Evaluation of melt flow as a measure of low density polyethylene processability into blown films

1972 ◽  
Vol 12 (6) ◽  
pp. 459-463 ◽  
Author(s):  
Andrew Plochocki ◽  
Lech Czarnecki
Keyword(s):  
Low Density Polyethylene ◽  
Low Density ◽  
Melt Flow ◽  
Blown Films

Blown Films from Linear Low Density Polyethylene Incorporating Biodegradable Additive

2003 ◽  
Vol 11 (2) ◽  
pp. 141-144
Author(s):  
Vivek Kale ◽  
Kalpesh Jani ◽  
Satish Awate ◽  
R Rangaprasad ◽  
Yatish Vasudeo
Keyword(s):  
Low Density Polyethylene ◽  
Second Step ◽  
Environmental Concerns ◽  
Natural Soil ◽  
Low Density ◽  
Linear Low Density Polyethylene ◽  
Blown Films ◽  
Polymer Resin ◽  
Innovative Materials ◽  
Different Levels

Environmental concerns are now driving additive suppliers and polymer resin manufacturers to step up efforts to create innovative materials for the future. In the present work, a “biodegradable” additive/promoter was incorporated into a butene-based linear low density polyethylene (LLDPE) at different levels. The properties of the blown films derived therefrom were investigated. In the first step the “degradation additive/promoter” was converted into a 50% masterbatch in LLDPE. In the second step, this concentrate was let down at 5, 10, 15 and 20% level in a butene-based film grade LLDPE. The properties of the films were characterized. In the third step, the films were subjected to “real-time” degradation tests; using natural soil and under vermicompost conditions. Films subjected to degradation under vermicompost conditions have shown encouraging results. After 3 months, the films containing 15 and 20% additive were found to have disintegrated to a practically unusable form.

scholarly journals Polyethylene-Matrix Composites with Halloysite Nanotubes with Enhanced Physical/Thermal Properties

Polymers ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 787 ◽  
Author(s):  
Janusz W. Sikora ◽  
Ivan Gajdoš ◽  
Andrzej Puszka
Keyword(s):  
Impact Strength ◽  
Flow Rate ◽  
Softening Temperature ◽  
Halloysite Nanotubes ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Melt Flow ◽  
Polyethylene Matrix ◽  
Melt Flow Rate ◽  
Heat Deflection Temperature

The aim of the present work is to investigate the effect of halloysite nanotubes (HNT) on the mechanical properties of low-density polyethylene composites modified by maleic anhydride-grafted PE (PE-graft-MA). Polyethylene nanocomposites were prepared using an injection molding machine, Arburg Allrounder 320 C 500–170; the HNT content was varied at 0 wt %, 2 wt %, 4 wt % and 6 wt %, and the PE-graft-MA content was varied at 5 wt %. The composites were examined for their ultimate tensile stress, strain at ultimate stress, hardness, impact strength, melt flow rate, heat deflection temperature, Vicat softening temperature, crystallinity degree and phase transition temperature. It was found that the addition of halloysite nanotubes to low-density polyethylene (LDPE) led to an increased heat deflection temperature (HDT, up to 47 °C) and ultimate tensile strength (up to 16.00 MPa) while the Vicat softening temperature, strain at ultimate stress, impact strength and hardness of examined specimens slightly decreased. Processing properties of the materials specified by the melt flow rate (MFR) deteriorated almost twice. The results have demonstrated that the nanoparticles can reinforce enhance LDPE at low filler content without any considerable loss of its ductility, but only when halloysite nanotubes are superbly distributed in the polyethylene matrix.

scholarly journals Effects of Flame Retardants Additives on the Properties of Low-Density Polyethylene

2018 ◽  
Vol 5 (3) ◽  
pp. 57-65
Author(s):  
Raed Ma'ali
Keyword(s):  
Magnesium Hydroxide ◽  
Flame Retardants ◽  
Diphenyl Ether ◽  
Melt Flow Index ◽  
Degree Of Crystallinity ◽  
Low Density Polyethylene ◽  
Flow Index ◽  
Low Density ◽  
Melt Flow ◽  
Flame Resistance

Low-density polyethylene (LDPE) has many unique properties such as lightweight and high chemical resistance. Unfortunately, it burns rapidly when it is exposed to a flame which limits its applications especially when flame resistance is to be considered. Different percentages of magnesium hydroxide and decabromide diphenyl ether (3.0, 5.0, 7.0, and 9.0 wt.%) were mixed with LDPE using a two-roll mill machine at 1600C for 2 minutes. Then, the tensile and flame retardancy tests samples were prepared by an injection molding process using an industrial plastic machine at 1600C. Flammability, rheological, tensile and thermal properties of the produced samples were tested using a flammability test apparatus, a melt flow index machine, a universal testing machine, and a differential scanning calorimeter, respectively. It was observed that the flame resistance of LDPE was improved with the addition of both flame retardants up to 7.0 wt.%, then it was reduced when 9.0 wt.% of flame retardants were used. This may be attributed to the poor mixing due to the increase in the polymer melt viscosity as observed from the melt flow index results. An increase in elastic modulus and a reduction in ductility of LDPE were observed with the increasing of flame-retardant contents while the ultimate tensile strength of LDPE was increased from 5.7 to 7.6 and 7.5 MPa when 9.0 wt.% and 7.0wt.% decabromide diphenyl ether and magnesium hydroxide were added. This is due to the fact that the additives act as a load carried and/or their effects on the degree of crystallinity of LDPE.

Tubular Film Blowing

2006 ◽  
Author(s):  
Chang Dae Han
Keyword(s):  
Elongational Flow ◽  
Fiber Spinning ◽  
Point Of View ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Film Blowing ◽  
Chain Branching ◽  
Blown Films ◽  
Long Chain Branching ◽  
Long Chain

Tubular film blowing has long been used to produce biaxially oriented films using such thermoplastic polymers as low-density polyethylene (LDPE), high-density polyethylene (HDPE), and polypropylene (PP). Here, LDPE refers to a polymer that is synthesized by free-radical polymerization under high pressure (Fawcett et al. 1937). The discovery of linear low-density polyethylene (LLDPE) in the 1980s via the Unipol process (Beret et al. 1986; Jones et al. 1985), which uses a low-pressure gas-phase process, has led to additions to the family of tubular blown films during the past two decades. The discovery of metallocene catalysts (Stevens and Neithamer 1991; Welborn and Ewen 1994) in the 1990s further increased the number of LLDPEs that have been used to produce tubular blown films during the last decade. To distinguish LLDPE from LDPE, LLDPE is sometimes referred to as low-pressure low-density polyethylene (LP-LDPE) and LDPE is referred to as high-pressure low-density polyethylene (HP-LDPE) (see Chapter 6 of Volume 1). In this chapter, however, we use the terminologies LDPE and LLDPE. As described in Chapter 6 of Volume 1, LDPE has a high degree of long-chain branching, while LLDPE has short-chain branching with little or no longchain branching. However, the metallocene catalysts apparently allow one to produce LLDPEs having a wide range of side chains, including a certain degree of long-chain branching. The details of the synthetic procedures for producing such a variety of LLDPEs are closely guarded industrial secrets. Biaxially oriented film can be strong and tough in all directions in the plane of the film. As in fiber spinning, the polymer melt exiting from the die flows under a mechanical tension in the direction of flow. However, in the film blowing process, the tube of molten polymer is extended in both the transverse and the axial (machine) directions. Therefore, rheologically speaking, the film blowing process may be treated from the point of view of biaxial elongational flow, whereas the fiber spinning process may be treated from the point of view of uniaxial elongational flow.

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