An open mouth block bottom paper sack is used mainly by food companies and animal feed producers. This type of sack can be printed on both sides and on the block bottom base.
Like all paper sacks it is formed with piles of paper coming together (generally three) which gives the sack it’s strength, then the block base is formed and glued in place.
The staple bag for the milling, animal feed and potato industries. These sacks are formed by piles of paper coming together and are then stitched at the base along with a Crape paper to form a seal.
A more up-market version of the sewn bottom sack. These sacks are designed with the end user in mind as they are predominantly for animal feed uses.
The paper plies are formed to create the sack size and the top is then rolled and glued to form a seal, which when forced by hand is opened.
This sack is technically manufactured upside down (they give this appearance because the print is upside down until filled) as they are filled with the product from the bottom. The outer ply of these sacks is generally a clay coated finish or gloss which gives the sack more appeal and is easy on the customer’s eye.
Paper Valve Sacks have been with us now for over a century, being invented in 1898 and patented in 1908. These sacks are used mainly for fine powders, foodstuff and cement markets. The valve sack has a valve (opening) in one corner which can be either of internal or external configurations.
Paper valve sacks are made from multiple plies of paper tubed together to give the sack it’s strength, to prevent water ingress a polythene ply can also be inserted as an inner ply.