US 3889444 A
A method and apparatus for packaging compressible material, fiber glass insulation in particular, in integrated mat form is described. The method involves sealing the roll to be packaging in a fluid impervious bag, applying a vacuum to the bag for a vacuum source shaped in the manner to insure uniform evacuation of air from the interior of the fluid impervious bag and restraining the reduced package with a restraining tube to prevent springback. Specific details of the vacuum unit are described.
Claims available in
Description (OCR text may contain errors)
United States Patent [191 Davis et al.
June 17, 1975 METHOD FOR PACKAGING FIBER GLASS INSULATION  Inventors: Frank H. Davis, Bethel Park, Pa.;
Homer 0. Wolfe, .lr., Shelby, NC; Billy D. Clapp, Shelbyville, Ind.
 Assignee: Certain-teed Products Corporation, Valley Forge, Pa.
 Filed: Apr. 8, i974 [2|] Appl. No.: 463,650
Related U.S. Application Data  Continuation of Ser. No. 322,658. Jan. ll, i973,
 U.S. Cl. 53/24; 53/22 B; 53/124 B [5 l] Int. Cl 1365b 63/02  Field of Search 53/24, 124 R, 124 E, 22 B,
 References Cited UNITED STATES PATENTS 3,458,966 Dunbar et al 53/24 3,511,020 S/l970 Kraft et a] 53/l 12 B Primary Examiner-Travis S. McGehee Annrney, Agent, or Firm-Edward J. Sites, Esq.
l 5 7 1 ABSTRACT A method and apparatus for packaging compressible material, fiber glass insulation in particular, in integrated mat form is described. The method involves sealing the roll to be packaging in a fluid impervious bag, applying a vacuum to the bag for a vacuum source shaped in the manner to insure uniform evacu ation of air from the interior of the fluid impervious bag and restraining the reduced package with a restraining tube to prevent springback. Specific details of the vacuum unit are described.
4 Claims, 4 Drawing Figures METHOD FOR PACKAGING FIBER GLASS INSULATION This is a continuation of application Ser. No. 322,658 filed Jan. I], 1973, now abandoned.
BACKGROUND OF THE INVENTION It has been of general practice in the art in preparing packages of fibrous materials such as fiber glass insulation to roll predetermined lengths of fibrous mats around a mandrel. During the rolling of the fibrous mats on the mandrel the fibers are mechanically compressed and the finished roll is placed within a sleeve or other packing means to retain the spiral roll in its packaged configuration for shipping and handling. It has also been described in the prior art with respect to the packaging of fiber glass materials that a vacuum source be applied to the materials to compress them to a predetermined degree and then place a retaining sleeve over them for shipment. Thus, in US. Pat. No. 3,458,966 a method of vacuum packaging fiber glass rollware which has interleaved between the layers of insulation a backing material is utilized and involves the application of suction to the rollware between the various layers of fiber glass having the backing thereon. In U.S. Pat. No. 3,307,319 a further method of packaging is disclosed for packaging filters which involves the application of suction from the central portion of an air pervious mandrel located in the center of the package to be compressed and evacuation of air from the out side of the package through the centrally located mandrel and then through a vacuum source located outside of a fluid impervious bag in which the vacuum is created.
THE PRESENT INVENTION While the various methods of packaging utilized by the prior art have found acceptance in the art, each suffers from various shortcomings. Thus, in [1.8. Pat. No. 3,307,3 [9 a centrally located perforated mandrel is utilized to remove the air from the package thus necessitating the use of a mandrel in the air evacuation system utilized. In US. Pat. No. 3,458,966 a plurality of apertures on a perforated mandrel are also employed, the mandrel drawing air from the various layers of material which have a backing on them. In accordance with the instant invention a method and apparatus is utilized to package insulation rollware that requires no backing on the insulation during the air evacuation and packaging operation and which requires the utilization of no cen tral perforated mandrel for air evacuation purposes.
In accordance with the present invention fiber glass rollware insulation product which has been previously compressed to a desired degree on a conventional forming mandrel, no more than a 3 to 1 compression ratio based on the machine thickness of the product being rolled, is introduced into a fluid impervious sleeve. One end of the sleeve is sealed from the atmosphere and the other end of the sleeve is placed over a vacuum source which is spaced from the insulation roll and sealed on the end of the vacuum source in such a manner that a cone-like chamber is provided between the end of the insulation roll and the end of the vacuum source. A vacuum is applied to the interior of the sleeve from a vacuum source to evacuate air from the insula tion roll and compress it by the ambient atmosphere. When the desired degree of compression has been obtained, overall no more than 9 to 1 basis the machine thickness of the initial insulation roll, a retaining sleeve is placed over the evacuated bag in which the insulation roll resides to maintain a sleeve pack of considerably reduced size and suction is then discontinued. It is found in packaging insulation rollware without backing on it in the aforementioned manner that good thickness recovery is obtainable and that this thickness recovery does not appear to be affected by prolonged periods of storage.
FIG. I is a diagrammatic illustration of the apparatus of the instant invention with an insulation roll in place prior to the application of suction;
FIG. 2 is a diagrammatic illustration of the installation roll and device of FIG. 1 with suction cap in place;
FIG. 3 is a diagrammatic illustration of the machine of FIG. I after suction has been applied and the insulation roll reduced in diameter; and
FIG. 4 is a cross section taken on the suction head of FIG. 2 taken along the lines 44 to show the configuration of the air outlets thereon.
As shown in the drawings the insulation roll to be compressed is placed in a retaining ring member 7 located at one end of the machine housing 6. A polyethylene sleeve 1 has been slipped through the underside ring 7 and has been gathered at the far end of the insulation roll where it has been sealed with a metal clip 8. The suction head 4 and its associated tubing 3 which communicates with a vacuum source 5 located beneath the housing 6 has not been positioned in place in FIG. 1. As shown in FIG. 2 the vinyl sleeve 1 has been cut and gathered around the throat of the suction head 4 and held with a metal clamp 9. In this position vacuum may be applied to the package and the polyethylene sleeve 2 and the insulation roll 1 which it surrounds are compressed by atmospheric pressure when suction is applied to the interior of the polyethylene enclosure 2. FIG. 3 illustrates the reduction in size of the insulation roll 1 which has been accomplished by applying suction through the suction head 4 and utilizing the suction fan 5 and the positioning of the paper retaining sleeve 11 which encompasses the reduced insulation roll 1. Suction head 4 is preferably a metal structure having the general appearance of a truncated cone and with a face plate diagrammatically illustrated in FIG. 4 having a plurality of apertures 10 in the illustration shown spaced equidistant from each other around the outer circumference of the face plate of the suction head 4.
The general taper of the truncated cone-shaped suction head 4 permits the engagement of the throat of the suction head of the polyethylene sleeve 2. Since one end of the polyethylene bag, after placing the insulation roll within it, has been sealed, there is provided a substantially airtight enclosure for the insulation roll 1. When the vacuum pump is actuated, suction is applied to the entire contents of the polyethylene enclosure formed by the sleeve 2 which has been gathered at both ends of clip 8 and clamp member 9 and the air trapped in the bag is evacuated from the interior of the package. As the air is evacuated, atmospheric pressure is exerted on the outside of the bag compressing it to any desired degree. When the bag reaches the desired degree of reduced dimension, the retaining sleeve 11 is placed over the bag, the suction pump 5 is shut off, the clamp is then loosened and the suction head is moved away from the interior of the bag and a metal clip is applied to the outside to firmly seal the second end of the polyethylene package.
In operating the machine it is not necessary that the suction device be removed prior to applying the paper sleeve and in general it is preferred to continue the application of suction on the polyethylene bag to main tain its reduced dimension while the paper sleeve is being applied to the far end of the insulation roll. Once this retaining sleeve is drawn over the reduced polyethylene bag, the suction source can then be removed. The polyethylene bag at that end can then be twisted and clipped to provide the airtight seal necessary to prevent reinflation of the package.
In a practical application of the instant invention a standard roll offiber glass insulation having a roll diameter of 37.75 inches and a compression ratio of 4.85 was utilized to prepare a sleeve pack insulation roll in accordance with the instant invention.
The fibrous materials forming the insulation were prepared by attenuation of molten fiber glass utilizing high velocity gaseous blasts in the manner described in US. Pat. No. 3,215,585. The fibers after attenuation are accumulated in haphazard or random assembly in accordance with that patent and were allowed to accumulate and form a mat of the desired thickness, in this instance 2.25 inches.
The roll prepared from this insulation was placed through the ring 7 as shown in FIG. 1 and the polyethylene sleeve was passed over the roll gathered at the far end and clipped with a metal clip to form a seal at that end of the bag. The polyethylene sleeve was then cut at the suction end of the machine as shown in FIG. 2, was gathered around the throat of the suction head 4 along the suction tube 3 and clamped with a metal Clamp to provide a seal. A vacuum capable of moving 200 cubic feet per minute of air was actuated for a period of seconds to reduce the size of the roll substantially. A paper sleeve 33.1 inches in diameter was then placed over the compressed roll and the suction was then discontinued. The suction head was moved away from the interior of the polyethylene sleeve and the end at which suction was applied was gathered, twisted and clamped with a metal clamp to seal the polyethylene bag within the paper sleeve. Upon completion of the operation the sleeve pack was found to have a roll diameter of 33.1 inches and an actual compression ratio of 6.31. The material was left standing for a period of several days and the paper sleeve was then removed and the insulation thickness after unpackaging was then measured against a standard 37.75 inch roll having a compression ratio of 4.85 to determine the springback characteristics of the roll. The average insulation thickness after unpackaging with respect to the sleeve pack was found to be at minimum 1.76, at maximum 2.22 and the average 2.00 inches. With the standard product not vacuum packaged these values were 1.73, 2.24 and 1.99 respectively.
In general the application of suction to the interior of the enclosure in which the insulation roll is to be reduced in size should be capable of carrying away at least 200 cubic feet per minute of air and of developing a 100 inch water lift. Vacuum sources greater than this can be employed though care should be taken to maintain the total compression ratio of the roll to be reduced in size at no greater than 9 to 1. It will be understood by those skilled in the art that in the ordinary 6 packaging on a mandrel of insulation rolls the mechanical compression of the mandrel itself is capable of producing compression ratios of about 3 to 5. Utilizing the suction packaging procedures of the instant invention, this ratio can be increased easily to 6 to 9 without damage to the insulation goods and provide a product which will spring back after unpackaging to desired thicknesses for a given product. As set forth hereinabove with respect to the specific example a compression ratio of 6.31 was achieved and the spring back of the material was as good as or better than the spring back achieved with a standard product compressed on a mandrel in the rolling operation.
The configuration of the suction head is of considerable importance in achieving the objects of the instant invention since its particular shape provides for the ease in connecting the polyethylene sleeve to the suction head and the cone-shaped configuration of the suction head provides for a small cone-like chamber at the suction end of the insulation rollware to permit ease of evacuation of air from the entire insulation roll. As will be readily understood once suction is applied, air rushes to the suction head from all portions of the roll. By providing the cone-shaped suction head a fairly large chamber is provided adjacent the suction head to permit evacuation of all air from the chamber rapidly and efficiently.
In the preferred embodiment of the instant invention, five circumferential apertures are provided in the face plate of the suction head to assist in removing air from all portions of the insulation roll being evacuated. in general the suction head should have a diameter which is approximately between US to /:s the diameter of the roll prior to the application of the vacuum. By providing a head of this character and spacing that head at least 3 inches from the end of the insulation roll prior to the application of the vacuum, a plenum of sufficient volume is provided at the suction end of the insulation roll to insure rapid and complete reduction of the roll diameter the desired degree in a minimum amount of time. The large plenum at the suction end of the roll is rapidly evacuated when suction is begun and air from the rear portion of the roll is rapidly removed to the plenum area. It is characteristic in using this vacuum system that compression of the bag appears to occur rapidly at the end containing clip 8 and moves forward to the suction end as the process proceeds. The vacuum head 4 is provided with sufficient tubing and may be adapted mechanically so that it is adjustable in height. This adjustable height permits the source to be placed at the center of the insulation and its bottom edge in accordance with the preferred embodiment of the instant invention. This is an important consideration since in actual operation the insulation roll 1 as shown in the drawings rests on the ring 7 and on the housing 6. 1n the drawings it has been shown spaced from the housing for illustrative purposes only, but in normal operation it rests in an arc-like cradle forming the top of the housing 6. Thus, by placing the vacuum head between the center and the bottom edge of the initial insulation roll, as compression occurs, the roll tends to move downwardly to conform to the contours of the vacuum head and provide for uniform evacuation of the air as the roll is compressed.
The fluid impermeable sleeve has been particularly described in connection with this invention as a polyethylene sleeve since this material lends itself readily to operations of this character. While polyethylene has been described in particular, the invention is not limited to the utilization of polyethylene and any fluid impermeable membrane or material may be utilized as the sleeve for the vacuum packaging method in the instant invention. The outer sleeve or retaining member 11 is preferably a heavy Kraft paper. Other materials such as corregated cardboard, plastic tubing and the like may be utilized if desired.
By compression ratio as utilized herein in the specification and claims is meant the length in feet times the nominal machine thickness of the mat times l5.3 over roll diameter in inches squared minus core diameter in inches squared.
While the invention has been described with reference to certain specific details and illustrative embodiments, it is not intended that the invention be limited thereby except insofar as appears in the accompanying claims.
1. A method of packaging a fiberglass sheet of insulation comprising the steps of a. forming a fiberglass sheet of insulation into a spiral roll,
b. positioning an airtight bag over said roll.
c. providing a cone-like chamber within said bag against the open end of said roll, said chamber having a diameter in the range of one-fifth to one-third of the diameter of said roll,
(1. applying a vacuum from said chamber to the interior of said roll, to evacuate air therefrom to compress said spiral layer of insulation sufficient to re duce the size of said roll and insufficient to produce a permanent deformation in the insulation thickness e. and then restraining said roll at the compressed size whereby the thickness recovery of said restrained sheet of insulation is substantially equal to the thickness recovery of a standard non vacuum packaged roll of a sheet of insulation.
2. The method defined in claim 1 wherein said conelike chamber is formed at the end of said roll between the center, and the bottom edge of said roll.
3. The method defined in claim 1 wherein said chamber has a diameter about one-third the diameter of said roll.
4. The method defined in claim 1 wherein said air is evacuated from said roll on substantially parallel flow paths, said flow paths ending in said chamber.