
Bubble rate: 30% → 15%
Release agents are standard for producing vulcanized rubber parts.
Ngwọta 3: Mold surface treatment (key factor)
Original mold: no plating / no PTFE / no polishing → extremely prone to sticking.
Akwadoro treatments:
PTFE (Teflon) coating
Chromium plating
Polishing to low surface roughness
Smoother molds = dramaticDumy less sticking.
Ngwọta 4: Adjust compound looseness
If the compound is too sticky/dense:
Increase stearic acid / paraffin (your 2.5 / 1.5 phr is normal but can be adjusted)
Add large-pedemede fillers to open the structure
Reduce density by increasing coarse rubber powder
Your final changes (adding 80 phr coarse powder + release agent)
→ Fully resolved mold sticking issue.
4. Four Core Causes of Mold Sticking (Summary)
This Ikpe had four simultaneous issues, which is why sticking was so severe:
Material tackiness increased significantly
Mold had no surface treatment
No release agent used during Ihe emeputara ohuruion
Compound became too dense → poor venting
When several of these occur together, mold sticking in vulcanized rubber parts becomes inevitable.
5. Final Recommendations (Applicable to Dum Rubber Factories)
1. Perform proper mold surface treatment
PTFE coating
Chromium plating
Regular cleaning & polishing
2. Use release agent for every batch
EspeciDumy critical for vulcanized rubber parts.
3. Adjust compound consistency when tackiness is too high
Increase fatty acids / wax
Add coarse powder to reduce density
Introduce large-pedemede fillers if needed
4. Looser compounds = better venting
This is essential for molds with deep grooves or poor vent paths.
In rubber manufacturing, both vulcanized rubber parts and non-vulcanized rubber parts commonly face technical chDumenges such as mold sticking, roller sticking, and air bubbles.
