Windscreen Rubber Extrusions: Enhancing Vehicle Safety

The integrity of any vehicle relies on all its components doing their jobs, no matter how small or simple. Windscreen seals are one such small and simply designed part that provides an ingenious benefit, keeping the vehicle in safe working condition.

When manufacturing windscreen seals, only one material comes out on top: rubber, specifically extruded rubber. Rubber extrusion is a process made for windscreen seals. In this article, we explain.

The Role of Windscreen Rubber Extrusions

Windscreen seals, strips, or gaskets, sometimes known as weatherstripping, are essential in keeping the car's interior free from water, air, or debris entering through the front. They form a seal between the windscreen and the car's body.

Key uses of a rubber windscreen seal:

• Weatherproofing the vehicle from rain, snow, and debris

• Minimising the noise of the road and other external elements

• Supporting the structural integrity of the windscreen

• Protecting the windshield component by absorbing and reducing vibrations by way of vibration-dampening

Cars are not the only vehicles that have rubber windscreens; they’re also needed in boats, aeroplanes, and types of heavy machinery like tractors and excavators.

Rubber in Windscreen Seal Manufacture

Rubber is a popular material for the manufacture of windscreen seals, thanks to its resilience to the varying elements in vehicle climates. Rubber’s high elasticity helps it conform to the shape of the windscreen, assists with installation, and absorbs vibration and noise.

Let’s take a look at the qualities and properties of different types of automotive rubber seals for windscreens.

Silicone

• Resistance to extreme temperatures and UV radiation

• Ensures a long lifespan and reduces the need for frequent replacement

• Easily conforms to the windscreen shape to provide a tight seal and stress-free installation

• Recyclable, reusable, and highly durable

• Silicone rubber extrusions are ideal for more extreme, harsh weather conditions.

EPDM (Ethylene Propylene Diene Monomer)

• Good resistance to weathering and UV radiation in a range of climates

• Generally more affordable than silicone

• Recyclable and performs well in harsh weather conditions

• Can become brittle and stiff over time

Nitrile Rubber

• Highly resistant to chemicals and oils, making it ideal for industrial use

• Known for its resistance to extreme temperatures

• Durable and flexible

• Good resistance to abrasion, heat, and water

Neoprene

• Highly resistant to UV radiation, ozone, and weathering, making it ideal for marine environments

• Good durability and flexibility in all climates

• Highly resistant to hot and cold temperatures compared with nitrile rubber

Benefits of Quality Windscreen Rubber Extrusions

Carefully selecting the best type of rubber for a windscreen seal depends on its application: the environment where it will be used. Silicone and EPDM are the best for extreme temperatures and offer eco-friendly benefits. Nitrile and neoprene are chosen for specific environments, nitrile for industrial settings where chemical and oil exposure are a hazard, such as heavy machinery, and neoprene in marine vehicles to protect against specific sea-bound weathering.

In situations where rubber is unsuitable, foam and PVC are sometimes used. Foam is lightweight, porous, and an excellent insulator. It is also used as a second seal or as a rubber extrusion for classic cars to preserve the integrity of the original design. It's also used as a temporary seal. It is cost-effective and easy to install.

PVC (Polyvinyl Chloride) is a robust material for making windscreen seals with relatively low maintenance. It’s highly resistant to elemental exposure without degrading and is also resistant to some chemicals, oils, grease, and petrol. PVC is lightweight and easy to cut to shape. It is commonly used in cars, lorries, and buses and is a popular, affordable choice where rubber can’t be used.

Installation Tips for Windscreen Rubber Extrusions

Installing rubber windscreen extrusions correctly ensures the longevity of both the seals and the vehicle. Here’s a step-by-step:

1. Ensure the windscreen is completely clean and dry before installation, and ensure it is free of oils. It is recommended that you use a glass cleaning solution and a lint-free cloth.

2. Warm the rubber seal to increase its flexibility. You can do this by soaking it in hot water or laying it in the sun.

3. Apply a good lubricant to the seal, such as KY Jelly or Simple Green cleaner.

4. Physically installing the windscreen seal requires two or three people to work together. Start by installing the seal onto the windscreen to fit snuggly around the glass.

5. Wrap waxed twine around the windscreen seal in the outer groove, leaving 6” extra around each end to use as pull handles. It’s recommended to wrap the twine around twice. This will help get the rubber over the metal lip of the channel when installing the windscreen. Tape both ends of the twine to the glass to keep them out of the way and ensure the twine doesn’t fall out of the groove. Make sure these are taped on the interior side of the glass.

6. Sitting inside the vehicle, place the windscreen on your knees, with the inside part face-down. Let the windscreen sit in the sun for another 10–20 minutes to allow the seal to soften further.

7. Insert any kind of reveal moulding, if needed, before the glass is installed back into the vehicle.

8. Lubricate the outer groove of the seal.

9. One person inside the vehicle should push the glass into the frame. Start by ensuring the bottom of the windscreen is pushed down into the frame first.

10. At the same time, the other person should begin to slowly pull the twine out of the seal at a 90-degree angle to the glass. Keep going until the lip of the seal is completely pulled out over the metal edge.

Common Problems and Solutions

Innovations in Windscreen Rubber Extrusions

Continuous development in the manufacturing process of rubber extrusion means design innovations are constantly taking place. Here are some innovations that make rubber windscreen extrusions even better for their intended application.

Multi-Durometer Extrusions

This involves merging two or more materials through a single die in the extrusion process to form a single structure. In doing this, manufacturers can produce a rubber seal with numerous structural benefits, such as a strong attachment base with a softer compound that enables a tighter seal. Multi-durometer extrusions offer exceptional compression set properties, easy installation, and minimised stretch, making them ideal for vehicle windscreen seals.

EPDM Co-Extrusion Technology

This involves co-extrusion of EPDM with different hardness levels within the same profile. This technique combines hard and soft EPDM materials in a single extrusion process, creating a seal with varied properties. The harder segments provide structural integrity and attachment points, while the softer sections ensure a snug fit and effective sealing. This improves the overall performance of the windscreen seal, particularly in maintaining a tight seal against the windshield and car body.

Browse our blog for more details on rubber extrusion applications and the properties of extruded rubber. You can also find out about all the rubber extrusions we produce.