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Friday, February 28, 2014

Semi embossed films in india

The fundamental mechanism in rotary embossing is the embossing nip, which is the area where two embossing rollers come into contact.  The simplest embossing applications use only a single nip.  Others may involve several embossing nips, either in series or in parallel.  Sometimes embossing is directly combined with other finishing processes, such as printing or laminating (which involves other nips).The types of embossing nips are named after the materials that have traditionally been used for the surfaces of the embossing rollers.  These materials are still the most common, but newer materials are being developed.
  • S/S (steel-to-steel):   Both rollers are engraved with patterns that are designed to engage each other in some way.  The surfaces of these rollers must be hard enough and durable enough so that the raised protuberances on each are able to deform the paper.  Traditionally, both surfaces have been steel, and therefore this type of embossing nip is called a "Steel-to-Steel" or S/S embossing nip.
  • R/S (rubber-to-steel):   Only one of the rollers is engraved, while the other roller is covered with a elastic material like rubber.  The surface of the elastic material is smooth, except while it is being pressed against the engraved roller in the embossing nip.  Elastic recovery to its original smooth shape is extremely rapid.  The surface of the engraved roller must be hard enough and durable enough to deform not only the paper that is being embossed, but also must deform the elastic material of the opposing roller (which requires much more force and energy than the paper does).  Traditionally, the engraved surface has been steel and the deformable surface has been rubber.  However, the engraved roller could have a laser engraved surface made of very hard rubber, while the smooth roller could have a surface made of an elastomeric plastic.
  • P/S (paper-to-steel):   There is another type of embossing nip which is really a hybrid between the two described above.  It is mostly used only for paper napkins where the embossing must produce bonding of multiple plies and/or high visual definition in the pattern.  In this case, the steel roller is engraved with the embossing pattern, while the opposing roller is a paper-filled roll that is initially smooth.  A "run-in" period is required to transfer the pattern from the engraved steel surface into the paper surface initially, and also to repair any damage that may later occur to the paper surface.
Embossing nips may be combined in parallel or in series.

  • Serial nips:   This is sometimes used to superimpose one embossing pattern over another, by passing the paper first through one embossing nip, and then through another.  It works best when the first pattern is a very fine-scale pattern that has complete coverage over the paper (like a micro embossing pattern), and the second pattern is composed of larger figures with large open areas between them (like a spot embossing pattern).  However, a very similar effect can often be achieved in a single nip less expensively.
  • Parallel nips:   This is only used for products that have two or more plies.  In a two-ply product, one ply is passed through one nip while the other ply is passed through the other nip, and then the two plies are brought back together again, usually with some method of bonding the plies together.  This is most often employed in two-ply laminated towel products, which use very carefully placed dots of glue to bond the plies together.  The choice of embossing patterns, how the pattern on each ply aligns with the pattern on the other ply, and the placement of the glue are all critical elements in the design of an embossed/laminated paper towel product.

Wednesday, February 26, 2014

Embossed polythene film

Film embossing is a mechanical process in which a flat film is transformed into an embossed product. During the process, thermal and stress fields are applied Lo the polymer, causing changes in the microstructure and physical dimensions of the material. The engineering analysis of the process requires the study of various aspects relating to the characterization of the microstructure before and after embossing, A variety of techniques were employed to characterize the properties and microstructure of the embossed film in relation to: crystallinity, orientation, mechanical properties, and dimensions of the embossed films. The thermal treatment of the polymer film was shown to be the most significant factor in the process. By controlling the thermal treatment of the film, it is possible to manipulate the properties and dimensions of the embossed film. The important aspects: influencing thermal treatment include the radiation heater temperature, preheat roll temperature, line velocity, and film thickness. The initial film orientation and embossing pressure have a minor effect on the final properties of the embossed film. The main effect of the embossing pressure is on the bulk thickness of the embossed film
Film products can be manufactured with materials such as polyethylene, polypropylene and their copolymers, and nylon resins; materials can include fillers, additives, and release agents, and various laminates. Our products can be manufactured in many widths and thicknesses depending on materials. Emboss patterns are available in taffeta, matte, and diamond, as well as dimple, linen, leather grain, and many more..


Friday, February 21, 2014

Polyethylene film is a resinous material with thermoplastic properties that is synthesized by inducing oxidation polymerization of ethylene gas. The degree of pressure used in its manufacturing varies according to the density and melting point of the virgin polymer resin being used. Most commonly, sheets of polyethylene film are produced using a process known as blown film extrusion, in which the polymer resin is melted to its flow point and then extruded through a die to produce a tube of plastic. While the polyethylene is still supple, the tube is closed off at one end and then blown to inflate and stretch the film into the desired length and thickness. The thickness of polyethylene film can be as thin as .0004 inch (10.16 microns).
The introduction of this film was considered groundbreaking in terms of its application in the packaging industry. Specifically, it has proven to be highly valuable in the flexible packaging market. In fact, it has captured the majority of the plastic packaging segment, which primarily consists of bags and wrapping material used for storage or to provide protection from the environment. This includes plastic wrap to protect agricultural crops, as well as ordinary kitchen wrap used to preserve food. Of course, polyethylene film is also essential in the manufacturing of bags, from dry cleaning protective covers to garbage and grocery bags.
One reason that polyethylene film dominates all other materials formerly used in packaging is its ability to self-seal under controlled heat. Shrink wrap, for example, protects items by literally shrinking around them to form a seal in response to the application of heat. This ability makes this film ideal for use in making tamper resistant packaging as well as to seal electrical wiring. In addition, polyethylene sheets can be sewn or stapled together, or even bonded with glue.
Polyethylenefilm is also used extensively in the agricultural industry where it has many applications. For one thing, it is used to protect crops and seeds from pests and disease. This material also helps to prevent the escape of moisture and heat.While most people are familiar with polyethylene film due to its presence in many consumer products, it has a few lesser-known applications. In fact, it is frequently used in building and construction. Aside from acting as a tarpaulin to protect equipment and building materials, it is also placed in the structural interior of buildings to prevent the invasion of moisture. Polyethylene film also serves as a blanket to promote the curing of concrete slabs.


Sunday, February 16, 2014

Stretch wrap films

Categories and sub-categories of stretch wrappers:
Manual (or HandWrappers:
·         Extended Core: An extension of the film's core serves as a handle for wrapping; this type of wrapper offers little stretch control and is hard on hands.
·      Mechanical Brake: A simple structure supports a film roll and a mechanical brake system provides resistance creating stretch of the film.
·         Pole Wrappers: Similar to the Mechanical Brake system, but the roll and brake are at the end of an extended pole, creating an ergonomic design which eliminates the need to bend to wrap the bottoms of loads and strain to reach the tops of loads. Used for space missions too.
Semi-Automatic Wrappers:
·         Turntable Wrappers: The load to be wrapped sits on a turntable which spins the load relative to the film roll, which is housed in a carriage which can move up and down a fixed "mast". Stretch is achieved by rotating the load at a faster rate than the film is fed.
·         Orbital Wrappers: The film is housed in a carriage on a vertical ring, the load is fed horizontally through the eye of the rotating ring, applying film to the load. A variation of an orbital stretch wrapper is a horizontal ring system, in which the load remains still while a horizontal ring is rotated around the load and moves up and down vertically relative to the load, similar to a rotary arm stretch wrapper.
·        Rotary Arm Wrappers: In this system, the load remains still while a rotating arm turns around it wrapping the load. This system is used for light loads or for speeds which would otherwise cause the load to topple due to high rotation speeds.
Automatic Wrappers:
Automatic wrappers are generally a variant of a semi-automatic system. Automatic wrappers include a conveyor system to automatically load the wrapping machine and automatic systems to apply, seal, and cut the film.
·         Turntable Wrappers: The load to be wrapped sits on a turntable which spins the load relative to the film roll, which is housed in a carriage which can move up and down a fixed "mast". Stretch is achieved by rotating the load at a faster rate than the film is fed.
·        Rotary Arm Wrappers: In this system, the load remains still while a rotating arm turns around it wrapping the load. This system is used for light loads or for speeds which would otherwise cause the load to topple due to high rotation speeds.
·         Rotary Ring Wrappers: The film is housed in a carriage on an horizontal ring in which the load remains static while the horizontal ring is rotating around the load and moves up and down vertically relative to the load, similar to a rotary arm stretch wrapper. The rotary ring technology is really a more balanced system with less wear and maintenance than the other available wrapping technologies. These wrappers are capable to reach the highest production capacities (up to 160 pallets/hour).


Wednesday, February 12, 2014

Plastic embossed film

Recycling of Plastic Films
Recycling means moving plastic from the agricultural waste stream back into the manufacturing process. To make recycling a reality, one must have a system or infrastructure in place. The following are the basic components of any such system:
·         Collecting
·         Sorting
·         Reprocessing
·         Marketing
Collecting
For recycling to be effective, one must collect a lot of material, from many farms. However, used plastic film is bulky and cannot be transported very effectively.To reduce transport cost for this bulky material the farmer can use a farm type small square baler that uses tine forks for cross feeding into the baling chamber to compact the plastic on the farm.
Feed the plastic into the baler by spreading the plastic into a windrow and driving the baler into the plastic. Make windrows approximately (1 m x 0.6 m deep) 3 feet by 2 feet high. Do not hand feed plastic into baler! This could cause serious injuries if feet or hands become tangled in the plastic. Large round balers can also be used, however the resulting size and shape of bale is too hard to handle. One may also have plastic compacted at a commercial compactor.The resulting compacted volume could be reduced to 15% of the original bulky volume
Sorting
Agricultural plastic film is mainly low density polyethylene. Sorting of this material is needed because there are different plastic products and additives. For example, plastic wrap is 0.5 to 1 mil thick and has tacifiers (glue) compared to tube plastic which is 4 to 15 mil thick with no tacifiers.

Reprocessing

Agricultural plastic films must be cleaned before being converted into pellets for film or formed into moulded products like plastic lumber and fence posts. Incoming plastics must be inspected for contamination and are accepted or rejected depending on the level of contamination. Contamination includes dirt, sand, stones, grease, vegetation, water, other types of plastic, glue, tape and ultraviolet (UV) light degradation. If the film has lost its flexibility and is crinkly, it has serious ultraviolet light damage. UV damage can severely limit the recyclability of agricultural plastic film.
Plastic films are then chopped in a grinder, washed to remove contaminates, then fed into an extruder where heat and pressure melt the plastics. The molten plastic is extruded into fine strands, then cooled and chopped into pellets. These pellets are used by manufacturers to make new plastic film products.Some plastic film is chopped then melted and formed directly into moulded products.

Marketing

Recycled Film

For agriculture, plastic films could be recycled back into plastic film. This is the best since there is no need to develop a market for the recycled plastic.

Plastic Moulded Products

Here are several options for molded products such as; landscape timbers, fencing, planking for farm pens, roadside posts, benches, picnic tables and pallets.All these options require a marketing plan for selling the new products.




Sunday, February 9, 2014

Embossed Film

Embossing Basics

Definition of embossing:  In the broadest sense, it means to change a surface from flat to shaped, so that there are regions that are raised up from a background.  This meaning would seem to encompass areas that are normally not called embossing:  carving figures into the face of a mountain (like Mt Rushmore), or engraving a steel block.  On this website, I use the word "embossing" only as it applies to thin and malleable materials.  Since the opposing surfaces of a thin material are very close to each other, each raised area on one surface is matched by a recessed area on the the opposite side, and vice versa.  One exception to this is sometimes called "pattern pressing" or "blind embossing".  This occurs when areas of one surface are recessed while the opposite side remains flat, causing the material to become thinner in those areas.  This is typical when embossing leather, for example.
Materials that are embossed:  Just about anything that is thin, flat, and malleable can be embossed.  This includes paper, plastic film, metal foil, nonwovens, textile fabric, leather, and even glass.  These materials may be provided in continuous form (like paper unwinding from a roll), or in discrete form (cut into individual sheets before embossing).
Purpose of embossing:  Sometimes embossing is done for purely decorative reasons.  However, in most cases, the purpose of embossing is to change the physical characteristics of the material.  Embossing a metal foil with a fine texture pattern makes it much easier to handle the foil within the machine that wraps it around a piece of chewing gum.  Embossing a plastic film changes its elastic properties dramatically.  Embossing tissue paper improves absorbency and flexibility, but almost always at the expense of strength.  Embossing increases the overall thickness of the material.
Methods of embossing are often determined by the properties of the material, and how it is provided.  The material may be malleable or fluid, or somewhere between.  It may be provided in continuous form (without breaks), or in discrete lengths or pieces.

  • For malleable materials, a permanent shape change is imposed simply by the application of force.  This usually has a very significant effect upon the mechanical properties of the material.  Most tissue paper is embossed this way, while the paper is completely dry.
  • For fluid materials, the embossing step starts out more like casting onto a mold while the material is still fluid, and then the material is changed from fluid to solid.  This reduces the effect of the embossing upon the strength and elasticity of the material.  In the case of tissue paper, the fluid state is the suspension of paper fibers in water, the mold is the forming wire, and the material becomes more solid as the water is removed.
  • Some embossed materials are somewhere between malleable and fluid.  For instance, tissue paper can be shaped after it is formed, but still very wet.  The results are much different from traditional "dry embossing".
  • When the material to be embossed has been cut into discrete lengths, it is usually necessary to employ an intermittent method like stamp embossing, where the sheet is pressed between two plates.
  • When the material to be embossed is provided in continuous form, without breaks, then the preferred method is rotary embossing, where the material is passed between embossing rollers.  Rotary embossing is much, much faster than any of the intermittent embossing methods.

Thursday, February 6, 2014

Embossed Polyethylene Film

Polyethylene film is a resinous material with thermoplastic properties that is synthesized by inducing oxidation polymerization of ethylene gas. The degree of pressure used in its manufacturing varies according to the density and melting point of the virgin polymer resin being used. Most commonly, sheets of polyethylene film are produced using a process known as blown film extrusion, in which the polymer resin is melted to its flow point and then extruded through a die to produce a tube of plastic. While the polyethylene is still supple, the tube is closed off at one end and then blown to inflate and stretch the film into the desired length and thickness. The thickness of polyethylene film can be as thin as .0004 inch (10.16 microns).
The introduction of this film was considered groundbreaking in terms of its application in the packaging industry. Specifically, it has proven to be highly valuable in the flexible packaging market. In fact, it has captured the majority of the plastic packaging segment, which primarily consists of bags and wrapping material used for storage or to provide protection from the environment. This includes plastic wrap to protect agricultural crops, as well as ordinary kitchen wrap used to preserve food. Of course, polyethylene film is also essential in the manufacturing of bags, from dry cleaning protective covers to garbage and grocery bags.


Sunday, February 2, 2014

Poly shrink film manufacturers

Shrink wrap is applied over or around the intended item, often by automated equipment. It is then heated by a heat gun or sent through a shrink tunnel or oven for shrinking.
Shrink wrap can be supplied in several forms. Flat rollstock can be wrapped around a product, often with heat sealing to tack the film together. Centerfolded film is supplied on a roll with the plastic is folded in half: product is placed in the center portion, the remaining three edges are sealed to form a bag, and the package then heated which causes the bag to shrink and conform to the product placed in the bag. Pre-formed shrink bags plastic bags are used with one end open: the product is placed in the bag, sealed, and sent for heat shrinking.
Shrink wrap can be used to wrap buildings. It can wrap roofs after hurricanes, earthquakes, tornadoes and other disasters. Shrink wrap can be used for environmental containments to facilitate safe removal of asbestos, lead and other hazards.
Shrink wrap is sometimes used to wrap up books, especially adult-oriented ones and certain comics and manga, mainly to prevent them from being read by minors.Software on carriers such as CDs or DVDs are often sold in boxes that are packaged in shrink wrap. The licenses of such software are typically put inside the boxes, making it impossible to read them before purchasing. This has raised questions about the validity of such shrink wrap licenses.
Shrink wrap is commonly used as an overwrap on many types of packaging, including cartons, boxes, beverage cans and pallet loads. A variety of products may be enclosed in shrink wrap to stabilize the products, unitize them, keep them clean or add tamper resistance. It can be the primary covering for some foods such as cheese, meats,vegetables and plants. Heat-shrink tubing is used to seal electric wiring.
Shrink bands are applied over parts of packages for tamper resistance or labels. It can also combine two packages or parts.Shrink wrap is also commonly used within more industrial applications using a heavier weight shrink film. The principles remain the same with a heat shrinking process using a hand held heat gun. The following shrink wrap applications are becoming more widely used and accepted:
  • Industrial shrink wrap containment of large plant equipment/components,
  • Scaffold wrap containment of buildings/bridges,
  • Building temporary shrink wrap structures for storage or other business operational uses,
  • Marine shrink wrapping of boats and other vehicles,
  • Shrink wrapping of palletized freight
  • Disaster contingency and relief projects such as damaged buildings/roofs.