Underlining its ongoing to commitment to plastic films, Milliken has launched a new nucleating agent that delivers optical improvements, an enhanced moisture barrier and improved mechanical properties for polyethylene (PE) resins. As a result, says the company, functionality in films and packaging can now be expanded.

Nucleating agents provide a physical, molecular-level trigger point around which highly-ordered crystalline structures called spherulites form rapidly. Known as Hyperform HPN-20E, this agent has recently been granted food contact notification (FCN), which opens up a range of new options for customers in the PE industry.

Target applications include monolayer and coextruded film for food packaging, agricultural applications and overwrap films. Early focus has been in the area of linear low density polyethylene (LLDPE) resins where optical enhancement is vital for shelf appeal. Traditionally this has been achieved through blending low density PE (LDPE) into LLDPE. Unfortunately, this can result in reduction of tear and impact strength of the resultant film. Nucleating LLDPE with HPN-20E can enhance optics without detriment to tear and impact, offering film producers a new and novel option for packaging film constructions.

In addition, the nucleating agent is showing some improvement in PE film hot-tack performance that can potentially speed up vertical form, fill, and seal lines (VFFS). It also permits potential down-gauging by enhancing stiffness and eliminating much of the reduction in tear and impact performance associated with LDPE blending. This presents potential new ways for cost effective film constructions.

According to Milliken, nucleating polyethylene with Hyperform HPN-20E is also showing exciting reductions in water vapour transmission rates (WVTR), hence enhancing the barrier properties of polyethylene film layers – high density PE (HDPE) and LLDPE – used in a range of different coextruded structures. WVTR reductions on the order of 40percent (LLDPE) and 20percent (HDPE) have been observed in trials.

A new, in-house blown film line underscores Milliken Chemical’s commitment to PE and film, both of which are relatively new initiatives for the company (Fig.1).

“Polyethylene and polyethylene film are a new area for Milliken,” said Martin Horrocks, global market manager, polyethylene additives, “but we are learning that nucleation can bring value to this polymer and our short term focus is to understand how the benefits of nucleation of PE can drive value for our customers. Polyethylene is a very difficult material to successfully nucleate and HPN-20E is the most efficient chemistry to achieve this. We want to help the market investigate the types of improvements this technology can deliver. Long term, we want to investigate other areas of PE outside of film where nucleation can create value. A first example of this involves cycle time reductions in blow molding high density polyethylene.”

Green building plastics

As part of its ecomagination initiative, GE Plastics is developing environmentally responsible engineered plastics that it says are excellent candidates for green applications. Specifically for the building and construction industry, the company’s wide array of sheet products for energy-efficient roofing and glazing applications, and resin grades for lightweight, recyclable roofing, offer builders a host of options for green structures.

“Green building is moving into the mainstream, and GE Plastics’ products give our customers the materials they need to succeed with this new opportunity,” said Carina Viola, the company’s industry manager for building and construction. “Our plastics can replace traditional building materials in glazing, roofing, and interior applications to deliver environmental benefits along with greater design freedom and reduced system costs.”

Today’s builders must balance the increasing demand for designs that admit large amounts of light with concerns about energy costs. The use of specialised polymer glazing instead of traditional glass can achieve both. One approach is the use of additives that block near-infrared (IR) heat but admit light.

For example, in the Netherlands, Lexan Solar Control IR polycarbonate (PC) sheet encloses the four escalators leading to the Amsterdam ArenA (Fig.2). The escalators are designed to help handle large crowds, which can lead to uncomfortable temperature levels within the enclosures. Lexan Solar Control IR sheet helps absorb infrared and near-IR radiation from the sun, potentially reducing interior heat build-up by as much as 40percent. In addition, it can offer up to 60percent more visible light transmission than other plastic-based, IR-absorbent glazing products.

Polyolefin meltblowns

At the same time, Borealis is investing in a polyolefin meltblown expertise facility to increase non-woven innovation. The investment includes the installation of an in-house pilot line alongside other laboratory equipment. It is the first time that a polyolefin supplier has installed an in-house meltblown pilot line and it will be located in Borealis’ international Innovation Centre in Linz, Austria (Fig.3).

The new pilot line will support the cost-effective testing of meltblown concepts together with customers and enable the delivery of innovative products to the market more quickly. Borealis is the market leader in this segment and further strengthens its commitment to the development of new solutions for the industry with this investment.

Polyolefins for the meltblown industry are used predominantly in hygiene applications, such as baby diapers and feminine care products, for medical and protective clothing, and face masks and other air and water filtration applications.

Axel Becker, international sales manager for machine manufacturer Reicofil, who supplied the new line, comments: “Borealis’ investment opens up new opportunities for the meltblown industry to research advanced applications. The in-house pilot line will make small-scale testing of a large number of samples economically viable. This will encourage exploratory testing that pushes existing boundaries, expanding meltblown into exciting new application areas.”

Nina Ackermans, application marketing manager with Borealis, adds: “The meltblown industry requires step-changes in the performance and processing properties of the materials it uses to expand the potential of non-wovens. Our in-house testing opportunities will provide the flexibility we and our customers need to develop new polymer concepts for the markets of the future.”

In another innovation, the company has created a novel opportunity for pail packaging converters to raise productivity and increase processing efficiency while delivering pails with excellent stacking performance, high impact resistance and good aesthetics. New polypropylene BH374MO has been developed specifically to meet converter and OEM demands for high quality, cost-effective and environmentally-friendly pail materials that reduce per unit packaging weights, offer storage and transport benefits, and improve performance (Fig.4).

BH374MO’s higher than normal melt flow rate (MFR) of 45, achieved through its low viscosity, allows easy and fast processing with unrivalled consistency in both single and multi-cavity moulds. The resulting potential for shorter production cycles and faster processing impacts both production output and speed, with the added environmental and cost benefits of reduced energy usage.

Added to this, OEM customers can take advantage of a number of transport, storage and aesthetic benefits thanks to the material’s high stiffness, lightweight, improved strength and excellent anti-static performance.