A Preliminary Discussion on Adhesive Mixing Systems in Oriented Component Board Production

Abstract: This paper briefly introduces the commonly used adhesives and additives in the production of oriented strand board (OSB) and the adhesive mixing system, and briefly compares the application and advantages and disadvantages of two types of adhesive mixers used in OSB production.

Commonly used adhesives and additives for OSB

Adhesive preparation is the process of selecting suitable adhesives and additives according to the requirements of the type of board being produced, and adding them in a certain proportion based on the corresponding particle flow rate. Adhesive preparation requires appropriate equipment. In recent years, newly installed continuous hot press production lines mostly use PMDI with additives, in addition to UF or MUF as the raw adhesive. Furthermore, a backup line is maintained, making the adhesive preparation system very complex. Each line (for each additive) requires not only a high-end screw metering pump but also a reliable and highly accurate mass flow metering system. Simultaneously, to ensure that a failure of the mass flow metering system does not affect normal production, a weighing system is also used. Currently, there is a gradual shift from simple, intuitive volumetric metering to a system supplemented by mass flow meters and weighing.

1) The glue preparation process for OSB production is basically the same as that for particleboard production. The adhesive, waterproofing agent, curing agent, process water, etc. are converted into dry matter according to density, volume, solid content or concentration, and added to the mixing tank at the same time according to the process requirements. After being fully mixed, it is sprayed into the glue mixer by volume metering.

2) Later, the method of directly measuring the mass of adhesives and various auxiliary agents by weighing sensors was developed, which is called the weight reduction method.

3) Then, the adhesive and its additives are measured by mass flow meter.

The four adhesive preparation systems mentioned above for OSB production each have their advantages and disadvantages. In terms of investment amount, they should be arranged from less to more to provide investors with a variety of options.

Title: A Preliminary Discussion on the Adhesive Mixing System in Oriented Strand Board Production

Authors: Guo Zhiwu, Ge Lijun, Zheng Fengshan

Source: China Wood-based Panels, Issue 9, 2018