How to solve the aging and cracking of rubber?

The excellent properties of rubber make it an excellent material for shock absorption, sealing, flexing, wear resistance, corrosion resistance, insulation and bonding in the industry, and are widely used in aerospace, automotive, electronic manufacturing and medical equipment and other fields.

Aging is one of the main reasons for the deterioration of rubber properties. Aging of rubber refers to the phenomenon that the performance and appearance of rubber deteriorate over time under the comprehensive influence of various conditions of natural and artificial environment during storage and use. Rubber products are often damaged by heat, oxygen and ozone in the air, sunlight, wind, rain, snow, moisture, and various mechanical stress or chemical solvents during use, which destroy the chemical structure of rubber and gradually lose use over time. value.

The common aging failure phenomena of rubber or rubber products are as follows:

Hardened, brittle, softened, powdered, sticky, discolored, cracked/cracked, etc. Some products will also be broken by hydrolysis or mildew will grow.

There are many reasons for rubber aging, specifically divided into external and internal causes.

1. External causes

· Physical factors: heat, electricity, light, mechanical force, radiation, etc.

· Chemical factors: oxygen, ozone, water vapor in the air, acid, alkali, salt, etc.

Biological factors: Microorganisms (bacteria, fungi, molds, etc.).

2. Internal factors

· Changes in the molecular structure of rubber

· Formula and composition of rubber

· Mechanical force and chemical action in the production process

In practice, the reason for the aging of rubber products is often caused by the combined action of the above-mentioned different factors, so the aging of rubber is a complex process. The aging process of rubber is an irreversible chemical reaction, like other chemical reactions, which will be accompanied by changes in appearance, structure and performance.

So, how can we prevent the rubber from aging or prolong the service life of the rubber?

First of all, we cannot absolutely prevent the occurrence of rubber aging. Secondly, only by carefully studying the various causes of rubber aging, and taking appropriate measures according to the cause, can the speed of rubber aging be delayed, so as to achieve the purpose of extending the service life of rubber.

Typical rubber aging failure cases

1. Background introduction

The front cantilever bushing under the cab of a vehicle was cracked during the use of the client. Therefore, the customer entrusted the Maxin testing laboratory to conduct a failure analysis of the cantilever bushing before the failure. At the same time, the customer was asked to provide the same batch of unused products for comparison, to find the root cause of the cracking failure of the front cantilever bushing, and to propose solutions.

2. Comprehensive analysis

Maxim's testing laboratory selected the failed samples (cracked front cantilever bushings) and the same batch of good products for comparative analysis:

① Visual inspection was carried out on the surface of the bushing groove of the failed sample and the good product with a stereo microscope. It was found that the surface of the bushing groove of the failed sample had yellow stains and cracks in different degrees, which were the lines of rubber aging and cracking, while the good product had yellow stains on the surface of the bushing groove. No obvious cracks were found.