how the paper cups come from

A paper cup is a disposable cup made out of paper and often line
or coated with plastic or wax to prevent liquid from leaking out or soaking through the paper. It may be made of recycled paper and is widely used around the world.

Paper cups have been documented in imperial China, where paper was invented by 2nd century BC. Paper cups were known as chih pei and were used for the serving of tea. They were constructed in different sizes and colors, and were adorned with decorative designs. Textual evidence of paper cups appears in a description of the possessions of the Yu family, from the city of Hangzhou.

The modern paper cup was developed in the 20th century. In the early 20th century, it was common to have shared glasses or dippers at water sources such as school faucets or water barrels in trains. This shared use caused public health concerns. One notable investigation into their use was the study by Alvin Davison, biology professor at Lafayette College, published with the sensational title "Death in School Drinking Cups" in Technical World Magazine in August 1908, based on research carried out in Easton, Pennsylvania's public schools. The article was reprinted and distributed by the Massachusetts State Board of Health in November 1909^.

Based on these concerns, and as paper goods (especially after the 1908 invention of the Dixie Cup) became cheaply and cleanly available, local bans were passed on the shared-use cup. One of the first railway companies to use disposable paper cups was the Lackawanna Railroad, which began using them in 1909. By 1917, the public glass had disappeared from railway carriages, replaced by paper cups even in jurisdictions where public glasses had yet to be banned.

Paper cups are also employed in hospitals for health reasons. In 1942 the Massachusetts State College found in one study that the cost of using washable glasses, re-used after being sanitized, was 1.6 times the cost of using single-service paper cups. These studies, as well as the reduction in the risk of cross-infection, encouraged the use of paper cups in hospitals.

Paper cup making machine

Waterproofing

Originally, paper cups for hot drinks were glued together and made waterproof by dropping a small amount of clay in the bottom of the cup, and then spinning at high speed so that clay would travel up the walls of the cup, making the paper water-resistant. However, this resulted in drinks smelling and tasting of cardboard.

Cups for cold drinks could not be treated in the same way, as condensation forms on the outside, then soaks into the board, making the cup unstable. To remedy this, cup manufacturers developed the technique of spraying both the inside and outside of the cup with wax. Clay- and wax-coated cups disappeared with the invention of polyethylene (PE)-coated cups; this process covers the surface of the board with a very thin layer of PE, waterproofing the board and welding the seams together.

In 2017, the Finnish board manufacturer Kotkamills launched a new kind of cup (food service) board which uses no wax or plastic for waterproofing, and thus can be recycled as part of the normal paper and board waste stream, biodegraded, or even composted in small quantities.

Printing on paper cups

Originally paper cups were printed using rubber blocks mounted on cylinders, with a different cylinder for each colour. Registration across different colours was very difficult, but later flexography plates became available and with the use of mounting systems it became easier to register across the colours, allowing for more complex designs. Printing flexographic has become ideal for long runs and manufacturers generally use this method when producing over a million cups. Machines such as Comexi are used for this, which have been adapted to take the extra large reels that are required by paper cup manufacturers. Ink technology has also changed and where solvent-based inks were being used, water-based inks are instead being utilised. One of the side effects of solvent-based inks is that hot drink cups in particular can smell of solvent, whereas water-based inks have eliminated this problem. Other methods of printing have been used for short runs such as offset printing, which can vary from anything 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 latest development is Direct-printing, which allows printing on very small quantities, typically from 1,000 cups, and is used by companies including Brendos ltd offering small quantities in short lead times. Rotogravure can also be used, but this is extremely expensive and is normally only utilised for items requiring extremely high quality printing like ice cream containers.

paper cup printing machine

Die cutting by die cutter

Environmental impact

Recycling

Most paper cups are designed for a single use and then disposal. Very little recycled paper is used to make paper cups because of contamination concerns and regulations. Since most paper cups are coated with plastic (polyethylene), then both composting and recycling of paper cups is uncommon because of the difficulty in separating the polyethylene in the recycling process of said cups. As of 2016, there are only two facilities in the UK able to properly recycle PE-coated cups; in the absence of such facilities, the cups are taken to landfill or incinerated.

A UK-based business group James Cropper have developed the world’s first facility for the effective recycling of the estimated 2.5 billion paper coffee cups used and disposed of by British businesses each year, and have become one of 14 international companies to formally join the Paper Recovery and Recycling Group (PCRRG).

James Cropper's Reclaimed Fibre Facility was opened by HM The Queen in July 2013, and recovers both the plastic and paper from the cups; ensuring nothing is wasted from the recycling process. Although paper cups are made from renewable resources (wood chips 95% by weight), paper products in a landfill might not decompose, or can release methane, if decomposed anaerobically.

A Newport Beach, CA company, Smart Planet Technologies has developed a process for modifying the polyethylene coating on paper cups and folding cartons so they are engineered for recyclability. Orange Coast College in Costa Mesa, CA has begun a program to use cups made with this technology to capture and sell the fibers to fund scholarships for their students.

In 2017, the Finnish board manufacturer Kotkamills launched a new kind of cup (food service) board which uses no wax or plastic for waterproofing, and thus can be recycled as part of the normal paper and board waste stream, biodegraded, or even composted in small quantities.

The manufacture of paper usually requires inorganic chemicals and creates water effluents. Paper cups may consume more non-renewable resources than cups made of polystyrene foam (whose only significant effluent is pentane).

Paper vs plastic

A life cycle inventory of a comparison of paper vs plastic cups shows environmental effects of both with no clear winner.

Polyethylene (PE) is a petroleum-based coating on paper cups that can slow down the process of biodegrading of the paper it coats.

Polylactic acid (PLA) is a biodegradable bio-plastic coating used on some paper cups. PLA is a renewable resource and is certified compostable, which means that when it biodegrades, it does not leave behind any toxic residues. Although PLA-lined cups are the only paper cups which can be composted fully, they can contaminate the waste stream, reportedly making other recycled plastics unsaleable.

All paper cups can only be recycled at a specialised treatment facility regardless of the lining.

A number of cities – including Portland, Oregon — have banned XPS foam cups in take-out and fast food restaurants.

Emissions

A study of one paper coffee cup with sleeve (16 ounce) shows that the CO₂ emissions is about 0.11 kilograms (0.24 lb) per cup with sleeve – including paper from trees, materials, production and shipping.

Habitat-loss trees used

The habitat loss from one 16 ounce paper coffee cup with a sleeve is estimated to be 0.09 square meters (0.93 square feet). Over 6.5 million trees were cut down to make 16 billion paper coffee cups used by U.S. in 2006, using 4 billion US gallons (15,000,000 m³) of water and resulting in 253 million pounds (115,000,000 kg) of waste. Overall, US Americans use 58% of all paper cups worldwide, amounting to 130 billion cups.