Regarding Steel Drum Coating, Several Commonly Overlooked Issues

Steel drum painting does not require cutting-edge high technology. Mastering some operational skills and correct specifications is necessary for suitable painting of steel drums to achieve desired results. The following topics including technical specifications and process discussions outline steel drum painting: 1) Surface pretreatment of steel drums; 2) Type of coating; 3) Coating equipment; 4) Coating film formation.

Surface pretreatment of steel drums

Any item to be painted requires an appropriate substrate state and the surface should be maintained before coating to ensure that the coating can adhere reliably to the metal. In some special production environments for steel drums, such as in factories along the coastal areas where there is salt in the air, rust-proof oil needs to be applied on the steel plate to protect the steel drum from corrosion. The process of this system treatment is critically important for obtaining good surface quality of the steel drum before painting.

Type of coating

In the world of steel drums, there are many different components, and coating technology has made great progress and innovation in the past decade. Each innovation has its own unique features, such as aesthetics, mechanical, chemical, or compliance with today's environmental regulations, etc. In fact, coatings today can be classified into three types:

• Solvent-based coatings;

• Water-based coatings;

• Powder coatings.

Solvent-based coatings are a steel drum coating system that has developed independently in the past decade. Perhaps solvent-based coatings are the most widely used steel drum coatings to date. The development of certain coating technologies has required years of research to protect the steel drum surface: they are elegant and can not only protect the metal surface, including the steel drum closures, from external corrosion, but also resist corrosion by various chemicals in the container.

Coating equipment

The feed rate of steel drums in spray booths must be given an accurate and fast timing output, but such speed must also be uniform and stable to avoid steel drum shaking or falling off the spray production line. During the entire spray cycle, the rotational speed of the steel drum requires a constant value with a fixed action program. In order to save paint and limit environmental pollution, paint overspray must be restricted. Unfortunately, this cannot be completely avoided, so a properly dried or water-curtain absorption system is essential. The high-speed rotating spray disk is currently the main method for interior spray painting of drums. This device can achieve a constant coating thickness along the entire length of the drum barrel.

Coating film formation

After spraying water-based, solvent-based or powder coatings on steel drum surfaces, they must be dried at a certain temperature and time. Different types of coatings have different standards, curing conditions, and quality inspection characteristics.