MIL-P-21755

Military Specification

MILITARY SPECIFICATION

Plotting Sheet, Polyester Film, 1,000 Meter Grid, 1:25,000 Scale

This specification is approved for use by the Natick Research and Development Center, Department of the Army, and is available for use by all Department Agencies of the Department of Defense.

1. SCOPE

1.1 Scope. This document covers a surface processed polyester film plotting sheet (see 6.1).

1.2 Classification. The plotting sheet shall be of the following sizes as specified (see 6.2).

22-1/2 by 30 inches
30 by 41-1/2 inches
35 by 47 inches

2.  APPLICABLE DOCUMENTS

2.1 Government documents. Unless otherwise specified, the following documents of the issue in effect on date of invitation for bids or request for proposal, form a part of this document to the specified herein

Beneficial comments (recommendations, additions, deletions) and any pertinent data which may be of use in improving this document should be addressed to: U.S. Army Natick Research and Development Center, Natick, MA 01760-5014 by using the self-addressed Standardization Document Improvement Proposal (DD Form 1426) appearing at the end if this document or by letter.

SPECIFICATIONS

Federal

L-P-377 - Plastic Sheet and Strip, Polyester.
L-P-378 - Plastic Sheet and Strip, Thin Gauge, Polyolefin.
TT-I-528 - Ink, Drawing, Waterproof, Black.
UU-C-282 - Chipboard.
UU-P-268 - Paper, Kraft, Wrapping.
PPP-B-26 - Bag, Plastic, Polyethylene.
PPP-B-601 - Boxes, Wood, Cleated-Plywood.
PPP-B-636 - Boxes, Shipping, Fiberboard.
PPP-B-1055 - Barrier, Material, Waterproofed, Flexible.
PPP-T-45 - Tape, Gummed, Paper, Reinforced and Plain, For Sealing and Securing.
PPP-T-60 - Tape, Pressure-Sensitive Adhesive, Waterproof, For Packaging.
PPP-T-76 - Tape, Pressure-Sensitive Adhesive, Paper (For Carton Sealing).

MILITARY

MIL-L-10547 - Liners, Case, and Sheet, Overwrap, Water-Vaporproof or Waterproof, Flexible

STANDARDS

FEDERAL

FED-STD-191 - Textile Test Methods.

MILITARY

MIL-STD-105 - Sampling Procedures and Tables for Inspection by Attributes.
MIL-STD-129 - Marking for Shipment and Storage.
MIL-STD-130 - Identification marking of U.S. Military Property.
MIL-STD-147 - Palletized Unit Loads.

(Copies of documents required by manufacturers in connection with specific acquisition functions should be obtained from the producing activity or as directed by the contracting officer. )

2.2 Other publications. Unless otherwise specified following documents of the issue in effect on date of invitation for bids or request for proposal, form a part of this document to the extent specified herein.

AMERICAN SOCIETY FOR TESTING AND MATERIALS (ASTM)

D 3951 - Standard Practice for Commercial Packaging

(Application for copies should be addressed to the American Society for Testing and Materials, 1916 Race Street, Philadelphia, PA 19103).

(Technical society and technical association documents are generally available for reference from libraries. They are also distributed among technical groups and using Federal agencies.)

2.3 Order of precedence. In the event of conflict between the text of this documents and the references cited herein, the text of this comment shall take precedence.

3. REQUIREMENTS

3.1 Material. The material shall conform to the applicable documents and requirements specified herein. Materials not specifically defined shall be of the quality normally used by the manufacturer provided the complete item complies with all the provisions of this document. The plotting sheet shall consist of a sheet of polyester film conforming to the requirements of L-P-377 uniformly processed on both sides with such materials or method necessary to insure compliance with the quality and performance requirements specified herein. After processing, the plotting sheet shall be not less than 0.004 nor more than 0.007 inch thick when tested as specified in 4.2.4.

3.2 Drafting surface. The obverse or drafting side of the plotting sheet shall be chemically coated, chemically etched, mechanically grained or otherwise treated in order to produce a surface that will readily accept pencil and drafting ink. Lines inked on the surface shall be sharply defined without feathering or breaks visible to the unaided eye and the ink shall not chip or flake from the surface when tested as specified in 4.2.3. After conditioning as specified in 4.3.1, the drafting surface shall accept, under normal pressure, without permanent indentation which would result in fracture ghosting, line drawn well-sharpened 6-H graphite drawing pencil. When tested in according with 4.2.4, the drafting surface shall not be removed completely from the base plastic at any spot.

3.3 Gridded surface. The reverse or gridded side of the plotting sheet shall be chemically coated, chemically etched, mechanically grained or otherwise treated in order to produce a surface that will readily accept the ink used to print the grids. The grid lines shall be sharply defined and without feathering or breaks visible to the unaided eye. The ink used shall be black waterproof of such quality as to produce opaque lines of uniform character and surface throughout the printed sheet. The printed lines shall not be obliterated when tested in accordance with 4.2.4

3.4 Grid. A 1000 meter rectangular grid system, plotted to scale of 1:25,000, shall be printed on the reverse side of the plotting sheet. Grid lines shall be parallel to the edges of the sheet, within 1/16 inch, and shall be printed in such a manner that the distance from any sheet edge to the nearest grid line parallel to that edge is not greater than 1 inch.

The grid lines shall extend to all edges of the printed grid rectangle on the sheet and shall be approximately centered on the sheet. The width of the grid lines shall be 0.008 inch, plus or minus 0.001 inch. The distance between centers of any two opposite grid lines in a grip square shall be 1.57 inches and the diagonal of the grid square shall measure 2.22 inches.

3.5 Accuracy. When the plotting sheets are measured in accordance with 4.2.4, the center-to-center between any two printed grid lines shall be correct to within one part in 2000 or 0.003 inch, whichever is greater, for grid lines 6 inched or less apart, the tolerance is ± 0.003 inches. For grid lines which are more than 6 inches apart, the tolerance is ± 1 part in 2000 i.e ± 0.05 percent of the theoretically correct distance

3.6 Light transmittance. The visual light transmittance of the plotting sheet shall be not les that 50 percent when tested as specified in 4.2.4

3.7 Abrasiveness. The drafting surface of the plotting sheet shall be such that when tested in accordance with 4.2.4, the lead of a 3H pencil shall not be worn down more than 0.015 inch.

3.8 Flexibility. The plotting sheet shall not crack or craze nor shall the surface become unfit for use when tested as specified in 4.2.4.

3.9 Size and trim. The plotting sheet shall be in the size specified in 1.2. (see 6.2). The tolerance for each size shall be ± 1/16 inch in each dimension. The sheet shall be trimmed square on four sides and shall have smooth edges. The dimension of the diagonal measurements shall be within ± 1/16 inch.

3.10 Identification marking. Each plotting sheet shall be identified in accordance with MIL-STD-130 and, in addition shall have ‘Plotting Sheet, Polyester Film, 1,000 Meter Grid, 1:25,000 Scale, Drafting Side, mark on this Side’ printed on the lower right hand corner of the sheet outside the grid rectangle end ¼ inch and ± 1/16 inch from the lower edge. The lettering shall be 0.15 inch high and shall be clear and distinct, as well as reading correctly when viewed from the drafting side of the plotting sheet.

3.11 Workmanship. The plotting sheet shall be free of any dirt spots, slime, oil or foreign matter: any tear, hole, blister, blow, check, lump: any warp, buckle, wave, wrinkle: any ragged, uneven, crushed or broken edges: or any other defects which may impair its appearance or serviceability. The coating shall be uniform and continuous on both sides of the sheet and shall show no evidence of adverse effects during any of the tests specified in section 4. The plotting shell shall conform to the standard of quality established by this document.

4. QUALITY ASSURANCE PROVISION

4.1 Responsibility for inspection. Unless otherwise specified in the contract or purchase order, the contractor is responsible for the performance of all inspection requirements as specified herein. Except as otherwise specified in the contract or purchase order, the contractor may use his own or any other facilities suitable for the performance of the inspection requirements specified herein, unless disapproved by the Government. The Government reserves the right to perform any of the inspections set forth in the document where such inspection are deemed necessary to assure supplies and service conform to prescribed requirements.

4.2 Quality conformance. Unless otherwise specified, sampling for inspection shall be performed in accordance with MIL-STD-105.

4.2.1 Component and material inspection. In accordance with 4.1, components and materials shall be inspected in accordance with all the requirements of the referenced documents unless otherwise excluded, amended, modified, or qualified in this document or applicable purchase document.

4.2.2 End item visual examination. The end item shall be examined for the defects listed in table I. The lot size shall be expressed in units of 12 sheets each. The sample unit shall be one sheet. The inspection level shall be I and AQL, expressed in terms of defects per hundred units, shall be 2.5

TABLE I. Visual defects

Examine Defects
Appearance Not clean, any evidence of dirt, strains, discoloration, finger marks, grease, or foreign matter .
Not a clear transparent sheet of plastic uniformly treated on both sides.
Workmanship Any blister, chalking, checks, crack , fracture, lumps, dent, hole (including pinholes, put, shrinkage, wrinkles or waves, cut, nicks, unfilled area, delamination or other irregularities affecting serviceability or appearance.
Any scuffed or abraded area.
Any edge not cut smoothly; not straight; ragged, crushed or uneven edges; corners not sharply cut.
Grid lines not printed in black waterproof ink; not sharp and clear; any line missing, feathered, smeared, smudged, or jagged.
Grid lines not extended to all edges of the printed rectangle on the sheets; grid lines not parallel to the edges of the sheet nearest grid line parallel to that edge greater than 1 inch.
Width of grid lines not within specified tolerance.
Identification markings, illegible, incorrect, incomplete, or does not conform to 3.10; not in position specified.

4.2.3 End item dimensional examination. The end item shall be examined for the defects listed in Table II. The lot size shall be expressed in units of 12 sheets each. The inspection level shall be S-3 and the AQL, expressed in terms of defects per hundred unit, shall be 2.5.

TABLE II. Dimensional defects

Examine Defect
Sheets size Length or width varies by more than ± 1/16 inch from dimension specified
Cut of sheet Not squared cut; i.e., the dimension of the two diagonal measurement not within ± 1/16 inch.

4.2.4 End item testing. The end item shall be examined for the characteristics specified in table III. The lot size shall be expressed in units of 12 sheets each. The sample unit shall be one sheet. The sample unit shall be one sheet. The sample shall consist of five sample units selected at random from the lot. Any failure to meet unit or average requirements, as applicable, shall be cause for rejection of the lot.

4.2.5 Packaging inspection. An examination shall be made to determine that the preservation, packing, and marking comply with the requirements of section 5. Defects shall be scored in accordance with table III. The sample unit shall be one shipping container fully packaged. The lot shall be the number of shipping containers in the inspection lot. The inspection level shall be S-2 and the AQL, expressed in terms of defects per hundred units, shall be 2.5.


INSTRUCTION FOR TESTING Table 111

Characteristics Specification Reference Requirements of Applicants to Number of Determination per unit Results reported as Inspect Level AQL
Requirement

Test Method

Individual
Unit
Lot
Aver
Pass or Fail Numerically to nearest
Thickness Processed 3.1 1/ X   Average of 3   0.001
Inch
   
Permanency of coating
Drafting surface
Grid Surface
3.2
3.3
4.3.1.1
4.3.1.1
X
X
  1
1
X
X
     
Pencil and ink line test 3.2 4.3.2 X   1 X      
Drafting surface stability 3.2 4.3.3 X   1 X      
Grid line stability 3.3 4.3.4 X   1 X      
Grid accuracy 3.5 4.3.5 X   1 X      
Light transmittance 3.6 4.3.6 X   6   5 percent    
Abrasiveness 3.7 4.3.7 X   Average of 5   0.001 inch    
Flexibility 3.8 4.3.8 X   1 X      
1 A micrometer caliper capable of measuring to within plus or minus 0.0001 inch shall be used

NATICK Form 598

TABLE IV Packaging Defects

Examine Defects
Marking (exterior and interior) Omitted; incorrect; illegible; of improper size, and location, sequence or method of application
Materials Any component missing
Any component damaged, affecting serviceability
Plotting sheets not interleaved with polyethylene sheets
No polyethylene sheet at the top or bottom of the stack
No chipboard at the top or bottom of the stack
Twelve plotting sheets of one size (when specified) not protected with polyethylene sheets are not
rolled individually on a chipboard tube
Workmanship Inadequate applications of components, such as improper closure of container flaps, loose strapping,
improper taping, inadequate stapling
Bulged or distorted container
Weight Weight of contents exceeds requirements
Content Number per interior package is more or less than required

4.4.6 Examination for palletization. An examination shall be made to determine that the palletization complies with the requirements of section 5 . Defects shall be scored in accordance with Table V. The sample unit shall be one palletized unit loads submitted for inspection at one time. The inspection level shall be S-1 and the AQL, expressed in terms of defects per hundred units, shall be 6.5.

TABLE V. Palletization defects

Examine Defects
Finished dimension Length, width, or height exceeding specified maximum requirements
Palletization Pallet pattern not as specified
Interlocking of loads not as required
Load not bonded with required straps as required
Weight Exceeds maximum load limits
Marking Omitted; incorrect; illegible; of improper size, location, sequence, or method of application

4.3 Methods of inspection

4.3.1 Conditioning of specimens. Specimens, selected in accordance with 4.2.4, for testing purposes shall immediately be subjected, from one test condition to the next, to the following atmospheric and exposure conditions until the cycle is completed

(a) 12 hours at 150° ± 5 °F and 10 ± 3 percent relative humidity in a circulating air oven.

(b) 72 hours at ~65° ± 5 °F.

(c) 72 hours at 85° ± 5 °F and 98 ± 2 percent relative humidity in a circulating air oven

(d) Weathering ~ The plotting sheets shall be completely submerged in distilled water at room temperature for a period of 1 minute.

(e) Air dried – Specimens conditioned as specified above specified above shall then be air dried at a temperature between 70° and 75°F for a period of at least 24 hours

4.3.1.1 Examination after conditioning. Upon completion of all conditioning specified in 4.3.1, the specimens shall be examined on both surface for processing defect such as loss of coating, flaking, cracking, or peeling of coating and also for any defects in relation to grid lines, as noted under 4.2.2. Upon completion of examination, these conditioned specimens shall be immediately subjected to the tests specific in 4.3.2, 4.3.3, and 4.3.4.

4.3.2 Pencil and ink test. On the drafting aide of each sheet two lines at least 4 inches long and at right angles to each other shall be drawn with a well sharpened 6-H pencil, specified in 3.2, using sufficient pressure to give well defined visible lines. Two additional lines, as described above shall be drawn with a ruling pen and waterproof black drawing ink conforming to type I TT-I-528. The lines shall be examined and the inked lines rubbed with finger tips to determine conformance with 3.2.

4.3.3 Drafting surface stability test. A 4-1/4 inch diameter specimen shall be tested in accordance with Method 5306 of FED-STD-191. The machine shall be equipped with 1000 gram weights and “Calibrase” wheels No. CS-10 with the drafting surface in contact with the calibrase wheels. After 50 wear cycles have been completed, the specimen shall be examined for evidence of loss of processed coating through to the base plastic.

4.3.4 Grid line stability test. The apparatus specimen size and procedure specified in 4.3.3 shall be employed, except that the gridded surface or reverse side of the specimen shall be in contact with the calibrase wheels. After 50 wear cycles have been completed, the specimen shall be examined for evidence of obliteration of the printed lines

4.3.5 Grid line stability test. The perpendicular distance between the extreme top and bottom and the extreme left and right and grid lines, the distance between opposite grid lines and diagonally opposite corners of any 10 by 50 grid internal square inclosing 100 or the 1000 meter squares on each conditioned sheet shall be measured, shall conform to the requirements of 3.5.

4.3.6 Light transmittance test. The visual light transmittance of the plotting sheet shall be checked in at least six different areas not containing grid lines, by means of direct reading photoelectric densitometer. No area checked shall be less than the required minimum percent.

4.3.7 Abrasiveness test. A 3-h pencil lead specified in 3.7 shall be sharpened to a 0.010 inch diameter conical point and placed in a chuck held vertically over the obverse side (drafting surface). The chuck shall be weighted to 5 ounces and moved horizontally for a distance of 10 inches. The pencil lead shall be measured before and after the test by any suitable means.

4.3.8 Flexibility test. The specimen shall be bent around a ¼ inch diameter mandrel maintaining full contact with the surface for not less than 180 degrees. The area of contact shall be flexed over the mandrel with each processed surface in contact with the rod in turn. The specimen shall be examined for evidence of cracking or crazing or for any surface imperfection which may render the plotting sheet unfit for use.

5. PACKAGING

5.1 Preservation. Preservation shall be level A or Commercial, as specified (see 6.2).

5.1.1 Level A. Twenty-four, 22-1/2 by 30 inch; twelve, 30 by 41-1/2 inch; or twelve, 35 by 47 inch plotting sheets shall be interleaved with minimum 0.001 inch thick polyethylene sheets conforming to type I. class I, grade C, finish 1 of L-P-378 and arranged in a uniform stack. The polyethylene sheets shall be of the same length and width as the plotting sheets in the stack. A sheets of chipboard, 0.026 inch (average thickness), conforming to UU-C-282 shall be placed at the of and bottom of the stack. The chipboard sheets shall be 1/8 inch larger in length and width then be completely wrapped with 30 pound minimum basis weight kraft paper conforming to type I, grade D of UU-P-268 and the wrap secured with 2-ich minimum width gummed paper tape conforming to type III, grade B of PPP-T-45.

5.1.1.1 When specified (see 6.2), twelve plotting sheets of one size only, protected with polyethylene sheets as specified in 5.1.1 shall be rolled on a chipboard tube. The ends of the tube shall be flush with, or extend not more than 1/4 –inch beyond, each side of the maximum width of the rolled plotting sheets. The plotting sheets shall be rolled individually on the tube in such a manner that when one sheet is removed, the next sheets is readily available. Each roll of plotting sheets shall be completely wrapped with waterproof barrier material conforming to C-1 of PPP-B-1055. The wrap shall be securely sealed with 2 inch minimum width pressure-sensitive taped conforming to PPP-T-60 or PPP-T-76. Alternatively, the roll shall be paper wrapped roll shall then be placed in a close-fitting 0.0015 inch minimum thickness polyethylene bag conforming to type I or II, grade A, style 1 of PPP-B-26. The polyethylene bag may also be closed be double-folding the plastic material at the mouth and taping it to the bag body with the specified pressure-sensitive tape. Prior to, or during the final closure operation, excess air within the polyethylene bag shall be expelled.

5.1.2 Commercial. Plotting sheets shall be preserved in accordance with ASTM D 3951.

5.2 Packing. Packing shall be level A, B or Commercial, as specified (see 6.2).

5.2.1 Level A packing. Plotting sheets of one size only, preserved as specified in 5.2, shall be packed flat in a snug-fitting shipping container conforming to style FTC, grade V2s of PPP-N-636; or overseas type, style A or I, grade A Or B, type 2 load of PPP-B-601, as specified (see 6.2). Each fiberboard container shall be closed, waterproof, and reinforced in accordance with the appendix of PPP-B-636. Each wood container shall be closed and reinforced in accordance with the appendix of PPP-B-601, and waterproofed with as sealed case liner conforming to type I or II, grade C of MIL-L-10547. The waterproofing requirement for shipping container shall not apply when waterproofed rolls are packed. The weight of the contents of each fiberboard shall not exceed 65 pounds, and for each wood container shall not exceed 150 pounds.

5.2.2 Level B packing. Plotting sheets of one size only, preserved as specified in 5.2, shall be packed flat in a snug-fitting shipping container conforming to style FTC, type CF (variety SW) or SF, class domestic, grade 275 of PPP-B-636; or domestic type, style A or I, grade B, type 2 load of PPP-B-601, in accordance with the appendix of the applicable container specification. The weight of the content of each fiberboard container shall not exceed 65 pounds, and for each wood container shall not exceed 150 pounds.

5.2.2.1 Weather-resistant fiberboard containers. When specified (see 6.2), the fiberboard shipping container shall be a grade V3c, V3s fiberboard box fabricated in accordance with PPP-B-636 and closed in accordance with the appendix of the container specification.

5.2.3 Commercial packing. Plotting sheets, preserved as specified in 5.1, shall be packed in accordance with ASTM D 3951.

5.3 Palletization. When specified (see 6.2) plotting sheets, packed in fiberboard shipping containers as specified in 5.2, shall be palletized on a 4-way entry pallet in accordance with load type Ia of MIL-STD-147. Each prepared load shall be bonded with primary and secondary straps in accordance with bonding means K and L or film bonding means O or P. pallet patterns shall be effected by reversing the pattern of each course. If the container is o as size which does not conform to any of the patterns specified in MIL-STD-147, the pallet pattern used shall first be approved by the contracting officer.

5.4 Marking. In addition to any special marking required by the contract or order, unit packs, shipping containers and palletized unit loads shall be marked in accordance with MIL-STD-129 or ASTM 3951, as applicable.

6. NOTES

6.1 Intended use. The plotting sheets are intended for use in the graphical determination of artillery ranges and deflection angles to targets from plotted gun position.

6.2 Ordering data. Acquisition documents should specify the following

a. Title, number, and date of this document.

b. Size of sheet required (see 1).

c. Selection of the applicable levels of preservation and packing (see 5.1 and 5.2).

d. When plotting sheets are desired to be rolled on the tubes and be waterproof unit pack(see 5.1.1.1).

e. Type of shipping container desired for level A or B packing (see 5.2.1 or 5.2.2).

f. When weather –resistance grade fiberboard shipping containers are required for level B packing (see 5.2.2.1)

6.3 Changes from previous issue. Asterisks are not used in this revision to identify changes with respect to the previous issue, due to the extensiveness of the changes

Custodian: Preparing activity:
Army – GL Army – GL
Project No. 7530-A198

INSTRUCTION: in a continuing effort to make our standardization documents letter , the DoD provides this form use in submitting comments and suggestions for improvements. all users of military standardization documents are invited to provide suggestion. this form may be detached, folded along the lines indicated, taped along the loose edge (DI NOT STAPLE), and mailed. in blocked 5, be as specific as possible about particular problem areas such as wording which required interpretation, was too rigid, restrictive, loose, ambiguous, or was incompatible, and give proposed wording changes which would alleviate the problem. enter in block 6 any remarks not related to a specific paragraph of the document. if blocked 7 is filled out, an acknowledgement will be mailed to you within 30 days to let you know that your comments were received and are being considered

NOTE: This form may not be used to request copies of documents, nor to request waivers, deviations, or clarifications of specification requirements on current contracts. Comments submitted on this form do not constitute or imply authorization to waive any portion of referenced document(s) or to amend contractual requirements