All external bag machines work by clamping the open end of the vacuum bag (sometimes called a vacuum pouch) whilst the air is being removed. Because the end of the bag is clamped shut, this type of machine needs to use a special type of bag with a finely ribbed or textured back surface so that the air can be removed easily. This type of vacuum pouch is usually referred to as a ‘ribbed’ or ‘textured’ vacuum pouch. You will always get the best result from an external bag machine by using this type of vacuum bag.

However, if you are packing large volumes then it is possible to cut your costs by about 30% by using non-ribbed vacuum pouches. These require slightly more care to use as the end of the pouch needs to be located into the machine in such a way that the air can still be drawn from the bag. This is illustrated below.

This takes a little practice but does work well once you have acquired the knack. There are two drawbacks to using this method; Firstly, the machine will take a little longer to remove the air from the bag and secondly, there is a slight twist to the top of the bag which does not look quite as neat as the result obtained with ribbed vacuum pouches.

You can minimise the first of these problems by choosing a bag size which closely matches the size of the item you are vacuum packing. This will have more effect on the time that it takes to vacuum the product than the type of bag that you are using. The second issue of the twist at the top of the bag is a purely aesthetic consideration and only needs to be thought about if you are selling the vacuum packed product to the public.

We supply three different sizes of non-ribbed food grade vacuum pouches.

Even though it is possible to use non-ribbed bags, you cannot use just any plastic bag. The bag needs to be at least 120 microns in thickness so that the heat sealer can melt the two surfaces of the bag together to make the seal. The bag must also have a side-seam so that the twist technique illustrated above will work. This technique will not work on bags that do not have a side seam unless the bags are very thick (approx 500 microns). We have found that some of the bags used to pack circuit boards and engineering components fall into this category. If you already have a supply of bags and you want to know if they will work with a Lava vacuum packing machine then please send us some samples and we will test them for you.