Splice trays are necessary for holding and protecting individual fusion splices or mechanical splices.
Normally splice trays should be matched to the type of splice used. A splice tray designed for holding mechanical splices usually can not be used for bare fiber fusion splices or heat-shrink fusion splices. Although there are splice holding chips you can purchase to make them work, it is not the ideal way.
Standard splice trays can hold up to 12 splices and you can use several splice trays together for higher strand number fiber optic cables. The splice tray has room for mounting fiber splices and excess fibers.
Fiber loose tubes enter the splice tray at one end and are secured to the splice tray. The loose tube stops at the splice tray end and individual fibers are exposed and spliced inside the splice tray.
NOTE: Bare fibers without protection tubes should never be exposed outside of a splice tray. When splicing a large fiber optic cable with more than 12 fiber strands, proper buffer tube splitters should be used when routing bare fibers to another splice tray.
Be very careful when mounting the splices inside the tray. Minimum fiber bending radius requirement should always be observed.
The following is a sample picture of a splice tray with fusion splices mounted inside.