Types of Paper Used In Food Packaging
There are mainly 4 types of paper used for the food packaging. Paper is coated or laminated with PE, PLA or waxes to improve its functional and protective properties.
- Kraft paper – Kraft paper is durable, a machine-made paper that’s made mostly from wood pulp. Kraft paper has a high tear resistance and contain highly-oriented fibers. It offers better protection than many other packaging materials. It is commonly used for takeaway bags, supermarkets grocery bags and other packaging. With the recovery boiler, Kraft paper manufacturers now reach a nearly closed-loop production cycle, meaning they recover and reuse almost all of the water and major chemicals used in the Kraft pulping process.
- Baking Paper/Parchment paper – A cellulose-based composite made from the acid-treated pulp, the acid modifies the cellulose to give it additional properties like non-stickiness, grease resistance, and resistance to humidity. It is commonly used in baking as a disposable non-stick, grease resistant surface. It should not be confused with waxed paper, which is paper that has been coated in wax. It is not a good barrier to air and moisture, is not heat sealable, and is used to pack fats, such as butter and lard.
- Greaseproof Paper – Greaseproof paper that is impermeable to oil or grease, and is normally used in cooking or food packaging. It is usually produced by refining the paper stock and thus creating a sheet with very low porosity. This is then passed between hard pressure rollers to further increase the density, creating a paper called glassine. The glassine is treated with starches, alginates or carboxymethyl cellulose (CMC) in a size press to fill pores or treat the paper chemically to make it fat repellent. Basis weights are usually 30–50 g/m2. Now greaseproof paper is being replaced by plastic films.
- Corrugated Cardboard – The corrugated board consists of 2 layers of Kraft flat linerboards with a central corrugating fluting paper. Its resistance to impact abrasion and crushing damage makes it widely used for the transportation of food such as pizza box or general packaging material.
REFERENCES: Wikipedia, PaperIndex Academy
Solid Bleached Sulphate (SBS) vs Folding Box Board (FBB)
Solid Bleached Sulphate (SBS)
Solid Bleached Sulphate (SBS) is made exclusively from bleached chemical pulp. It usually has a coated top surface and some grades are also coated on the reverse side. This is a medium density board with printing properties that meet the high requirements of graphical and packaging products. SBS can be die cut, creased, hot foil stamped and embossed with ease. It therefore gives wide scope for advanced structural and surface designs. It is pure and hygienic and is therefore suitable for the packaging of aroma and flavour sensitive products.
The surface brightness is 90 % ISO – top surface roughness is less than 1.2 microns PPS – Hunter Gloss of top surface more than 75 %
SBS– Available in 200 to 600 GSM – Suitable for all types of Printing Process – Considered as premium grades for packaging and graphical purposes – Suitable for packing aroma and flavor sensitive products – In general SBS are superior when purity good appearance and runnability of the packaging material are required.
Folding Box Board (FBB)
Folding box board is a multi-ply board. A layer, or layers, made of mechanical pulp is placed between layers of chemical pulp. Mechanical pulp may be stone-ground wood (GW), pressurized ground wood (PGW), thermo mechanical pulp (TMP) or chemi thermo mechanical pulp (CTMP). The top layer is bleached chemical pulp and the reverse layer may be bleached or unbleached chemical pulp. The top and reverse side may be coated with mineral pigments.
The combination of inner layers of mechanical pulp with outer layers of chemical pulp creates a strong and stiff sheet, taking advantage of the well-known I-beam phenomenon in physics. This is a low density material with high stiffness. Fully coated grades give excellent printing and visual impact. This is a virgin fibre paperboard with consistent purity for product safety.
The basis weight ranges from 200 to 450 GSM – Ideal for Food packaging, cigarettes cosmetics, pharmaceuticals and graphical applications.
REFERENCE: Iggesund Paperboard, Metsa Board