SpongeBar.com is the official online retailer of the Ultra Sponge Bar Strip. The Ultra Sponge Bar was designed by a Parsons School of Design educated fashion designer who also worked as a knitwear designer for Calvin Klein.

What makes the Ultra Sponge Bar Strip so Ultra? Get ready for some science!

1. The type of Foam  is very important when it comes to knitting machine sponge bars. The reason why so many DIY sponge bars fail is because the kind of foam needed to make a resilient sponge bar strip is generally not available outside of industrial resources. There are two main factors when it comes to foam – the density and the structure of the cells of the foam. Let’s start with Foam Cell Structure. The reason DIY Weather Stripping / Weatherseal foam fails is because it is made from closed cell foam most of the time – especially in the USA. It may work for the first couple of weeks, but eventually the sponge is not able to regain its original shape and quickly gets flattened and therefore useless. Unless you like replacing your Sponge every month – this is not a good option. The Ultra Sponge Bar is made with Open Cell Foam – a cell structure that provides maximum resiliency. Think of it kind of like a new kitchen sponge – you can squeeze it, but it quickly bounces back to its original shape.

2. Okay, now onto Foam Density. Generally, foam comes in three classes: High Density, Medium Density, and Low Density. Density is exactly what it sounds like – the higher the Density the heavier the sponge will be. While super high density sponge is great for certain hardware applications, it is not great for a knitting machine because the needles literally end up getting squashed against the machine. They have no room to move up and down and can get stuck because of this. Low Density may be good for certain home insulation purposes – but again, not good for the knitting machine. You may have heard you can use Craft Foam from your local fabric store to make your own sponge. While, yes, this is true – your sponge will not last very long. Here’s why: Low Density foam is very cheap and weak. It deteriorates quickly and because of how light (or ‘soft’) it is – it will stop working in your machine within a year, maybe even a few months. All foam degrades with time, but low density foam degrades the fastest by far. The Ultra Sponge Bar is made with Medium/High Density Foam – allowing the perfect combination of strength, resiliency, and endurance. 

3. And then there’s the Fabric on the Ultra Sponge Bar.  The Tight Knit Jersey of the Ultra Sponge Bar creates a smooth surface for the knitting machine needles to rest on and bounce off of.

4. To stick or not to stick? To stick! It makes installing and (years later) removing the sponge infinitely easier! Keep in mind that most plastic machines do not need this (such as the Singer LK150 and LK100).

Take Care of Your Ultra Sponge – Basic Tips to Ensure Your Ultra Sponge Lasts A Long Time:

Do not get water on the Ultra Sponge – this will significantly reduce its lifespan. You can gently steam the sponge if you really need to, but we do not recommend it. All moisture is bad for this foam, so if you live in a very humid area keep your unused Ultra Sponges in a ziplock plastic bag to prevent moisture damage.

If you need to cut down your sponge bar, use scissors. Please be safe and avoid using razors as it can slip and we want you to be safe!