Frequently asked questions

“Molecular Sieve” is a pretty general reference term used by chemists. It is most commonly used to describe forms of synthetic aluminosilicate known as ‘Zeolites’.

Zeolites such as 3A SUPERSIV are referred to as ‘Molecular Sieves’, because they tend to preferentially absorb one molecule from a selection of other molecules on-offer. Thus, they appear to ‘sieve out’ some molecules and not others.

Molecular Sieves are used in many different industrial applications. Some are used as reacting surfaces for catalysts in Petroleum Chemistry, others are used for their abrasive properties (e.g. in Laundry Detergent powder), and some, such as 3A SUPERSIV are used as desiccants (‘desiccants’ are a form of ‘drying agent’).

A-Type Zeolites are the most common form of Desiccant Molecular Sieves. You will most frequently see types 4A and 3A used in polymer formulations. 3A Zeolites tend to sieve-out water (and not much else) when exposed to a mixture of different chemicals. 4A Zeolites can also be used as an alternative but are not as effective. Both 4A and 3A Zeolite are used for the removal of Carbon Dioxide from Polyurethane Systems (and from Polyurea Systems also).

Zeolite Powder material looks like a fine white baking flour and has the exact same appearance when dry and also when completely saturated.

These powders differentially attract molecules from the air, or differentially attract molecules from within a mixed solution. In performing this task, the powder “sieves out” certain molecules and not others, and this is why these Zeolite Powders are known as “Molecular Sieves”

One of the most common uses of Molecular Sieve is for the removal of water from within polymer reactions , to prevent the chemical reaction from proceeding along an undesirable reaction pathway, which leads to unwanted end-products.

To achieve zero bubbles, manufacturers of PU-Elastomers and PU-Resins, use 3A SUPERSIV Powder (also known as Molecular Sieve and Moisture Scavenger) to remove this water, which can cause the bubbles to appear. The result is an attractive PU-Paint or PU Casting without any surface blemishes, or ugly blisters.

A Zeolite Powder such as 3A SUPERSIV is used to absorb the excess water that may be present in the Isocyanate, Polyol or filler components.

Molecular Sieve is used for the removal of water from polymer reactions , to prevent the chemical reaction from proceeding along an unattractive reaction pathway, which leads to unwanted end-products.

Manufacturers of solvent-based PU adhesives typically use a Zeolite Powder such as 3A SUPERSIV , to absorb the excess water that may be present in the Isocyanate, Polyol or filler components. Once the water has been removed, the remaining raw materials will react together, to create a bubble-free 2KPU adhesive.

Manufacturers who do not have the processing machinery required for the dispersion of fine powders into liquids, should note that there is also a convenience product available called 3A SUPERSIV Paste . This is a pre-blended liquid that manufacturers can simply pour-in to their formulation. It is easy to handle, and it mixes into polymers very well.

If you are making a 2-component polyurethane glue, and you are experiencing problems with unsightly bubbles, then add Zeolite Powder to your formulation. This material acts as a moisture scavenger and enables the reaction to proceed without the presence of water.

When you add Zeolite Powder in the formulation of Polyurethane Glue, this new ‘water free’ reaction mixture cannot generate any CO2 gas (which is the cause of the bubbles) and therefore, your problem is solved !

When tackling problems such as the removal of (water-generated) CO2 bubbles from Polyurethane formulations, most chemists opt to use molecular sieve such as 3A SUPERSIV Powder , as their moisture-scavenger. This is a proven solution, and it has been used for many years within the Coatings, Sealants, Adhesives and Elastomer industry (also known as the C.A.S.E. Market).

Zeolite Paste is typically a 50:50 mix of Zeolite Powder and high-quality Castor Oil paste. This pre-dispersed material can easily be poured into a liquid polymer coating or adhesive, during manufacture.

Our own 3A SUPERSIV Paste uses castor oil, because this oil is naturally hydroxylated, and thus aids polymerisation reactions.

Foil packaging provides a barrier against oxygen and moisture keeping it safe after manufacture, in transit and when stored until it reaches the end user.

B-SURE™ Barrier Foil Pouches use special 3-laminate and 4-laminate structures that offer your product protection against moisture ingress, and class-leading puncture resistance. These pouches can also be used to maintain a given in-pack humidity that’s ideal for your specific product, when combined with our HUMI-BALANCE™ Sachets.

These pouches are used for the packaging of diagnostic test strips, such as those used by diabetes patients, and for the protection of Diagnostic Test Kits and Lateral Flow Devices, such as those used by patients in their own home.

SUPERDRYPAK™ Stoppers contain desiccant and are designed to be used in conjunction with our standard range of tubes. Together they keep your tube-packed product completely dry.

SUPERDRYPAK™ Stoppers are used in conjunction with sugar-coated pills, where moisture can cause the sugar-coating to dissolve. This can then lead to a situation where all the pills stick-together in a single lump.

SUPERDRYPAK™ Desiccant Canisters are widely used in the pharmaceutical industry, to protect pill-based formulations. They are mainly used for high-speed production lines, where their rigidity and dimensional regularity enables them to be incorporated into the customer’s products very quickly.

SUPERDRYPAK™ Desiccant Canisters are either dropped straight into the pill bottle, before it is filled with tablets, or they are incorporated into the bottle’s screw cap, so that there is no risk of ingestion by the person taking the tablets.

HUMI-BALANCE™ Sachets are designed to maintain a specific Humidity within a package, rather than reducing it to zero. This new range of products has been created for items that need protection from moisture and protection from over-drying (e.g., gelatine capsules, which become brittle and vulnerable to cracking when overly dry).

Silica Gel packets will absorb 35% of their own weight compared to Molecular Sieve Sachets which pull-in closer to 22%. Molecular Sieve has higher affinity for water absorption. Hence, manufacturers of pharmaceutical pills, who require zero moisture, will favour Molecular Sieve Sachets above Silica Gel Sachets.

Silica Gel Sachets are generally less expensive than those containing molecular sieve, so in the cases where ‘absolute zero’ humidity is not required, they are normally the desiccant of choice.

Silica Gel Sachets are widely used in the pharmaceutical industry, to protect pill-based formulations. They are also used to protect Diagnostic Kits in the medical industry, to test for pregnancy, diabetes, and even drugs of abuse, in the lab and home environment. You can check out SUPERDRYPAK™ Silica Gel Sachets here.

Our Reliant Oxygen Absorber Sachets remove oxygen from within hermetically-sealed packaging, to protect goods (such as pharmaceutical formulations and packaged foods) from spoilage, mould, discolouration, and odour issues.

Reliant Oxygen Absorbers rely on the presence of moisture within the package to become activated. Non-Reliant Oxygen Absorbers do not rely on the presence of moisture within the package, they are ready to work immediately.

SUPERDRYPAK™ Indicating Silica Gel Sachets are used where manufacturers want to ensure that the desiccant packaging is 100% active thus keeping the product good working order and remains suitable to use. For instance, keeping a freshly opened test kit valid for use anywhere.

SUPERDRYPAK™ Indicating Silica Gel Sachets are used in preference to Humidity Indicator Cards , where the pack needs both a desiccant and a humidity indicator, because they perform both tasks at once!

Large size Silica Gel Bags (25g to 500g) are widely used in the industrial packing sector, to protect water-based adhesives from dissolving.

Yes, silica gel bags smaller than 25g that are often referred to as ‘ Silica Gel Sachets ’ can be found here .

Silica Gel Bags are used to protect ferrous metal items from rusting, and to protect electronic items from damage. They are also used in the manufacturing process to protect micronized powders from clumping-together when stored within ‘work-in-progress’ drums.

Yes, we sell Silica Gel in pre-bagged sachets ( see here ) and we also sell it in bulk quantities.

The main use for the bulk format is to fill or (re-fill) desiccant towers, breathers, and dryers. Check out SUPERDRYPACK™ Silica Gel here .

EUROGEL™ is our brand name for indicating Silica Gel commonly used in the railway industry for the protection of compressed air systems.

Moisture can be avoided by using tank vent dryers to dry incoming air at the top of the drum, thus maintaining the quality of the stored material. Our product TRANSFORMADRY™ Tank Vent Dryers is used to protect drums of solvents, oils and fuels from moisture damage.

Yes. Our PRONTOPACKER™ Desiccant Dispensers are aimed at fully-automated high-speed production lines.

PRONTOPACKER™ Dry-Boxes are designed to complement our range of Desiccant Dispenser Machines and allow manufactures to keep continuous-strip desiccant sachets in optimum condition during work-breaks and overnight stoppages when your packing line is not running.

Our TRANSFORMADRY™-600 Desiccant Breathers are used to protect high-voltage power transformers from moisture ingress, via their air-intake vents. By preventing this moisture ingress, the safety of the electricity sub-station is maintained, and the risk of dangerous flash-over events is mitigated.

SUPERDRYPAK™ Humidity Indicator Cards show when the relative humidity has risen above a certain level within a sealed package. These cards are widely used in the packaging industry, offering assurance that goods have arrived in working order. Learn more here .

Our Reliant Oxygen Absorber Sachets remove oxygen from within hermetically-sealed packaging, to protect goods (such as pharmaceutical formulations and packaged foods) from spoilage, mould, discolouration, and odour issues.

Reliant Oxygen Absorbers rely on the presence of moisture within the package to become activated. Non-Reliant Oxygen Absorbers do not rely on the presence of moisture within the package, they are ready to work immediately.

SUPERDRYPAK™ Indicating Silica Gel Sachets are used where manufacturers want to ensure that the desiccant packaging is 100% active thus keeping the product good working order and remains suitable to use. For instance, keeping a freshly opened test kit valid for use anywhere.

SUPERDRYPAK™ Indicating Silica Gel Sachets are used in preference to Humidity Indicator Cards , where the pack needs both a desiccant and a humidity indicator, because they perform both tasks at once!

You can find them here: Datasheets and MSDS Sheets

You can find them here: Datasheets and MSDS Sheets

Desiccants are materials that have a “drying effect” on the materials and or environment around them. Desiccants are typically used to remove water vapour (humidity) from the air. Common forms of desiccant used within packaging are Silica Gel Sachets and Molecular Sieve sachets .

For manufacturers of plastics, where the desiccant is required within the polymer itself, 3A Zeolite Molecular Sieve Powder is a common desiccant.

Common forms of desiccants include: silica gel, molecular sieves, activated alumina, etc. in many shapes and formats. You can find out more about products that contain these chemicals here:

– Silica Gel sachets

– Desiccant Canisters

– Molecular Sieve Sachets

– Silica Gel Beads (bulk)

– Molecular Sieve Beads

– Activated Alumina Beads

Desiccants are commonly used to prevent moisture damaging sensitive products during storage and distribution.

– They help to maintain the shelf-life pharmaceutical preparations and food stuffs

(see: Molecular Sieve Sachets )

– They protect against mould and rot, with textile products

(See: Container Rainstop )

– They help to ensure the consistency of plastic polymers, such as polyurethane

(See 3A SUPERSIV Powder )

– They help to protect ferrous metal objects from corrosion in long term storage

(See: VCI Products ), and

– They also help to protect electronic items form system failure due to humidity ingress

(See: SUPERDRYPAK Silica Gel bags )

If you need further assistance, then we will be very happy to help you. Just click on the green button below, and one of our Product Experts will call you back straight-away…

Technically speaking, both a desiccant and an absorbent soak-up water. However, in industrial terms the term ‘desiccant’ is typically used to describe a product that adsorbs water when it is in vapour state (i.e. when it is invisible ‘humidity’), and the term ‘absorbent’ is typically used to describe a product that soaks-up water when the water is in a visible liquid state (e.g. a fluid that has been spilt on the floor). Worldwide, the most common form of Desiccant is silica gel bags and our most popular form or Absorbent is our range of dissolving liquid adsorbents .

Silica Gels are a form of beaded or granular desiccant that is used for drying or dehumidifying sealed environments. Most people will have seen these gels where they are sealed in small white ‘sachets ’ and are included in the packaging of medicines or electronic equipment. However, in industry, they are also used in bulk quantities , as free-fill media for air dryers and desiccant breathers .

Indicating silica gels are small round beads of crystalline alumino-silicate that function as a desiccant or drying agent, just like normal silica gel does. However, they differ from regular silica gel in that they change colour from Orange (when they are dry) to Dark Green (when they are wet), so not only desiccate but also indicate.

Molecular Sieves are zeolites crystals, made from synthetic alumino-silicates. They are available with different pore sizes. These pore sizes dictate the size and type of molecules that they can absorb. By using different forms of these zeolites, with different pore sizes, you can thus sieve out various molecules based on their molecular diameter. You can think of this process as being exactly the same as the sieving and grading of industrial rocks/aggregates, but just done on a molecular level. At Baltimore, we specialise in 3A Zeolite Powder and Pastes . They can actually remove very small molecules such as water and thus they function as desiccants.

Barrier foils are a flexible sheet material, made-up of a thin aluminium foil layer, combined with 2 or 3 layers of polymer films, all laminated together to form one single sheet of material. They provide an excellent barrier to moisture, and it is used to form a hermetically sealed pouch in which a desiccant can then work. For more information, please click here , or speak to one of our Product Experts.

HICs are small paper cards with special (reactive) ink-spots on them. They are designed to measure the relative humidity within a packaged environment. The humidity level is indicated by a colour change of the dots, from blue (when dry) to pink (when saturated). For more information, please click here , or speak to one of our Product Experts.

SUPERDRYSIM™ is our advanced software for modelling moisture-behaviour within a sealed package. We use it to help manufacturers optimise their packaging in response to specific temperature and relative humidity conditions, and decreases the lead-time required to achieve product stability compared to more traditional techniques. In this way, manufacturers are guaranteed precise packaging solution at the minimum cost. For more information, please click here , or speak to one of our Product Experts.

PRONTOPACKER™ is an advanced and reliable desiccant dispenser, designed to insert accurately desiccant sachets into automated high-speed production lines. This machine takes continuous-strip desiccants, cuts them into individual sachets, and then places them into your packaging, whether that be a bottle (on a high-speed bottling line) or a pouch (produced on an automated flow-wrapper). For more information, please click here , or speak to one of our Product Experts.

HUMIBALANCE™ sachets are designed to maintain a specific humidity level, rather than reducing it to zero. If in-pack humidity is too high, then they adsorb moisture and if it is too low, then they release moisture. The overall effect is humidity maintenance at a specific level that is suitable for your product. For more information, please click here, or speak to one of our Product Experts.

Oxygen absorbers are used to remove oxygen from within the product’s sealed packaging.

They are used to protect pharmaceutical, nutraceutical, diagnostic, food products from oxygen degradation and oxidative reactions, thus extending the shelf life – There are 2 types of oxygen absorber the Reliant type and Self-Reliant type . The reliant type (sometimes known as “moisture-activated”) relies on the presence of moisture inside the packaging to become activate – The Non-reliant (sometimes known as “self-activating”) do not rely on the presence of moisture within the package, in order to become activated

In addition to a range of physical products, we also offer our expert advice through our Consultancy. This service is particularly useful for start-up companies who don’t have a large R&D Department that can answer their packaging questions for them. It is also very useful for larger companies who are either working against a tight deadline, and need answers quickly, and/or established companies who are launching a new product into a new market sector in which they have little prior experience. For more information, please click here , or speak to one of our Product Experts.

It is possible to regenerate silica gel by re-heating it, but we do NOT recommend this, for three main reasons:

With every heat-and-saturation cycle the crystal structure within the silica gel becomes more and more damaged (it’s just like photo-copying a photo-copy), and with every re-heating cycle the product’s quality decreases, and total adsorption capacity decreases.

In Europe and the USA, the cost of energy for heating the silica gel, is actually more than the cost of buying a brand new silica gel sachet. So it costs you more to regenerate these bags yourself.

In almost all cases, the temperature at which you need to heat the Silica Gel is higher than the burning temperature of the sachet or plastic housing that contains the Silica Gel. Therefore, you have a choice of: [a] heating the silica effectively and setting fire to the sachet/housing, or [b] not setting fire to the exterior sachet, and in doing so, not drying the silica beads to a level required to regenerate them. For all of these reasons, we do NOT recommend re-generating your silica gel.

Note also that if you are using a standard white packet of white silica gel, then it’s not easy to tell when the silica has been saturated, and when it needs replacing. For this reason, we have developed a range of indicating silica gels, which clearly shows (via a colour change) when the silica has become saturated, and when you need to replace the sachet.