The Concept

DIAB advanced core materials, when used with high strength skins, provide the ideal combination of strength, stiffness and toughness. DIAB structural cores and composites sandwich solutions work by increasing the performance of composite parts while optimizing weight.

In principle a sandwich consists of two skins or facings with a core material in between. The skins take up normal stresses and give the structure a hardwearing surface. The core material absorbs the shear stresses generated by loads, distributing them over a larger area.

Compared to single skin laminates, the sandwich concept offers substantial improvements in both flexural rigidity and flexural strength. By doubling the thickness of the core, the improvements are even greater yet the weight increase is negligible.

Key Benifits

High Strength to Weight Ratio
The higher strength-to-weight ratio of the sandwich concept can be used in a variety of ways - higher speeds, longer range, greater payload capacity or reduced power demand – all of which give better operating economy. DIAB sandwich composites also offer:

Good Dynamic Strength
DIAB core materials have good dynamic properties making them ideal for applications where shock and impact loads could be experienced.

Low Water Absorption
Divinycell and Klegecell core materials are both closed cell materials and are therefore virtual impervious to the ingress of moisture.

Excellent Insulation
The good insulation and acoustic properties of DIAB core materials eliminate the need for additional insulation materials that normally add extra weight to the structure.

Performance Advantaged

The DIAB sandwich concept is one of the best ways to reduce weight whether it is used for structural members or interior paneling. But this is just the first step in the weight saving spiral. The DIAB sandwich concept also inherently increases stiffness and provides excellent sound and thermal insulation properties thus eliminating the need for subsidiary materials. This further weight reduction results in even lower energy consumption and consequently a much lower environmental impact.

This saving in weight can be used in a wide variety of ways including:

• Higher speeds
• Longer range
• Better fuel economy
• Larger payloads

In addition DIAB sandwich composites require the minimum of maintenance and repairs can often be carried out easily without any loss of structural integrity.

Production Benifits

Freedom of Design
The inherent nature of sandwich composites gives designers and engineers tremendous freedom in terms of both form and function. Compound curves can be readily incorporated. Also as the outer skins can be orientated to align with the load paths, structural integrity and performance can be maximized.

Production Flexibility
Components can be manufactured using low cost tooling. A wide variety of manufacturing processes can be employed including hand and spray laminating, vacuum consolidation, press molding and resin infusion.

DIAB sandwich core materials are also compatible with all commonly used composite materials including polyester, vinylester and epoxy resin systems and glass, aramid and carbon fiber reinforcements.

Less waste
DIAB core materials can be supplied in ready to use kits. This reduces fabrication times, saves labor, improves quality and virtually eliminates scrap.

Ideal for a Wide Range of Applications
Divinycell H has been widely used over many years in virtually every application area where sandwich composites are employed. These include the marine (leisure, military and commercial), land transportation, wind energy, civil engineering/infrastructure and general industrial markets.

Material & Process Compatibility
Divinycell H is compatible with virtually all commonly used resin systems (polyester, vinyl ester and epoxy) including those with high styrene contents. Its good temperature performance with high residual strength and good dimensional stability, makes Divinycell H ideal for hand laminating, vacuum bagging, RTM (resin transfer molding) and other closed molding processes.

Mechanical Properties
In its application range Divinycell H has the highest strength to density ratio. It exhibits at both ambient and elevated temperatures impressive compressive strength and shear properties (normally the most important for a sandwich core material).

In addition the ductile qualities of Divinycell H make it ideal for applications subject to fatigue, slamming or impact loads. Where a more brittle core material might well shatter or delaminate as a result of an impact, the ductility of Divinycell H allows it to absorb energy when deflected without structural failure. Other key features of Divinycell H include consistent high quality, excellent adhesion / peel strength, excellent chemical resistance, low water absorption and good thermal / acoustic insulation.

Full details of the core's properties are contained in the comprehensive Divinycell H Technical Manual that can be downloaded here.

Widest Range of Densities
Divinycell H is available in an ultra-wide density range - 38 to 250 kg/cu.m. This enables designers to optimize the structure by choosing the correct density for their application.

Standard & Special Finishing
Divinycell H sandwich core can be supplied with probably the widest range of finishes available in the industry. The aim is to facilitate and speed core installation, enhance component quality / performance and to meet specific process requirements. These include grid-scored, double cut and 'infusion' grooved/perforated forms.

Ready-Made Kits
For those involved in series production, Divinycell H can be supplied in ready-made construction kits where each piece is pre-cut, shaped, as necessary, and numbered to fit exactly into its designated place in the mold. This substantially reduces build times, saves labor costs, improves quality and cuts waste.

File Name	File type	Download
Divinycell H specification	PDF

Ideal for a Wide Range of Applications
Although suitable for a wide range of uses, Divinycell P is a cost effective solution for sandwich composite applications in the public transportation, wind energy and industrial/construction markets.

The energy efficiency of a Divinycell P sandwich makes it ideal for transport applications such as interior panelling, floors and exterior panels for trains, trams, buses and coaches.

In the wind energy market the excellent properties and good processing characteristics of Divinycell P has meant that it can be used in both blades and nacelles.

For industrial/construction applications, sandwich composites based on Divinycell P provide not only lightweight solutions but also give designers and architects new creative freedom. Typical applications include domes, architectural claddings, industrial housings, portable buildings and heating and ventilation insulation.

Mechanical Properties
In addition to its good compression and shear properties, Divinycell P has low water absorption and excellent acoustic/thermal insulation properties. It exhibits at both ambient and elevated temperatures impressive compression strength and shear properties.

Material & Process Compatibility
P is compatible with most commonly used resin systems (polyester, vinyl ester, epoxy and phenolics) including those with high styrene contents. It can also be processed using hand laminating, vacuum bagging and closed molding processes such as infusion and RTM (resin transfer molding).

With its high residual strength and good dimensional stability at elevated processing temperatures, Divinycell P can be readily used with a wide variety of 'industrial' medium temperature prepreg systems. Furthermore, it can be thermoformed and used in pultrusion molding.

Details of the core's properties are contained in the Divinycell P data sheet that can be downloaded here.

Standard & Special Finishing
Divinycell P sandwich core can be supplied with a wide range of finishes to facilitate installation, enhance component quality and to meet specific process requirements. These include grid-scored, double cut and 'infusion' grooved/perforated forms.

Ready-Made Kits
For those involved in series production, Divinycell P can be supplied in ready-made construction kits where each piece is pre-cut, shaped, as necessary, and numbered to fit exactly into its designated place in the mold. This substantially reduces build times, saves labor costs, improves quality and virtually eliminates waste.

File Name	File type	Download
Divinycell P specification	PDF