Эластомер кушымталарында белгеч
1998 елдан башлап NVH өчен иң яхшы чишелешләр
Chinese rubber parts factory

Яңалыклар

Technical Analysis and Improvement Plan for Mold Sticking and Air-Trapping Issues in Rubber Processing

Posted on15 December 2025

In rubber manufacturing, both vulcanized rubber parts and non-vulcanized rubber parts commonly face technical chБарысы даenges such as mold sticking, roller sticking, and air bubbles.

The following is a complete Эш analysis and systematic improvement plan, applicable to rubber rollers, rubber sheets, seals, and most general rubber Продуктлар.



1. Background: Material Changes Causing Severe Mold Sticking & Air Bubbles

After raw material adjustments, the Продуктion experienced severe mold sticking, trapped air, and unstable processing:

Reclaimed rubber: low rubber Эчтәлек → high rubber Эчтәлек (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 Алдагы 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 Продуктion.


2. Technical Cause Analysis: Why Mold Sticking and Air Bubbles Occurred

1) Increased intrinsic tackiness of materials

Higher-rubber-Эчтәлек 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)

Чишү 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 — especiБарысы даy helpful for non-vulcanized processing.


Чишү 2: Use mold release agent (critical step)

The factory Алдагыly used no release agent at Барысы да (high-risk practice).

After applying release agent:
Bubble rate: 30% → 15%

Release agents are standard for producing vulcanized rubber parts.


Чишү 3: Mold surface treatment (key factor)

Original mold: no plating / no PTFE / no polishing → extremely prone to sticking.

Тәкъдим ителә treatments:

PTFE (Teflon) coating

Chromium plating

Polishing to low surface roughness

Smoother molds = dramaticБарысы даy less sticking.


Чишү 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-pмәкалә 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 Эш 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 Продуктion

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 Барысы да Rubber Factories)

1. Perform proper mold surface treatment

PTFE coating

Chromium plating

Regular cleaning & polishing

2. Use release agent for every batch

EspeciБарысы даy 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-pмәкалә fillers if needed

4. Looser compounds = better venting

This is essential for molds with deep grooves or poor vent paths.

Technical Analysis and Improvement Plan for Mold Sticking and Air-Trapping Issues in Rubber Processing

In rubber manufacturing, both vulcanized rubber parts and non-vulcanized rubber parts commonly face technical chБарысы даenges such as mold stickingroller sticking, and air bubbles.

Бәйләнешле яңалыклар
Бәйләнешле продуктлар

Әгәр дә сез безнең продуктлар белән кызыксынсагыз, сез монда мәгълүматыгызны монда калдыра аласыз, һәм тиздән сезнең белән элемтәдә торырбыз.

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