Full definition
A cold splice is a technique used primarily for joining the ends of conveyor belts without the need for a vulcanizing press. This method is particularly advantageous for applications where mobility and accessibility are limited, allowing repairs to be conducted on-site in various environmental conditions. The process involves several critical steps: firstly, the ends of the belt must be properly prepared by stripping back the cover rubber and stepping the plies at predetermined lengths, following a finger splice pattern for multi-ply belts. This ensures that the splice can bear the operational loads without premature failure.
Once the belt ends are prepared, a primer is applied to enhance adhesion, followed by the application of a two-component cement, such as Rema Tip Top SC 4000 with hardener E-40. The splice rubber is then laid into place, and a hand roller or stitcher is used to create adequate compression and contact between the surfaces. The curing process typically takes between 4 to 12 hours at a temperature of 20°C, but this duration can vary significantly with ambient temperatures—longer curing times are required in cooler conditions, while warmer environments can reduce the time needed.
The strength of a cold splice generally reaches 60-80% of the original belt strength, which positions it as a middle ground between mechanical splices (50-70% strength) and hot vulcanized splices (90-100% strength). While cold splices offer the convenience of being field-portable and lower in equipment costs, they do come with trade-offs, including extended downtime during the curing phase and a sensitivity to humidity and temperature fluctuations. It is essential that skilled technicians perform the procedure to ensure optimal results, as the splice's longevity is typically around 50-80% that of a hot vulcanized splice, making them best suited for medium-duty belts up to EP800/4.