What is PUL fabric?

What is PUL fabric?

Polyurethane Laminate Fabric” or PUL is a soft, flexible, hardwearing and waterproof fabric. 

PUL is a laminate fabric comprised of 2 layers:  a polyester fabric (typically 1mm thick) with a very thin layer of polyurethane film bonded to the reverse.  Polyester is preferred to cotton because it is difficult to have a really water-resistant product using cotton.

The polyester side can be plain or printed with a design.  It will retain its stretchability even with the additional polyurethane layer. This makes for an extremely resilient fabric which will last for many years.

It’s important to note that PUL remains supple and soft to the touch, unlike a cotton fabric backed with a separate plastic fabric or an ‘oil cloth’ type fabric.

These characteristics make PUL the ideal fabric for our range of lunch bags and reusable freezer bags.

Manufacturing PUL

For our products, we only use Eco-PUL. In this particular version of PUL, the polyurethane is made from renewable raw materials, such as vegetable oils rather than mineral oil. Eco-PUL is a smart choice for the environment.

The high quality polyester jersey fabric and the polyurethane film are bonded to create a single layered fabric using a combination of heat, pressure and adhesion.

Eco-PUL is manufactured using a ‘green’, solvent-free adhesive in the spirit of environmental sustainability.  The resulting laminated fabric – the PUL – is totally safe for health.  

Eco-PUL is made in the USA from a 73% polyester, 27% polyurethane mix and meets CPSIA standards.

Certified Food Safe

In addition to the manufacturer's safety certificates, we commissioned our own tests at Celabor in Belgium to provide complete assurance that our chosen PUL is safe for food-use.

The result of these laboratory tests is that our quality PUL fabric is certified to comply with food standards for repeated use, contact with fat, meat, fish, ... all types of food!

Let's take a closer look...

The Patterned, Polyester Side

Microscopic View of the PUL Polyester Side with pin for scale.

Let’s look in more detail using a microscope – this photo shows the polyester side of the PUL with a pin for scale. The weave of the fabric and even the individual fibres are visible.

The Waterproof, Polyurethane Side

Microscopic View of the PUL Polyurethane Side with pin for scale.

This photo shows the polyurethane laminate side of the PUL. You can see that the polyurethane has coated the polyester. However, some holes remain – these are large enough allow the fabric to ‘breathe’, but too small for water to pass through.

The 'Droplet Test'

Microscopic View of PUL Polyurethane Side with droplet of water and pin for scale.

This photo shows a droplet of water on the polyurethane side of the fabric. You can see that the droplet sits on the surface and does not soak in. This demonstrates the ‘waterproof’ aspect of the PUL.

If the polyester side comes into contact with water, it will become damp, but water will not penetrate the interior, polyurethane layer.