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FGI 2014 HOPnew Intensive Care Medicine

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Specifications

  • Product Name: Factory Fabrication Guideline
  • Author: Fabricated Geomembrane Institute
  • Date: February 12, 2024
  • Number of Pages: 21

Product Usage Instructions

Disclaimer
The contents of this guideline provide information on factory fabrication of geomembranes. It is essential that the fabrication is carried out by qualified and experienced technicians. The guideline does not constitute a standard, specification, or regulation.

Safety
Proper safety measures must be followed during the factory fabrication process. Before starting any work, a thorough safety analysis of the factory conditions should be conducted. A factory-specific safety plan addressing various safety aspects is required. Some safety rules to be observed include:

  • Workers should wear gloves, safety glasses, and relevant personal protective equipment.
  • No fewer than two workers should be present during any work in the factory.
  • Sharp knives must be properly sheathed to prevent injury.
  • Workers should be cautious of the slipperiness of the geomembrane when wet.
  • Electrical tools used for repairs should be protected by appropriate devices.

Purpose of Guideline
The guideline aims to establish a quality control system for the factory fabrication, testing, handling, and shipping of flexible geomembrane panels.

FAQs

  • Q: Who should perform factory fabrication of geomembranes?
    A: Factory fabrication should be performed by appropriately qualified and experienced technicians.
  • Q: What safety measures should be followed during factory fabrication?
    A: Safety protocols should include wearing protective equipment, conducting safety analyses, and adhering to specific safety rules such as having at least two workers present during work.

Disclaimer
The contents of this guideline reflect the view of the authors, who are responsible for the facts and the accuracy of the information and data presented herein. The contents do not necessarily reflect the official views or policies of any organization, entity, or company and this guideline does not constitute a standard, specification, or regulation. Factory fabrication of geomembranes should be performed by appropriately qualified and experienced technicians.
Trademark or manufacturer’s names may appear in this report only because they are considered essential to the object of this document and do not constitute an endorsement of a product or service by the FGI or any other organization, entity, or company.

Safety

This guideline does not purport to address all the safety concerns associated with its use, especially in the environment in and around factory fabrication operations. It is the responsibility of the user of this guideline to establish appropriate safety protocols.
The fabrication of factory fabricated geomembrane panels requires a factory-specific safety plan addressing safety training and equipment. Specifically, the following inspections should be conducted before starting fabrication:

  • a. Conduct a thorough safety analysis of the factory conditions before commencing any work.
  • b. A factory-specific safety plan is required that addresses safe work conditions including fire suppression equipment, non-sparking equipment, evacuation routes, nearby medical facilities and contact information, and overall safety training.

Proper safety procedures should be observed at all times when work is being performed on or around geomembrane fabrication. Specifically, the following minimum safety rules should be adopted and enforced by the fabricator:

  • a. Workers should wear gloves/hand protection, safety glasses, and other relevant personal protective equipment (PPE) in the factory.
  • b. No fewer than two workers should be present at a location when work of any nature is taking place in the factory.
  • c. Sharp knives should be properly sheathed and secured to prevent personal injury and damage to the geosynthetics/geomembrane.
  • d. All individuals accessing the top of a geomembrane should be advised that the geomembrane may be slippery when wet.
  • e. As much as possible, all workers should walk on access pathways. If personnel walk on the geomembrane, soft and debris free sole footwear should be used.
  • f. Welding equipment, e.g., generators or electrical supply, should not be placed on the geomembrane. Only welders should be placed on the extended geomembrane.
  • g. Electrical tools used to facilitate repairs to the geomembrane should be protected by an appropriate ground fault circuit interrupting (GFCI) device at the source of of power and be certified non-sparking.

Purpose of Guideline

The purpose of this guideline is to present a minimum quality control (QC) system for the factory fabrication, testing, packaging, handling, and shipping of flexible geomembrane panels.
The procedures presented herein are a guide for factory fabrication of flexible geomembranes. Deviation from these standards and procedures may be required to meet project plans and specifications according to the terms and conditions of the contract.

Fabrication (In-Factory) Welding Overview

  • Rolls of geomembrane sheets are manufactured and transported to the fabricator in individual rolls, i.e., rolled goods. The fabricator welds the entire roll and/or cuts the rolls to desired lengths and welds them together in a factory to create large panels. The rolled goods are factory seamed into maximum sized panels that are designed to minimize field seaming and still meet project requirements. Each individual roll of geomembrane is numbered to correspond with fabrication drawings to ensure accurate panel size. Each factory fabricated panel should be logged by serial number, size, fabrication date, material lot number, roll number, and fabrication crew.
  • As individual rolls are unwound or unrolled, they should be visually inspected for possible defects or damage before welding begins as discussed below. The welds are inspected and tested for seam integrity by the fabricator before packaging and shipping the geomembrane panel to the project site. Project specifications supersede the welding recommendations presented below.
  • The typical minimum seam width for welding is normally 44.5 mm (1.75 inches). Other weld widths can be used but 44.5 mm (1.75 inches) is the typical weld width. The minimum welding width by any method should be at least 25 mm (1.00 inch) to meet the seam peel and shear strength requirements discussed below. Project specifications can require other weld widths but the seams still must meet the seam strength requirements presented below.
  • Seams typically represent the critical part of a factory fabricated geomembrane panel. Welding techniques in the factory may include radio frequency welding, solvent, hot air welding, and hot wedge welding, which are described in Section 8 under Terminology. In the field, typical welding techniques are solvent, hot air welding, and hot wedge welding. Different materials may require more specific welding methodologies. Cross seams should be avoided in certain locations as discussed in Section 10 below.

Terminology

  • Some terms related to this guideline are defined within this section. Additional terms may also appear in ASTM D 4439 and D7865.
  • Geomembrane Roll: refers to the raw material that is shipped direct from the manufacturer to be put into factory fabricated panels.
  • Fabricated panel: refers to a geomembrane panel fabricated at a manufacturing facility into a larger panel than the original roll stock material. A fabricated panel may be a larger rectangular panel of geomembrane or may be a specific fabricated shape or may contain special job-specific detail work.
  • Sheet: individual roll width of factory material within the fabricated panel.
  • Factory Fabricated Panel: completed or finished product of the individual sheets welded together.
  • Rolled panel: refers to a fabricated panel that is rolled from one end or in some cases from both ends to the middle.
  • Accordion-folded panel: refers to a fabricated panel where the material is folded back and forth in a “Z” formation in the same principal direction as the seams. This folding takes a wider panel of material and makes it into a narrow stack. For example, a 30 m by 30 m (98 ft x 98 ft) prefabricated panel could be accordion-folded into a 3 m (9.8 ft) wide stack of material 10 layers deep and 30 m long.
  • Accordion-folded and rolled panel: refers to an accordion-folded fabricated panel that is first accordion-folded to the desired width and then rolled to form a finished, rolled bundle for transport.
  • Double accordion-folded panel: refers to an accordion-folded fabricated panel that is accordion-folded to the desired width and then accordion-folded in the length direction onto a pallet (or into a container). Double accordion-folded panels typically appear as a “cube” of material with square corners.
  • Fabricator: the person or organization by whom the geomembrane material is fabricated into a fabricated panel.
  • Test Seam–A seam made prior to or after production welding, made by the same personnel, using the same geomembrane material, the same welding unit and the same seaming conditions used in the actual production seaming process. Test seams are used to provide representative destructive test samples without damaging fabrication seams.
  • Test Strip–A strip of material at the end of a panel, e.g., 0.3 m (1 ft) to prove seam sample that is representative of the production seaming process without damaging the fabricated panel for seam testing.
  • Destructive Test Sample –A seam sample taken before, during, or after production seaming that is used to determine the compliance of fabrication production seams with project specification.
  • Pre-production test – a destructive sample taken from a test seam, which is tested before production welding begins to qualify subsequent production seams.
  • Post-production test—a destructive sample is tested at the conclusion of a set of fabrication seams (production seam or test seam) to qualify the previously produced production seams.
  • Hot air welding – hot air welding is mostly used in conjunction with scrim reinforced geomembranes, and it may otherwise cause deformation in unreinforced or non-supported materials. This method typically involves the introduction of hot pressurized air through a nozzle between two overlapped sheets of geomembrane quickly followed by pinch rollers that press the heated sheets together as welding progresses.
  • Radio frequency welding – radio frequency welding, also known as high-frequency welding and dielectric welding, is a process that utilizes high-frequency electric fields to induce heating and melting of thermoplastic based materials. This process requires repeated clamping of the overlapped materials between a conductive sealing bar and platen that passes the radio frequency field through the material in incremental steps to advance from one end of a seam to the other. The method is only practical for factory welding and can be utilized for materials that have dipoles, such as, PVC, most Ethylene Interpolymer Alloy (EIA) geomembranes, and polyurethane based geomembranes.
  • Solvent welding – a chemical solvent or fusing agent is applied to the overlap of two geomembrane panels in the field with a squeeze bottle or paintbrush to create a 50 mm (2 inch) wide seam between two factory fabricated panels together or to patch/repair an area. After applying the chemical solvent or fusing agent, the two geomembranes should be pressed together while the solvent is still liquid using a hand-held roller and cotton rags to wipe up any excess solvent.
  • Geomembranes that can use solvent welding include PVC, EIA, and CSPE geomembranes.
  • Thermal/hot wedge welding – thermal wedge welding is a process utilizing a heating element that makes intimate contact with the surfaces of overlapped geomembranes being welded. This method of welding is usually applicable to all geomembrane types either monolithic, non-supported, or supported with a reinforcing scrim fabric layer.

Geomembrane Polymer Terminology

  • CSPE Geomembranes — Unreinforced (CSPE) and reinforced (CSPE-R) Chlorosulfonated Polyethylene (CSPE) geomembranes.
  • EIA Geomembranes — Ethylene Interpolymer Alloy (EIA) geomembranes, which is comprised on PVC resin and ketone ethylene ester (KEE) plasticizer.
  • HDPE and HDPE-R Geomembranes — Unreinforced (HDPE) and reinforced (HDPE-R) high density polyethylene geomembranes.
  • LLDPE and LLDPE-R Geomembranes — Unreinforced (LLDPE) and reinforced (LLDPE-R) linear low density polyethylene geomembranes.
  • PVC Geomembranes — Polyvinyl chloride (PVC) geomembranes, which is comprised on PVC resin and liquid plasticizer(s).
  • RPE Geomembranes — Reinforced polyethylene geomembranes.
  • RPP Geomembranes — Reinforced polypropylene geomembranes.
  • WCPE Geomembranes — Woven-coated polyethylene geomembranes.

Quality Control of Manufactured Materials

This section describes some of the minimum QC activities that should be performed by the factory fabricator on the manufactured rolls of geomembrane material before fabrication of large panels begins.

Geomembrane Roll Inspection
This sub-section describes the minimum inspection of the Geomembrane Roll that should be conducted before factory fabrication begins:

  • a. Confirm the manufacturer’s written certification shows that all of the geomembrane material properties meet or exceed the manufacturer’s specifications and also the Project Specifications.
  • b. Prior to factory seaming, each sheet of geomembrane should be unrolled/unwound to the desired length of the panel and visually inspected for contaminants, defects, gels, holes, undispersed raw materials, and edge and surface uniformity. However, this inspection may not be possible if the panels are manufactured using an automated process, e.g., using a welding machine, or if possible at the time the panel is folded. If not, the inspection should be conducted during manufacturing of the individual rolls.
  • c. Wherever practical, personnel should observe the backside of the geomembrane as it is unrolled/unwound because it may be the only time to observe the bottom of the sheet for defects and other anomalies.
  • d. Personnel should walk along the unrolled/unwound sheets and look for defects and other anomalies because it is easier to inspect in the factory than the field.
  • e. If any defects or impurities exist in the manufactured geomembrane, they will be removed from the sheet prior to fabricating the material into panels, or the geomembrane sheet will be rejected.
  • f. Geomembrane rolls also can be rejected for poor “lay flat” edges or “race tracking,” i.e., curvature of the geomembrane sheet, caused by inconsistent sheet thickness. If the curvature is significant, it may/will be difficult to weld two geomembrane rolls together.
  • g. Edges of the geomembrane rolled goods can be wavy when delivered. Wavy edges can be caused by an inconsistency on the tightness of the geomembrane when being wound. If the tension of the winder is off, it will pull the material one way more than the other and cause curvature and/or wavy edges. If the wave is significant, it can be difficult to weld two geomembranes together. If the waves are present the geomembrane roll can be deemed unusable. In addition, a wavy weld may not be acceptable to the owner or inspector(s).
  • h. Geomembrane roll certification(s) will be supplied by the manufacturer to the fabricator for the properties specified or per the respective geomembrane specification.

Sample Retention
This sub-section describes retention of archive samples of the geomembrane material for future purposes by the geomembrane manufacturer. There is a range of sample retention processes by the geomembrane manufacturers surveyed for this guideline, such as: (1) a 203 mm x 254 mm (8” x 10”) sample of each master production roll (1,000 to 2,000 m long) for a minimum of 10 years, (2) four 216 mm x 279 mm (8.5” x 11”) retain coupons usually form the first roll of every geomembrane lot for at least seven years, (2) at least a 152 mm by 152 mm (6 inch by 6 inch) sample from each roll tested of the 10% of raw goods tested is retained by the manufacturer along with the original roll tag and saved for up to two calendar years, (3) a 10 m sample of the original shipment for three calendar years, (4) a 3 m sample of each manufactured lot shipped for two calendar years or until the end of the warranty period, e.g., 20 years. In addition, some manufacturers retain samples of incoming resin and additives and in-process (subcomponents) for each manufactured lot for at two years. If the original roll tag is not available or applicable, all of the manufacturing information of the roll should be written on the sample itself. The storing of the retention samples varies for each manufacturer, but it should involve a temperature controlled environment with no UV exposure.

Manufactured Material Testing
This sub-section describes the minimum testing that should be performed by the fabricator on the manufactured rolls of geomembrane before factory fabrication begins:

  • a. Thickness Testing on Every Roll
    Thickness testing should be performed on every manufactured roll of geomembrane at least at the beginning and end of the roll. The thickness testing should be performed in accordance with the applicable ASTM test method based on geomembrane polymer type in Table 1 below. This testing should be performed to ensure the manufactured rolls meet manufacturer specifications.
  • b. Random Fabricator Tensile Testing
    Random tensile testing should be performed on manufactured rolls of geomembrane at least every 10,000 pounds of material or per truckload of manufactured rolls. The tensile testing should be performed in accordance with the applicable ASTM test method based on geomembrane polymer type in Table 1 with a calibrated tensiometer. The tensile test equipment should be calibrated as scheduled by an independent testing laboratory. The test equipment calibration should be verified weekly by the fabricator. The following tensile properties should be determined from this testing and compared with project specifications to ensure the manufactured geomembrane meets project requirements:
    • Breaking factor or strength in lbs./inch,
    • Elongation at break in %, and
    • Modulus at 100% elongation in lbs./inch.

FGI-2014-HOPnew-Intensive-Care-Medicine-FIG-1

Factory Fabrication Guideline

Geomembranes sheets are manufactured and transported in individual rolls, i.e., rolled goods. The rolls are shipped to a geomembrane fabricator. The fabricator cuts the rolls to desired lengths and welds them together to create large panels. As discussed above, individual rolls should first be unrolled/unwound and visually inspected for possible defects or damage before welding begins. The welds are inspected and tested for seam integrity by the fabricator before packaging and shipping to the project site. The typical minimum seam width for welding is normally 44.5 mm (1.75 inches).
Factory seaming of geomembranes has been occurring successfully for many years and it provides many advantages over field seaming, including optimal temperature, wind, and sunlight, dirt free environment, and firm subgrade. This results in factory welds being stronger and more consistent than field seams (Stark et al., 2020). The large amount of factory seaming that can be performed also reduces the amount of field seaming, which results in a better overall product. In summary, the ability to factory fabricate geomembranes provides many substantial benefits over geomembranes that must be seamed in the field, such as higher quality and consistent seams, reduced installation time and cost, better visual inspection of the materials before installation, and less potential for construction induced damage (Stark et al., 2020).

Typical Welding Defects
This sub-section describes some of the typical welding defects that can occur during factory welding of rolled goods into large panels so these issues can be recognized by personnel and inspectors.

  • a. Slippage
    When edges of geomembrane rolls are overlapped and being welded together, they separate or slip apart from each other causing the seam to not have a full width of the weld. This slippage can be caused by wavy material, too small of an overlap of the geomembrane rolls, the nip rollers pulling too hard on one of the rolls, etc.
  • b. Burn or Hot Spot
    This occurs when the welder burns through one or both of the geomembrane rolls during welding. This can be caused by the welder stopping in one place or the temperature setting being too high. The welder can stop in one place due to it: (1) coming unplugged, (2) being stopped by an object on the floor or in the machine track.
  • c. Material Gets Folded in Weld
    This occurs when the geomembrane gets folded onto itself during the welding process and the welder continues moving down the seam. This can be caused by a long or heavy overlap of geomembrane material, a wavy edge of the geomembrane material, etc.
  • d. Welding Wedge not Engaged
    When the hot wedge of a welder is not fully engaged over the width of the weld, this results in a partial weld. This can be caused by operator error, defective welder, etc.
  • e. Gap in Weld
    This occurs when there is a gap in the weld, i.e., a length of the seam is not welded together, which can create a wrinkle or simply an unbonded zone. This can be caused by dirt or moisture in the seam, a welder defect, improper welder temperature or speed, etc.
  • f. Foreign Matter in Weld
    When foreign matter, e.g., dirt and/or moisture, is in the weld, this usually results in a partial weld or no weld at all. This can be caused by poor house cleaning, dirty material, moisture on the on the geomembrane, etc.
  • g. Excessive Weld Lip
    This occurs when the overlap of geomembrane rolls from the weld (lip of the weld) This can be caused by improper adjustment of the welder guide bars/plates, operator error, etc. This defect may be remedied by trimming off the excess geomembrane materials after completion of the seam or by adjusting the machines or lap.

Seam Testing

  • This section is a summary of destructive quality control test methods for determining the integrity of factory seams used in joining rolled goods into factory fabricated geomembrane panels These test methods are applicable to manufactured flexible polymeric geomembranes/linings that are non-reinforced and scrim reinforced.
  • Unexplainably, the typical field requirement of one destructive seam test at a minimum of once every 500 lineal feet (152.5 m) of thermally welded seam has been referenced and required for factory welded seams. This is overly conservative because of the optimal conditions under which factory seaming is performed and the consistently acceptable seams created in the factory versus the field (Stark et al., 2020). This section of the guideline presents a recommendation for the testing frequency of factory fabricated seams. All seam tests and inspections should be completed prior to packaging and shipment of the panel.
  • The seam testing recommendation is broken into the following two categories: (1) Pre- and Post-Qualification Seam Testing and (2) Production Seam Testing.

Pre- and Post-Qualification Seam Testing

  1. Pre- or Post-Qualification Test Seams shall be prepared and tested by the Geomembrane Fabricator either (1) prior to production or (2) after production seaming is completed for that production period, respectively, to verify that the seaming parameters, equipment, and personnel for each welding station are adequate.
  2. Test seams shall be made by joining two pieces of the geomembrane to be seamed at least 6 ft (2 m) long using the same equipment, operator, and conditions anticipated during production welding. Test seams will be tested in both shear and peel strength using the applicable ASTM test Method based on geomembrane polymer type in Table 1, e.g., ASTM D 6392 (heat welded) or ASTM D 6214 (chemical welded).
  3. Samples shall be tested and evaluated in accordance with the project specification.
  4. If a test seam fails, an additional test seam shall be immediately completed. If the additional test seam fails, the seaming equipment shall be rejected and not used until the deficiencies are corrected and a successful test seam can be produced for a pre-qualification test. If a post-qualification test fails, then the seams produced with that equipment will be inspected and repaired.
  5. The results of each test seam shall be recorded including panel identification, seam number or test location, technician performing the test seam and a pass or fail description.

Production Seam Testing

  1. All completed factory seams should be 100% visually inspected. Factory seams will be visually inspected for full seam continuity over their full length during the folding operation by tensioning the seam perpendicular to the seam length. Any areas that do not meet the specified requirements shall be removed and repaired as described below. This is an important step in the quality control process because it is easier to inspect in the factory than the field.
  2. A Production Test Seam shall be prepared and tested by the Geomembrane Fabricator during production to verify that the seaming parameters, equipment, and personnel for each welding station are adequate.
  3. During production the Geomembrane Fabricator should adopt the typical industry testing frequency of sampling once every shift change or every 4 hours of production, whichever is more frequent, to ensure high quality factory seams.
  4. Test seams shall be made by joining two pieces of the geomembrane to be seamed at least 2 m (6 ft) long using the same equipment, operator, and conditions anticipated during production welding. Test seams will be tested in both shear and peel strength using the applicable ASTM test Method based on geomembrane polymer type in Table 1, e.g., ASTM D 6392 (heat welded) or ASTM D 6214 (chemical welded).
  5. Samples shall be tested and evaluated in accordance with the project specification.
  6. If a production seam test fails the seams affected by this test specimen will be inspected and repaired as required.
  7. The results of each test seam shall be recorded including panel identification, seam number or test location, technician performing the test seam and a pass or fail description.

Testing Factory Welds

  • Testing should be in accordance with using the applicable ASTM test Method based on geomembrane polymer type in Table 1, e.g., ASTM D 7982, D7747 (reinforced geomembranes), D6392, D6214, D882 (unreinforced geomembranes), or other relevant test method(s). Test seams will be welded and should be evaluated prior to starting any panel fabrication. The test seams must pass all seam peel and shear strength testing requirements before any panel production starts.
  • Welder(s) should be retested at 4-hour intervals or when material type changes. In addition, it is recommended that all patches, repairs, and detail work be 100% air-lance tested per ASTM D-4437. The results of all testing must be documented and available to the owner and/or engineer responsible for the project.
  • Prior to installation of the fabricated geomembrane panel, the fabricator will provide to the Engineer or Owner, manufacturer material certifications and/or a copy of quality control test results for all of the panels to be installed to verify conformance with this specification and the project requirements. The location of any defects and repairs and all necessary retesting results will also be documented in the report.

Patching, Repairs, and Cross Seams/Intersections

  • This section provides some techniques for repairing and/or patching geomembrane panels before they are folded and/or rolled for shipment. In addition, this section covers sealing cross seams/intersections. When a seam sample is removed from the panel being fabricated due to a defect, the resulting hole will be repaired with a patch with a minimum of a 25 mm (one inch) bonded area around the patch and the patch will be rounded on all corners. Typically, no more than two patches are allowed for every 30 m (100 ft) of weld or seam.
  • To patch a geomembrane panel, use the same material as the original geomembrane, e.g., polypropylene, LLDPE, PVC, etc., prepare/clean the area to be patched, use a patch with a minimum of 152 mm (6 inches) overlap extending beyond the damaged area, and then apply the patch via suitable means, e.g., heat air or solvent. All edges of the patch and repair materials should be rounded. The patch should be continuously welded in place flat over the damaged area with roller pressure applied to the two surfaces to achieve a thermal or solvent bond between the geomembrane surfaces. The welded or bonded area is normally 2.5-cm (1-inch) minimum wide
  • If the geomembrane is scrim reinforced, the full perimeter edge of the patch should be sealed via heat gun capping with an unsupported film version of the geomembrane or extrusion welded to prevent wicking of moisture. For scrim reinforced material that is susceptible to wicking, no exposed scrim areas should be allowed. In addition, the edges of all patches with reinforced materials should also follow manufacturer recommendations for sealing.

The various patching techniques include:

  • The edges of all patches created with reinforced materials are sealed per manufacturer recommendation. If a scrim reinforced geomembrane is being used and the scrim is susceptible to wicking, the exposed scrim areas should be covered to prevent wicking.
  • Table 2 presents different patching techniques that should be used for a given geomembrane type. Note that reinforced materials that are subject to moisture wicking, require re-sealing around their edges when cut to seal the reinforcing scrim.

FGI-2014-HOPnew-Intensive-Care-Medicine-FIG-2FGI-2014-HOPnew-Intensive-Care-Medicine-FIG-3

Patching Requirements
This sub-section describes some of the requirements for patching factory fabricated geomembrane panels. These requirements include:

  1. There should be no more than two patches per 30 m (100 ft) of weld. More than two patches per 30 m (100 ft) requires supervisor approval and the supervisor will document the reason for the patches on the QC document;
  2. Patches should extend 150 mm (6”) in all directions from the edge of the repair/damage;
  3. Patches should be 100% welded in most applications;
  4. Patch and cap strip length should be limited to less than 5% of the total length of the seam;
  5. No patches will be allowed within 1.5 m (5 ft) from the edge of the fabricated panel. If a patch is needed, cut out the weld and put a larger patch over the area. The resulting material should be no thicker than two sheets thick in any one place on the panel. In the event of a scrim product, stop the extrudate one foot from the edge of the panel;
  6. All patches should be air-lance tested in accordance with ASTM D4437 and marked with the initials of the tester;
  7. Extrusion weld all exposed scrim edges of reinforced geomembrane material that is susceptible to wicking;
  8. A patch should never be longer than one-half of the width of the geomembrane rolled good;
  9. All cross seams shall be patched at each end of the cross seam unless the product is a scrim reinforced geomembrane. In this case extrusion weld only the cross seam. An exception of this rule is reinforced polypropylene geomembranes which require a six inch diameter patch that is extrusion welded;
  10. Any defects in the manufactured geomembrane material should be patched and if it is a scrim reinforced geomembrane, the defect should be extrusion welded;
  11. Any factory fabricated panel that requires repairs or secondary quality control checks after initial production requires that all repairs be documented;
  12. In the event a seam has to be cutout of a reinforced geomembrane, a new sheet is placed in between the two edges of exposed scrim to allow for factory edge to be on both sides of the replaced seam;

Testing of Patches
The patches should be tested using at least one of the following methods:

  1. Vacuum chamber/box tests in accordance with ASTM D5641 (see https://www.youtube.com/watch?v=6K85L11-ehE).
  2. Air lance testing in accordance with ASTM D4437 (see https://www.youtube.com/watch?v=U6yXgq4LzxE).
  3. Spark testing in accordance with ASTM D4437, D6365, and/or D7240.

Factory Cross Seams/Intersections

This section provides some techniques for creating, inspecting, repairing, and patching factory cross seams or roll intersections. Cross seams are used to help reduce scrap and make the best use of purchased rolled goods. Cross seams or welds are rolled goods welded together to create part of a fabricated geomembrane panel. Factory cross seams are usually not tested but visually inspected. During inspection make sure the weld lip at each edge of the panel are trimmed off and the panels are welded together straight so they appear flat and straight after being welded together. When the panels with a cross seam(s) are welded into a panel, inspector(s) must inspect the “T” section (area where the cross seamed panel joins the edge of another panel that it is welded to) to ensure proper adhesion of the weld. Depending on the type of geomembrane being welded, extrusion welds may be needed on the “T” section, e.g., reinforced geomembranes because of exposed reinforcing scrim that may be susceptible to wicking. Cross seams require a patch at the end of each cross seam. If the product is a scrim reinforced product, the fabricator will only need to extrusion weld the cross seam. A polypropylene geomembrane will require a 0.15 m (6 inch) diameter patch with an extrusion weld around the entire patch. Cross seams created by the geomembrane manufacturer should be cut out and discarded by the fabricator, i.e., not relied upon. Factory fabricated cross seams should be created according to standards determined by material type, customer and contract specifications, and product application. To facilitate welding of factory fabricated panels in the field, it is recommended that:

  1. Cross-seams/intersections be in the middle of panel not along an edge of the panel.
  2. Each factory fabricated panel should contain no more than two cross seams/intersections within a single sheet.
  3. NO cross seams/intersections should occur within 4.6 m (15 ft) of either end of the fabricated panel to facilitate welding of the factory fabricated panels together in the field.

In the case of any variance from these recommendations due to project specific requirements, there must be approval from the Customer.

Testing of Cross Seams/Intersections

  • This section discusses the testing of cross seams/intersections, which is similar to the seam testing described in Section 8 above. Testing of cross seams/intersections should be in accordance with the applicable ASTM test Method based on geomembrane polymer type based on geomembrane polymer type in Table 1, e.g., ASTM D 7982, D7747 (reinforced geomembranes), D6392, D6214, D882 (unreinforced geomembranes), or other relevant test method. In addition, to the destructive seam testing described in Section 8, the following tests could/should be performed on the cross seam/intersection to ensure the connection is sealed: (1) vacuum chamber (ASTM D4437, D5641),(2) air lance testing (ASTM D 4437), and spark testing (ASTM D4437, D6365, and D7240). Each cross seam/intersection that is tested should be labeled with the date, tester, method of testing, test result (pass/fail), and other pertinent information.

Fabrication and Identification of Factory Geomembrane Panels

  • ASTM D7865 provides guidelines for the identification, packaging, handling, storage, and deployment of factory fabricated geomembrane panels. This guide is intended to aid fabricators, suppliers, purchasers, and users of fabricated panels in the identification, packaging, handling, storage, and deployment of fabricated geomembrane panels, which is summarized in the following sections.
  • This is important because a fabricated geomembrane panel must be: (1) adequately identified and packaged and (2) handled and stored in such a way that its physical properties are not degraded prior to installation. Failure to follow good practice may result in the unnecessary failure of the fabricated panel in a properly designed application. The following requirements and thus in ASTM D7865 may be augmented by project-specific storage, handling, identification, packaging, or installation requirements or quality assurance programs.
  • All factory fabricated geomembrane panels should be uniquely identified with a number or other identification markings. These identification markings should clearly identify where the panel will be placed in the project layout. Each fabricated geomembrane panel should be identified with a durable, gummed weather resistant label, or equivalent. One label should be placed directly on the material after fabrication and one label should be attached to the outside of the packaging.
  • Panel identification information should include, at a minimum, the name of the fabricator, product or style number, and the unique panel identification number or marking. All designations should be clearly marked and readable for the anticipated storage period. The identification label should also include the width and length of the fabricated panel. For special fabricated panels a description of the panel features is recommended. In addition, all fabricated geomembrane panels should include a marking that shows how the panel will unroll or unfold on site. This marking is important to the installer so that the panel can be properly positioned before deployment.

Folding, Rolling, and Packaging Factory Geomembrane Panels
This section provides some techniques for folding, rolling, and packaging factory fabricated geomembrane panels before shipment. The fabricated panel can either be rolled “as is” (rolled panel), or accordion-folded and then rolled or double accordion folded for transport. Rolled panels are typically not wider than 10 m (30 ft) as it is difficult to physically handle rolls this wide without damaging them. Most fabricated panels are accordion folded to a narrower width of between 2 to 4 m. An accordion folded and rolled panel is wound onto a sturdy core suitable for the weight of the panel. Accordion folded and rolled panels are often placed on a sturdy pallet designed for fork-lift access for transport. For double accordion-folded panels the narrow, accordion-folded panel is folded once more lengthwise onto a sturdy pallet (or often into a cardboard container or crate). The resulting package is typically rectangular. Double accordion folded panels are often sized to fit into transport trucks. Smaller, i.e., less than 90.7 kg (500 lbs.), are rolled on a core, and placed on a pallet. Pallets should have a protective layer (i.e.: cardboard or excess liner) on the surface of the pallet and between the liner and the banding to prevent damage to the liner. When a pallet is used to support the fabricated geomembrane panel it should extend past the finished dimensions of the panel. One or two layers of geotextile, geomembrane, cardboard, or other suitable material should be placed on the pallet to protect the finished panel from coming into direct contact with the pallet. All pallets and crates should be inspected to make sure that there are no protruding fasteners that could damage the material. Pallets and crates should be in good condition. Packaging for fabricated geomembrane panels should be suitably weather resistant for the anticipated storage conditions. A common packaging is a wrap of a weather resistant material that protects the fabricated panel from UV damage and precipitation. Other packaging such as a large cardboard box with a lid is also sometimes used. Slings, rope, or other handling and deployment aids are attached to the panel after the packaging is completed and often prior to the panel being placed on a pallet. The outside label is applied, and the unfolding marking is carefully checked and aligned on the packaged panel.

Transportation, Handling, and Storage

  • This section provides some techniques for transportation, handling, and storage of factory fabricated geomembrane panels before shipment. Transportation is usually the responsibility of the fabricator, unless otherwise specified. Fabricated panels should be shipped in either a closed trailer or on a flatbed trailer with adequate tarps and delivered to the site only after the required submittals have been approved and received by the fabricator from the project engineer.
  • Factory fabricated geomembrane panels should be transported to the project site using the most direct method. Transferring fabricated panels from truck to truck during interline transfers can cause damage due to handling so direct shipments are recommended. If multiple handling is required then adding protection to the sides of the packaging is recommended to protect the edges of the panel during interline transfers. If extensive handling is required in transit, then crating the panels is recommended. While unloading or transferring the fabricated panels from one location to another, prevent damage to the wrapping and to the fabricated panel itself. If the fabricated panel is palletized or stored in a crate, a standard forklift with forks long enough to reach through the pallet or crate should be used. Slings may be used to carry relatively large, fabricated panels, provided that the slings do not cause damage to the panels. Do not drag the panels as damage may result.
  • Inspect fabricated panels at time of delivery to the project site and immediately make any claims for damage with the carrier. Any damage incurred during transit should be noted on the bill of lading and reported immediately to the freight company and the fabricator that shipped the material. The receiving inspection should verify the number and identity of the panels, ensure that the packaging is intact, the panels are not damaged, and the labels and deployment markings are in place.
  • Fabricated panels, when possible, should be stored on pallets off the ground. The storage area should be dry with a firm base. Ensure that the packaging on each panel remains in place and is suitable to protect the fabricated panels from ultraviolet radiation and other expected weathering. These recommendations may be augmented by site or project specifications and/or manufacturer’s recommendations for handling and installation of factory fabricated geomembrane panels.

Deployment

  • This section provides some techniques for deploying factory fabricated geomembrane panels. Before deploying a fabricated panel at the job site, verify its identification. If there is a project layout diagram, then match the panel identification marking to the project layout diagram. Move the fabricated geomembrane panel to the proper location with suitable lifting equipment following all site safety requirements.
  • Fabricated geomembrane panels are normally placed at a starting point on one corner of the area to be lined. The deployment markings on the packaging or label will indicate which direction the panel will unfold. Accordion-folded and rolled panels will unroll in only one principal direction while double accordion-folded panels may unfold in either principal direction.
  • Remove panel packaging prior to deployment. Double check the unrolling direction of rolled, and accordion-folded and rolled panels, and adjust the starting point if necessary. Unroll, unfold the fabricated panel into the area to be lined. Do not deploy panels if winds are above site safety specifications or above the manufacturer’s (or fabricator’s) recommended wind speed for deployment. Provide suitable wind uplift protection with sandbags or other ballast. While unrolling and/or unfolding inspect the fabricated panel for damage or defects. Repair any damage found per project specifications.

Summary
The purpose of this guideline is to present a minimum quality control system for the factory fabrication, packaging, and testing of flexible geomembranes. The system presented herein may also be applicable to other geomembrane materials. The procedures presented herein should be adhered to at all times. Deviation from these standards and procedures herein will only be as required to meet the project plans and specifications according to the terms and conditions of the contract. Conformance to the established policies and procedures described herein should be monitored by internal audits on a random basis.

References

  1. ASTM D882 (2020). “Standard Test Method for Tensile Properties of Thin Plastic Sheeting”, ASTM International, West Conshohocken, PA, 2020, https://www.astm.org/d882.html.
  2. ASTM D1593 (2020). “Standard Specification for Nonrigid Vinyl Chloride Plastic Film and Sheeting”, ASTM International, West Conshohocken, PA, 2020, https://www.astm.org/d1593.html
  3. ASTM D4437 (2020). “Non-destructive Testing (NDT) for Determining the integrity of Seams Used in Joining Flexible Polymeric Sheet Geomembranes ”, ASTM International, West Conshohocken, PA, 2020, https://www.astm.org/d4437.html
  4. ASTM D4439 (2023). “Standard Terminology for Geosynthetics”, ASTM International, West Conshohocken, PA, 2023, https://www.astm.org/d4439.html.
  5. ASTM D6392 (2020). “Standard Test Method for Determining the Integrity of Nonreinforced Geomembrane Seams Produced Using Thermo-Fusion Method”, ASTM International, West Conshohocken, PA, 2020, https://www.astm.org/d6392.html
  6. ASTM D7700 (2020). “Standard Guide for Selecting Test Methods for Geomembrane Seams”, ASTM International, West Conshohocken, PA, 2020, https://www.astm.org/d7700.html
  7. ASTM D7408 (2020). “Standard Specification for Non Reinforced PVC (Polyvinyl Chloride) Geomembrane Seams”, ASTM International, West Conshohocken, PA, 2020, https://www.astm.org/d7408.html
  8. ASTM D7749 (2020). “Standard Test Method for Determining Integrity of Seams Produced Using Thermo- Fusion Methods for Reinforced Geomembranes by the Grab Method”, ASTM International, West Conshohocken, PA, 2020, https://www.astm.org/d7749.htm
  9. ASTM D7865 (2020). “Standard Guide for Identification, Packaging, Handling, Storage, and Deployment of Fabricated Geomembrane Panels”, ASTM International, West Conshohocken, PA, 2020, https://www.astm.org/d7865.html
  10. ASTM D7982 (2020). “Standard Practice for Testing of Factory Thermo-Fusion Seams for Fabricated Geomembrane Panels”, ASTM International, West Conshohocken, PA, 2020, https://www.astm.org/d7982.html
  11. FGI Testing Frequency for Factory Seams, Fabricated Geomembrane Institute, University of Illinois at Urbana-Champaign, July 12, 2010.
  12. Stark, T.D., Hernandez, M.A., and Rohe, D.S., (2020). “Geomembrane Factory and Field Thermally Welded Geomembrane Seams Comparison,” Geotextiles and Geomembranes Journal, 48(4), August, 2020, 454-467,
    https://doi.org/10.1016/j.geotexmem.2020.02.004.

Documents / Resources

FGI 2014 HOPnew Intensive Care Medicine [pdf] User Guide
2014 HOPnew Intensive Care Medicine, 2014, HOPnew Intensive Care Medicine, Intensive Care Medicine, Care Medicine

References

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