STiR coffee and tea magazine

40 STiR coffee and tea / Issue 3, 2018 (June / July) "If you consider that with one kg of aluminum wire we can produce about 77,000 tea bags and today the number of tea bags produced with the knot on IMA machines per year are about 50-52 billion, we can say that more than 650 (metric) tons of wire are not thrown in the waste bin each year," Menetti calculates. "This for the environ- ment has a big impact." And, one less production material results in a lower production cost, he says. With the pyramid, however, ultrasound is a common way to seal the contents inside. "Ultrasonic (sealing) is the first important thing," Wang says. "If you're not sealing well, the tea bag is not looking good." With ultrasound, heat is generated by vibrating the bag material at a precise fre- quency. In an ultrasonic weld, the mechanical vibrations applied between two sealing surfaces create frictional heat which melts the surfaces, which are then compressed into a welded seal. Maintaining freshness A tea bag alone cannot preserve freshness, however. Premium teas are enclosed in outer envelopes—known as overwraps—to seal in the qualities that make each variety unique. Foil paper, transparent film, and oriented polypropylene (OPP) are used to make overwraps. All with the goal of keeping air out and freshness in. "Packing in a good-looking envelope bag is a basic function," Wang says, noting that Eastsign uses multi-layer foil laminates for its envelopes. These are then heat sealed. Since freshness escapes from filter paper, it is important to seal the bag in an outer envelope to protect each product. ACMA uses a "fold-seal-cut" method in which each envelope or overwrap is folded around the bag, then sealed and finally cut. In compari- son to systems that cut the envelope and seal it around the bag, a company spokesper- son says the ACMA solution avoids envelope misalignment and the waste of expensive packaging material. IMA, a long-time developer of the "aroma barrier" sealable envelope, is working with envelope (material) suppliers to produce recyclable envelopes that also guarantee aroma protection. Adding environmen- tally sensitive materials comes at a price but "consumers can play a big role," Menetti says. "If they start to ask only for this type of packaging, the producers have to follow the demand." Turn to nitrogen gas "Pyramid envelope packing is very diffi- cult because of the shape," says Tecpack- ing spokesman Paul Zhang. "Before in the market, people had to use a big enve- lope. That was a waste of material and it did not look nice." Tecpacking, the first supplier in Chi- na to provide the pyramid tea bag pack- ing machine, is now developing a more efficient machine that can save on waste. "We make the bag first, then re-open the bag and insert the pyramid tea bags," Zhang says. "With this process we can have a very nice bag. Then we can do the nitrogen flushing." Nitrogen, that odorless gas that dis- places oxygen and surrounds all living things, has been surrounding tea bags in Japan for decades. Fuso International in- troduced nitrogen flushing 20 years in the Japanese market and it has been a com- mon way to protect tea bags ever since. "In Japan, we drink green tea. Green tea is very fresh tea," FUSO's Yajima says. "Oxygen is bad for green tea be- cause it effects flavor and taste. So to keep the tea bag fresh we use nitrogen gas flushing." FUSO's flushing process typically pro- tects freshness for about a year, Yajima says. Tea & Chemical Electronics (TNCE) is developing an improved envelope machine for triangular bags that can produce 50- 60 units per minute, company spokesman Hanbyul Byun says. "Our goal is (an enve- lope that protects freshness) for two years." Here are a few tea bag machines on the market: ACMA ACMA's TL 180 processes whole tea leaves with single chamber with lace and tags at low speed (180 bpm). Other features: - The machine produces thermos sealed bags using both recyclable and biodegradable materials. - ACMA machines can ensure cor- rect processing based on different types of tea and herbal tea blends. - The company offers a range of options for secondary packaging from glue or flat cardboard to pouches, from

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