Patented in 1996, the conical IBC was developed by Macro to improve bubble cooling. As with other IBC hardware, the conical IBC contains an air supply passage through the interior of the die to supply cooling air to the bubble's interior surface, and an exhaust passage for the air removal chimney. The main difference with this IBC when compared to conventional IBCs is that the conical IBC consists of a set of annular components that increase in diameter with height to form a conical shape similar to that of the bubble. The result is that the cooling outlets, which are positioned within the cone, conform to the shape of the bubble and remain relatively close to the interior of the film as it leaves the die and travels upward.
Compact Edge Guide
Macro has recently developed a compact edge guide that uses air-cushioned turning bars to provide frictionless edge control of the web. By guiding the web with near-frictionless turning bars, as opposed to conventional systems that utilize steering rollers, the generation of tension memory in the web is avoided. See the Fall 2007 MacroLetter for more.
Oscillating Haul-Off for Sticky Films
Macro received a 2007 patent for the development of an oscillating primary nip designed to handle sticky films. The haul-off contains a slitting assembly to split the tube into two webs near the primary nip. The randomizing equipment following the nip is designed to ensure that the sticky side of the film does not contact the turning bar surfaces. Additional description of this haul-off system will be published in an upcoming MacroLetter.
All of the above mentioned innovations can be incorporated into Macro’s blown film extrusion systems to improve film quality and/or enhance productivity.
PVdC
Perhaps some of Macro's most notable achievements have come in the development of equipment and processes for Polyvinylidene Chloride (PVdC). PVdC is one of the best performing barrier polymers. It provides an outstanding barrier to both gas and moisture. It is also insensitive to moisture, has good formability and is heat sealable. The problem with PVdC is that it is difficult to extrude because of its sensitivity to heat. It degrades quickly and can cause extensive corrosion to extrusion equipment. For this reason, special processing equipment is required for successful PVdC extrusion.
Commercial Single-Layer PVdC Extrusion
In 1992 Macro built the first commercial single-layer biaxially-oriented PVdC film line for use in the food packaging industry.
Cast Coextrusion with PVdC
Macro designed and constructed the first 5-layer cast film coextrusion line with PVdC in 1995.
In addition to running PVdC, the line also featured the ability to run numerous combinations of EVOH, Nylon, PP, LLDPE and ionomers. In 1998, the line was made commercially available, primarily for the production of films for the food packaging industry.
Commercial PVdC Extrusion Coating
A significant challenge still lay ahead in the form of extrusion coating of PVdC without the need for encapsulation. In 1996, armed with the knowledge gained during previous PVdC work, Macro developed the world's first single-pass PVdC extrusion coating line to coat a thin layer of PVdC onto substrates such as PVC sheet. The main product for the line was blister packaging film for the pharmaceutical industry. See the Winter 1998 MacroLetter for more.
Commercial Blown Film Coextrusion with PVdC
In 1997 Macro developed the first commercial PVdC coextrusion blown film lines for use in the food packaging industry. The lines utilized specially designed extruders and dies with corrosion resistant surfaces and very short residence times. The specially designed coextrusion die used in these lines was patented at about the same time and marketed as the MacroPack Die. The MacroPack is a stacked coextrusion die that allows for the extrusion of highly degradable polymers in combination with high melt temperature polymers.
Commercial Biaxially-Oriented Coextrusion with PVdC
In 2000 Macro developed a commercial double-bubble process for the coextrusion of biaxially-oriented PVdC shrink film. These lines are now in operation in Europe and South America and are used for the production of food related shrink films, typically for meats and cheeses.
R&D Equipment
Glass Window Extruder
In the early 2000s, in collaboration with Beijing University, Macro engineered and built its Glass Window Extruder, the first commercially available extruder of its kind. It was specifically designed to allow
the extrusion process to be visible through transparent sections of the barrel. It proved to be a useful tool for organizations involved in education, research, screw design and resin formulation.
2 in 1 Cast-Blown Film Lab Line
Macro has recently designed a combination 5-layer cast-blown film lab line that allows the researcher to quickly switch between running blown film trials to running cast film trials, and vice versa in less than a day. The system contains all the necessary components of both a commercial blown film line and cast film line. The key comes in the flexibility in both the mechanical design and system programming to facilitate an easy transition between the two processes. The bulk of the work involved in switching is in swapping the die and aligning the casting unit. The operator interface is designed to run the equipment in either cast mode or blown mode. We expect to release more information about this line in the coming months.
PVB
PVB sheet is used primarily as a glass laminate to produce glass end products with high impact resistance, such as vehicle windshields and architectural glass for construction. In 1994 Macro designed and constructed the first commercial line to produce PVB sheeting.
Today, Macro continues to be a world leader in PVB sheet line design and production.
Winding Technology
Aside from the technologies available on winding equipment that come standard on Macro's extrusion systems, Macro provides comprehensive winding solutions for a wide range of materials and automation requirements. Over the past 30 years, Macro has built a worldwide reputation as a leading designer of sophisticated winding machinery. Hundreds of custom designed winders have been manufactured by Macro for a wide variety of materials including:
Flexible films
Extensible and tacky films
Stretch wrap films
Embossed films
Bubble wrap
Sheet of varying thickness and rigidity
Roofing material
Shallow thermoformed sheet
Corrugated sheet
Many of Macro's more recent winding innovations have evolved out of strong customer requests for high levels of automation. These enhancements in winding automation improve safety and product quality and reduce the processor's operating costs. In general, these automation enhancements have included roll unloading, core loading, roll labeling, roll taping, roll wrapping, and roll conveying.
A great deal of change has occurred in the plastic film and sheet industry over the past three decades. Thanks to the innovative developments that were made possible by a strong commitment to R&D and the determination to find solutions to challenges created by the market's ever changing needs, Macro has earned itself a reputation as a technology leader. We have every intention to continue with this tradition and hope to generate many new innovations to help shape the continually evolving future of plastic films and sheet.
