WO2001070497A2

WO2001070497A2 - Co-extruded bale wrap

Info

Publication number: WO2001070497A2
Application number: PCT/US2001/007451
Authority: WO
Inventors: Jeffrey A. Middlesworth; Vi N. Schmidt
Original assignee: Tredegar Film Products Corporation
Priority date: 2000-03-17
Filing date: 2001-03-07
Publication date: 2001-09-27
Also published as: AU2001243509A1; WO2001070497A3

Abstract

A co-extruded polymer film used for wrapping bales of rubber ('bale wrap') is disclosed. The bale wrap includes a first layer having a low melting point and a second layer having a relatively higher melting point. The bale wrap has a low melting point overall, which is desirable because a lower melting point improves the ability of the film to be incorporated into a homogeneous mixture of rubber and rubber compounding ingredients. Bale wraps having a low melting point often result in a film that tears or becomes quite sticky when wrapping hot rubber. When this occurs, the bales often stick to each other within shipping containers, which makes it difficult to remove the bales from the container and to separate the bales from one another. This condition is known as 'blocking'. The disclosed bale wrap is co-extruded to provide a composite low melting point while still having an outer layer exhibiting a relatively higher melting point layer thereby preventing the wrapped bales from blocking.

Description

CO-EXTRUDED BALE WRAP BACKGROUND OF THE INVENTION

Field of the Invention

This invention relates to an extruded thermoplastic bale wrap film ("bale wrap") having a melting point sufficiently low such that the bale wrap may be incorporated into a homogeneous mixture of rubber and rubber compounding ingredients. More particularly, the bale wrap of the invention has a first layer having components with a low melting point and low Vicat softening point and a second layer having components with a relatively higher melting point and a relatively higher Vicat softening point to minimize the bale-to-bale blocking tendency of the bale wrap. The overall melting point of the extruded bale wrap approximates that of the melting point of the better monolayer films currently known in the art.

Related Art

In the manufacture of synthetic rubber, such as butyl, chlorobutyl, EPDM, and EPR, raw rubber pieces (referred to as "crumbs") are passed from a reactor through a drying oven, and collected in a compression mold where they are compressed into bales generally in the range of 14"x28"x8". The bales are then placed in large containers, such as cardboard boxes or metal crates ("shipping containers") that are sized to receive a number of the bales for storage and transport. At the location of use (a tire manufacturing plant for example), the bales are withdrawn from the container and individually processed.

The bales are placed in the shipping container at elevated temperatures (120°- 210° F., 48° C-98°C), which can cause bale-to-bale sticking if the bales are in direct contact with each other. The sticking and cold flow of the rubber makes it difficult to remove individual bales from the shipping container. It is generally not practical to permit the bales to cool to room temperature before placing them in the containers because doing so slows the production process, thereby adversely affecting manufacturing economies. Exposure to elevated temperatures during storage and transit cause further sticking and cold flow.

The bale-to-bale sticking led to the development of thermoplastic film bale wrap. Bale wrap film is applied by conventional in-line equipment to completely encapsulate or wrap the rubber bale after the drying and molding steps prior to being placed in the shipping container. The film prevents rubber-to-rubber contact and also resists the cold flow of the rubber. The bales are typically boxed for shipment with the bales arranged within the shipping container in stacks that are multiple layers high. Typically, up to nine layers of the bales are stacked one on top of the other within the container, which results in high pressures on the bottom layers due to the weight of the bales acting on the bottom bale. The bales may be 170 to 190° F at the time that they are baled. At the time of packing, the bales are normally still hot from the manufacturing process. Additionally, the bales may also be placed within the container in a compressed condition to save space. On arrival at the manufacturing location, the bales are removed from the container where the wrapped bales are then processed.

A bale wrap that possesses comparable DSC melting point and Vicat softening point characteristics, while exhibiting lower Reblock and Peel Force properties at elevated temperatures is desirable. DSC Melt Point and Vicat softening properties should be comparable to existing bale wrap film so that the bale wrap may be incorporated into a homogeneous mixture of rubber and rubber compounding ingredients as is the current practice. A bale wrap that exhibits lower Reblock and Peel Force properties at elevated temperatures would permit wrapped bales to be placed within containers at elevated temperatures. Such a bale wrap would allow a manufacturer to increase the rate of the manufacturer's production process and favorably impact manufacturing economies.

SUMMARY OF THE INVENTION

This invention relates to a thermoplastic film used primarily for wrapping bales of synthetic rubber, i.e. "bale wrap". The bale wrap of the present invention is coextruded to provide a first layer having a low melting point and a second layer having a relatively higher melting point. A bale wrap having a low melting point overall, i.e. for the bulk of the film, is desirable because a lower melting point improves the ability of the film to melt and for the film and the contents of the bale to be incorporated into a homogeneous mixture of rubber and rubber compounding ingredients. The resulting homogeneous mixture is used to form homogeneous rubber compounds. Low melting points result in short cycle times thereby maximizing the productivity of a production process. However, bale wraps having a low melting point often result in a film that tears or becomes quite sticky when wrapping the hot rubber. When this occurs, the bales often stick to each other in a shipping container making it difficult to separate the bales. This condition is referred to in the industry as "blocking". It is desirable to have a bale wrap having an outside layer with a relatively higher melting point to prevent the wrapped bales from sticking to one another within a container.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a schematic of an extrusion apparatus for making the co-extruded bale wrap of the present invention.

Figure 2 is a cross-sectional view of a prior art monolayer film.

Figure 3 is a cross-sectional view of a monolayer film having a 50-50 blend of plastomer and EVA with slip and anti-block material.

Figure 4 is a cross-sectional view of a co-extruded embodiment having a 50% of its thickness comprising plastomer and 50% EVA with slip and anti-block material.

Figure 5 is a cross-sectional view of a co-extruded embodiment having a 75% of its thickness comprising plastomer and 25% EVA with slip and anti-block material. Figure 6 is a graphical representation of thermal analysis results from a thermal analysis conducted on the film of Figure 2.

Figure 7 is a graphical representation of thermal analysis results from a thermal analysis conducted on the film of Figure 3.

Figure 8 is a graphical representation of thermal analysis results from a thermal analysis conducted on the film of Figure 4.

Figure 9 is a graphical representation of thermal analysis results from a thermal analysis conducted on the film of Figure 5.

Figure 10 is a perspective view of a Reblock tester.

Figure 11 is a perspective view of a sample film of Figure 2, 3, 4, or 5 being folded and prepared for cutting prior to Reblock testing. DETAILED DESCRIPTION OF THE INVENTION

Referring now to Figure 1 , an extruder 1 heats material and forces the material through die 2. The molten material solidifies to form a film 3 after contact with air. The film 3 is guided by process rollers, such as roller 4, so that the film may be further treated if desired. The extrusion process is well known to those skilled in the art. One such process is described in United States patent 5,865,926, which is incorporated herein by reference. An example of further treating of the film is corona treating one side of the film, which is schematically shown by device 5. Among other purposes known in the art, corona treating may be used to enhance the ability of the film surface to accept printing. A further example of treating the film is embossing the film. This process is described in United States patent 4,848,564, which is incorporated herein by reference. Among other purposes for embossing as known in the art, embossing may be useful to minimize blocking. Finally, the film 3 is collected on take-up roll 6 for subsequent shipping.

I. Attributes of Four Example Films a. Prior Art Design Mono-layer film (EMB-675)

A widely used prior art design (EMB-675) is a mono-layer film 10 (Figure 2) having 88% metallocene catalyzed linear low density polyethylene "plastomer", 9% ethyl vinyl acetate "EVA" and 3% slip and anti-block concentrate. The plastomer is available from Exxon as Exact 3027. Exact 3027 has a melting temperature of 92 °C and Vicat softening point of 78 °C. The EVA is available from Exxon-Mobil as LD 317.09.

LD 317.09 has a melting temperature of 104 °C and a Vicat softening point of 86 ° C. The slip and anti-block concentrate is available from Ampacet as Amp 10568. Amp 10568 is 75% EVA, 20% silica and 5% Erucamide. Properties for this film 10 are disclosed in TABLE 1 , below. Of particular note, this film exhibits a machine direction "MD" Elongation of 621%, which is greater than the requirement of 250% desired by industry.

The DSC Melt Point is 92.7 °C, as seen in the graph of thermal analysis results in Figure 6. The Vicat softening point is 79.9 °C, which is approximate to the target softening point of 82 °C dictated by a typical manufacturer's process. The ash remaining from the anti-block additive concentrate, e.g. silica, is 6448 ppm, which is roughly equivalent to the target of 6000 ppm. The Reblock at 170° F is 77.3g. The Reblock at 190° F is greater than 214g, but may not be determined accurately due to exceeding an instrument's ability to read the forces. The maximum measuring capability of the test equipment is approximately 214 g. The Peel Force at 190 degrees is 95g. The Reblock and Peel Force is determined by the standard protocols discussed hereinafter.

b. Monolayer 50-50 Blended Embodiment for Comparison Purposes (208-03-01)

The 208-03-01 material is a mono-layer structure 20 (Figure 3) having 50% plastomer, 47% EVA and 3% slip and anti-block concentrate. The plastomer component is preferably Exact 3027. The EVA compound is preferably LD 317.09. The slip and anti-block component is preferably Amp 10568. Properties for this film 20 are discussed in TABLE 1, below. Of particular note, the film 20 exhibits an MD elongation 418%, which is greater than the requirement of 250% imposed by industry. The DSC Melt Point is 99.0°C, as seen in the graph of thermal analysis results in Figure 7. The Vicat softening point is 81.1 °C, which is approximately the limit softening point of 82 °C. The ash content remaining from the anti-block additive, e.g. silica, is 5813 ppm, which is roughly equivalent to the target of 6000. The Reblock at 190 deg F is 136.8g. The Peel

Force at 190 degrees is 8.7g. The Reblock and Peel Force are determined in accordance with the standard protocols discussed hereinafter.

c. Layered 50-50 Embodiment for Comparison Purposes (208-07-04)

The 208-07-04 material is a co-extrusion 30 (Figure 4) of two layers. Layer A comprises approximately 50% of the total thickness of the co-extrusion. Layer B comprises approximately 50% of the total thickness of the extrusion. Layer A (having the higher melting point) is intended to be the outside layer of the film and is comprised of 97% EVA and 3% slip and anti-block concentrate. In layer A the EVA is preferably LD317.09 and the slip and anti-block additive is preferably Amp 10568. Layer B is intended to be the inside layer of the film 30 or the side contacting the rubber. Layer B is preferably comprised of 97% plastomer and 3% slip and anti-block concentrate. In layer B the plastomer is preferably Exact 3027 and the slip and anti-block additive is preferably Amp 10568. Properties for this embodiment of the present invention are disclosed in TABLE 1, below. Of note, the embodiment exhibits an MD elongation of 331%, which is greater than the requirement of 250% elongation imposed by industry. The composite DSC Melt Point for the film 30 is represented by a primary peak at 92.4°C and a small peak at 101.9°C as seen in the graph of thermal analysis result in Figure 8. The Vicat softening point of the layered material is 81.0°C, which is approximately the target softening point of 82 °C. The ash content remaining from the anti-block additive, e.g. silica, is 5474 ppm, which is roughly the target of 6000. The

Reblock at 190 deg F is 99.8g. The Peel Force at 190 degrees is 7.6g. The Reblock and Peel Force are determined in accordance with the standard protocol discussed hereinafter.

d. The Preferred Layered Embodiment (208-07-05)

The 208-07-05 material 40 (Figure 5) is an extrusion of two layers. Layer A comprises 25% of the total thickness of the extrusion. Layer B comprises 75% of the total thickness of the extrusion. It will be understood by those skilled in the art that the relative percentages of the thicknesses of the layers may be changed without departing from the scope of the invention. Layer A is intended to be the outside layer of the film and is comprised of 97% EVA and 3% slip and anti-block concentrate. In layer A the EVA is preferably LD302.32 and the slip and anti-block is preferably Amp 10568.

LD302.32 has a melt temperature of 104°C and a Vicat softening point of 89°C. Layer B is intended to be the inside layer of the film or the side contacting the rubber. Layer B is comprised of 97% plastomer and 3% slip and anti-block concentrate. Although the plastomer as disclosed herein is the preferred material, it should be understood by those skilled in the art that any polyethylene with a melting point of less than 105°C may be used instead of or in combination with the plastomer disclosed herein. In layer B the plastomer is preferably comprised of Exact 3027 and the slip and anti-block additive is Amp 10568. Properties for the preferred embodiment of the present invention are disclosed in TABLE 1 , below. Of interest is an MD Elongation of 472%, which is greater than the requirement of 250% imposed by industry. The composite DSC Melt

Point for the film 40 is represented by a primary peak at 92.5 °C and a small peak at 102°C as seen in the graph of thermal analysis results in Figure 8. The Vicat softening point of the layered material is 80.6 °C, which is roughly approximate to the target softening point of 82 °C. The ash remaining from the anti-block additive content, e.g. silica, is 5289 ppm, which is roughly equivalent to the target of 6000 ppm. The Reblock at 190 deg F is 74.4. The Peel Force at 190 degrees is 5.9g. The Reblock and Peel Force are determined in accordance with standard protocol discussed hereinafter.

e. Comparison of the Data at 190°F

Both the 208-03-01 monolayer material 20 and the 208-07-04 layered material 30 have approximately 50% plastomer and approximately 50% EVA. By extruding the material 30 into layers (208-07-04), the Reblock force is substantially decreased as compared to the monolayer embodiment (208-07-01 ) at a testing temperature of 190 deg F. The layered material exhibited 99.8 g resistence in a Reblock test compared to the 136.8 grams resistence in a Reblock test for monolayer film 20. Similarly, at a testing temperature of 190 deg F, the layered material exhibited a Peel Force of 7.6 grams versus a Peel Force of 8.7 grams for the monolayer embodiment.

Therefore, it can be seen that by extruding the metallocene and EVA into separate layers rather than mixing the materials into a monolayer, a lower Reblock force and Peel Force may be obtained for a material at higher temperatures.

By forming a film comprised of extruded metallocene and EVA in desired percentages, the Reblock and Peel Force may be further depressed. For example, film

40 (208-07-05) exhibits a Reblock force of 74.4 grams and a Peel Force of 5.9 grams at 190 deg F. These properties compare well to the Reblock measurement of 77.3 and Peel Force of 4.7 grams exhibited by the prior art preferred monolayer EMB-675 material at 170 deg F., which is 20 degrees lower. Consequently, by using the multi-layered film 40 (208-07-05) in place of a typical monolayer film, such as film 10 (EMB-675), a manufacturer may run its process faster because the manufacturer may wrap the bales at higher temperatures and subsequently place the bales at higher temperatures into containers.

II. Test Protocols To determine material properties for comparison purposes, various tests may be performed on the materials. As noted below, some of these tests are conducted in accordance with the standard ASTM protocols and incorporated by reference. Additional tests to determine Reblock properties and ash concentration are further described hereinafter. a. Melt Index:

The Melt Index may be determined by testing methods in accordance ASTM 1238, Condition E, 190°C, 2.16 kg mass, expressed in g/10 min.

b. Standard Test Method for VICAT Softening Temperature of Plastics: The Vicat softening point for film may be determined by testing methods in accordance with ASTM Test Method D 1525.

c. Standard Test Method for Transition Temperatures of Polymers by Thermal Analysis:

The DSC Melt Point may be determined by testing methods in accordance with ASTM Test Method D 3418 - 82.

d. Lab Test Method - Reblock:

Reblocking results from storage of film or bags with prolonged contact of film layers. Stacks of bags stored in boxes under storehouse conditions, in shipment or on store shelves have a tendency to stick together. This adhesion is called Reblocking.

Reblock is measured as the force, in grams, necessary to separate two layers of film after aging at controlled temperature and pressure.

The equipment necessary to perform a Reblock analysis is as follows: 1. Kayeness™ Block - Reblock Tester Model D-9040, designated generally 90 (Figure 10): A fine electro mechanical instrument with a high degree of accuracy. 2. Precision™ Mechanical Convection Oven.

3. One sample template - 4" x 7".

4. One flat weight - 6" x 5", weighing 4.2 lb. for each stack of samples to be tested.

5. One sample base for receiving the test samples.

The Kayeness™ Block - Reblock Tester is shown in Figure 10. The Reblock

Tester 90 includes digital display A, on/off switch B, fuse C, leveling feet D, hold-down clamp E, manual return button F, magnetic clamp strips G, upper platen H 1 , lower platen H2, run test button I, and knurled tare knob J. In practice, samples for testing by the Reblock Tester 90 should be prepared as follows:

1. Samples should be conditioned in the Lab a minimum of 48 hours prior to testing. 2. Working on a clean glass surface (Fig. 11), fold the film so that the surfaces 104 to be tested are in contact: for example, a corona treated side should be in contact with a corona treated side, an untreated side should be in contact with an untreated side, Layer A should be in contact with Layer A, Layer B should be in contact with Layer B, and with regard to embossed films the female to female or male to male side should be in contact, etc., as requested. Film surfaces 104 should be clean and wrinkle free.

3. Covering as much area of the sample width as possible, cut 5 pairs of specimens from areas 106 using a 4" x 7" template, with the 7" dimension in the machine direction. After cutting, pairs of samples must be separated to insure the specimens are not "welded" together at the razor cuts.

4. Stack the pairs of specimens with a 4" x 7" piece of plain, white paper between each pair. A stack of samples should not exceed 25 pairs. The stack of samples makes up a sample base.

5. Place the stack of specimens in an oven at 140°F. If the oven has been turned off, allow 24 hours for the oven to stabilize. A Reblock weight is placed on top of the sample base. The sample base and Reblock Weight must be in the oven during the pre- heating period. The samples are then aged 24 hours in the oven.

After 24 hours, the Reblock weight is lifted off of the specimen stack and the specimen stack is removed from the oven. The specimens are allowed to cool for 1 hour before testing.

After preparation of the samples, the procedure for testing the samples is as follows:

1. Referring to Figure 10, the Reblock tester 90 must be leveled and adjusted prior to testing. First, two magnetic clamp strips G are placed on the upper platen HI. Knurled tare knob J is adjusted until the upper platen HI is just kissing the lower platen H2. Then, the leveling feet D are adjusted until the upper platen HI lowers exactly onto lower platen H2.

2. Still referring to Figure 10, the Reblock tester must be cycled several times "dry". To "dry" run, the RUN TEST button I is pressed. This permits the circuitry to warm up and the bearings to lubricate in the Reblock tester. Magnetic clamp strips G should be in place on the upper platen HI during "dry" running.

3. A pair of specimens are then inserted between the upper platens HI and lower platens H2. Upper platen HI is clamped in place with hold down clamp E. Edges of the specimens should be aligned with upper platens HI and lower platens H2. 4. A lower specimen is attached to the lower platen H2 and an upper specimen is attached to the upper platen H 1 using magnetic clamp strips G. When attaching upper and lower specimens to upper platen HI and lower platen H2, respectively, the specimens should be pulled taut since slack samples reduce force required for separation.

5. Hold down clamp E is then removed and RUN TEST button I is depressed to return the digital display to zero and to commence loading of platens HI and H2 in 1/10 gram increments.

6. At the completion of the test the display will show the highest load recorded. This is the Reblock value to be reported. The maximum test load is 210 grams.

7. The tested sample is then removed from the Reblock tester 90 and four more samples (total of 5) are tested. The load display for each is then recorded.

e. Lab Test Method: Ash

An additional test that is performed to determine properties of the bale wrap film material is an Ash test. The ash test requires the following equipment: a microwave muffle furnace, ashing crucibles - either quartz fiber disposables or Coors porcelain crucibles, a scale sensitive to .0001 grams, heat resistant gloves, tongs (to handle crucibles), and a desiccator. In practice, the procedure for ashing standard PE, PP and materials not containing calcium carbonate is as follows:

1. Bring the oven temperature to 650 °C.

2. Remove a crucible from the desiccator and weigh the crucible to the nearest .0001 gram. 3. Prepare an ASH test sample by folding a film sample multiple times. Place the folded sample on a plastic piece backing and position the die cut of the plastic piece backing on the sample. Using a rawhide mallet, hit the die cut of the plastic piece backing squarely. It may take more than one hit to separate the sample completely.

4. Add the sample to the crucible. Record the crucible plus sample weight to the nearest .0001 gram.

5. Turn off the microwave oven.

6. Remove the furnace door of the muffle furnace. Place the crucibles containing the samples into the furnace and replace the furnace door.

7. Replace the furnace door and close the instrument door.

8. Start the microwave oven.

9. Ash the film sample. 10. Stop the microwave. Remove the ashing crucible containing the sample.

Place the sample in the desiccator. Replace the furnace door, close the instrument door and maintain the set temperature. 1 1. After one minute, the crucible/sample may be removed from the desiccator and weighed. This weight is then recorded.

After the sample has been ashed, the ppm of ash may be calculated as follows:

1. Subtract the crucible weight from the beginning sample/crucible weight. This is the weight for the actual sample. Record this weight. 2. Subtract the crucible weight from the ashed crucible/sample weight. This is the weight of the sample left after ashing. 3. Divide the ashed sample weight by the beginning sample weight.

Multiply this by 1 ,000,000 to convert to PPM (parts per million).

f. Lab Test Method: Peel Test

The Peel Test is conducted with 1 " wide strips of film cut from the samples prepared for the Reblock tester. The layers are separated on one end of the specimen strip. One layer is affixed to the upper jaw of an Instron, the second layer is affixed to the lower jaw of the Instron. The initial gap between the jaw grips is 2". The jaws are then separated to 2.2" and the resistance force is recorded. The jaws are then separated further to 2.5"and the resistance force is again recorded. The two force values are then averaged to obtain a Peel Force result.

III. Test Data Obtained from the Above Described Tests and Other Standard ASTM

Tests

The properties of the films of the invention may be illustrated by a comparison of the four films discussed above. First, a film designated as EMB-675 is a mono-layer structure having 88% plastomer, 9% EVA and 3% slip and anti-block concentrate, as previously discussed. A second film is designated by 208-03-01 and is a mono-layer structure having 50% plastomer, 47% EVA and 3% slip and anti-block concentrate or approximately 50% plastomer and 50% EVA. A third film is designated by 208-07-04 and is a co-extrusion of two layers. Layer A comprises 50% of the total thickness of the co-extrusion. Layer B comprises 50% of the total thickness of the extrusion. Layer A (having the higher melting point) is intended to be the outside layer of the film and is comprised of 97% EVA and 3% slip and anti-block concentrate. Layer B is intended to be the inside layer of the film or the side contacting the rubber. Layer B is preferably comprised of 97% plastomer and 3% slip and anti -block concentrate, as previously discussed. The fourth film is designated by 208-07-05 and is a an extrusion of two layers. Layer A comprises 25% of the total thickness of the extrusion. Layer B comprises 75% of the total thickness of the extrusion. Layer A is intended to be the outside layer of the film and is comprised of 97% EVA and 3% slip and anti-block concentrate. Layer B is intended to be the inside layer of the film or the side contacting the rubber. Layer B is comprised of 97% plastomer and 3% slip and anti-block concentrate, as described in greater detail below.

The physical properties of the films EMB-675, 208-03-01, 208-07-04 and 208- 07-05 are set forth in the below table:

TABLE 1

All tests were done using Tredegar's Lake Zurich Testing Methods and where applicable ASTM test methods. * LD302.32 replaced LD317.09

From the above examples and data, it can be seen that the film of the invention provides numerous advantages. These advantages include a film possessing DSC melting point and Vicat Softening Point characteristics comparable to prior art films, while demonstrating highly desirable low Reblock and Peel Force properties comparable to existing films at a temperature that is only obtainable for comparable films at temperatures at least 20 °F lower. Therefore, manufacturers may increase their process speed. At increased process speeds, the bale wrap of the present invention may be applied to hotter bales without blocking. If prior art bale wrap is used, the manufacturer must invest in expensive equipment to cool the rubber pieces or crumbs prior to bale forming or slow the through put rate to allow the crumbs to cool to an acceptable level prior to wrapping. Applicant's film allows for the higher process speeds since applicant's film is able to provide the desired Reblock and Peel Force properties at higher temperatures. The comparable DSC Melt Point and Vicat Softening properties allow the bale wrap of the present invention to be incorporated into a homogeneous mixture of rubber and rubber compounding ingredients as is the current practice.

Claims

WHAT IS CLAIMED IS:

1. A co-extruded thermoplastic bale wrap film comprising: a first layer of said thermoplastic bale wrap film for positioning adjacent to a bale of synthetic rubber product to be wrapped, said first layer having a first melting point; at least a second layer of said thermoplastic bale wrap film for positioning on an outside away from said bale of synthetic rubber to be wrapped, said second layer having a higher melting point relative to the melting point of the first layer; wherein said co-extruded bale wrap film has a composite Vicat softening point less than 100 degrees C.

2. The co-extruded thermoplastic bale wrap film according to Claim 1 wherein: said co-extruded bale wrap film has a composite Vicat softening point less than

82 degrees C.

3. The co-extruded thermoplastic bale wrap film according to Claim 1 wherein said co-extruded bale wrap film has a composite DSC melting point having a primary peak of less than 105 degrees C.

4. The co-extruded thermoplastic bale wrap film according to Claim 1 wherein said co-extruded bale wrap film has a composite DSC melting point having a primary peak of less than 93 degrees C.

5. The co-extruded thermoplastic bale wrap film according to Claim 1 wherein the bale wrap film exhibits a Reblock Force block of less than 120 grams at 190 degrees F.

6. The co-extruded thermoplastic bale wrap film according to Claim 1 wherein the bale wrap film exhibits a Peel Force of less than 8.5 grams at 190 degrees F.

7. The co-extruded thermoplastic bale wrap film according to Claim 1 wherein the bale wrap film exhibits a Peel Force of less than 15 grams at 190 degrees F.

8. The co-extruded thermoplastic bale wrap film according to claim 1 wherein: the thickness of said first layer comprises less than about 30 % of the composite film thickness.

9. The co-extruded thermoplastic bale wrap film according to claim 1 wherein: the thickness said second layer comprises greater than about 70 % of the composite film thickness.

10. The co-extruded thermoplastic bale wrap film according to claim 1 wherein: the first layer is comprised of 97% EVA and 3% slip and anti-block concentrate and the second layer is comprised of 97 % plastomer and 3 % slip and anti-block concentrate.

11. A process for making a co-extruded thermoplastic bale wrap film comprising: extruding a first layer of said thermoplastic bale wrap film for positioning proximate to a bale of synthetic rubber product to be wrapped, said first layer having a first melting point; co-extruding with said first layer at least a second layer of said thermoplastic bale wrap film for positioning on an outside away from said bale of synthetic rubber to be wrapped, said second layer having a relatively higher melting point; wherein said composite co-extruded bale wrap film has a composite Vicat softening point less than 100 degrees C.

12. The process for making a co-extruded thermoplastic bale wrap film according to claim 11 wherein said composite co-extruded bale wrap film has a composite Vicat softening point less than 82 degrees C.

13. The process for making a co-extruded thermoplastic bale wrap film according to claim 11 wherein co-extruded bale wrap film has a composite DSC melting point having a primary peak of less than 105 degrees C.

14. The process for making a co-extruded thermoplastic bale wrap film according to claim 1 1 wherein the co-extruded bale wrap film has a composite DSC melting point having a primary peak of less than 93 degrees C.

15. The process for making a co-extruded thermoplastic bale wrap film according to claim 11 wherein the thickness of said first layer comprises less than about 30 % of the composite film thickness.

16. The process for making a co-extruded thermoplastic bale wrap film according to claim 11 wherein the thickness of said second layer comprises greater than about 70 % of the composite film thickness.

17. The process for making a co-extruded thermoplastic bale wrap film according to claim 11 wherein: the first layer is comprised of approximately 97% EVA and about 3% slip and anti-block concentrate and the second layer is comprised of about 97 % plastomer and 3 % slip and anti-block concentrate.

18. The process for making a co-extruded thermoplastic bale wrap film according to claim 11 wherein the bale wrap film exhibits a Peel Force of less than 8.5 grams at 190 degrees F.

19. The process for making a co-extruded thermoplastic bale wrap film according to claim 11 wherein the bale wrap film exhibits a Peel Force of less than 15 grams at 190 degrees F.

20. The process for making a co-extruded thermoplastic bale wrap film according to claim 11 wherein the bale wrap film exhibits a Reblock Force of less than 120 grams at 190 degrees F.