dry storage products

When you are dealing with moisture sensitive devices it can sometimes be hard to tell if they are dry enough. Even if you use silica or clay desiccants to keep your products dry you still need to monitor the humidity in your storage containers. Also, by keeping an eye on the humidity level in your storage you can make sure you replace or recharge your desiccants before they become oversaturated.

Humidity Indicator Card Humidity indicator cards typically have circles on them that change color as the moisture in the air rises. The main differences between cards are the sensitivity to humidity as well as how many levels they can indicate. If you have products that are extremely sensitive then you may want a card that shows 5-10-15% humidity, but if your device can stand a bit of humidity then a 30-40-50% card may be more appropriate. Likewise, if you need to know the humidity in your storage to a higher degree then you should get a card with more indicators, such as a card with 6 spots between 10-60%.

One thing to keep in mind with humidity indicator cards is that they are best for small packages. They will not let you know the humidity in your entire warehouse, as it may change from place to place. Typically these cards are best used in moisture barrier bags or small containers and should be used so that you know when to replace your desiccant.

That is all for this week’s dry storage option. Come back next Monday for more on moisture barrier bags!

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Dry Storage Options: Types of Desiccants

by Andy on June 26, 2012

In electronics manufacturing, there are many products that are sensitive to moisture. It is important to protect these products, especially when they are out of sight in storage or shipping. There are many dry storage options to keep your products moisture free in storage, but it can be difficult to decide which to use.

Clay vs Silica Desiccants

clay desc Clay desiccants and silica desiccants are two of the most common products used for effective dry storage. Both offer protection against moisture, but at different levels of effectiveness. For most typical usage, clay and silica are very similar; they both work best at room temperature and neither swells as they absorb moisture. Also, they recharge easily, as you can heat them up to release their moisture.

If you look at the pricing for clay and silica, you can see that clay is much cheaper. This is because of the effective temperature range. While both work very well at room temperature, clay desiccants will stop working and even release moisture if they get above 120°F. Silica has a much larger range, as it works up to about 220°F.

While it may seem like this makes silica better, but it can depend on your application. If you are storing your product below 120°F then clay is not only cheaper, but easier to recharge. You need to heat silica much higher than clay to recharge their absorbent ability, so take that into account when purchasing your desiccants.

That is all for clay and silica desiccants today! Check in next Monday when we will be going over moisture indicators.


All-Spec’s Moisture Barrier Bags

by Andy on July 14, 2011

All-Spec Moisture Barrier Bag Moisture barrier bags are used to protect moisture sensitive items from damage during transport and storage. All-Spec carries different types of moisture barrier bags that offer EMI, RFI, and static shielding properties in addition to moisture protection. The added EMI, RFI and static protection makes the All-Spec bags ideal for items like surface mount devices (SMD’s), printed circuit boards (PCB’s) and any items that need to be protected from rust or corrosion.

All-Spec carries three different options of moisture barrier bags including the 60 Series, 63 Series, and 64 Series. These bags are constructed differently and thus offer slightly different specifications and features. Made from multiple layers of plastic and aluminum, All-Spec’s moisture barrier bags all offer similar EMI, RFI and static shielding properties but varying levels of puncture resistance and moisture vapor transmission rates (MVTR). The MVTR is measured using the ASTM F-1249 standard which is the amount of water in grams that will move through 100 in2 of the tested material at 100oF in a 24 hour period.

Determining which series of moisture barrier bag to use is based strictly upon your application. Based on the MVTR, thickness and puncture resistance you can choose which bag will work best for you. The 7mil bags, although more puncture resistant, can “crease” easier than the 3.6 mil bags and cause a weak area in the material, leading to potential failure. The 3.6mil bags are generally more flexible but less puncture resistant than the 7mil bags. The 6.1mil bags have the best MVTR which means that less desiccant will be required to eliminate the moisture that does get into the bag. On the other hand, they are less puncture resistant than the 7mil bags and are less flexible than the 3.6 mil bags.

Series Thickness MVTR Puncture Resistance
60 Series 3.6 mils (.0036”) MVTR – < .02 grams 21 lbs
63 Series 6.1 mils (.0061”) MVTR – < .0003 grams 21 lbs
64 Series 7.0 mils (.0070”) MVTR – < .005 grams 30 lbs


Humidity Indicator Card

In addition to moisture barrier bags, All-Spec Industries carries a variety of dry storage products to use during the packaging process. It is recommended that you place a humidity indicator card (HIC) and desiccant inside each bag. The desiccant absorbs the moisture that penetrates the bag and the humidity card allows the person who opens the bag to know what amount of moisture has gotten into the bag. In order for the bag to function properly, you can then use a vacuum sealer to remove any existing air. Moisture labels are also available to identify the item as moisture sensitive.

If you have any questions or you need a sample to review for your application please give our customer service a call at 1-800-537-0351 or email us at sales@all-spec.com. We enjoy receiving feedback and if you have any recommendations on what you would like to see on our blog, email us at marvlop@all-spec.com.