Substrate Secrets
Discusses how films are made (extrusion, coextrusion, coating, etc.), formulated, converted and how they function for the end user.
Pigmented skins for opacity improvement
In reply to the suggestion to add a pigmented layer to improve the 7 layer product opacity variation, while the addition of a percentage or two of a 60% TiO2 master batch to the skins of the 7 layer opaque film might improve the overall appearance, it does not really fix the problem of the core layer distribution, the fundamental problem. Adding the white pigment to other layers will a ...... Read More
Comments (0)Interlayer forces impact on continuous nano layers
Mr Oliver has commented that splitting layers of barrier resin may not improve the barrier, but he is discussing the impact of creating 1,200 layers which are very thin. My comments are related to the splitting into several “macro” layers as opposed to the “nano” layer dimensions. In the macro case, the layer-splitting is to reduce the impact of a layer defect, an ...... Read More
Comments (0)Using PP concentrate for PE concentrates
Jivan Ahir has asked if the layer distribution of a film can it be solved by using PP-based carrier resin in White MB instead of PE carrier resin? The original posting was related to a 5- and 7-layer opaque PE film with variable opacity. So, in this case, I don’t think simply using a PP-based pigment. This is because it is the viscosity of the pigmented layer relative to the oth ...... Read More
Comments (0)Orientation and oxygen barrier for oriented polypropylene
A few posts ago I had some information on the impact of orientation on moisture barrier and I thought I would fill out the information by looking at the impact on oxygen barrier as well. In my files I have a paper on the subject and the reference is: A. K. Taraiya, G. A. J. Orchard and I. M. Ward, “Diffusion of Oxygen through Uniaxially and Biaxially Drawn Polypropylene”, J. Ap ...... Read More
Comments (1)Can 7- & 5-layer CPP be replaced by cavitated OPP?
Q: What are the applications of seven- and five-layer CPP, and can it be replaced by opaque BOPP or double-bubble PP or white TQPP? A: Well the applications can be many so it is hard to answer that directly. I have a client who uses white films for heat sealing into a pouch. The white layer is for light barrier and it has two clear outer layers, one sealant and one for printing. ...... Read More
Comments (1)Is it possible to metallize PE or PS film?
The short answer is yes, and there’s a great deal of metallized PE used in packaging and for mulch. While I have not seen a great deal of metallized-polystyrene films, it should be easy to do, as long as the metallizer can handle the film without damage. In general, oriented-PS films tend to be thick as they are used for thermoforming so the cost would be relatively high as the ...... Read More
Comments (0)Polymer orientation processing resource
A few posts back we were discussing how to find a book focused on film orientation. While searching for sources it was determined that the book is out of print, and I confirmed with one of the editors that there were no more copies that he was aware of. In the mean time there is a new book in the same “Progress in Polymer Processing Series” published by Hanser. I have pur ...... Read More
Comments (1)Plasma pretreatment
Plasma pretreatment is an existing technology that is experiencing an emergence into a new metallizing market segment defined by packaging films. It’s apparent from the suppliers of metallizing equipment and plasma-treater manufacturers that the technology has been in use for a long time but in markets focused on sputtered films where the added equipment expense was not much of an issue due ...... Read More
Comments (0)Vacuum technology & coating article on PET films
There is an interesting article on polyester films you might be interested in reading. It’s titled “Optimizing polyester films for flexible electronic applications” and can be found in the February edition of Vacuum Technology and Coating. If you do not subscribe to the magazine, you can find the article on the Website: www.vactechmag.com Go there and click on the digita ...... Read More
Comments (0)Follow up to a response to "Impact of orientation on moisture barrier"
Ryan Breese has commented on his work with orientation and moisture barrier and I would like to thank him for his additional information and thoughtful comment. He comments: In my experiments, the orientation function obtained from birefringence correlated well with WVTR data for oriented PE. I saw little/no correlation with orientation functions calculated with other techniques, such as SAXS, XRD ...... Read More
Comments (1)Seven-layer CPP problem
I received the following problem statement by e-mail and thought you might review my answer and make suggestions as well. Problem: We have a seven-layer CPP line, but in the case of white film we used only five extruders instead of seven, the seven layers are produced by the plug which is inserted in the feed block just before the die. So in this case the layer (cor ...... Read More
Comments (4)Aroma barrier of metallized films
In an earlier post, I stated that the addition of a vacuum-deposited layer of aluminum onto an OPP film does not guarantee an improvement in flavor and aroma (chemical) barrier. I first discussed this in an SME barrier conference in 1997 and later the expanded work was published in Mount III, Eldridge, M., Wagner, John R., “Aroma, Oxygen and Moisture Barrier Behavior of Coated and Vac ...... Read More
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