Novel PVC window profiles - solutions for recycling

PVC windows are characterized by many positive properties and therefore have an ever-increasing market share. The reason for this are ongoing improvements to the PVC window profile, sealing systems, fittings, design and, of course, the material PVC itself. Leading manufacturers have now begun to further improve the already very good insulation properties of PVC windows, for example, by using glass fibers.

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In 2012, for example, several major manufacturers presented new types of PVC window profiles with reinforcements made of glass fibers or other non-metallic reinforcing materials. The aim of such profiles is to improve not only the mechanical properties but also the already very good insulation values of PVC windows. This is achieved, for example, by avoiding undesirable thermal or cold bridges.

Options for reinforcing PVC window profiles

There are various conceivable ways in which the window profiles are reinforced by glass fibers or materials containing glass fibers:

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Inserted reinforcements: Instead of steel sheet, the reinforcements are made of plastic with glass fibers and are loosely inserted into one of the chambers of the profile.
Fused-in reinforcing strips: In this process, a strip or angle profile made of a special plastic reinforced with glass fibers is extruded into the PVC window profile.
Glass fiber reinforcements: Glass fibers are incorporated into the profile exterior as continuous glass fiber bundles.
Incorporated short fibers: Here, a PVC material is used in certain areas of the window that has been selectively reinforced by incorporated short glass fibers.

Solutions for recycling window profiles containing glass fibers

The challenge is to selectively separate the glass fiber-containing parts of the PVC window profiles from the glass fiber-free PVC materials when recycling production waste, profile sections or, later, old windows. This is necessary in order to produce high-quality PVC regrinds from the recyclate again, which can then be used again without any problems in the production of new profiles.

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hamos offers the following solutions for the separation of these materials containing glass fibers:

• During the shredding of PVC materials containing glass fibers, dusts containing glass fibers are produced, which can be easily removed by air separation. For this purpose hamos offers the DRS device.
• Due to physical laws, glass and glass fibers are almost always positively charged in the hamos EKS electrostatic separator compared to PVC and rubber. In the hamos EKS, therefore, the material containing glass fibers is almost completely separated together with the unwanted sealing rubber.  

In addition, hamos has developed other separation processes with which it is possible to separate sorted PVC regrinds interspersed with glass fiber-containing materials:

• The PVC material containing glass fibers is provided with a fluorescent marker. "Normal" PVC does not contain a marker.
• The PVC parts marked in this way fluoresce in the yellow or yellow-green color range when illuminated with blue light, for example, and can be easily blown out by an opto-electronic color sorting system.
• PVC pieces that do not contain glass fibers and therefore do not have a marker do not fluoresce and end up in the good product.

Detailed tests on the recyclability of PVC containing glass fibers can be carried out at any time in our hamos technical center. All the equipment needed for a meaningful separation test is available there. In this way we can show you which PVC qualities we can achieve with your waste containing glass fibers.