Fiber

There are mainly two types of fiber used in making paper, softwood and hardwood. Softwoods are conifers, such as pines. Hardwoods are broad-leafed trees like oaks. Softwood fibers are in general twice as long as hardwood fibers. The blend of fibers used for a particular type of paper is dependent on its end-use and economics. In most cases hardwood fiber is more expensive, mainly due to the longer period of time it takes for a hardwood tree to mature as compared to a softwood. However, depending on past land management there are cases where hardwoods are cheaper than softwoods. In any case the best mix is the least expensive mix that will produce the desired results. For grades that require more strength more softwood fiber is required. The longer the fiber the stronger the paper. If a sheet needs to be smoother and have better formation, a more uniform appearance, then more hardwood should be used. For economic purposes fillers are also added to reach the desired result. For example, for an inkjet paper the most important aspects of the sheet are appearance, printability, and curl. For this type of sheet a higher percentage of hardwood fiber would be required as opposed to say a bag grade. Fillers can be added to make a smoother sheet and improve print quality. Calcium carbonate can be added to offset fiber costs and still provide the required result. The more calcium carbonate that can be added, the more savings can be accumulated. There are two types of calcium carbonates, precipitated calcium carbonate and ground calcium carbonate. More on that in a later post. This one is supposed to be about fiber. Another chemical that can be added to improve print quality is a sizing agent. This is added at the size press, but this chemical can be expensive so less is best. Anyhow, back to fiber, there are ways to make softwood fibers mimic hardwood fibers. By increasing the refiner load on softwood fibers this will cut the fibers which makes them closer to the length of hardwood fibers. However, doing this will also increase energy cost and may not be worth the offset of softwood fiber replacing the hardwood fiber. I apologize for this post I feel like I'm rambling a bit. Just remember that for strength add softwood, for looks add hardwood. There's more to it than that actually. I think I'll leave it at that for now. Just don't seem to be real focused right now for some reason. Maybe I need a five hour energy shot or something.