Here is technical information on plastic bags.
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Here is technical information on plastic bags.
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December 24, 2007 in Current Affairs, Film, Flexo, Food and Drink, laminated film and bags, low melt valve bags, Packaging, Packaging product suppliers, paper bags, Plastic Bags, Plastic film, plastic manufacture, printed bags, Science, Valve Bags, Web/Tech, Weblogs | Permalink | Comments (1)
Batch Inclusion film or bags derive their name from the fact the bag itself,along with contents,is actually included in the production batch or during rubber compounding. The bag, once melted and dispersed, becomes part of the product being made. Batch inclusion bags typically hold chemical additives for large scale industries, such as synthetic rubber and plastic compounding. Often the additives involved are difficult to handle, weigh to little or are used to hard to dispense automatically. These could include colorants, fillers, resins and even some polymers for large scale mixing. Because the bag and its contents become part of the batch, the user will realize a cleaner environment, along with other benefits such as reduce labor cost, reduce disposal cost and clean up cost, better hygiene. The bags or film has a number of benefits like more efficient use of raw materials and a more consistent mixtures of compounds. Also, you will find the use of material in a sealed bag allows for a reduction in storage space when compared to an open container, such as metal containers or plastic and sometimes paper bags. As sealed bags can pile in a bin, cardboard boxes, tubs, or carts.
Benefits of using Batch Inclusion Bags are they improve quality and batch uniformity insures 100% compound ingredients go into the mixing of the material when doing in house weighing, batch inclusion bags eliminate the risk of cross-contamination due to chemical residue in tubs and weighing containers. Will increases productivity and eliminates the need to weigh ingredients in-house through the use of having the product weighed and ready to be thrown into a batch of rubber also eliminates the need to clean out tubs and weighing containers. Reduces the amount of solid waste disposal going into the land fills. You will have less product loss due to spillage and minimizes the accumulation of costly additives in the dust collectors. The idea is to minimizes worker exposure to hazardous materials.
November 21, 2007 in Current Affairs, Film, Flexo, laminated film and bags, low melt valve bags, Packaging, Packaging product suppliers, paper bags, Plastic Bags, Plastic film, plastic manufacture, printed bags, Science, Valve Bags, Weblogs | Permalink | Comments (0)
What is slip and how does it work in manufacturing plastic film and bags. Slip is an organic chemical that is added to the blend during film extrusion process to modify the coefficient of friction (COF). COF is a measurement of the amount of friction between two surfaces as they begin to slide and as they continue to drag against one another.
The amount of energy it takes to put an object in motion is always greater than the amount of energy that it takes to keep it moving while it is in motion.
Although there are a number of chemicals that are used to modify the COF the two main ones used in Polyethylene and Polypropylene are Erucamide (which is considered a slow bloom) and Oleamide ( which is a fast bloom. The materials are sometimes called primary amides.
Slip is a very efficient molecule it has been added to a plastic film in very low concentrations typically 500 to 1500 parts per million (PPM). The slip additive can be let down at the levels of 1 to 3% by weight in blending while extruding the plastic film.
Slip molecules are very low in molecular weight as compared to the polymer in which they are used. These molecules are somewhat incompatible because of their nature. This means the material is bi-polar and has one end that has a positive charge and the other has a neutral charge. This incompatibility causes the molecule to migrate referred to as bloom through the polymer to the surface of the plastic film. The more slip that migrates on the surface the lower the COF and the more slippery the plastic film becomes.
The COF relates to packaging because the substrates used to package objects always come in contact with other surfaces or themselves. As most packaging operations are very high speed, COF plays a very large role. The packaging material must have just the right COF in order to track properly on the packaging machines. If a material is too slippery the film will not track properly and may cause issues such as bad sealing or cause a powder substance that builds up on the tracking rolls which will cause packaging failures. If a material becomes to sticky can have the opposite effect. It may not allow the film to un-wind properly and cause web brakes or other tracking problems. Either scenario can shut a packaging line down.
dbanig@prflexbag.com
November 15, 2007 in Current Affairs, Film, Flexo, Food and Drink, laminated film and bags, low melt valve bags, Packaging, Packaging product suppliers, paper bags, Plastic Bags, Plastic film, plastic manufacture, printed bags, Science, Valve Bags, Weblogs | Permalink | Comments (1)
Flexible Pouches Stand Up to Maximize Shelf Appeal
Today’s retail markets are finding endless benefits to using stand up pouches as they have maximized how products can be displayed at retail stores. With the different types of material structures available you can package food products, liquids, chemicals, etc.
Pouches use much less material than other traditional packaging methods like corrugated cartons or laminated boxes. Pouches can be customized to fit any of your needs but you need to understand why stand up pouches can be so beneficial to your business. Once you really understand how they are made, as they can be cheaper and run more efficiently than you may think.
The first thing to remember stand up pouches is that they are made up of co-extruded material from 3- layer, 5-layer, 7-layer, 9-layer or the material can be a single mono layer and laminated with a number of other film structures from p.e.t., nylon, metalized p.e.t., foil etc. They can be printed any color up to 10 color line print to 10 color process print with your logo or design, so the potential to really make an impact on retail shelves is very high.
Pouches are made from a continuous web of material where the first step in manufacturing process of a stand up pouch happens when it goes through a set of plows that folds the material into a w-shape guesset into the bottom so the pouch will be able to stand up. Now if you want a re-closable zipper as part of your pouch it is sealed on the inside of the face of the web near the top edge of the material. Re-closable zippers are the most common method, but spouts, perforations, and other re-closable openings are also available.
Once the gusset is formed vertical seals are then made along the pouches side and the re-closable zipper is pressed into the same area to seal the ends and flattens out. The laminated pouch is then cut apart vertically through the center of the of the side seals to create the finished stand up pouch.
After the product is dispensed into the pouch it travels thru the filling station where the re-closable zipper is closed and the pouch is sealed above the zipper.
Stand up pouches are becoming more and more popular options for liquids, dry chemicals, pet foods, personal care products, granular products like cereal, sugar, salt.
The stand up pouch is very user friendly both for consumers and to help reduce packaging cost.
September 11, 2007 in Current Affairs, Film, Flexo, Food and Drink, laminated film and bags, low melt valve bags, Packaging, Packaging product suppliers, paper bags, Plastic Bags, Plastic film, plastic manufacture, printed bags, Science, Valve Bags, Weblogs | Permalink | Comments (1)
Flexographic printing is defined as a method of direct rotary printing that uses special rubber or photopolymer material. The printing plates are affixed to plate cylinders of various repeat lengths, which are inked by a cell structure (anolox roll) which is used to meter the flow of the ink on roll. It carries a fast drying fluid ink to the plates that print on a variety of substrates (paper / plastic / nylon / polypropylene / cellophane / LDPE / LLDPE / etc.).
Flexographic printing is a rotating method for every revolution of the printing plate cylinder an image is produced. If the image is stepped several times around a cylinder several images may be produced in one revolution.
Due to the nature of the printing process there are factors that don’t exist with other print methods such as offset and gravure. Because flexographic employs a flat but flexible printing plate that is stretched around a curved cylinder and the image on the plate distorts when the plate is mounted on the printing cylinder. A circle shape for example distorts into an egg shape. The amount of distortion depends on many factors including cylinder size, plate size, and the amount of distortion depends on a number of factors, including cylinder size, plate size, and the amount of adhesive mounting tape used to attach the plate cylinder.
Another aspect of flexographic printing is the solids (line art) print differently than screens (dot patterns). That is because the printing plate is relatively soft and the ink on its surface must be pressed against the substrate to print. Thus the amount of pressure applied to the printing plate is critical For example more pressure is needed to print a dense and heavy solid than to print a screen tint.
Whichever method used to set up the printing press, one design implication must remain clear is that you may not be able to successfully print one color screens and solids on the same printing plate or printing station. This is very different from offset printing where the solids and screens of a given color can be printed with a single printing plate.
All possible plastic film defects ought to be detected and eliminated by the film extruder before the roll gets shipped to the customer. But in practice, through oversight and inattention to detail defects can slip by that may be all too easily spotted by the customer or the customer's customer. I have found a variety of unrelated faults that fit into this category.
First is the appearance and a good looking finished plastic roll of film this aspect can be half of the battle. Keep in mind is that first impression what you see is what you get! A superficially ugly looking roll which may convert on the filling machine or bag machine can have the operator looking at the roll much closer for the entire lot for real or imaginary defects.
A roll that has a machine cylinder look means no scuff marks, damaged edges, and fuzzy ends, protruding or buried core ends, or crushed cores. The solutions to these problems are self evident. There are other finer detailed defects that can be buried in the roll, and may be if the production line is never approached by the operator except during a roll change. There is no excuse for the customer being the first to see these.
I have a couple of areas for helping prevent roll defects:
How to Tackle Blocking of the Plastic Film - a common reason for blocking is too much winding tension. This maybe over looked unless tension is so great as to crush the core as the film is being wound on the roll. This makes it impossible for the operator to remove the roll from the winder shaft. With a case of crushed cores, the rolls may be hard to get off of the shaft, only to have the customer find them impossible to remount on a un-wind stand.
Just as bad of a problem can arise if the winding tension is too light, no blocking but the film may telescope from one end of the roll, making it impossible to convert into finished product.
Hot weather can bring its share of blocking problems. Plastic Film is insufficiently cooled and the inner surface blocks as they pass through the nip rolls. For a cure you must reduce the output, raise the tower height or nip rolls, or use refrigerated air or other means of improving cooling efficiency. It also can be an inefficient air ring.
An entirely different cause of blocking can be using a resin to produce 1 mil film that has a slip and anti-block additive level designed for heavier gauges like 4 mil. There just isn't enough additive to do the proper job. Over-treatment and or high gloss can aggravate if not cause blocking with any of the above conditions.
Tendency to Split
Good operator observations to equipment maintenance, quality testing of roll samples and putting the proper procedures in place will help in building customer loyalty.
www.prflexbag.com
dbanig@prflexbag.com
April 07, 2007 in Current Affairs, Film, Flexo, Food and Drink, laminated film and bags, low melt valve bags, Packaging, paper bags, Plastic Bags, Plastic film, plastic manufacture, printed bags, Science, Valve Bags, Weblogs | Permalink | Comments (0)
Stretch Hooder Films
Stretch Hooder film allow for an environmentally safe, cost effective, energy saving and convenient way to palletized materials. Stretch Hooder Films combine the weather protection and load stability advantage of pallet covers with the economy of stretch film.
Stretch Hooder films make use of co-polymers to stretch a film without permanent deformation. The film stretches in the elastic region of a typical engineering stress strain curve, and never reaches the plastic region of permanent deformation. This allows the film to snugly form around the dimensions of the pallet, which limits movement and protects the contents from dirt and water contamination.
A one piece hood is made in the machine from a continuous roll of lay flat tubing or gusseted film. The hood is stretched over the load and secured under the pallet. Stretch Hooder Films are ideally suited for applications where pallet loads require five sided protection, encounter stress during shipping or where products are sensitive to heat.
Benefits of Using Stretch Hooder Films
Pallet loads that have been packaged using stretch hooder films are secured for transportation. You get great tension in both horizontal and vertical directions which mean that the finished goods are pressed downwards on the pallet preventing the load from shifting.
The unbroken stretch hooder film utilizes packaging film without the use of any heat or glue. This method minimizes energy usage that is usually used by a heat gun to shrink the material. Improves safety in the workplace of a potential fire.
Pallets packaged with stretch hooder films are better than your standard shrink pallet covers or stretch film.
Stretch Hooder Film is well suited for printing a logo or company name which allows for promotion during distribution of finished pallets.
Stretch Hooder technology has the opportunity to increase the process of securing and palletizing of your load over stretch film or shrink film.
dbanig@prflexbag.com
March 14, 2007 in Current Affairs, Film, Flexo, Food and Drink, laminated film and bags, low melt valve bags, Packaging, paper bags, Plastic Bags, Plastic film, plastic manufacture, printed bags, Science, Valve Bags, Weblogs | Permalink | Comments (0)
Sustainable packaging addresses performance and cost along with maximizing the use of renewable types of plastic materials or the use of recycling of other various materials like paper or cardboard. I figure the following factors would contribute to cost savings. The use of renewable or recycled source materials; able to manufactured using clean production technologies and best practices; make products from materials healthy in all end-of-life scenarios; designed to optimize materials and energy; effectively recover and utilized in biological or industrial cycles.
If we look at improving packaging sustainability it will result in less waste and will allow for fewer materials going into the land fill. Looking at the entire life cycle of packaging, the definition gives us a vision for the packaging industry all of which must be addressed if sustainable packaging is to become a major factor. It presents a challenge to those that stay status-quo but will offer guidance to identify the opportunities and the strategies to help us move forward. One of the key strategies is to challenge the product design, as it stands to point out we can prevent waste, if we optimize our use of resources, select safer materials and plan for the recycle process or some recoverability of our packaging.
However, even the most well designed packaging does not meet the sustainability test the real challenge is to be able to put effective systems into recoverability of the value of the materials. Building effective and closed-loop recycling and composting systems for packaging materials will be one of the biggest challenges to the creation of the sustainable packaging industry, but is one from which everyone stands to gain from personal use and manufacturing.
March 11, 2007 in Current Affairs, Film, Flexo, laminated film and bags, low melt valve bags, Packaging, paper bags, Plastic Bags, Plastic film, plastic manufacture, printed bags, Science, Valve Bags, Weblogs | Permalink | Comments (0)
Static Bags making the right choice!
Static Shielding, Moisture Barrier, Dissipative Poly Bags (Pink)
Scuffing one’s shoes on the carpet and touching a person, metal door handle produces a shock. Drying synthetic clothing in the cloths dryer will often produce “static cling”. The static electricity behind these common events can destroy modern electronic circuits and devices.
As electronic circuits and their connecting pathways have continued to shrink in size, their susceptibly to damage from static electricity has increased.
Protective handling and packaging techniques have been adopted by the electronics industry from the chip foundry to production floor.
Bags
One of the most common static preventive measures is a bag. The use of protective bag began in the 60’s with introduction 0f “Pink Poly Bags”. Static shielding bags were introduced in the late 70’s and while the military has used moisture barrier bags. The surface mount technology has greatly increased usage.
Static Threats
Electronic device needs to be protected from 3 primary static threats:
1) Direct Discharge (ESD): A discharge directly to a bag can subject the device inside to high current, melting or fusing the circuit.
2) Static Fields: Fields can induce destructive currents in circuit conductors. Field differentials can break down the circuit dielectric.
3) Tribocharging: Friction between the bag and the device can produce damaging static voltage and fields.
Below, the protection abilities, construction, and applications of several of the most common bag types are described.
Pink Poly Bags or Dissipative Poly Bags
The bag has the ability to dissipate a static charge to ground. This keeps static electricity from building up on the package or device. The material is also antistatic, suggesting that it will not charge up (tribocharge) when rubbed against other materials. Unfortunately these bags have no shielding ability. A static field or discharge occurring outside the bag will penetrate the bag and damage electronics inside.
Construction: Pink Poly Bags consist of polyethylene (plastic) that has been loaded or surface coated with a chemical called antistat. The “Pink Poly” is only a colorant that was added to differentiate static control materials from standard packaging.
Applications: Pink Poly Bags are useful for packaging items that have no static susceptibility. Their primary use is to package support or processing material that will be close proximity to static sensitive devices. This keeps static generating packaging materials away from sensitive areas. Poly bags are also known as type ll bags from the U.S.
Black Conductive Poly Bags
Black Poly is very conductive and will dissipate a charge very fast. Unfortunately this fast dissipation also means that a charged person or object can spark (ESD) to its surface. The general idea in static control is to swap charges at a slow so as to allow a static build up. Because the material is conductive it does provide some small measure of shielding. However there is no plastic layer (dielectric) to isolate a device inside a bag. The charge may be transferred through the thickness of the material to the device instead of around the material to ground.
Construction: Black Poly Bags are a polyethylene plastic that is loaded with a conductive form of carbon. The material is black and opaque in appearance.
Applications: Black Poly was used as a barrier between pink poly and shield bags because of the slightly lower cost offering some shielding as opposed to non with pink poly. However, as the price of shield bags continues to drop the usage of black poly will likely drop as well. Because black poly bags are opaque the bags contents must be removed for identification. This creates a new opportunity for static damage.
Shielding Bags
Shield Bags provide the dissipative and antistatic attributes of the poly bag but add a metal shield and polyester dielectric to stop static from entering the bag. The test for shielding demonstrates the difference between the various bags. Shield Bags will generally stop 97% of a 1,000 volt static pulse applied to the outside of the bag from reaching the inside. Pink Poly will stop only about 10% and black poly about 30%.
Construction: Static Shielding Bags consist of several layers. Dissipative poly laminated to metalized polyester. The outside polyester has an antistatic coating. The metal is vapor deposited in a vacuum chamber. Aluminum is the metal most used in this process, with nickel and copper also being used. The structure of a shield bag has metal between two layers of plastic.
Applications: Static Shield Bags should be used for all electronic components, boards, assemblies. Shield bags are referred to as TYPE lll under MIL-B81705C.
Moisture Barrier Bags
Moisture Barrier Bags provide dissipation, antistatic properties, static shielding, and add a moisture vapor barrier. The moisture barrier protects moisture sensitive items and improves long term storage.
Construction: Type of bag is physically stronger than a shield bag. Moisture barrier bags are similar in structure to the shield bags. The two types are “foil and tyvek” and heavy metallization.
The heavy metallization structure is essentially that of a shield bag but with opaque, thick aluminum metallization or multiple layers of metallization. Nylon may be used in place of Tyvek or polyester. It provides the needed strength at a lower cost than tyvek. Both foil and metalized moisture barriers provide a good product.
Applications: The moisture barrier bag is used when barrier protection is needed or when maximum shielding protection is desired but transparency is not an issue.
The moisture barrier bag is also referred to as Mil-B81705 TYPE l.
Summary:
Static protective bags are an integral part of a static control program. Selecting the right bag can help reduce static damage and save money on costly repairs and rework. Thee cost of static protective packaging is insignificant when compared to the protection it affords the costly items placed in the package.
December 10, 2006 in Current Affairs, Science, Web/Tech, Weblogs | Permalink | Comments (0) | TrackBack (0)
Protective Release Film
We call all of our materials used for release liners R" series.
R-1 & R-20 represent a new generation of protective release film for the rubber and tire industry. We special formulated polyethylene compounds that do not interact with other materials present in the various rubber compounds. R-series is specialty formulated film that is a substitute for the regular embossed film. You wonder what the benefits might be? It is easy to clean release and peeling, retaining freshness and stickiness of the rubber compound, prevents pollution and improves mechanical features, economizes volume and storage and enables 100% recycling with high resistance to heat especially the R-20.
The film is much more cost effective up to 10 times than that of regular embossed film. The use of this material increases the number of feet per roll which reduces the number of roll changes saving time and cost and in the mean time increases productivity. The R-1 & R-20 film comes in a variety of width, length, thickness and not to mention a variety of colors.
R-1 Cold Calendaring process (up to 40 degrees C)
R-15 Hot Compounds / Rich rubber Cobalt and Sulfur compounds such as steel calendaring / (Hot Compounds).R-15 absorbs the sulfur and cobalt incorporated in the compound.
R-20 Hot Compounds
Advantages of release film in comparison to Liners.
*Length of the film in a roll is about 10 times more than a liner roll with the same diameter.
* Change to a jumbo roll which decreases the number of roll changes.
*Reduce storage space.
*Excellent product quality
*Taylor made to desired width, length, thickness,and color.
This product is a new generation of material that helps in reducing waste, storage, cost, etc.
September 18, 2006 in Current Affairs, Film, Science, Web/Tech, Weblogs | Permalink | Comments (0)