Economical and efficient processing of insulating profiles in windows

60 % of windows in China are made from metal, creating a need for solutions for the energy-efficient insulation of aluminium windows

There is a good reason why windows with aluminium frames are becoming more and more popular in China. Almost indestructible when subjected to the effects of weather and wear and tear, metal windows are durable and flexible in their use. With the right insulation, they also comply with the stringent requirements imposed by the state and by environmental policy with regard to the energy efficiency and sustainability of buildings.

Systems manufacturers and metal and window construction companies in China are benefiting from the many advantages offered by aluminium frames in windows and doors. However, they also have to confront several challenges in the production process. The stipulated values for e.g. permeability of joints, resistance to driving rain, wind load, heat insulation, airborne sound insulation and burglar resistance of the window must be complied with. It is very important in today’s modern China to meet the high standards when it comes to environmental protection and the energy efficiency of the building.

Reducing energy losses at the window

It is precisely this which is the starting point for China’s processing companies and window manufacturers, because around 40 % of a building’s heat loss is through its windows. With plastic thermal insulating bars, the aluminium profiles can be reliably insulated from the inner and outer shells. Systems manufacturers and metal and window construction companies that want to produce fit-for-the-future windows and doors need high-quality, durable and energy-efficient solutions for the insulation of the window frames.

Ensinger is exhibiting:

China Glass
19. – 22. April 2018
Shanghai – together with our partner LiSEC

23. – 26. October 2018
Düsseldorf, Germany

13.-16. November 2018
Madrid, Spain

Aluminium windows are the premium choice for high-end buildings due to their special material properties. Efficient thermal insulation is provided e.g. by insulbar® insulating profiles, which link the inner and outer shells of the metal frame and thus thermally separate them. Precious heat thereby stays in the living area.

Economical, energy-efficient insulation

Nowadays there are insulating profiles which permit outstanding Uf values in windows and doors which achieve the passive house standard. A good example of high-quality insulating profiles in this field is insulbar® from Ensinger. The insulating profiles made in Germany are impressive above all thanks to their excellent durability, quality and stability along with their considerable ease of processing. This is because the insulating profiles can be incorporated easily and cost-effectively, in a huge variety of geometries, into all metal window designs and thereby thermally separate the outer and inner shells of the aluminium profiles from each other.

Simple and fast processing

In order to optimise the quality of products from systems manufacturers and metal and window constructors, to speed up their processes and increase their profits, the German manufacturer Ensinger, for example, supplies fully processed profiles with customisable profile properties. And what’s more, in a way that fits the customers’ applications or areas of use:

For greater energy efficiency

All profiles can be equipped with flags coated with a highly reflective Low-E film in order to reduce heat loss even more effectively. This also allows existing profiles to also be optimised with flags without changing their geometry, i.e. without additional development and tooling costs. The Uf values correspond to those of window systems using foam. But this does not give rise to any additional process or logistics requirements, as the insulating bar is delivered ready-coated with film.

Insulating profile with Low-E film – minimises losses through heat radiation at windows, doors and façades

For a reduction in bimetal effects

Profiles with wall thicknesses of up to 3 mm can be equipped cost-effectively ex works with punched holes for drainage, attachment or pressure equalisation openings and for achieving shear-flexible connections (ladder profiles) for reducing bimetal effects. This eliminates the need for subsequent punching by processing companies. Application-specific boreholes or milling operations are also possible, saving processing companies both time and money.

Insulating profile with punched holes for drainage openings

For an improved look

Previously used mainly in Europe, powder coating of the insulating bars is sure to play a role in China in the future too. So that the paint powder can adhere better, the surfaces of the insulating profiles can be roughened by means of dust blasting. This increases surface energy, improves paint adhesion when powder coating, and ensures a good, durable painted result and an improved appearance.

Where the demands are even higher when it comes to coatability, it is advantageous to use a material with improved electrostatic properties for optimum powder attraction. This material can also be dust blasted.

Dust-blasted insulating profiles increase the paint adhesion in powder coating – a profile frequently used in Europe.

For greater flexibility when painting

Profile areas where no paint is required can be covered with a reusable clip-on profile during painting. This reliably protects against unwanted paint application. Cover profiles reduce the work load and ensure reliable results – particularly when working with complex profile geometries. Alternatively, a temperature-resistant film can also protect certain profile areas during powder coating prior to paint application; this can subsequently be removed again without leaving any residues.

A cover profile reliably protects against unwanted paint application

For high tolerances

For the rare applications in which the tolerances achievable using the extrusion process are not sufficient, we offer subsequent machining of the thermal insulating bars using a high-speed milling station. This enables the achievement of tolerance fields of 0.05 mm, irrespective of the profile size.

For easy introduction into the frame

To improve the drawing-in behaviour of the insulating profiles into the aluminium cavities, the ends of the profile lengths are “sharpened to a point”. This simplifies and speeds up the automatic introduction of profiles into the aluminium half-shells and thus enhances productivity during window and door production.

Sharpened insulating bar for simpler drawing-in into the aluminium cavities

For easy post-processing

The insulating bars can be conditioned in a warm water bath following production. This enables the moisture content of the profiles to be adjusted precisely to individual requirements. This can simplify post-process machining in the customer’s own workshop, for instance. The moisture content depends on the profile geometry, water temperature and conditioning period.

For the protection of the surfaces

Insulating profiles can be equipped with a protective film which protects effectively against damage, scratches and soiling during the entire processing phase. The film is primarily intended for the surface of the insulating bar which are in the visible area in the metal frame and therefore have to look flawless.

The protective film that can be applied to insulating bars ensures a flawless look


For identification as per the customer’s request

Product markings can be applied in certain areas and at certain intervals according to customer specifications. This guarantees the traceability of all relevant data within the framework of optimised quality assurance.

Insulating profiles can be marked in line with customer requests

For coordinated logistics

The insulating profiles are bundled into the required piece numbers to simplify handling. Processors benefit from cost and time benefits during storage, order picking and also during actual processing. Systems manufacturers and processors whose logistics and processing operations are configured for coils can also be supplied with their profiles in coil form where the geometry allows.


With the right quality insulating profile – supplied ready to install and, depending on the requirements of the window, equipped with different profile properties – systems manufacturers and metal and window constructors in China can improve the quality of their windows, optimise their processes and significantly increase the profitability of their production.