Paper cups are the future, but are they safe?

The paper used in paper cups is bio-degradable,but not the ldpe used to make the cups sturdy. Anand srinivasan looks at the complexities surrounding the paper cups

25 May 2015 | By Anand Srinivasan

The next time you pick up a café latte from your neighbourhood Barista or Starbucks, do take a look at the cup itself. In all likelihood, it would be a paper cup, perhaps lined with plastic or wax. However, if you fancy tea from the vendor next to your office, chances are you will be served a tiny plastic cup. 
It is important to understand this dichotomy. While thanks to the government’s ban on non-biodegradable plastic there has been a surge in demand for paper cups, the market is still dominated by plastic.
  In the beverage market, plastic cups still have a share of 80%, with the rest 20% being paper cups. This, by no means, is a small number. According to a recent survey, more than one crore paper cups are being used every day.
This makes paper cups manufacturers in India optimistic about the future. Some even go to the extent of saying that in the near future, the demand for paper cups will be 100%, due to the awareness being created and steps being taken by the government to promote the use of paper cups.
This is evident in the major cities like the NCR (National Capital Region, including Gurgaon, Faridabad, Noida and Ghaziabad), Mumbai, Bengaluru, Hyderabad, Chennai, etc, where manufacturers say the demand has catapulted much more than the supply. 
Issues of recycling
The real question remains, are paper cups better?
“They obviously are, because of  their decomposable and biodegradable nature,” says a manufacturer. Another manufacturer counters, “Plastic cups has its own trade-offs like paper cups.” He argues that the carbon footprint and greenhouse gas emission during the life cycle of a plastic cup is less than that of a paper cup.
When you compare the recyclability of both paper cups and plastic cups, paper cups wins hands down. This is because paper is the main constituent in a paper cup and is biodegradable by nature.
This is an advantage. However, when you see the manufacturing process of a paper cup, it involves a stage called water-proofing, which packs a layer of low density poly-ethylene (LDPE) on the sides and bottom of the cup to prevent water from getting absorbed by the paper. This LDPE is the only disadvantage in a paper cup. This is because the LDPE, which is a plastic material, prevents the recycling of the paper.
Thus, paper cups cannot be recycled under normal conditions. It requires a specialised process to separate the LDPE coating and the paper, where the cup waste is warmed in a solution to remove the plastic lining. Following this, the paper waste is pulverised and recycled, finally filtering out the impurities. The final pulp can be used to make other paper-based products.
If we see today, the paper cup industry is witnessing a significant growth both due to the demand and ethical production processes. The product’s innocuous nature, upon disposal, due to its easily degradable quality makes it a desirable and preferably convenient essential product. Another reason for its abundant supply and corresponding demand is its impact on production costs.
At present, paper cups have taken a major share in the beverage industry like tea, coffee, cold drinks for railways, hotels and some household appliances and domestic applications as well as replacing glass items.
Considering the environment 
As an industry for entrepreneurs to invest in, the paper cups industry, compared to other industries, is not capital intensive. But what the statistics say is it actually is a resource intensive industry. This is because the entire process of paper-making for a paper cup requires substantial amount of water, energy… and a lot of trees.
When it comes to the criticality in opting for paper cups, there are two main aspects to be considered. One is the use of the paper required for manufacturing the cups. This is a high risk aspect that requires an FDA approval, since the substrate is in direct contact with the liquid.
Typical paper coffee cups, which are being used currently, are not made from recycled papers. Instead, most cups are manufactured using 100% bleached virgin paperboard. Why don’t manufacturers use recycled paper? First of all, FDA regulations are strict when it comes to allowing recycled paper pulp to be in direct contact with food and beverages. 
The second risk factor is the environmental impact of the paper cups. Statistics say, nearly 6.5 billion trees are cut to produce paper for paper cups due to which around four billion pounds of carbon dioxide is released into the atmosphere. This is a serious issue. Also, to add to this problem is the difficulty to recycle the cups due to the use of poly-ethylene.
  Every paper cup that is manufactured and coated with LDPE ends up in a landfill. Once in a landfill, the paper will begin to decompose. This process releases methane, a greenhouse gas with 23 times the heat-trapping power of carbon dioxide.
Market potential 
Currently, paper cups are being used in all sorts of ready-to-eat products. The available sizes range from 50 ml to 550 ml. Today, food grade paperboards are used for the manufacturing of paper cups, which are fast expanding as a viable substitute to plastics and its families. 
Traditionally, paper packaging has been used consistently in our country. With the quantum jump in the consumption and growing demand pattern, the future of paper cup industry looks promising. A recent survey carried out in the NCR region shows the usage of paper cups as around two lakh cups per month. Seasonal demand created by weddings and the festival season adds to another one to 1.5 lakh cups per month to this figure.
Ideally, a paper cup manufacturing is not very complex. The base paper for paper cups are called cup board and are made on special multi-ply paper machines and have a barrier coating for waterproofing. This is done to provide the paper with high stiffness and strong wet-sizing. The cup board grades have a special design for the cup manufacturing processes. The mouth roll forming process requires good elongation properties of the board and the plastic coating. A well formed mouth roll provides good stiffness and handling properties in the cup. The basis weights of the cup boards are 170-350 gm.
Flexography is the most common process used for printing when the quantities are usually long runs. It is used for quantities over a million cups. Offset is the other alternative when it comes to short-run jobs, which can vary from 10,000 to 100,000 cups. Offset printing inks have also been developed and although in the past these were solvent-based, the latest soya-based inks have reduced the danger of cups smelling. The very latest development in the printing segment is DirectXprinting, which allows printing on very small quantities, typically from 1,000 cups.