There are many membranes on the market and ALFA has chosen to work with GORE-TEX which is the world leader in this type of technology. Its quality and durability ensure that ALFA customers receive footwear that will last for a long time and withstand a wide range of conditions.
Did you know that ALFA is one of the shoe manufacturers in the world with the longest experience with GORE-TEX? We've been working together since the 1970s, so we know how important it is that the membrane is applied correctly according to strict guidelines. On an ALFA shoe, you know that everything is done properly.
The GORE-TEX membrane itself is a durable microporous film laminated to a fabric. The GORE-TEX film has small pores that allow moisture (water vapour) to pass through, but not water droplets. This is because the pores are about 20,000 times smaller than a water droplet, while being large enough to allow evaporating water vapour to pass through. In this way, it makes the material waterproof and breathable. The membrane is placed closest to the foot to optimise its properties. The closer the membrane is to the body, the better its moisture-wicking properties work.
As mentioned, the GORE-TEX membrane is laminated to a textile. This durable combination is carefully tailored to the shoe's application to optimise both function and comfort. To ensure the best conditions for the GORE-TEX membrane, all other materials in the product are also specially selected and treated/impregnated so that the materials do not draw water.
The GORE-TEX technology is laminated onto a protective textile that is tailored to the shoe. In order for the shape of the membrane to fit, different parts must be sewn together. In this process, there are small holes from the needles that may seem microscopic and insignificant. However, one small hole is enough to create a leak, and therefore the seams must be sealed to keep the feet dry and comfortable. Once all seams are taped and sealed, the product will be waterproof and breathable.
Sealing seams is very important to keep the product waterproof.
In addition to testing all the materials to be used in a shoe model, a selection of shoes is also tested during production and as a finished product. This happens in many ways:
- At least 2% of all GORE-TEX shoes produced are checked in a centrifuge to make sure they are tight. This centrifuge test will detect even the smallest leak and is important to ensure that GORE-TEX is of high quality.
- To ensure that GORE-TEX footwear is also waterproof during heavy use, several of the shoes are set to run for two consecutive days under water in a machine. These are extreme tests that go far beyond what many other suppliers do on their membranes.
- There are also devices that can test the water column, which means how much pressure the water must have before it can penetrate the textile.
The centrifuge test quickly reveals leaking shoes and ensures high quality.
In addition to being waterproof and breathable, the membrane can also be used to increase the insulation capacity of the shoe. This is common in winter shoes designed for very cold conditions, but not in low shoes for hot summer days. Fortunately, there are several different variants, and the different GORE-TEX membranes have different technical properties. Among the many different products divided into four categories, we choose an appropriate membrane based on the shoe's intended use:
This type of membrane is used in our winter models for extra insulation at low temperatures. The membrane is 100% waterproof, so water and snow are blocked, while sweat evaporates easily from the inside. The insulating lining protects against low temperatures and ensures a dry, warm and comfortable climate for your feet. The insulating properties combined with the durability make it well suited for use in cold weather conditions.
GORE-TEX PERFORMANCE COMFORT
This type of membrane is 100% waterproof and has good breathability. The good breathability combined with the durability makes this type of membrane suitable for shoes for a little more demanding use, such as products in our categories for mountain, hiking and hunting.
The Surround membrane is a newly developed technology that combines 100% waterproofness and excellent breathability in an innovative way. The exceptional breathability comes from the air channels under the foot, so the shoes breathe 360 degrees around the foot. The membrane is 100% waterproof, so water is blocked while sweat easily evaporates from the entire foot. This technology is best suited for use in hot conditions and/or high activity.
The open construction of these shoes means that water can also permeate through the air channels on the side, for example if you step on water or bogs. You may then experience a slightly unusual sensation when your feet are cooled by the water. This is perfectly normal and has no bearing on keeping your feet dry - the waterproof GORE-TEX inner sock ensures this. This feature can also be used to cool your feet on a hot summer day without getting wet.
Although the membrane is waterproof, this does not necessarily mean that the shoes will keep your feet dry in all conditions. With a GORE-TEX shoe, you are guaranteed that water will not penetrate the shoe itself, but it may instead "creep over" the upper in very humid conditions.
Several factors such as the shoe's outer material, shaft height, waterproofing and whether you have wrapped your trousers around the shoe's shaft will play a big part here. Generally speaking, textile shoes will be able to conduct water more easily up the shaft and over the top, whereas it takes more for moisture to creep up a leather boot or AlfaAir™. This means that a leather shoe will be able to keep you dry longer than a textile shoe. In addition, shank height also plays an important role in how far water "creeps" and therefore how quickly it reaches the upper.
The terrain and conditions you use your shoes in will be an important factor in choosing the right shoes. Therefore, think carefully about where and when you will use the shoe before buying a pair. Are you often out in bad weather, damp areas or areas with high, wet grass, for example? Then it is advantageous to have a higher shaft on the shoe. In many cases, leather or AlfaAir™ also works well for this type of use. On the other hand, if you travel more in dry areas or on days with less precipitation, a lower textile shoe will do to keep your foot dry.
GORE-TEX AND THE ENVIRONMENT
Through a life cycle analysis of several products, Gore has concluded that the best way to reduce the footprint of outdoor clothing and footwear is to increase quality and longevity. They have concluded that the production and shipping of a hiking shoe accounts for as much as 77% of carbon emissions, so the longer a product is used, the less its annual environmental impact. Gore has quantified its goals for the future and uses several certification and measurement tools in its sustainability work:
The Higg Index tool identifies potential footprint reduction across the value chain and is used to increase long-term sustainability. It focuses on several areas, such as water and energy use, waste and chemicals.
bluesign® certifications are applied to many of the products, ensuring that only proven safe and traceable chemicals have been used.
OEKO-TEX® Standard 100 is an independent certification scheme for both raw materials and finished products and is considered the most widely used worldwide.
Want to know more about GORE-TEX and the environment? Watch this video.