Lapas attēli
PDF
ePub
[graphic][merged small][subsumed][subsumed][merged small][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][merged small]
[blocks in formation]

20 Total volume of solvent used in dissolving the sample.

Specify the solvent used along with the ercent soluble result.

(ii) Method II-Ethyl acetate or hexne extractable.

A sample is refluxed in the solvent for 2 Ours and filtered at the boiling point. The trate is evaporated and the total residue eighed as a measure of the solvent extractole fraction.

Apparatus. 1. Erlenmeyer flasks, 250Lilliliter, with ground joint.

2. Condensers, Allihn, 400-millimeter jack=, with ground joint.

3. Funnels, ribbed, 75-millimeter diameter, em cut to 40 millimeters.

4. Funnels, Buchner type, with fritted sc, 60-milliliter, porosity coarse.

5. Bell jar for vacuum filtration into eaker.

6. Laboratory mill, Wiley, intermediate odel.

Reagents. 1. Ethyl acetate, 99 percent 20° C. ecific gravity 0.899-0.902. 20° C. 2. n-Hexane, commercial grade, specific 20° C. avity 0.663-0.667; boiling range 66° 20° C. -69° C., or equivalent. Preparation of sample. Flake-No treat

ent.

Film, 2 to 5 mil-Cut into approximately -inch squares and separate into individual

eces.

Heavy film; molding powder or molded ticles-Cut or tear into pieces no larger man 6-inch cubes. (Two pairs of pliers Lay be used.) Mix with pulverized dry ice ne part polypropylene to 15-20 parts of lid CO2) and allow to stand 1 to 2 hours. eanwhile, place a 10-mesh screen in the iley mill and pass pulverized dry ice rough the mill until it is thoroughly illed. Then pass the sample through owly, adding more dry ice if necessary to -event heat build-up and fusion. Make a cond pass of the ground sample and dry ice rough the mill. Place the mixture in a rge evaporating dish, allow the dry ice to sappear, and continue air drying (or vacun drying) at room temperature until conensed moisture has evaporated. This produre will give particles of which approxiately 85 percent by weight will pass rough a 16-mesh screen and 50 percent rough a 20-mesh screen.

Procedure. Weigh 1 gram of sample accurately and place in a 250-milliliter Erlenmeyer flask containing two or three boiling stones. Add 100 milliliters of solvent, attach the flask to the condenser (use no grease) and reflux the mixture for two hours.1

Remove the flask from the heat, disconnect the condenser, and filter rapidly while still hot through a small wad of glass wool packed in a short stem funnel 2 into a tared 150milliliter beaker. Rinse the flask and filter with two 10-milliliter portions of the hot solvent, and add the rinsings to the filtrate. Evaporate the filtrate on a steam bath with the aid of a stream of nitrogen. Dry the residue in a vacuum oven at 110° C. for two hours, cool in a desiccator and weigh to 0.0001 gram.

Determine the blank on 100 milliliters of solvent evaporated in a tared 150-milliliter beaker. Correct the sample residue for this

blank if significant.

Calculation:

Grams of residue Grams of sample

X 100

= percent extractable with

Specify the solvent used along with the percent extractable result.

[25 F.R. 3320, Apr. 16, 1960, as amended at 25 F.R. 4544, May 24, 1960, 26 F.R. 6429, July 18, 1961]

[blocks in formation]

(b) Melting point... 475 F.-495° F. The melting point is determined as follows: Use a hot-stage apparatus. The use of crossed nicol prisms with a microscope hot stage and reading of the thermometer when the birefringence disappears increase the accuracy. If the crossed nicol apparatus is not available, use the lowest temperature at which the sample becomes transparent or the sharp edges or corners of the sample become rounded as the melting point. In case of doubt as to the onset of melting, the sample is prodded with a sharp instrument. If it sticks to the heating block, it is considered to have melted. If the melting point is low, dry the sample in an oven at 85° C. for 24 hours in a nitrogen atmosphere.

[blocks in formation]

(c) The procedure for determining the material extractable from nylon resins by selected solvents is as follows:

(1) Film should be cut with ordinary scissors into pieces of a convenient size such as 4-inch squares, for the extraction tests described in this section. The granules of nylon molding powders are in the proper form for the extraction tests. Samples of fabricated articles such as pipe, fittings, and other similar articles must be cut to approximately the size of the molding powder. This can be done conveniently by using a small-scale commercial plastics granulator and cutting the sample through a screen having 14-inch mesh. Fine particles should be separated from the cut resin by screening through a 20-mesh screen. The material retained on the screen is suitable for the extraction tests.

(2) The organic solvents must be of American Chemical Society analytical reagent grade; distilled water is used. Approximately 30 grams of the prepared sample is weighed to the nearest milligram. The weighed resin is transferred to a 500-milliliter round-bottom flask equipped with a reflux condenser. Approximately 300-milliliters of solvent is

added to the flask and the contents refluxed gently for 8 hours with a heating mantle. The solvent is then filtered off immediately while still hot, using a Buchner funnel approximately 5 inches in diameter, a suction flask, and a hardened filter paper (Whatman No. 50 or equivalent). The paper is wet with the solvent and a slight suction applied just before starting the filtration. The resin is washed twice with approximately 100milliliter portions of solvent and the combined filtrate and washings are reduced to approximately 25 milliliters by evaporation at reduced pressure (50 millimeters to 100 millimeters of mercury. absolute), heating as necessary. The contents of the flask are transferred to an evaporation dish (which has been held in a vacuum desiccator over anhydrous calcium sulfate until constant weight has been attained) and carefully evaporated to dryness. The weight of the solid residue is determined by difference after holding in a vacuum desiccator over anhydrous calcium sulfate until constant weight has been attained. The percent of solids extracted is calculated by dividing the weight of the solid residue by the weight of the sample and multiplying by 100.

[25 F.R. 13749, Dec. 28, 1960, as amended at 27 F.R. 4063, Apr. 28, 1962]

[blocks in formation]

610 Nylon (polyhexamethylene sebacamide) as defined in paragraph (a) of this section, and subject to the further conditions prescribed in this section, may safely be used to produce articles intended for use in processing, handling, and packaging food.

(a) 610 Nylon is manufactured by the condensation of hexamethylenediamine and sebacic acid, under controlled conditions, whereby it meets the specifications and tests prescribed in paragraphs (b) and (c) of this section.

(b) Specifications—(1) Qualitative tests—(i) Infrared identification. 610 Nylon has characteristic infrared spectra useful for identification purposes. (ii) Other properties for identifying 610 nylon:

(a) Specific gravity-... 1.09+0.018 Determined by weighing a 1-gram to 5gram specimen first in air and then in freshly boiled distilled water at 23* C. +2° C.

Melting point---.

405° F.-425° F. The melting point is determined as follows: Use a hot-stage apparatus. The use of crossed nicol prisms with a microscope hot stage and reading of the theromometer when the birefringence disappears increase the accuracy. If the crossed nicol apparatus is not available, use the lowest temperature at which the sample becomes transparent or the sharp edges or corners of the sample become rounded as the melting point. In case of doubt as to the onset of melting, the sample is prodded with a sharp instrument. If it sticks to the heating block, it is considered to have melted. If the melting point is low, dry the sample in an oven at 85° C. for 24 hours in a nitrogen atmosphere.

Solubility in boiling 4.2N Insoluble

[blocks in formation]

(a) Specific gravity-.. 1.10±0.015 Determined by weighing a 1-gram to 5gram specimen first in air and then in freshly boiled distilled water at 32° C. +2° C.

(b) Melting point_________ 375° F.-395° F. The melting point is determined as fol

lows: Use a hot-stage apparatus. The use of crossed nicol prisms with a microscope hot stage and reading of the thermometer when the birefringence disappears increase the accuracy. If the crossed nicol apparatus is not available, use the lowest temperature at which the sample becomes transparent or the sharp edges or corners of the sample become rounded as the melting point. In case of doubt as to onset of melting, the sample is prodded with a sharp instrument. If it sticks to the heating block, it is considered to have melted. If the melting point is low, dry the sample in an oven at 85° C. for 24 hours in a nitrogen atmosphere. (c) Solubility in boiling 4.2N HCI.

Dissolves in

(2) Extractability limitations.

Nylon copolymer 66/610:

Water

Percent

1.0

2.0

1.0

1.0

Ethyl acetate__

c) Procedure for determining the aterial extractable from nylon resins selected solvents is described in 21.2502(c).

¡ F.R. 13749, Dec. 28, 1960, as amended at F.R. 4064, Apr. 28, 1962]

121.2504 66/610 Nylon resin. Copolymer 66/610 nylon, as defined in ragraph (a) of this section, and furer subject to the conditions prescribed this section, may safely be used to oduce articles intended for use in ocessing, handling, and packaging ǝd.

(a) Copolymer 66/610 nylon is manuctured by polymerizing equal weights the 66 and 610 monomeric salts under ntrolled conditions whereby it meets e specifications and tests prescribed paragraphs (b) and (c) of this

ction.

(b) Specifications—(1) Qualitative sts-(i) Infrared identification. Colymer 66/610 nylon has characteristic frared spectra useful for identification rposes.

(ii) Other properties for identifying polymer 66/610 nylon:

95% ethyl alcohol---.

[blocks in formation]

1 hour.

Percent

1.5

2.0

1.0

1.0

(c) Procedure for determining the material extractable from nylon resins by selected solvents is described in § 121.2502(c).

[25 F.R. 13749, Dec. 28, 1960, as amended at 27 F.R. 4064, Apr. 28, 1962]

§ 121.2505 Slimicides.

(a) Slimicides may be safely used in the manufacture of paper and paperboard that contact food, in accordance with the following prescribed conditions:

(1) Slimicides are used as antimicrobial agents to control slime in the manufacture of paper and paperboard.

(2) Subject to any prescribed limitations, slimicides are prepared from one or more of the slime-control substances named in paragraph (c) of this section, to which may be added optional adjuvant substances as provided for under paragraph (d) of this section.

(3) Slimicides are added to the process water used in the production of paper or paperboard, and the quantity added shall not exceed the amount necessary to accomplish the intended technical effect.

[blocks in formation]

(d) Adjuvant substances permitted to be used in the preparation of slimicides include substances generally recognized as safe for use in food, substances generally recognized as safe for use in paper and paperboard, substances permitted to be used in paper and paperboard by other regulations in this chapter, and the following:

[26 F.R. 8974, Sept. 23, 1961, as amended at 27 F.R. 46, Jan. 4, 1962, 27 F.R. 6928, July 21, 1962, 28 F.R. 3260, Apr. 4, 1963, 28 F.R. 3448, Apr. 9, 1963, 28 F.R. 5562, June 6, 1963; 28 F.R. 6012, June 13, 1963; 28 F.R. 11628, Oct. 31, 1963]

[blocks in formation]

cordance with good manufacturing prac tice has been structurally altered in par in one of the following ways:

(1) By treatment with ethylene oxid so that the finished modified starch con tains not more than 3.0 percent of re acted ethylene oxide.

(2) By treatment with not more tha 4.0 percent B-diethylaminoethylchlorid hydrochloride and 3.0 percent propylen oxide, individually or in combination.

(3) By treatment of food starch-modi fied (§ 121.1031(a) (1)) with not mor than 0.3 percent epichlorohydrin.

(4) By treatment with not more tha 1.0 percent sodium hydroxide.

(5) By treatment with not more tha 3.0 percent dimethylaminoethylmetha crylate.

(6) By treatment with not more tha 5.0 percent of 2,3-epoxypropyltrimethy ammonium chloride.

(7) By treatment with not more tha 0.375 percent of dimethylol ethyler urea; Provided, however, That industri starch modified by this treatment sha be used only as internal sizing for pap and paperboard intended for fo packaging.

(b) Industrial starch-modified is i tended for use as follows, subject to a limitations prescribed in paragraph ( of this section:

(1) In the preparation of sizing coatings for paper, paperboard, or te tiles intended for food packaging.

(2) In the fabrication of other fo packaging materials when so authoriz by the regulations in this subpart.

(c) To assure safe use of the additiv the label of the food additive contain shall bear, in addition to the other i formation required by the act:

(1) The name of the additive. (2) Information describing how t starch is modified.

(d) The following adjuvants may used as surface-active agents in t processing of industrial starch-modif in accordance with any prescribed lir tations:

Polyethylene glycol 400 monolaurate.
Polyethylene glycol 400 dilaurate.
Polyoxyethylene (4) lauryl ether.
Polyoxyethylene (20) sorbitan trioleate.
Sorbitan monolaurate.

[27 F.R. 223, Jan. 9, 1962, as amended 27 F.R. 7493, July 31, 1962, 27 F.R. 11 Dec. 4, 1962, 28 F.R. 5047, May 21, 1963: F.R. 7219, July 13, 1963; 28 F.R. 7426, July 1963]

« iepriekšējāTurpināt »