End-use requirements may drive the growth of more complex, highly layered structures. #Polyolefin

According to Mastio, most conversion membrane structures (59%) are still single-layered. 

We reported on stretch films, T-shirt bags, institutional tank linings, consumer tank linings and shrink films, production films, bags, and agricultural films in the previous installments of this blog series, which provided a snapshot of the 2017 research results Research on the PE film industry conducted by Mastio & Co., a market research company in St. Joseph, Missouri. Next, let's take a look at its analysis of the conversion film.

The conversion film is intended to be used or converted into a variety of different end-use applications or products. In the research, Mastio divided the conversion membranes into two categories:

Sheets are cast films manufactured in sizes less than 12 mils and sold in roll form to film processors, industrial end users, or wholesale packaging distributors. The pipe is a blown film and is sold in the form of a roll of pipe laid flat. The pipes can be partially pre-processed, such as pipes with gussets.

According to Mastio, in 2017, approximately 988.6 million pounds of PE were used to produce conversion films. According to Mastio's forecast of an average annual growth rate (AAGR) of 2.3%, the consumption of PE resin for the production of conversion film will reach 1.0584 million pounds by 2020.

Several film extrusion companies regularly participate in this market, manufacturing converters on an "on-demand" basis to take advantage of excess capacity during periods when demand for other traditional PE film products is slow. Other PE film extrusion companies report that they produce this film according to the specifications of the film processor or end user. Some players in this market only extrude films, while others extrude films and convert films into various packaging products.

According to Mastio's research, the six major players in the conversion film market last year were Sigma Plastics Group; Berry Global Group; Embalages Polystar (Polystar Packaging Canada Inc. Div.); Inteplast Group Ltd. (Inteplast Engineered Films Div./Engineered Films Div.) . and Danafilms Div.); Zhongnan Extrusion; and IMAFLEX, Inc.. The market share of these companies in 2017 was approximately 49.6%.

According to Mastio, the total consumption of LLDPE-butene, LLDPE-hexene, LLDPE-superhexene, LLDPE-octene and mLLDPE resin exceeds the total consumption of LDPE resin in the market. LLDPE produces greater impact strength and puncture resistance than LDPE at lower specifications. Compared with the previous use of LDPE/LLDPE blends, the high transparency grade of LLDPE allows processors to produce films with high optical properties in thinner specifications. This further weakened LDPE's dominant position in this market.

According to Mastio, LDPE is the second most preferred material for the production of sheets and pipes, and can be used alone, mixed or used for multi-layer film coextrusion. LDPE has the characteristics of high transparency, easy processing, relatively low cost, and adaptability to be mixed with other PE resins, which are some of the reasons for its more use. LDPE-copolymers, such as LDPE-ethylene vinyl acetate copolymer (LDPEEVA copolymer), LDPE-ethylene methyl acrylate copolymer (LDPE-EMA copolymer) and LDPE-ethylene acrylic acid copolymer (LDPE-EAA copolymer) The material) resin will continue to be used for blending with other PE resins or co-extrusion in multilayer films.

Medium molecular weight-HDPE (MMW-HDPE), high molecular weight-HDPE (HMW-HDPE) and ultra-high molecular weight-HDPE (UHMW-HDPE) resins can be extruded separately, blended or co-extruded with low density polyethylene and film LLDPE Resin. HDPE resin allows for further thinning while providing greater film strength than LLDPE resin. HDPE resin can also be used as an additive for blending with LDPE or LLDPE, or as a processing aid to increase stiffness and bubble stability in blown film extrusion. Mastio says this is especially useful for bubbles larger than 80 inches in diameter.

Other benefits of using HDPE resin are increased barrier properties, excellent environmental stress cracking (ESCR), and easier conversion of the film into finished bags or sacks. However, when using HDPE resin, some film transparency will be sacrificed. Other resins reported on the market in 2017 include medium density polyethylene (MDPE), polypropylene (PP), nylon, and ethylene-vinyl alcohol copolymer (EVOH).

Mastio reports that in 2017, the majority of conversion films (99.1%) were produced using the blown film process. The improvement of film co-extrusion and PE resin technology has greatly increased the complexity of PE film. It is now possible to achieve a wider variety of film properties, such as three-layer forms with different coefficient of friction (COF) levels, filling and sealing sheets. The film can have high external adhesion, high internal smoothness, and sandwich LLDPE manufactured using the metallocene single-site catalyst process (mLLDPE). The high veneer helps prevent the packaged products from shifting or sliding after being stacked. The high sliding on one side makes it easier to insert the product into the package. The inner layer of mLLDPE resin achieves faster production speed by providing higher thermal tack strength than traditionally produced PE resin.

Film thinning is another advantage of film coextrusion technology, which allows film processors to combine LDPE with stronger LLDPE or HDPE resins. The structure of the co-extruded conversion film ranges from two to nine layers, with the three-layer structure being the most typical.

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