Method for packaging and transporting compressed foam sponges at up to 20 times higher density than normal without losing shape or size after returning the sponge to its original form.

Abstract

A method is disclosed for compressing and packaging an open cell foam sponge to more than 20 times its normal density, transporting it without any constraints related to pressure and temperature and then returning the article to its original size and shape without losing any of its resilience, shape or form. The invention is particularly useful for transporting large volumes of foam sponge materials by compressing them to less than 20% of their original volume thereby reducing transportation costs by 80% or more.

Claims

1.1. This invention claims a method for compressing and packaging an open cell foam to more than 20 times its normal density, transporting it without any constraints related to pressure and temperature and then returning the article to its original size and shape without losing any of its resilience, shape or form. The method of this invention consists of the following steps: 1.1.1. Making an open cell foam by reacting a mixture of polymer ingredients and a blowing agent that may or may not include a plasticizer to make a foam with density between 5 and 60 kg/m3. 1.1.2. Cutting the foam into product units of any size and form such as sponges or any other size, shape or form of foam product. 1.1.3. Adding between 0% and 30% water to the foam product units prior to packaging it. The most desirable water addition is between 0 and 13% by weight to the foam. This water can include an antimicrobial that is compatible with the sponge material in sufficient quantity to prevent fungi and bacterial activity in the foam. Such an antimicrobial can be Sodium chloride, Zinc Pyrithione, Quaternary Ammonium compounds, various metal oxides, stearates and silver to name a few. These antimicrobials can readily be acquired from commercial sources. Concentration by weight of 0.1 to 4% of antimicrobial is effective in eliminating any fungal or micro-organism activity. The most desirable concentrations are between 0.1 and 0.3% by weight of ingredient to foam weight. 1.1.4. The next step is Inserting the foam into a sealable plastic bag or sleeve or into any container of any form, size and shape that can hold the compressed foam without breakage or rupture. The foam insertion can be with or without supporting inserts. The compression of the foam is achieved while inside the package and both the foam and the package are compressed mechanically or while under vacuum to achieve a foam density between 1 and 20 times the foam's original density. The compression can be achieved by either mechanically pressing the foam package between 2 plates and sealing the package or by using vacuum or a combination of both vacuum and mechanical compression. See Appendix 1. 1.1.5. This invention also claims high density compression or vacuum packaging in which graphic inserts are used to improve the aesthetic appearance of the package to eliminate wrinkles and provide a merchandizing and graphics surface for information related to the product and its use. Without the inserts the difference in compression between the less flexible packaging material and the softer foam inside would lead to the formation of wrinkles at the foam/package interface. The inserts can be made of cardboard, paper, plastic, film, metal or any other viable material to cover parts or all of the foam surfaces inside the compressed package. Thickness shape and size of the inserts can be varied to achieve the correct amount of structure and support to prevent the appearance of wrinkles on the package surface. See Appendix 2 for inserts and wrinkles illustration. 1.1.6. This method of packaging can be applied to single product units or to multiple product units of foam in a single package. The most desirable method is to make compressed or vacuum-packed individual foam product units and then to repack these into multi-packs. The multi-packs can consist of 2, 3, 6 or any number of units of individually compressed or vacuum-packed foams in a single master package. This method reduces the risk of rupture of the compressed packages during transit. 1.1.7. The compressed foam is held in the desired high-density state during the process of transportation, warehousing, retail presentation until final use by a user. This product logistics and retail sale cycle can take from days to many months and in some cases years. During this time the foam can be subjected to temperatures below freezing to and or greater than 60 C. 1.1.8. At the end of the logistics transportation and retail sales cycle, up to 6 or more months after initial compression, the foam is unpacked and released from its vacuum or compressed state. 1.1.9. With or without the method described in 1.1.3 above comprising of the addition of a plasticizer and water, the foam may not return to its original size and shape. 1.1.10. To achieve full recovery after lengthy and severe conditions of compaction, the unpacked foam is subjected water and or heat either by rinsing the foam in household water between 25 C. to 50 C. or by using a hot air blower at temperatures above 25 C., but most favorably 50 C. Full shape and form recovery will occur within 5 to 60 seconds making the foam sponge immediately available for use.

1.2. This invention's claim 1.1 is a method applicable to Polymers having both hard segment crystalline regions and soft segment amorphous regions in their structure. 1.2.1. This invention claims a method for polymers of claim 1.1 that include polyurethane, melamine-formaldehyde, polycaprolactone, cellulose acetate, silicone and others that exist in the rubbery state under ambient conditions with temperatures above their glass transition temperatures. 1.2.2. It claims a method for polymers of claim 1.1 that can be plasticized to create an artificial increase in molecular free volume to adequately ensure their existence in the rubbery state with the ambient temperature being above their glass transition state. Ambient conditions for these polymers include temperatures between 15 C. and 60 C. 1.2.3. It claims a method for polymers of claim 1.1 that contain polar functional groups in their structure. 1.2.4. It claims a method for polymers of claim 1.1 that can be compressed either mechanically or under vacuum. 1.2.5. It claims a method for polymers of claim 1.1 that lose some degree of their ability to recover full size and shape after being under compression for any period of time, but most desirably for more than 30 days.

1.3. The invention claims a method for compressing, packaging and transporting foam articles that is particularly useful for transporting large volumes of foam materials by compressing them up to 20 times their original density thereby reducing transportation costs by 95% or more. More desirably this method can be used to compress foam materials like commercial sponges to 5 or 6 times their original density leading to a reduction on freight costs of approximately 80 to 83%.

Description

[0037] b. Example 1, drawing 1 showing size recovery vs time for a polyurethane ester based sponge that is not plasticized with water versus one that is plasticized with water. [0038] c. Example 2, drawing 2. This drawing shows the rate of size and shape recovery for a test group of polyurethane foam sponges when soaked in water at 5 different temperatures. With water at 20 C., 100% sponge size is regained after 180 seconds. At 70 C. size and shape is completely regained after 2 to 4 seconds.

[0039] i. Sponges are make using an ingredient composition by weight of 20% toluene diisocynate, 45% polyether polyol, 30% polyester polyol, 4% water and the rest comprising extender amines, catalytic tin laurates and stopper. [0040] ii. Seven sponges from this composition are tested after being compression packed for 1440 days (approximately 4 years) using the method of this invention. [0041] iii. Sponge 1 is removed from its compression package and over a period of 5 minutes relaxes to a recovered size of approximately 50%. The sponge is monitored for 3 months and remains at approximately 50% recovery. It is exhibiting permanent loss of recovery. [0042] iv. Sponge 2, 3, 4, 5 and 6 are removed from their compression packages in turn and subjected to a short 1 second dipping into water at specified temperatures of 70, 50,30,26 and 20 C. The time for the sponge to recover 100% of its size was measured against time with the flowing results (Drawing 2): [0043] 1. Sponge 2water temperature of 70 C. 100% recovery in 2 seconds. [0044] 2. Sponge 3water temperature of 50 C. 100% recovery in 20 seconds. [0045] 3. Sponge 4water temperature of 30 C. 100% recovery in 30 seconds. [0046] 4. Sponge 5water temperature of 26 C. 100% recovery in 75 seconds. [0047] 5. Sponge 6water temperature of 20 C. 100% recovery in 3-5 minutes. [0048] d. Example 3. This example demonstrates the impact of time under compression and the sponges subsequent permanent loss of recovery. It also demonstrated the method of using hot air to release permanent loss of resilience and regain 100% size and shape. [0049] i. 5 sponges with a rectangular shape with original dimensions 191 mm131 mm47 mm (LWH were held at 72 C. and atmospheric pressure with no compression for 4 years. An additional 5 sponges with the same dimensions were compressed in one dimension to a density 9 times their normal density and packed into a polybag and sealed. The height H of the compressed sponges were measured to be approximately 5 mm or 11% of its original height. All 5 sponges were stored at 72 dg C in individually sealed compression packages for 4 years. During the 4 years there was an expectation that the sponges under compression would undergo a localized change in glass transition temperature such that when released from compression at room temperature the sponges would permanently loss their resilience. The 5 sponges were unpacked from their sealed packages and allowed to recover their original shape. All 5 sponges recovered approximately 40% of their original size within 10 seconds of releasing from the vacuum compression. After recovery of the initial 40% of their original size the sponges remained unchanged for 2 months. The sponges exhibited a permanent loss of resilience. At the end of 2 months, each of the 5 sponges were heated with hot air to 50 C. and they regained full 100% recovery of their original size within 5 seconds of applying the heat. The 5 sponges that were not compressed remain dimensionally unchanged throughout the test. [0050] e. Example 4. A set of 5 foam sponges with original dimensions 190 mm135 mm50 mm (LWH) were packed into 3 mil thick polyethylene bags and were then compressed using a mechanical device consisting of 2 metal plates of a size no more than 5 mm larger than the sponges' length and width in both directions. The top metal plate was driven by pneumatic cylinders while the bottom plate was static. When the sponges were compressed the polyethylene bags were sealed using a hot impulse line sealer. When the package consisting of the compressed sponge was removed from the compression plates it dimensions were measured to be 195 mm136 mm8 mm (LWH). The 5 sponges averaged a weight of 31.4 g and a bulk density of 24.5 Kg/m3 prior to compression. After compression the average bulk density was measured to be 148.1 kg/m3. This represents a 6-fold increase in density from the original sponges. After 3 months of storage at 72 C. and in their compressed state the sponges were released from their packaged. All sponges recovered approximately 80% of their size and form within 12 minutes. When the sponges were rinsed in hot water at 50 C. they recovered 100% of their size and form with 2 seconds.