How Long Does Rubber Molding Last?

January 20, 2023

Rubber molds can last several years on the shelf with proper storage, depending on the type of rubber. But it’s difficult to predict how many casts you’ll get from a single rubber molding during its production life. Once in use, the level of care you give the mold will determine how long it lasts.

What Is the Library Life of Rubber Molds?

The library life of a rubber mold refers to how long it will last on the shelf without using it. Molds can live for several years if you take good care of them. Some rubber molds will last longer than others because of their specific material composition.

With proper storage, the library life of platinum catalyst silicone and polyurethane rubber molds is the longest. Tin catalyst silicone molds have the shortest shelf life.

What Is the Useful Life of Rubber Molds?

A rubber mold’s useful life refers to the period it is used in production. Estimating the production life of a mold is impossible because various factors will affect its useful life once you take it off the shelf. Here are four factors that may determine how long your rubber molding lasts:

1. Mold Release

Using mold release every time you cast extends the life of your mold. The mold release prevents the substrate from bonding to the rubber surface, leaving it in its original state. When you fail to use mold release, there will be a stuck substrate pile-up. This pile-up makes your mold less effective.

2. Mold Structure

Simple molds tend to last longer than complex molds with many details. The structural complexity makes the detailed mold weaker than its simpler counterparts. Since detailed molds are fragile, they may only be used to make a few casts before they lose their effectiveness.

3. Mold Storage

How you store your molding after each use has an impact on how long it will serve you. Check where you place your rubber molds and keep them free from hazards like moisture and objects that cause wear and tear. With proper storage, your molds will serve you for the longest possible time.

4. Mold Casting Material

The materials you use to cast the molds will determine the useful life of the molds. The hotter the casting material gets while curing, the more destructive it is to the mold, shortening its life. If you cast abrasive substances, your rubber molds will also wear and tear sooner.

What Is the Proper Way To Store Rubber Molds?

How you store your rubber mold may shorten or lengthen its overall lifespan. Here is how you should store your molds to enjoy the longest possible lifespan:

Store in a Cool and Dry Place

Keep your molds away from sunlight in a cool and dry place. Rubber molds are not UV-resistant. When you expose them to direct sunlight, they will chalk up and turn yellow, shortening their lifespan. The heat from other sources will also have a similar effect, while moisture will cause natural rubber molds to expand.

Maintain the Original Mold Shape

Always keep your molds in their original shape. Rubber may never return to its original shape if kept in a distorted position for an extended period. Keep the corners straight, and don’t place heavy objects below or on the molds.

Use Original Models for Support

Keep a poured blanket mold or brush-on molds in their mother molds. Intricate blanket molds may need you to store them with the original attached model. Some of these rubber moldings could collapse after some time. You will need to fasten two-piece mold shells together with the proper hardware before storing them.

Do Not Combine Rubbers When Storing

When in storage, avoid letting molds made of one type of rubber touch molds made of a different kind of rubber. This rule also applies to rubbers from the same series. Plasticizers and oils may migrate if you place one type of polyurethane rubber directly on top of another. This migration could include shrinkage, swelling, or distortion of the rubber molds.