DK163051B - PACKAGING MATERIAL OF SYNTHETIC RESIN PACKAGING PARTS - Google Patents

Abstract

Expanded, resilient, thermoplastic dunnage particles are rendered more effective by coating the outer surface of the particles with an additive which increases the coefficient of friction of that outer surface. The additive also promotes at least a minimum amount of adhesion between the dunnage particles.

Description

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BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to a wrapping material comprising any number of expanded, elastic, thermoplastic, synthetic resin-containing garnish particles having a friction-increasing amount of a friction-increasing additive deposited on at least a majority of an outer surface area of most of said garnet. a packaging material which has improved shock absorbing properties and which reduces the propensity for articles to move through the garnishing particles.

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Decoration materials, such as foamed plastic particles or strands, are known to be highly desirable for use in the packaging of articles. The foamed particles or strands protect items during shipping by absorbing shock 15 and by insulating the items from the shipping container walls. Typical particles or strands are disclosed in U.S. Patents 3,188,264 and 3,723,240.

Decoration materials are usually used under, over and 20 along the sides of the articles being packaged to insulate the items from the container walls. Packaging of relatively light objects in this way is generally effective. Packaging of fragile but relatively heavy objects, such as electronic or optical equipment, in this way is less effective.

It has been found that relatively heavy objects tend to sink and shift or move through the garnish materials due to vibration or handling. In the case of shipments in a truck, van or freight van, these heavy items frequently move until contact with a shipping container wall occurs and breakage or other damage occurs. Damage to this and other causes can amount to as much as 15% or even more, especially 35 in the case of prolonged shipping or handling.

A number of attempts have been made to reduce migration through garnish materials.

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2 In US Patent 3,292,859, Landen describes the use of very small expanded garnish particles with a surface coating of an adhesive or sticky substance.

In U.S. Patent 3,188,264, Holden describes particles with a series of concave surface depressions to promote bonding between the particles.

In U.S. Patent 3,723,240, Skochdopole et al. asymmetrically foamable strands that curl at foam to form a usually helical structure. The spiral structures lock to some extent when placed under pressure.

In U.S. Patent No. 3,251,728, Humbert et al. a garnish material consisting essentially of an entangled closely knit mass of non-linear, elongated foamed polymer pieces.

In U.S. Pat. No. 3,047,136, Graham discloses a garnishing material consisting of a series of hollow, curled cylinders, each of the strings being partially intersected. An elastic or rubbery outer coating may be applied to the strands to reduce the mutual friction between the strands and to supplement the bonding between the strands.

The present invention is characterized by the characterizing part of claim 1.

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Referring to claim 1, the present invention relates to an improved packaging material comprising a plurality of expanded resilient thermoplastic synthetic resin coating particles comprising a friction-increasing amount of a friction-increasing additive deposited on at least a majority of the outer surface. surface area of a majority of these garnishing particles, resulting in additive

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3 in that the packaging material has improved shock-absorbing properties and reduces the tendency of the articles to migrate through the garnishing particles, the improvement of which involves the use of particles having an average maximum 5 cross-sectional dimension of at least 1.27 cm.

In preparing the packaging material in the form of foamed garnish particles, conventional methods can be used to provide a plurality of foamed particles and apply a friction-increasing amount of a friction-increasing additive to at least a portion of an outer surface area of a majority of these. foamed particles having an average maximum cross-sectional dimension of at least 1.27 cm.

The packaging material of the invention may be used in a method of packaging articles comprising: (a) providing a packaging container, the container having at least one wall, one top and one bottom, and the container also having sufficient size to contain (1) at least one article to be packaged, and (2) an amount of packaging material sufficient to separate the article from the wall, top and bottom of the container; (b) adding an amount of improved packaging material particles to the packaging container, the amount being sufficient to provide a layer of suitable thickness to separate the article to be packaged from the bottom of the container; (C) placing the article to be packaged onto the layer of packing material particles; (d) adding an additional amount of improved packaging material particles to the packaging container, the additional amount being placed around the sides, in and on top of the article to separate it from the walls and top of the container and from other articles, an additional amount being sufficient to provide a slight overfill of the packaging container;

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0 4 (e) closing the eni-packaging container for weak compression of the particles by pressing down on the overfill.

One modification is to add a step in which a first deformable material layer is placed over the layer of the garnishing particle layer applied to the container and a second deformable material layer is placed over the article to be packaged.

When pressurized, the first and second deformable layers will generally deform such that portions of the second deformable layer come into contact with portions of the first deformable layer, thereby forming a jacket around the article.

Another modification involves wrapping at least one deformable material layer around the article before it is applied to the layer of garnishing particles.

The improved packaging material may also advantageously be used when the article to be packaged is placed in contact with the wall, top or bottom of the container.

Decoration particles suitable for use in the present invention are readily prepared from a wide variety of synthetic resin-containing thermoplastic polymers. 25

A group of suitable thermoplastic polymers comprises polymers containing in chemically bonded form at least 70% by weight of at least one aromatic alkenyl compound. Such compounds have the general formula

30 R

Ar-C = CH2 wherein Ar represents an aromatic hydrocarbon group or a ring-substituted halohydrocarbon group from the benzene series and R 35 is hydrogen or a methyl group. Examples of such aromatic alkenyl polymers are homopolymers of styrene, alpha-methylstyrene, ortho-, meta ~ and para-methylstyrene. Ar-ethylstyrene, tert-butylstyrene and Ar-chlorostyrene; the copolymers of two

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0 or more such aromatic alkenyl compounds with each other; and copolymers of one or more such aromatic alkenyl compounds with minor amounts of other readily polymerizable olefinic compounds such as divinylbenzene, methyl methacrylate or acrylonitrile. Another group of suitable thermoplastic polymers suitable for the preparation of expanded garnishing particles comprises aliphatic olefin polymers which are usually solid polymers obtained by polymerizing at least one alpha-monoolefinic aliphatic hydrocarbon containing from 2 to 8 carbon atoms. per. molecule. Examples of such hydrocarbons include ethylene, propylene, butene-1, pentene-1, 3-methylbutene-1, 4-methylpenten-1, 4-methylhexene-1 and 5-methylhexene-1. The hydrocarbons may also be polymerized alone, with each other or with various other polymerizable compounds. The polymers of ethylene or propylene alone are favorable because they form cool, elastic, fine-celled, chemically inactive products.

Examples of suitable polymerizable organic compounds which can be polymerized with ethylene or propylene are vinyl acetate, C 1 -C 4 alkyl acrylates such as ethyl acrylate; styrene; lower alkyl esters of methacrylic acid such as methyl methacrylate; tetrafluoroethylene and acrylonitrile.

25 Copolymers containing in chemically bonded form 75% by weight or more ethylene or propylene having not more than 25% of one or more such polymerizable organic compounds also give suitable results. 1 2 3 4 5 6

The aliphatic olefin polymers can be modified by blending 2 with polymeric substances. Examples of polymeric substances include 3 polyisobutylene, acrylonitrile / butadiene rubbers, poly (2-chloro-4-butadiene-1,3), polyisoprene, ethylene / acrylic acid copolymers and 5 ethylene / vinyl acetate copolymers.

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A third group of suitable thermoplastic polymers suitable for the preparation of expanded gamer particles further comprises halogenated aliphatic olefin polymers, as well as polymers of a wide variety of ethylenically unsaturated monomers which form foamable thermoplastic materials.

Examples of polymers include those polymers produced by polymerization of isopropenyltoluene? vinyl napthalen esters of alpha-methylene aliphatic monocarboxylic acids such as methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, dodecyl acrylate, 2-chloroethyl acrylate, 2-chloropropoyl acrylate, 2,2'-dichloroisopropyl acrylate, 2,2'-dichloroisopropyl acrylate alpha-chloroacrylate, methylmethacrylate, ethylmethacrylate and methylethacrylate nitriles such as acrylonitrile and methacrylonitrile; vinyl esters such as vinyl acetate, vinyl chloroacetate, vinyl propionate, vinyl butyrate, vinyl laurate and vinyl stearate; vinyl ethers, such as vinyl methyl ethers, vinylis obu l ether and vinyl 2-chloroethyl ether; vinyl ketone methyl isopropenyl ketone isobutylene; vinylidene halides such as vinylidene chloride and vinylidene chlorofluoride N-vinyl compounds such as N-vinylpyrrole, N-vinylcarbazole, N-vinylindole, N-vinylsuccinimide, acrolein, methacryolein, acrylamide, methylacrylamide and N-crylamide. , allyl acetate, allyl methacrylate, allyl lactate, allyl alpha hydroxyisobutyrate, allyl trichlorosilane, allyl acrylate and methallyl phosphate.

Foamable materials of polymers are readily prepared therein by incorporating a gas, a volatile liquid, a solid gas-emitting blowing agent or a combination of two or more of these which causes expansion of the polymeric material by heating.

In order to achieve an improved cushion effect or cushioning according to the invention, "it is desirable to use expanding garnish particles having an average maximum cross-sectional dimension of at least 1.27 cm. The particles preferably have an average minimum cross-sectional dimension of at least 1 , 27 cm.

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In a process for preparing the improved packaging material, a hot plasticized mass of synthetic resin-containing material is provided in a first step. The hot plasticized mass contains an expanding agent.

The mass is capable of expanding to form a large number of closed gas-filled cells. In another step, the hot plasticized mass is brought and kept under pressure. In a third step, the hot plasticized mass is cooled to a temperature below the temperature at which the hot plasticized mass would foam under reduced pressure. In this step, a cooled thermoplastic mass is obtained. In a fourth step, the cooled heat-plasticized mass is extruded without significant foaming from a forming device to form extended strands. In a fifth step, the elongated 15 strands serve to form a large number of foamable components having a relatively high room weight. Alternatively, a nozzle front cutter or similar apparatus may be used to pellet the cooled thermoplastic mass when extruded. In a sixth step, the foamable ingredients or pellets are heated to an elevated temperature. The elevated temperature is sufficient to cause the components to expand, thereby forming foamed particles with a large number of gas-filled cells. In a seventh step, a friction increasing amount of an additive is applied to at least a portion of the outer surface of a large number of the foamed particles.

Conveniently, the friction-increasing additive is any material that meets three criteria. First, it must be capable of being deposited on the outer surface of the garnishing particles. Secondly, it must remain on the outside surface of the garnishing particles for a sufficient period of time.

The sufficient time is the time sufficient to allow one or more articles (a) to be packaged with the garnishing particles, (b). shipped or transported to a desired destination with or without intermediate

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0 8 horizontal storage periods and (c) unpacked again with or without intermediate storage periods. Third, the additive must provide an increased coefficient of friction to the outer surface of the garnish particles. The additive preferably promotes at least a minimal adhesion between the garnish particles.

To determine whether the additive meets the aforementioned criteria, a modified test method was developed in the form of a so-called "peel test". The results of the Peel test were compared with the results of a vibration precipitation test to establish a correlation between these test methods. The test methods are set out below.

Substances that meet the aforementioned criteria include synthetic polymer latexes, pressure sensitive adhesives and adhesives, low molecular weight polymers, waxes, contact adhesives, starch-based adhesives, urethane adhesives and protein-based adhesives.

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Low molecular weight polymers used herein are those polymers having a ring and sphere softening point of more than approx. 30 ° C, preferably above ca. 50 ° C. Ring and ball softening points are determined in accordance with the American Society for Testing and Materials Test E-28.

Starch-based adhesives include pastes such as wheat paste, dextrins, borated dextrins, rubber gels and the like. Suitable starches may be indicated by the formula 30 ° C 6 H 10 O 5 1,000,000.

Protein-based adhesives include animal glue, casein and the like. 1

Suitable synthetic polymer latexes are those which meet the aforementioned criteria and which are aqueous colloidal suspensions of particles of a polymer obtained by emulsion polymerization. The colloidal suspensions are generally stabilized by the addition of one or more suitable surface ac 0

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9 tive funds.

Suitable latexes include those based on e.g. styrene-butadiene copolymers, acyl copolymers, butadiene acrylonitrile polymers, vinylidene chloride copolymers, vinyl chloride copolymers and copolymers of vinyl alkanoates such as vinyl acetate.

Favorable results are obtained when the polymer latex contains a carboxyl function. A suitable size for the carboxyl function 10 is from 0.01 to 25% by weight of polymer. The carboxyl function is achieved by the inclusion of one or more alpha, beta-olefinically unsaturated carboxylic acid monomers with other polymerizable monomers to be used in the preparation of the aforementioned latexes.

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Suitable carboxylic acid monomers contain from 3 to 12 carbon atoms per molecule. Such acidic monomers include acrylic acid, methacrylic acid, ethacrylic acid, alpha-chloroacrylic acid, apha-cyanoacrylic acid, crotonic acid, beta-acryloxypropionic acid, hydrosorbic acid, sorbic acid, alpha-chlorosorbic acid, cinnamic acid, citric acid, beta-styrylacrylic acid fumaric acid, mesaconic acid and aconitic acid. Favorable results are obtained with carboxylic acid monomers containing from 3 to 6 carbon atoms per molecule such as acrylic acid and methacrylic acid.

Satisfactory results are obtained when the additive is a latex of a styrene-butadiene copolymer or blend polymer having a carboxyl function. Such copolymers typically have there polymerized (a) styrene in an amount of from 40 to 70% by weight of copolymer; (b) butadiene in an amount of from 15 to 40% by weight per unit weight. copolymer and (c) carboxylic acid monomers or monomers in an amount of 0.1 to 20% by weight of copolymer. 1

Acrylic copolymers typically therein polymerize (a) one or more acrylic acrylates containing from 1 to 18 carbon atoms.

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10 o more .pr. alkyl moiety and (b) one or more monomers which can be copolymerized therewith. The alkyl acrylates suitably have from 4 to 10 carbon atoms per moiety. Examples of alkyl acrylates include butyl acrylate, amyl acrylate, hexyl acrylate, heptyl acrylate, octyl acrylate, nonyl acrylate, decyl acrylate and various isomers of these acrylates such as isooctyl acrylate and 2-ethylhexyl acrylate.

Satisfactory results are obtained when the additive is a 10 acrylic copolymer or interpolymer having therein polymerized (a) from 40 to 80% by weight polymer of at least one alkyl acrylate and (b) from 20 to 60% by weight polymer of at least one ethylenically unsaturated monomer which can be copolymerized therewith.

Examples of copolymerizable ethylenically unsaturated monomers include alpha-olefins containing from 2 to 10 carbon atoms; vinyl esters of alkanoic acids containing 3-10 carbon atoms such as vinyl acetate and vinyloctoate, ethyl and methyl esters of methacrylic acid, styrene and vinyl chloride.

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Vinyl chloride latexes which contain either vinyl chloride homopolymer or interpolymers of vinyl chloride also give satisfactory results. Typically, vinyl chloride interpolymers therein have polymerized from 50 to 97 weight percent polymer of 25 vinyl chloride and from 3 to 50 weight polymer of at least one ethylenically unsaturated monomer which can be copolymerized therewith. Examples of copolymerizable monomers include the alkyl acrylates listed above, the vinyl esters of alkanoic acids listed above, alkyl esters of methacrylic acid containing from 1 to 4 carbon atoms per liter. alkyl part, as well as vinylidene chloride.

Latexes are generally prepared by emulsion polymerization using anionic or nonionic surfactants or mixtures thereof. Suitable anionic surfactants include sodium dioctyl sulfosuccinate, o

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11 sodium diamylsulfosuccinate, sodium dihexylsulfosuccinate, sodium laurylsulfate and sodium dodecylbenzenesulfonate. The nonionic surfactants which may be cited as examples include nonyl or octylphenoxypolyethoxyethanol condensates wherein the ethylene oxide content may range from 5 to 50 moles. Conveniently, two or more of these nonionic surfactants may be used. Latex preparation is achieved using conventional polymerization methods.

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Polymer latexes containing up to approx. 60% by weight of polymer solids in total can be suitably sprayed. For optimum results, solids concentrations of 35-55% are preferred.

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Any spraying method capable of atomizing the additive can be used. Therefore, the spraying method in question is not critical to the production of the improved garnish particles of the present invention. Thus, air, air-free or aerosol systems can be used. It is advisable to use low fluid supply rates and low atomization pressures as this will reduce o-spraying and atomization of the additive to the ambient atmosphere. The liquid delivery system is most conveniently an air-free syringe system with a pneumatic pump. Other own spraying equipment includes a pressure vessel in combination with a conventional air spraying equipment and peristatically acting pumps. 1 2 3 4 5 6

The additive to be sprayed is usually fed into Syringe 2 equipped at a rate of 50-500 g wet additive per day. per minute, 3 preferably 100-400 g wet additive per minute. minute. The size of the distress 4 applied atomizing pressure will be proportional to the feed rate of the additive and will typically range from 35 to 550, preferably from 70 to 550 kilopascals 0 12

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The supply of additives to foamed garnishing particles is not limited to spraying equipment and methods using such spraying equipment. Additives can therefore be applied by brush, roll or any other conceivable means, provided that a sufficient amount of additive is applied to the garnishing particles.

The improved garnishing particles, if prepared and dried prior to packaging, can be prepared for use by simply applying a light water mist or steam spray on the surface thereof. The improved decoration particles may be applied to the mist or spray before or simultaneously with or after addition to a packaging container. If the improved garnish particles are lumped together as they occur when the improved garnish particles are reused, the mist or spray will favorably moisten the additive sufficiently to enable the improved garnish particles to be separated into single particles or small but useful lumps.

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The additive is acceptable if, during the modified peel test described below, it has a peel strength of at least 1.5 g / ml. cm. The additive advantageously provides a peel strength of more than 9 g / ml. cm. The additive desirably provides a peel strength of more than 40 g / ml. cm. Preferably, the additive provides a peel strength of 150 g / ml. cm. Greater peel strength is acceptable but not necessary.

Another way of determining whether or not the additive is acceptable is to determine the total settling value during the modified vibration settling test described below. The total settling value is suitably below 65, advantageously below 45, desirably below 30 and preferably below 25.

Peel-s Turks and the total precipitation values used 35 0 13

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given above is readily obtained with an additive amount of from 1400 to 6000 g of wet additive per day. m foamed decoration material. Favorable results are obtained with an additive amount from 1600 to 3400 g wet additive per day. foamed garnish material.

Additive amounts of over 6000 g wet additive per m of garnishing material will satisfactorily modify the friction coefficient of the foamed garnish. Amounts 10 of wet additive up to 10,000 or more grams of wet additive 3 per In other words, m decoration can be used in accordance with the present invention. However, such quantities are very large and may be undesirable for many reasons, such as cost, efficiency, uneconomical drying rates and damage to the article or articles being packaged.

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Additive amounts of less than 1400 g wet additive per m foamed garnish is generally unsatisfactory due to the fact that they do not provide sufficient coverage of the foamed garnish.

An advantage of the improved garnish particles of the present invention is that they provide lower vibration settling values than conventional garnish particles.

In other words, displacement of objects through the improved garnishing particles is less likely than with conventional garnishing particles. 1 35

Another advantage is that the improved garnishing particles, when used for packaging, provide reproducible bump properties. Conventional garnish particles provide erratic cushioning properties. Reproducibility is highly desirable in the design of packaging * 0

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A third advantage is that the improved garnishing particles of the present invention tend to adhere until separated, especially when the additive is an adhesive, an adhesive, a contact binder, and the like. Conventional garnish particles have no tendency to stick together and, as you know, tend to be spilled out of the packaging and spread on the surface where the packaging is located. Collecting the spilled garnish particles is irritating and takes time. The improved garnish particles will, depending on the amount of additive, be removed from the packaging either as several small chunks of particles or as a few large masses of particles.

A fourth advantage is that by varying the amount of additive applied to the improved garnishing particles, a wide range of packaging properties can be obtained. In other words, it is possible to tailor the improved garnish particles to meet a special need. With conventional yarn particles, there is a very narrow range of packaging properties.

These advantages are obtained with relatively low additive amounts. Applying the additive to the garnish particles is neither complicated nor expensive. With small amounts of additive, the drying time is short, thereby minimizing the impact on the normal packaging process.

Modified peel test.

30 Polystyrene foil for usual use and one side of which is sulfonated was used for peel testing. The film had a thickness of 6.35 microns and was marketed by The Dow Chemical Company under the trade designation Trycite © 1101. Pieces were cut with a width of 2.54 cm and a length of 35 33 cm of the film. the last dimension was in the machine direction.

island

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The specimens were prepared for peel testing as follows. Using the No. 10 Meyer rod, one end of the sulfonated side of the film was placed on a ca. 10 cm long piece coated with additive to be examined. The foil sample was then folded so that an equal length of sulfonated surface from the other end of the sample was in intimate contact with the coated portion. The foil samples were then placed in a desiccator and aged for a period of "42 hours. The desiccator had a relative humidity of 15 to 20% and a temperature setting of 21 to 24 ° C.

After aging, the samples were taken from the desiccator. The sample had a fixed end and a loop end. The loop end was then cut to form two free ends of approximately the same length. The free ends had not applied any additive.

An Instron universal testing machine, model # 1123, was used to determine the peel strength. The Instron machine had two sets of jaws placed apart and over 20 for each other. One of the jaw kits was stationary and attached to the machine. The second set of jaws was attached to a load cell, which in turn was attached to the machine's mobile crosshead. 1 2 3 4 5 6 7 8 9 10 35

The free ends of the specimens were placed in the two sets of jaws. A free 2 end was jammed by the stationary sets of jaws. Another 3 free end was attached by the set of jaws attached 4 to the load cell. The cross head of the machine was activated so that the jaw set attached to the load cell moved away from the stationary jaw set at a rate of 7 either 200 or 254 mm per second. minute. The crosshead velocity has no effect on the peel strength. The samples were torn 9 apart until separated throughout their length. Load 10 cell recorded the peel strength of the sample.

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Vibrationsstabiliseringstest.

The purpose of this test was to determine / whether an item / that is wrapped in garnish material moved due to vibration and, if so, how much. The test was a modified version of the vibration precipitation test described in United States Federal Specification PPP-C-1683, section 4.9 / regarding expanded polystyrene buffer material / loosely filled.

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Ca. 57,000 cm of decoration material was placed in a box that is open at the top. The box had a length of 100 cm, a width of 60 cm and a height of 60 cm. A 0.635 cm mesh screen was placed over the box opening.

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A Craftsman spray gun, model 919.1561410, with the option of either internal or external liquid for air mixing. The spray gun is available from Sears, Roebuck and Co. and was used to spray a mixture of a color and the additive to be examined for friction increase down through the screen of the garnish. The color was used to provide a visual indicator of coverage of the additive on garnish material. The spray gun had a reservoir portion in which the mixture was placed for application to the garnish material. The reservoir portion was pressurized to 275 kilopascals to provide a constant flow rate of approx. 0.11 liters of the mixture per liter. minute. The flow rate provided a spray force sufficient to cause mixing of the garnish with the box.

Spraying was continued until a visual examination of the garnish showed that a generally uniform coating of the mixture was deposited on the garnish. 1

The spray rate, expressed as g wet additive per minute, varied with the additive applied. When the density of the additive changes to 0 17

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in other words, the spray speed also changes. By way of example only, an additive having a density of approx. 1.0 at a temperature of 24 ° C when applied using the aforementioned spray gun 5 at a pressure of 275 kilopascals had a flow rate of about 100 to approx. 140 g wet additive per per minute to a minimum flow rate of 125 g wet additive per minute. minute.

A cardboard box measuring 30 cm on the inside of each joint was filled with approx. half with the coated garnish.

A load box measuring 15 cm externally on each joint and weighing either 2.4 or 7.3 kg was placed in the cardboard box in such a way that there was a 7.6 cm gap between the top of the cargo box and the top of the cardboard box . The 2.4 kg load box was used to provide a load of 1035 2

Newton pr. m. The 7.3 kg load box was used to give a load of 3105 Newton per kg. m.

An additional amount of coated garnish was added to the cardboard box for loading it to the top of the cardboard box. In accordance with recommended guidelines for packing with expanded thermoplastic wrapping materials that are loosely filled, the cardboard box was then filled with a pyramid or top of the coated coating material. The top had a height of approx. 2.54 cm, the height being measured from the top of the cardboard box to the top of the garnish material. The lid of the box was then closed and adhered with fiberglass reinforced adhesive tape. 1 2 3 4 5 6

After closing, the cardboard boxes and their contents were allowed to dry at a temperature of 21 ° C to 9 ° C for a period of approx.

3 16 hours. No special regulation 4 of humidity or temperature during drying was provided.

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A small hole with a diameter of 0.356 cm was made in the middle of the top of the cardboard box.

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A piece of rigid stainless steel wire, also 0.356 in diameter, was inserted into the hole and then, pushed through the garnish material, until it came into contact with the top of the load box. The thread length between the top of the 5 cardboard box and the top of the load box was measured and recorded as "initial offset".

The cardboard box with contents was placed on a table capable of vibrating at a frequency of 4.5 hertz with a vertical displacement of 2.54 cm. The table was named MTS Series 840 Servohydralic Vibration Test System and was marketed by MTS Systems Corporation.

The table had a square sample receiving surface with a side length of 90 cm. An inner screw-turned opening with a diameter of 0.953 cm had been drilled into the sample receiving surface in each corner. An externally screwed rod was screwed into each of these openings. Four rubber strips with a length of 66 cm, a width of 1.91 cm and a thickness of 0.64 cm and with loops at both ends were connected between adjacent ice-screwed rods to form an outside boundary around the table. The four rubber strips, also known as boundary strips, were placed over the table surface at a distance of approx. 13 cm. Two additional rubber -25 strips similar to the other rubber's trim were connected between opposite boundary strips to divide the sample receiving surface into four equal square applications. 1 2 3 4 5 6

Four cardboard boxes, prepared as previously described and about 2 times the same weight, were placed on the sample recipient over 3 faces. One of the cardboard boxes was placed in each of the sample application areas. The cardboard boxes were not attached to the table in accordance with the guidelines set out in United 6

States Federal Specification PPP-C-1683, Section 4.9. The cardboard boxes must have about the same weight to keep an even load on the table.

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After the four cardboard boxes were placed in their respective sample application areas, the table was set in motion.

After a period of 30 minutes, the table was stopped. The same piece of rigid steel wire was inserted through the hole again, 5 until it touched the top of the load box. The thread length between the top of the cardboard box and the top of the load box was measured and recorded as "final displacement".

An increase in the length from initial displacement to final displacement was converted to a percentage indication and indicated as "percent precipitation".

It was found that the percent precipitation values at 2 load 3105 Newton per m (7.3 kg load box) were 2 15 far greater than at load 1035 Newton per m. m (2.4 kg load box). In order to obtain a meaningful passed unsuccessful assessment, a total precipitation value was calculated.

The total settling value was determined by multiplying the settling value by the load 1035 Newton 20 per m by a factor of 6.71 to obtain a product, and then add the product to the settling value at the load 3105 Newton per second. m.

The following experiment has been carried out solely for the purpose of illumination, and should not be construed as limiting the scope of the present invention.

A number of additives were assessed for suitability using the "peel test" and "vibration precipitation test" as described above. Table I provides a description of the additives along with a list of abbreviations for these additives. Table II runs peel test data and vibration precipitation test data for each of the additives and for a control for which no additive has been added. The garnish material used in the vibration precipitation studies was an expanded particulate polystyrene material from The Dow 20

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Chemical Company, sold under the trade name Pe-laspan-Pac®, the particles having an average minimum cross-sectional dimension of approx. 1.27 cm and an average maximum cross section dimen s in on of approx. 2.86 cm.

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Table I

Additive identification.

10 Code Description of tested additive

Al Smoked silica A2 * Ground pepper 15 A3 A carboxylated styrene butadiene copolymer latex, the copolymer therein having polymerized styrene in an amount of 48% by weight of polymer and butadiene in an amount of 50% by weight of copolymer and fumaric acid in an amount of 2 % by weight of polymer. The latex had a nominal particle size range of approx.

0.16 to approx. 0.2 µm, a density of 1.02, and a dry matter content of approx. 47 to approx. 49% respectively. The Dow Chemical Comapny supplied the latex under the trade designation XD-30586.20.

A4 A vinylidene chloride polymer latex, the polymer therein having polymerized (a) vinylidene chloride in an amount of 82% by weight of polymer, (b) methyl acrylate in an amount of 18% by weight of polymer, 35 *

Experimentally intended not to be a friction-increasing additive for the purposes of the present invention.

Table I, continued

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Code Description of tested additive 21 5 (c) acrylic acid in an amount of 4 parts per 100 parts of (a) and (b), and (d) 0/5 parts of sodium sulfoethyl methacrylate per liter. 100 parts of (a) and (b). The latex had a particle size of approx.

10/1 to approx. 0.14 pmf a viscosity - measured at 25 ° C using Brookfield viscometer with a spindle # 1 and a rotor speed of 60 rpm. minute - in less than approx.

15 1/5 pascal seconds (Pa * s) a dry matter content of approx. 48 to approx. 50%, and a surface tension between 0.045 and approx. 0.055 Newton per meters (N / m). The Dow Chemical Company supplied the latex under the trade designation XD-30452.22.

A5 A cross-linking polyvinyl acetate homopolymer latex having a nominal particle size of 0.7 µm, a pH of 3.0, a density of 1.08, a viscosity - measured at 25 ° C using a Brookfield viscometer with a spindle # 1 and a rotor speed of 60 rpm. about 30 minutes of 0.06 Pais, and a surface tension of 0.041 N / m. Borden Chemical supplied the latex under the trade agreement POLYCO® 2136.

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Table I, continued

Code Description of tested additive 22

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5 A6 A vinyl chloride homopolymer latex having a nominal particle size of 0/16 yuan, a pH of 9.5, a density of 1.18 / a viscosity - measured at 25 ° C using a Brookfield vis-10 cosimeter with a spindle No. 1 and a rotor speed of 60 rpm. per minute - at 0.03 Pa * s, and a surface tension of 0. 04 N / m. Borden Chemical supplied the latex under the trade name POLYCO (g) 2622.

A7 A fine particle paint pigment latex containing a styrene copolymer and having a nominal particle size of 0.13 20 µm, a nominal average molecular weight by weight of 100,000 g / ml. mole, a solids content of 45-50% and a density of 1.05 (at a temperature of 25 ° C). The copolymer therein polymerized approx. 99.2 parts of styrene and approx. 0.8 parts of itaconic acid. The Dow Chemical Company supplied the latex uncommercial designation DPP 788.

£ 30

Experimentally intended not to be a friction-increasing additive for the purposes of the present invention.

35

Table 1 / continued

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Code Description of tested additive 23 5 A8 A large-particle paint pigment latex containing a styrene copolymer and having a nominal particle size of 0.35 µm, a nominal average molecular weight of 350,000 g / kg. mole, a solids content of 45-50% and a density of 1.05. The copolymer therein had approx. 97 parts of styrene and approx. 3 parts of acrylic acid. The Dow Chemical Company supplied the latex under the trade designation DPP 722.

A9 A vinylidene chloride polymer latex having the polymer therein having polymerized (a) vinylidene chloride in an amount of about (B) acrylonitrile in an amount of about 90% by weight of polymer; (C) butyl acrylate in an amount of about 5% by weight of polymer; (D) 1.4 parts sodium sulfoethyl methacrylate 25 per cent by weight; 100 parts (a) plus (b) plus (c).

The latex had a particle size of approx. 0.1 µm to approx. 0.13 µm, a viscosity - measured at 25 ° C using Brookfiel's viscometer with a spin part # 1 and a rotor speed of 60 rpm. - less than 0.05 Pa * s, a dry matter content of approx. 55-55%, and a surface tension of approx. 0.06 to approx. 0.073 N / m. The Dow Chemical 35 Company supplied the latex under the sub-designation SL143.

Code Description of tested additive

Table_I, continued 0 24

DK 163051 B

5 AlO A styrene copolymer latex having a minimum particle size of 0.03 µm, a nominal average molecular weight by weight of 500,000 g / ml. mols, a solids content of 35-40% and a density of 1/05. The copolymer therein had polymerized styrene in an amount of 96 parts by weight and acrylic acid in an amount of 4 parts by weight, both amounts being based on copolymer weight. The 15 Dow Chemical Company supplied the latex under the trade designation XD 8510.

All wheat paste adhesives made by stirring wheat flour in water, the paste containing 18% by weight wheat flour. The amount of demel / which was prepared by grinding hard winter wheat contained a non-toxic worm. The wallpaper sticker was provided by Bondex International 25 Inc. under the trade description wheat loss stickers, item number 61102.

A12 An urethane laminating adhesive which contained (a) approx. 55% by weight of an isocyanate completed prepolymer (b) approx. 32% by weight methylene chloride, (c) approx.

5% by weight of toluene (d) approx. 5% by weight ethyl acetate and (e) approx. 2.5% by weight of free diphenylmethane diisocyanate, all percentages being based on the weight of the adhesive.

Table I, continued

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Code Description of tested additive 25 5 The adhesive had a solids content of 58 - 1% and a density of 1.13. Morton Chemical Company supplied the adhesive under the trade designation Mor-Ad-337.

A13 A carboxylated styrene butadiene copolymer latex, the copolymer therein having polymerized styrene in an amount of 42% by weight of copolymer, butadiene in an amount of 55% by weight of copolymer, and itaconic acid in an amount of 3% by weight of copolymer. The latex had a nominal particle size of approx. 0.14 to approx. 0.18 µm, a density of 1.01, and a dry matter content of from about 44 to about

47%. The Dow Chemical Company supplied the latex under the trade name DL-219A.

25 1 35

Table II

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0 26

Test data vibration bottom precipitation test, 5 Peel percent precipitation strength 1035 3105 Total

Example g / centi- Newton Newton precipitation 2 2

No._ Additive meter_ pr. m per m value_ 10 1 * 0 8 41 95 2 * Al 0 40 70 338 3 * A2 0 36 59 301 4 A3 252 0 25 25 5 A4 47 0 29 29 15 6 A5 1.57 3 37 57 7 * A6 0.08 4 58 85 8 A7 9.5 0 13 13 9 A8 10 3 22 42 10 A9 35 0 18 18 20 11 A10 4.7 3 43 63 12 All 35 0 17 17 13 A12 175 0 17 17 14 Al3 190 0 24 24 25 *

Comparative experiments not representative of the present invention.

From the data listed in Table II, it is clear that there is a difference in the nature of different additives. Thus, some, such as additives A3, A4, A7 - A9, All, A12 and A13, markedly improve the overall precipitation value of the garnish material. Others, such as the additives A1 and A2y, actually promote sedimentation, as indicated by an increased overall sedimentation value.

Claims (4)

5 Patent claims. A packaging material comprising any number of expanded, elastic, thermoplastic, synthetic resin containing 10 particles, with a friction increasing amount of a friction increasing additive deposited on at least a majority of an outer surface area on most of said garment particles. a packaging material having improved shock absorbing properties and reducing the propensity for articles to pass through the garnishing particles, characterized in that the particles have an average maximum cross-sectional dimension of at least 1.27 cm, the friction enhancing additive being selected from synthetic polymer latex , pressure sensitive adhesives, 20 glue, low molecular weight polymers, waxes, contact binders, urethane adhesives, starch-based adhesives and protein-based adhesives, so that the additive gives a peel strength greater than 1.5 g per cm and a total settling value of less than 65. 25 Packaging material according to claim 1, characterized in that the additive is a synthetic polymer latex, the latex containing a polymer selected from styrene-butadiene copolymers, acrylic copolymers, butadiene acrylonitrile 1- 30 copolymers, vinylidene chloride copolymer, vinyl chloride copolymer and vinyl chloride copolymer. Packaging material according to claim 2, characterized in that the polymer therein has polymerized styrene in an amount of from 40 to 70 weight * of polymer, butadiene in an amount of 15 to 40 weight * of polymer and acrylic acid in an amount of 0.1 to 20 weight * of polymer. DK 163051 B Wrapping material according to claim 1, characterized in that the amount of additive is from 1400 to 6000 g wet additive per m3 expanded garnishing particles. 5 10 15 20 25 30 35