1、Designation: D7770 12Standard Test Method forStandard Test Method for Collection of Volatile OrganicCompounds Emitted During Simulated Manufacturing ofEngineered Wood Products Via a Sealed Caul Plate Method1This standard is issued under the fixed designation D7770; the number immediately following t
2、he designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method provid
3、es a method for the collection ofvolatile organic compounds (VOC) that are emitted during themanufacture of engineered wood products using a laboratoryenvironment designed to simulate a defined production pro-cess. The method is used for the determination of the amountsof methanol, formaldehyde, phe
4、nol and other VOC that may beemitted during conditions designed to simulate production suchas hot pressing, the conditions of hot stacking and cool-down that occurs post-press.1.2 The test method was originally developed to measurecertain VOC from exterior plywood meeting Voluntary ProductStandard P
5、S 109 and structural composite lumber productssuch as laminated veneer lumber (LVL) meeting SpecificationD5456. Both of these product types are typically manufacturedusing phenol-formaldehyde resin based adhesives that meetSpecification D2559.1.3 The test method is suitable for many types of woodpro
6、ducts bonded with adhesives.1.4 This test method is specific for collecting VOC duringsimulated production of wood products and is not designed todetermine general organic emissions from all indoor materialsor sources.1.5 The values stated in SI units are to be regarded asstandard. The values given
7、in parentheses are for informationonly.1.6 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory l
8、imitations prior to use. Some specifichazards statements are given in Section 7 on Hazards.2. Referenced Documents2.1 ASTM Standards:2D2145 Method of Test for Phenol Content of Phenol-WaterMixtures (Withdrawn 1978)3D2559 Specification for Adhesives for Bonded StructuralWood Products for Use Under Ex
9、terior Exposure Condi-tionsD4442 Test Methods for Direct Moisture Content Measure-ment of Wood and Wood-Base MaterialsD4933 Guide for Moisture Conditioning of Wood andWood-Based MaterialsD5456 Specification for Evaluation of Structural CompositeLumber ProductsE346 Test Methods for Analysis of Methan
10、olE1333 Test Method for Determining Formaldehyde Concen-trations in Air and Emission Rates from Wood ProductsUsing a Large Chamber2.2 Other Standards:Voluntary Product Standard PS 109 Structural Plywood3. Terminology3.1 Definitions:3.1.1 target production processa set of specified manufac-turing par
11、ameters that define the production of an adhesivebonded wood product. For the purposes of this standard, thoseparameters are designed to be representative of a specificproduction facility and are used to derive the test specimen.3.1.2 test specimena combination of defined wood ele-ments with or with
12、out applied adhesive that is exposed topressing and post pressing conditions in a defined laboratorysetting that is designed to simulate the Target ProductionProcess (see 3.1.1).3.1.3 VOCfor the purposes of this standard, the term VOCmeans the specific volatile organic compounds of1This test method
13、is under the jurisdiction of ASTM Committee D07 on Woodand is the direct responsibility of Subcommittee D07.03 on Panel Products.Current edition approved Nov. 1, 2012. Published December 2012. DOI:10.1520/D7770-122For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Cu
14、stomer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700
15、, West Conshohocken, PA 19428-2959. United States1formaldehyde, methanol and phenol that are emitted from a testspecimen during the pressing and post pressing measurements.4. Summary of Test Method4.1 A laboratory scale press is used to simulate the targetproduction process with respect to the key v
16、ariables thatinfluence the production process and that may affect theemission of VOC. The lab press is fitted with a caul system tocreate a seal around the press system to permit collection of theVOC discharged during the process. The sealed caul platecontains inlet and outlet ports to permit the co
17、ntrolled collec-tion of the emitted VOC.4.2 During the test, emitted VOC collect in the air spaceencompassed within the sealed caul plate. The VOC arecollected by mixing them into a continuous flow of clean, dryair that is injected into the sealed space via a controlled,pressurized supply cylinder.4
18、.3 The VOC within the collected air stream are removedfrom the sealed caul system and then condensed into a watersolution using impingers submerged into an ice bath.4.4 The collected solutions are diluted to concentrationsideally suited for instrumental analysis. They are analyzed todetermine their
19、methanol, formaldehyde and phenol content.Several suitable analytical procedures are referenced in .4.5 The weight of the wood elements used to assemble thewood test specimen, the weight of the adhesive applied to thewood elements, and the concentrations of the VOC detected inthe collection solution
20、s are determined to be used to calculatethe relative amount of methanol, formaldehyde, and phenolthat are emitted during the test.4.6 At least three test replications shall be conducted andresults separately reported for each of the tests.5. Significance and Use5.1 Compliance with national and local
21、 air emission regu-lations create the need to determine volatile organic compound(VOC) emissions from adhesive-bonded structural wood prod-ucts.5.2 This method has been used to estimate the types andamounts of certain VOC that are emitted during productionoperations.5.3 The method was originally dev
22、eloped to measure themethanol, formaldehyde, and phenol emitted in a laboratorysetting that is designed to simulate the hot pressing, and postpressing conditions of hot stacking and cool down period forexterior plywood and laminated veneer lumber (LVL) pro-cesses. This current method generalizes the
23、 concept foradhesive-bonded wood products.6. Apparatus6.1 Laboratory Press. A laboratory scale press shall beequipped with automatic temperature (if hot pressing is used)and pressure controls to control the pressing conditions tosimulate the production process. If required, the hot pressplatens can
24、be heated with any suitable means such aselectrical, hot oil or steam to control the press temperaturewithin 62C (64F) during the pressing operation. The hotpress platens shall be at least 600 by 600 mm (24 by 24 in.) andshall accommodate the sealed caul plate described in 6.2.6.2 Sealed Caul Plate.
25、 A machined aluminum caul plate isfabricated to fit within the laboratory press.As shown in Fig. 1,the outside dimensions of the plate are within 125 mm (5 in.)of the outside dimension of the laboratory press. The sealedcaul plate is fabricated with holes in the sides to create airinlet and outlet p
26、aths. The inlet and outlets are tapped toFIG. 1 Schematic of Sealed Caul Plate and Test PanelD7770 122receive threaded stainless steel tubing. It is permissible to fitthe inlet and outlet tubes with quick-disconnect couplings.4The thickness of the sealed caul plate shall be thick enough totest the r
27、epresentative wood test specimen. See Fig. 2 and Note1.NOTE 1Use of a spacer plate has been suitable to provide variableoverall caul thicknesses to fit products with different thicknesses. In suchcases, the spacer plate must be of compatible width and length to mateclosely and tightly with the seale
28、d caul plate during the test.6.3 VOC Collection Equipment. The following equipmentis required to collect the VOC during the simulated pressingoperations.6.3.1 Compressed air cylinder containing a supply of clean,dry, breathable air.6.3.2 Gas flow meter. A meter suitable to measure gas flowrates to a
29、n accuracy of 61.0 cm3/min (60.061 in.3/min).46.3.3 Collection impingers.46.3.4 Teflon Socket Adapters.46.3.5 #28 Ball Joint Clips.46.3.6 Connection tubing. Teflon tubing, 6 mm (.25 in.)inside diameter with at least 1.6 mm (1/16 in.) wall thickness.6.3.7 Ice bath. A chest or cooler of sufficient siz
30、e to containand surround three impingers with ice.6.3.8 Amber Glass bottles6.3.9 Gasket Material.6.3.10 O-ring gaskets.7. Hazards7.1 This test method involves heating, handling of woodand adhesives, pressure, presence and handling of VOC andhandling of laboratory glassware.8. Test Specimen8.1 The te
31、st specimen is designed to simulate the targetproduction process with respect to wood element(s), adhesiveand production process. The test specimen is defined inaccordance with the sections below.8.2 Product type and wood elements. Define the woodelement(s) used in the test as defined in this sectio
32、n.8.2.1 Define the product type with specifics that are appro-priate for that type. See Note 2.NOTE 2For example, plywood would be defined with respect tonominal thickness and number of plies and layers.8.2.2 Type of wood element(s) (for example, veneer, solidsawn wood, strands, particles, and fiber
33、s).8.2.3 Species of the wood element(s).8.2.4 Pre-conditioning applied to the wood elements such aspreheating, drying, steam exposure, chemical additions, orcombinations thereof.8.2.5 Moisture content of the wood elements shall beconditioned to be within 62 % of the expected moisturecontent of the d
34、efined target production process. See Note 3.Measure the moisture content of representative matched speci-mens using Test Methods D4442.4The subcommittee chair can provide a list of suitable supplies for conductingthis test.FIG. 2 Schematic of Air Source and Collection ImpingersD7770 123NOTE 3 Suita
35、ble methods to achieve proper moisture preconditioningof the wood elements includes: (a) Sampling wood elements from theactual production process and storing the elements in controlled condi-tions to prevent subsequent moisture change, and (b) Conditioning thewood elements at a controlled humidity d
36、esigned to result in the targetmoisture condition.8.2.6 Temperature of the wood elements prior to testingshall be within 65C (610F) of the target production process.8.2.7 Dimensions of the wood elements.8.2.8 Overall dimensions of the test specimen. The testspecimen shall be at least 300 by 300 mm (
37、12 by 12 in.).8.2.9 Configuration and alignments of the wood elements intest specimen. See Note 4.NOTE 4The configuration and alignment of the wood elements willdepend upon the target production.8.3 Adhesive. Define the adhesive and application methodused in the test.8.3.1 Adhesive Type (for example
38、, phenol-formaldehyde,pMDI, urea formaldehyde, etc.)8.3.2 Adhesive manufacturer, product number, date ofmanufacturing.8.3.3 Target application rate of adhesive.8.3.4 Application method used for the test.8.4 Target Production Process. The test conditions shall becontrolled to simulate the target prod
39、uction process as definedin this section.8.4.1 The adhesive application method and application rate.The specified time between adhesive application and pre-press.8.4.2 The prepress condition (time, prepress pressure, etc).8.4.3 The pressing condition (time, pressure, temperature,etc.).9. VOC Collect
40、ion Procedures9.1 Obtain and moisture condition wood elements to targetmoisture/temperature condition.9.2 Obtain adhesive. Precondition adhesive if that is part ofthe target test condition.9.3 Prepare hot press and sealed caul plate. Permit stabili-zation of the hot press and sealed caul plate to th
41、e target platentemperature.9.4 Prepare one set of three collection impingers for thepressing stage and another set of three impingers for thepost-pressing stage, if needed, as follows:9.4.1 Determine and record weight of each collection im-pinger to an accuracy of 0.1 g.9.4.2 Add 200 ml 65 ml of dei
42、onized water to eachcollection impinger, remeasure, and record wet weight.9.4.3 Assemble one set of three collection impingers in theice bath. Assure that the impingers are below the level of thecollection solution (deionized water). Connection of the im-pingers to the outlets is not made at this ti
43、me.9.5 Apply the adhesive to the wood elements. Record thefollowing information:9.5.1 Temperature of surrounding conditions,9.5.2 Temperature of adhesive,9.5.3 Temperature of wood elements,9.5.4 Weight of wood elements before adhesive application,9.5.5 Weight of wood elements after adhesive applicat
44、ion,and9.5.6 Time between adhesive application and pressing.9.6 Connect the collection impingers to the outlet ports ofthe sealed caul plate and open all valves between the sealedcaul and the impingers.9.7 Turn the clean air supply on and adjust to maintain aflow rate of 1.8 6.1 L/min (110 66.1 in.3
45、/min). See Note 5.NOTE 5There should be no gas flow through the impingers at thispoint because the caul system is still open to the atmosphere.9.8 Assemble the test specimen into the press and begin thepressing process. When properly adjusted, the press pressureshall be sufficient to create a tight
46、seal between the press andsealed caul plate. Record the press pressure. See Note 6. Thisresults in the air supply creating a positive gas pressure suchthat there is a gas flow from the sealed space around the testspecimen to the impingers.NOTE 6The press pressure may be greater than the target press
47、ure forthe process.9.9 When required, the hot pressing conditions are con-trolled to the defined test conditions (see 8.4.3). During thisstep, the air flow rate is maintained at 1.8 60.1 L/min (11066.1 in.3/min).9.10 At the end of the press process, the press heat (if used)is turned off and the firs
48、t set of impingers is detached from theoutlet air stream, sealed and removed from the ice bath. At thatpoint, the second set of three impingers are used to collect anemission sample in accordance with sections 9.11 and 9.12 todetermine VOC emissions representative of the post-press“hot-stack” condit
49、ion. The steps in sections 9.11 and 9.12 arenot required if not representative of the target productionprocess.9.11 The press pressure is maintained to continue the tightseal between the press platen and sealed caul plate. The secondset of impingers collects the output from the outlet air streamas soon as the press process is completed. See Notes 7 and 8.NOTE 7Since the press pressure must be maintained to continue thetight seal, the post press stage may not be representative of actualproduction processes where there is full release of press pressure andp
