foamed films: find new niches.

For more than 30 years, thin foam has been cast and blown in niche products, from shiny ribbons to shrink sleeves of bottles.
The new process makes it thinner and stronger, and manufacturers are chasing new markets.
Thin olefin foam for decorative ribbons, wire packaging and sleeves has been manufactured for decadestype labels.
These early foam films are now mature products in relatively flat markets.
\"Growth comes from new products,\" said John Huber, general manager of lunjin plastic Co. , Ltd. , an Austrian Renjin foam polypropylene belt manufacturer.
Over the past decade, dozens of new thin bubbles have been created for the packaging sector, including labeling, tampering
Clear seal, Pearl wrapping paper and carrier tray padding.
Now, stronger resin, better understanding of the effect of additives, and new technologies all contribute to the development of new products.
Most thin foam is still polypropylene and polystyrene, which is the resin used in traditional ribbons and shrinkagesleeve labels.
But the bigger market is coming, especially the thin polyethylene foam.
Some of the growing uses, such as washers for mobile phones and electronics, become too big to be considered a niche market any longer.
How foam value-added foam can expand the thickness of the film by 20% to 100% or more, while reducing its density by 40% to 60%.
Foaming can save the resin, but this is not the main attraction of the film.
Blistering than 20 thin things
30 miles is expensive and complicated.
Therefore, thin foam is made for applications that add value.
Introduction to microbubbles
Bubbles give properties from soft to stiff, from transparent to opaque.
\"One area of growth is much thinner.
\"Layer extrusion with special surface effects, such as a soft touch,\" Manfred Dicks said . \"p.
Total batch of clear agent additives.
Rising soft International
Touch effect using soft foamfeel ethylene-
The ethylene interpolymer produced by Dow Plastics is the carrier of its new FPE400 CBA concentrate.
Foaming has an advantage in packaging because it produces a gloss with anti-slip properties without additives.
Other features include electrical, thermal insulation, and tear-free.
Reducing tear strength may be a benefit or a responsibility, depending on the application.
Another noteworthy drawback is that blistering will dilute the paint.
The whitening effect of the same Pearl will make the bright color pale, so the foam needs more paint.
A variety of technologies used film through several complex, multi-
One-Step foaming process, even by combining filler with orientation to make microvoids.
Thin cast foam is a chemical foaming agent (CBAs)--
Heat release based on nitrogen or heat release based on bicarbonate.
Flat coating for cast foam
Hook the mold, then the guide roller.
If more orientation is required, the film can be stretched at secondary heat
Hot bath or hot waterair oven.
The film blowing film is made with a physical or chemical blow molding agent using horizontal bubbles and ring molds.
Very thin foam can also be blown with vertical bubbles.
Compared to CBAs, the density of physical foaming with nitrogen, CO 2, isotinone or fluorine-containing carbon is much lower, and CBAs usually reduces the density by only about half.
Fine cell structure is achieved by adding nuclear agents such as talc or professional CBA as a nuclear agent. (
The latter example is the Hydrocerol CF4OT of Corine and the fine and long Safoam FPN3049 PS or FPE5O for the use of polyolene. )
Whether blown or cast, thin foam can be made with a long single screw extruder, a tandem extruder or a twin screw extruderscrew.
One of the thinnest bubbles ever ---a 3-mil, three-
PE film with foam core layer--
It is produced on the basis of traditional blowing.
Ampacet\'s film series
Use its 703061
High absorption of OBA.
The film was not commercialized.
Depending on the resin, color, foamer type, and process technology, thin foam may need support that can come from orientation, cross-linking, coextrusion, or lamination.
Most foam films are oriented.
Thin cast foam usually uses a separate machine direction Guide (MDO)
The blowing film obtains the inherent simulated two-way orientation from the expansion bubble. Two-
Step two-way orientation does not apply to foam film because it breaks the bubble and weakens the film horizontally.
One of the earliest foam films since the 1970 s was the shiny ribbon.
The single layer streamer film is blown at 2% CBA, and the tensile ratio is about 4:1.
When the melt leaves the modified coating, the film thickness expands to about 20 miles. hanger die.
After winding the roller MDO with a series of gaps, the film ends up with a thickness of about 5 miles.
Direction makes the movie very powerful in the direction of the machine (MD)
But in the landscape (TD)
, So that the ribbon has the characteristic appearance of textile made from parallel lines.
Before the split, the ribbon Netcom is about 5 feet wide.
For more than ten years, insulation data and power cables have also produced very similar one-way directional single-layer PP foam belts. Electrica-
The insulating tape is also very thin in MD, but this is not a problem because the tape is usually spiral
Wrap around the wire before the wire is coated with PVC.
The wire package is thick from 3 to 20 mil and from 0. 55 to 0.
Density 70g/cc.
It is usually produced by the same company that makes ribbons.
Lenzing, which produces both products, has also developed new thin directional PP and other foam for laminating on paper and making labels for fruit bags.
Foaming contributes to opacity and MD strength;
Paper helps printing.
The professional label is \"a very narrow market with only a few players, but now it\'s growing very fast,\" says Huber of Lenzing\"
Screw extruder and roller-
Gap Extrusion Technology Co. , Ltd. also provides Gap guidance devices in Lenzing.
SML is opening an American company. S.
Office next month
The sleeve market is shrinking and thin-
The foam products that started in 1970s are shrinking.
Sleeve Label of beverage bottle.
These are thin PS foam, mainly blown with a physical foaming agent and squeezed together with the surface layer to obtain printability.
Because the foam is thin and the bubbles are small, they are soft and flexible.
Shrink labels solve the problem of sticky paper labels: When juice bottles are displayed in the refrigerated buckets of convenience stores, they fall off in the water.
Foam PS can also isolate bottles and keep drinks cool.
A product called Plasti.
Shield was developed by Owens.
Illinois in Basil, Kentucky.
In 1970s, the use of a single
Spiral series foam production line with horizontal bubbles and patented mixing technology combine CBA with injecting gas into the extruder.
They realized 30 together-
35% less weight.
The foam is opaque white from the size of the bubble, so Ti [O. sub. 2]
Used only in solid surface layers. Plasti-
The shielding shrink label was originally 12-
Mill single layer foam, then converted into two-at 1980 s-
The layers are crowded together.
It started at 14 miles, but gradually dropped to only 4-6 mils thick.
It is tricky to squeeze out with foam, because if it is not
The foam layer is hotter than the foam layer, and the heat breaks the foam.
After 80, Owens-Illinois (0-I)
Also adjusted its mixed chemistry-
Physical foaming technology from PS to PE.
PE is more flexible than PS.
Therefore, adaptation means a shift from horizontal foam to vertical foam --
The Addex film series provides a larger extension (blow-up)ratio.
This method produces threelayer, foam-
Core structure of In-
Mold label called DuraCore. O-
The label division, which sold to Fuji Seal in the United States last year, continued to introduce new thin coex foam.
It just developed a two.
For Japanese coffee containers that are only 6 miles thick, there is a layer of foam film.
Fuji seals also made three.
Film for bonding
The overall label is 15 miles thick, but the foam core is only 5 miles thick.
Duraplas is reportedly the first coex foam product that combines PS and PP.
The transparent white PS foam core is sandwiched between clear printable PP surface layers.
Other professional film companies are also operating soft pe foam.
Sealed Air Company
Headquartered in Saddlebrook, New York, USA. J.
, Protect the surface of furniture and other goods during transportation, making the single-layer low density polyethylene foam thin to 20 miles.
\"The trend is a new combination of film, foam and density below 0. 2-0.
\"3g/cc . \"S. T.
Lee, R & D director of Sealed Air.
Thin PE foam, however, is more difficult to wrap than PS because PE is very elastic.
Within three to four days of making a roll of FE film, the stretched foam begins to relax and expand in the roll.
Therefore, if the tension inside the roll is too large, the expansion will crush the bubbles in the core.
One way to prevent this is to reduce the tension as the roll is established.
This requires a special winding machine with complex tension control.
Thinner meters also need a winding machine that can improve the speed of the line-
A source from Battenfeld Gloucester said that up to 500/mm, the company makes a dedicated hoist for thin FE foam.
However, there are some alternatives for special windmills.
For example, The Sealed Air says just for the thinnest 20-mil LDPE foams.
Instead, it increases the density of thin foam.
For example, it\'s 20-
The mill low density polyethylene foam is 0. 020 to 0.
025g/cc, while its 125-
Wood Poly low density polyethylene foam is 0. 0176 g/cc.
With the development of new applications, industrial olefin foam for strength has also become thinner and stronger.
For example, Super
Thin cross-linked foam may enter the big market of washers used in electronic organizers, mobile phones and computer monitors.
It was reported that a year ago, Alveo, the Sekisui division based in Lucerne, Switzerland, made the world\'s thinnest cross-linked polyethylene foam ---a 16-
Thick foam low density polyethylene polymer film for mobile phone lens gasket.
The product was made in romonde, the Netherlands.
By last April, the thinnest foam in Alveo had dropped to 12 pieces. 75 mil.
On last October, just in time for the German K 2001 exhibition, there were only 9 cross-linked PE foam produced by Alveo.
Thick band of 9 mil 【:+ or -]10% tolerance.
The fracture elongation was 313% MD and 412% TD, and the density was 0. 33 g/cc, vs. 0.
Original FE resin 91.
This is a much larger reduction in density (64%)
More typical than CBAs.
The density of the conventional PP foam belt is reduced by less than 50%.
The process of Alveo is unusual
It stands out in a single cast.
Foam screw;
The film is then cross-linked by electron beam;
Finally, it goes through a foaming oven in which it is expanded and oriented.
Alveo is trying to trim another 0.
The foam thickness is 2 mil and the target is lower.
\"If we can drop to 8 miles, the film will have a wider range of applications,\" said Hans coang, sales and marketing director at Alveo . \".
\"Our goal is to make it thinner and thinner.
\"Cellect LLC of Cellis, quality.
We are also focusing on the new gasket market.
\"We are doing a lot of development work,\" said Scott Smith, president and CEO . \".
Cellect\'s Senflex T product is its thinnest foam (20 mils)
Commercialized in last August
Cellect aims to reduce to 15 miles.
\"We think we can replace a lot of thin
PVC and propylene rubber foam.
Mobile phones and personal washers have a big market.
\"Care packaging,\" Smith said.
\"There are washers in the computer and printer.
You give it a name with a washer inside.
\"The huge growth will be reflected in the finer meters,\" he predicted.
A suitable material thin foam requires a resin with additional melting strength and possibly additional density.
Several PP suppliers have introduced foaming grades.
The northern European chemical industry increased its PP melt strength by increasing its length
Use the reaction extrusion process to branch the chain of its Daploy grade.
One is to mix into the foam to increase the melting strength, to create finer, more uniform bubbles and to provide a higher gloss.
It is not available in the United States. S.
However, but borewald said it received so many inquiries from the United States. S.
Thanks to the introduction of Daploy products at the 2001 show, it is considering openingS. office.
Cellect changed the flow properties of its PE resin before foaming with a patented process, which uses active silicon to hold low levels of length-chain-
Branch into Mao metal PE.
Cellect says the result is a double peak resin that is easier to foam with greater tensile strength and lower compression permanent deformation.
But for thin foam, the right resin is not just a matter of density or melting strength, be careful that the resin does not contain components that interfere with the foam.
Michael Reddy, president of Reedy International, explained: \"PP usually contains calcium eighteen as a catalyst scavenger, but calcium eighteen is also an active Defoamer . \".
\"So it limits your ability to get good foam cells.
You really want a special foaming PP.
\"The color also affects the quality of the thin foam.
\"Most Masterbatch contains hard fat calcium salt as an external lubricant.
\"Calcium eighteen breaks bubbles even at low concentrations,\" Reedy warned . \".
He said White was the most serious criminal. O. sub. 2]
It is not one that is applied, but two kinds of dispersing agents, both of which break up the bubbles.
\"Every time a white pigment is added to the foam plastic, big bubbles are generated,\" Reedy said . \".
\"The whole industry is looking for someone who doesn\'t have a plastic dispersing agent to produce white paint.
\"The easiest solution is not to put Ti [O. sub. 2]in the foam.
Without paint, the film has been whitened by blistering.
If more transparency is needed, Ti [O. sub. 2]
It can be added to the unfoamed surface layer of the extrusion or stack.
Add wax to the parent material of the dispersed pigment to make a foam film stretcher.
Because the foam will dilute the color, more paint is needed for the foam.
If you need 2% paint to be bright
Red foam-free film, if there is foam, it may take 5% of the pigment to get the same color.
More paint means more wax.
This is why the pigment foam is much higher than the tensile ratio of the pigment-free foam.
Foam without gas?
Using microvoid instead of bubbles to reduce density, a rainbow-like and opaque white film can be made.
When the film is composite with the submicron-
The size of the clay filler is oriented, the plastic is drawn from the filler particles, open the Micro
Make the film a shiny pearl-like void.
One example is the Melinex cast PET film, which was patented by ICI and acquired by DuPont in 1997.
OPP can also be \"pearl\" with mineral filler \".
The Dole film represented by the Dole film of Israeli CamilleJ.
, Make metal BOPP Film for gift packaging and label stock. It\'s a three-
Squeeze in the core layer with the cakium carbonate filler layer. Micro-
When the film is oriented in two directions, a void is created, making it 25% lighter.
The film density from 0. 91 g/cc to 0.
73g/cc after orientation.
Micro density
The gap film is usually much higher than the one inflated with gas.
Foam becomes harder foam usually does not survive twice
Unless they are first cross-linked like the film of Alveo, they are oriented in both directions. A new biaxial-
Testing Orientation possibilities on thin foam under development.
This is the simultaneous two-way orientation process of Maschinenbau GmbH in brürkner, Germany, called LISIM. Bruckner (which has a U. S. office)
Two-way directional casting foam has been proved, which claims to be much stronger than the foam made by blowing film.
The tensile ratio of foam PP film made with LISIM process is about 3. 5:1 MD and 4. 5:1 TD, vs.
Blown 3:1 MD and 4:1 TDfilm foams.
But those made by LISIM are stronger because when the film is mostly melted, two-way stretching occurs in the blown film.
The LISIM film is stretched in a solid state at the same time, which gives it greater strength, brürkner said.
There are many thin film foam films under development in Brukner, including a single layer PP foam made of approximately 2% of the absorbent OBA; a three-
PP film layer with foam core and filled outer layer; a 10-
Mil single layer mixture of PP and Nylon 6 with density of 0. 25 g/cc; a 4. 5-
The density of mill PP is 0. 31 g/cc;
Foam mixture of standard PP and long PPchain-branched PP;
Block polymer with ethylene rubber content of about 12%.
The latter produces a soft film with a very fine foam structure and fabric feel.
Another test sample is 8-mil, high-
Tear the glossy pp film of d print like paper, but the moisture permeability is very 1 w (10 g/[m. sup. 2]in 24 hr).
Brunkner also produced t in PET foam using LISIM.