Doubling

In doubling, two layers of material are joined using heat, pressure and usually adhesives or other bonding agents. The bond is made in such a way that the materials form a homogeneous unit and no delamination (separation of the layers) occurs.

Process steps

• Preparing the materials: the layers to be joined are cut to size and cleaned to ensure optimum adhesion.

• Applying adhesive or bonding agent: if necessary, a special adhesive or bonding agent is applied to support the bond.

• Bringing the layers together: the materials are placed on top of each other and fixed with pressure and/or heat.

• Curing or vulcanisation: depending on the material, vulcanisation or curing takes place to stabilise the bond.

Doubling makes it possible to produce composite materials that offer specific properties that could not be achieved with a single material. It is used to improve materials, extend their range of applications or increase material thickness cost-effectively.

Improving material properties

Doubling allows the properties of different layers to be combined, such as the chemical resistance of an outer layer with the flexibility of an inner layer. This is particularly important in industries that place high demands on material performance.

Reducing material costs

The process allows lower-cost materials to be used in inner layers, while more expensive, high-performance materials can be used for the outer layers. This reduces overall costs without impairing product performance.

Doubling is used in many industries and applications, particularly where material composites are needed to withstand high loads and extreme conditions, or simply to achieve a certain material thickness.

Seals and membranes

In seal manufacturing, materials with different properties are often doubled to ensure reliable sealing under pressure or chemical exposure. For example, a rubber seal can be doubled with a chemical-resistant outer layer.

Automotive industry

In the automotive industry, doubling is used to manufacture components that must withstand both thermal and mechanical loads, such as door seals or engine mounts.

Doubling offers a wide range of advantages that make it an indispensable process in the rubber and plastics industry:

• Combination of properties: materials can be combined so that they are optimally matched to the specific requirements of the application.

• Design flexibility: doubled materials can be adapted to different requirements such as chemical resistance, abrasion resistance or temperature tolerance.

• Cost efficiency: using lower-cost materials in certain layers can reduce production costs.

• Material thickness: cost-effective increase to the required material thickness

Despite its advantages, doubling requires careful planning and execution to achieve optimum results.

Material compatibility

Not all materials can easily be doubled together. The chemical and mechanical compatibility of the layers must be ensured to prevent delamination.

Process control

The parameters for pressure, temperature and time must be precisely controlled to ensure uniform bonding and curing.

Quality control

After doubling, the products must be checked for possible defects such as air pockets, incomplete adhesion or delamination to ensure quality.

1. Which materials can be doubled?

A wide range of materials can be doubled, including elastomers, plastics, textiles, fabric inserts and metals. The choice of materials depends on the specific requirements of the application.

2. Can doubling be done without adhesive?

Yes, in some cases doubling is carried out by vulcanisation or other thermal processes that do not require additional adhesives.

3. How is the quality of a doubled bond tested?

Quality is checked by visual inspections, adhesion tests and mechanical load tests to ensure that the bond meets the requirements.

4. Which industries benefit most from doubling?

Doubling is particularly widespread in the automotive, construction, food and chemical industries, where demanding material composites or large material thicknesses are often required for rubber sheets and water jet cut blanks.

Doubling is an indispensable process in the rubber and plastics industry, as it enables the production of material composites that meet the requirements of demanding applications. By combining the properties of different materials, products with optimised performance, improved durability and cost efficiency can be manufactured.