Issue 58 2014-05-16 購読

Producing T-shirt Bags with 3 Layer Blown Film Machine Significantly Reduces Cost

Producing T-shirt bags with 3 layer blown film machine significantly reduces cost
In some markets such as Turkey, Thailand and Vietnam where T-shirt bag production has become extremely competitive, film producers are now replacing their existing mono layer extruders with ABA 3 layer blown film machines, mainly to save production cost. One of the biggest T-shirt bag producers in Vietnam has already replaced half of its mono layer extruders with ABA machines in the past 3 years to stay competitive in the local market.

The A-B-A blown film machine consists of two extruders, normally of two different sizes. The most common ones today are the combination of a 45mm screw diameter together with a 55mm for T-shirt bag production. For garbage bags, normally a 55mm screw with a bigger 65mm is used. In the A-A outer layer, normally 20% of CACO3 (Calcium Carbonate) is used, with 3% color masterbatch, 7% LLDPE and 70% HDPE. The B layer generally consists of 60% CaCo3 with 40% HDPE. A large percentage of recycled pellets (from in-house waste) can also be added to the mixture.

The new ABA is the most economic and efficient way to produce T-shirt bags in the market today
V 30% stronger film

V 50% cost saving

V 60% CaCO3 added

V 100% recycled

material used

Besides reducing a significant amount of raw material used in the formula, another advantage of the ABA machine is that the 3 layer film that it produces is 30% stronger than film produced by a mono layer extruder. The ABA machine is also much more economic comparing to an ABC three layer machine as it has one extruder less.

Polystar has shifted its main focus onto making and re-engineering ABA technology, because it has noticed this big shift in market trend in many countries where it exports to. In Russia, for example, the mono layer blown film market has decreased significantly for Polystar, despite the fact that it used to sell at least 50 mono layer blown film machines to the market annually for almost a decade. Instead, 90% of the blown film machines that Polystar has sold to Russia since 2010 has been the ABA type. One of the leading and largest film and bag producers in St. Petersburg (Russia) who currently with 60 sets of Polystar's mono layer blown film machines, has also been very active in upgrading their machines to the ABA type from mono layer extruders.

Polystar has recently installed 22 sets of mono layer blown film machines in Yangon, Myanmar in a newly-established film production factory. The production line was purchased by one of the largest Japanese investment groups, who aims to produce films locally in Myanmar, and later exports the packaging film products back to Japan. Its main products include flat bags, T-shirt and garbage bags. However, Polystar believes that this type of set up is only likely in a country where labor cost is still relatively low. In markets where labor cost is higher and more competition exists, producers must find a way to lower their production cost in order to increase profit margin. In Taipei Plas 2014, Polystar will exhibit an ABA blown film machine at the show to introduce this technology to the visitors.