Storage and shipping of coating materials
Shelf life, temperature control and transport basics for silazane-based products.
4 min
·
Technical articles
Silazane resins react with water, so most of what goes wrong in storage and transport is moisture ingress rather than temperature abuse. Viscosity rise, gel particles, haze and gas pressure in a part-used container are all symptoms of the same reaction that is supposed to happen on the substrate, not in the drum. The handling rules below are generic; the binding numbers are always those on the product data sheet and safety data sheet for the specific grade.
Storage and shelf life
Store containers tightly closed, in a cool, dry, well-ventilated area away from direct sunlight and heat sources, and away from water, acids, bases, alcohols and oxidising agents. Typical recommended storage for reactive silazane grades sits in the region of 5-25 C, but the correct window varies by grade and solvent system and should be taken from the data sheet.
Shelf life for unopened, correctly stored material is commonly quoted in the range of six to twelve months and varies by grade; some highly reactive grades are shorter. Treat the stated date as conditional on the storage conditions actually maintained, and re-test viscosity and appearance before use if material has been held near or past that date.
Once a container is opened, headspace air becomes the main source of moisture. Blanketing the headspace with dry nitrogen or argon before resealing is standard practice for moisture-sensitive resins, as is decanting into smaller containers so that a large drum is not repeatedly opened. Never return decanted material to the original container.
Transport and receiving
Most silazane products ship as solutions in organic solvents, so transport classification is driven by the solvent system and by the reactivity of the specific grade. The applicable UN number, packing group, hazard class and any air transport restrictions must be taken from the safety data sheet issued for that grade and confirmed with the carrier; they are not something to infer from the product family. Air freight in particular can be restricted or require specific packaging for some grades.
Packaging should combine a chemically compatible primary container with an intact closure and liner, plus outer packaging that protects against impact and puncture. Keep material out of direct sun during loading and staging, and avoid leaving pallets on hot tarmac or in unventilated containers.
On receipt, check container integrity and closure seals before moving stock, record batch numbers and dates, and rotate stock first-in first-out. Let cold-shipped material equilibrate to room temperature while still sealed, so that condensation forms on the outside of the container rather than inside it.
Documentation and incoming checks
Each grade has its own documentation set. The technical data sheet gives the storage window, shelf life and processing conditions; the safety data sheet gives incompatibilities, personal protection and the transport classification. Certificates of analysis and any additional compliance documents are issued per batch or per grade on request rather than published, so ask for them together with the quotation if they are needed for incoming inspection.
A workable incoming procedure is short: confirm that the grade, batch number and quantity match the documents, inspect closures and outer packaging for damage, and check appearance and viscosity against the value stated for that batch. Quarantine anything that arrives with a damaged seal or visible haze until it has been checked.
Record the storage location and date of receipt, and keep the data sheets with the stock rather than in a separate file. Because shelf life is conditional on the storage conditions actually maintained, a stock record that shows where and how material was held is what makes a shelf-life claim meaningful later.
Practical application note
Decant only what a shift will use, work under dry conditions, and purge both the drum headspace and the decant container with dry nitrogen before sealing. Before applying a batch that has been in storage, check appearance and viscosity against the incoming value; haze, gel particles or a marked viscosity rise indicate partial reaction and the batch should not go onto production parts. Keep the safety data sheet for the specific grade with the stock, since storage limits, incompatibilities and transport classification are all grade-specific. The common pitfalls are repeated opening of a single large drum, storing near a moisture source or in direct sun, and opening a cold container immediately on arrival so that condensation enters the resin.
In practice
Products and applications connected to this topic.