Classification of paper and corrugated paper introduction

Classification of paper

Paper can be classified into the following categories based on numerous parameters.

Based on the grade: Firstly processed paper from raw wood pulp is called as virgin paper or virgin grade paperRecycled paper is the paper obtained after reprocessing of virgin paper, recycled waste paper itself or their combination.

Based on the smoothness and treatment given to pulp and paper, it is broadly divided into two categories: Papers used for printing, labelling, writing, books etc. are made of bleached pulp and called as fine paper, and paper used in packaging of food materials which is made of unbleached pulp are called as coarse paper.

According to Food Safety and Standard Authority of India (FSSAI), only virgin grade packaging material should be used for direct food contact (FSSR 2011). Paper for food packaging can be classified into two broad categories (1) based on pulp or paper treatment (2) based on shape and combination of various materials. Wood pulp treatment effects the paper properties and its use significantly. The next section discusses about the various types of paper based on pulp and paper treatment and their use in food packaging.

 

Corrugated fibreboard (CFB)

The raw material for CFB is mainly kraft paper however agave bagasse, by-products from the tequila industry had also been used for the fibreboard production (Iñiguez-Covarrubias et al. 2001). Corrugated fibreboard usually consists of two or more layers of flat kraft paper (liner) and layers of corrugated material (flute) is sandwiched between the flat layers to provide cushioning effect and abrasion resistance. Fluted material is developed using corrugator which involves passage of flat kraft paper between two serrated rollers, followed by application of adhesive to the tips of corrugations and liner is stuck to the corrugated material using pressure (Kirwan 2005). If it is having only one liner, it is single wall; if lined on both sides than three ply or double faced and so on. According to Bureau of Indian Standards (IS 2771(1) 1990), A (Broad), B (Narrow), C (Medium) and E (Micro) flute types had been defined. A type of flutes is used when cushioning properties are of prime importance, B type is stronger than A and C, C is compromise of properties between A and B and E is easiest to fold with best printability (IS:SP-7 NBC 2016). Food packaging singly utilizes thirty-two percent of total corrugated board in European countries and forty percent if beverage packaging segment is also included (Kirwan 2005). It is used in direct food contact surface mainly for fruits and vegetables, where all grades of waste paper can be used as internal layers but the specified requirement on the level of pentachlorophenol (PCP), phthalate and benzophenone had to be fulfilled.

Compartment based CFB cartons are typically used for multipacks of yoghurt cups of polystyrene. Meat, fish, pizza, burgers, fast food, bread, poultry and French fries can be packed in fibreboards (Begley et al. 2005). Fruits and vegetables can also be packed for supply to markets on daily basis.


Post time: Dec-16-2021