Reduced rosin content

Variations found in CTO composition result primarily from the species of wood pulped and the location and climate where the trees are grown. Pulping process variations further affect CTO composition. The best CTO is produced from pine wood. However, many U.S. mills mix hardwood with pine to reduce fiber costs, or mix hardwood black Hquor with pine black Hquor. This lowers the rosin content. The composition of CTO produced in the southeastern United States and of typical Canadian and Scandinavian CTOs are shown in Table 2. 

LSFs allow the use of spray fluxers, which are prone to maintenance problems at higher rosin levels. Reducing the rosin content by a factor of flve or more and the amount of flux dispersed on a card by a factor of about four (depending on the spray flux application system) has resulted in flux reduction during wave soldering of up to 100 times less than originally utilized. This follows... 

If ASA is subject to heat and moisture at the same time, it will hydrolyse and react at similar rates, resulting in reduced efficiency. Therefore, it should be dried similarly to rosin size, but with sufficient heat to break the ASA particle at a low moisture content... 

Depending on the properties required, the vinyl content in the EVA copolymer may be varied and varying quantities of tackifying resins (e.g., rosin esters) and waxes are incorporated. Tackifying resins affect the adhesion at elevated temperatures, the time the adhesive takes to harden and the quality of final adhesion achieved. The main purpose of the waxes is to reduce the melt viscosity and thereby improve the wetting of the substrates. 

The original water content is 40-60%, which is reduced to 15-18% by air drying. It consists of 45-50% ->cellulose, 25-30% ->lignin and 15-20% pentoses and hexoses (- hemicelluloses). There are a few other minor ingredients, such as resins (- rosin), waxes, - terpenes and minerals. 

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