A solar reactive mulch film comprising one or more layers of heat shrink material pre-strained at a predetermined temperature and tension. Immediately cooling the pre-strained layers retains molecular deformation stresses in the material which facilitate shrinkage but not expansion on exposure to solar radiation. The mulch film adapted to be laid over longitudinal growing beds and held tautly by burying its side edges in soil. Exposure of uncovered portions of film to solar radiation causes shrinkage in one or more directions whereby in combination with the weight of the soil holding it down, maintains tautness of the mulch over a growing period. Methods of manufacture and use of the same.

An improved longitudinal stretching unit is disclosed, in addition to the installation position or operating position (A) for the assembly to be replaced, a standby position (D) and/or standby station at which a further assembly is kept on standby. The standby position (D) and/or the standby station is arranged and/or configured in relation to the longitudinal stretching unit such that the further assembly provided at this standby position (D) and/or standby station, already before the installation at the operating position (A), is brought or can be brought to operating temperature or at least to a preheating temperature that is higher or less than 30° C. lower than operating temperature.

An improved longitudinal stretching unit is disclosed, in addition to the installation position or operating position (A) for the assembly to be replaced, a standby position (D) and/or standby station at which a further assembly is kept on standby. The standby position (D) and/or the standby station is arranged and/or configured in relation to the longitudinal stretching unit such that the further assembly provided at this standby position (D) and/or standby station, already before the installation at the operating position (A), is brought or can be brought to operating temperature or at least to a preheating temperature that is higher or less than 30° C. lower than operating temperature.

A composition having a breaking strength of 10.0 N or more, containing a polytetrafluoroethylene, and substantially free from a compound represented by the following general formula (3):

(H—(CF.sub.2).sub.8—SO.sub.3).sub.qM.sup.2  General Formula (3): wherein M.sup.2 is H, a metal atom, NR.sup.5.sub.4, where each R.sup.5 may be the same or different and is H or an organic group having 1 to 10 carbon atoms, imidazolium optionally having a substituent, pyridinium optionally having a substituent, or phosphonium optionally having a substituent; and q is 1 or 2.

A method for producing a fluoropolymer, which includes polymerizing a fluoromonomer in an aqueous medium in the presence of a polymer (1), the polymer (1) including a polymerized unit derived from a monomer CX.sub.2═CY(—CZ.sub.2—O—Rf-A), wherein X is the same or different and is —H or —F; Y is —H, —F, an alkyl group, or a fluorine-containing alkyl group; Z is the same or different and is —H, —F, an alkyl group, or a fluoroalkyl group; Rf is a C1-C40 fluorine-containing alkylene group or a C—C100 fluorine-containing alkylene group and having an ether bond; and A is —COOM, —SO.sub.3M, or —OSO.sub.3M, wherein M is —H, a metal atom, —NR.sup.7.sub.4, imidazolium optionally having a substituent, pyridinium optionally having a substituent, or phosphonium optionally having a substituent, wherein R.sup.7 is H or an organic group, providing that at least one of X, Y, and Z contains a fluorine atom.

To provide a piezoelectric body film that can suppress decrease in the piezoelectric constant d31, a method of producing a piezoelectric body film, and a piezoelectric body device. A piezoelectric body film comprising a fluororesin as a piezoelectric material, the fluororesin containing, as a main constituent unit, a repeating unit derived from vinylidene fluoride, a piezoelectric constant d31 of the piezoelectric body film being 20 pC/N or greater, and an extrapolated onset temperature at start of shrinkage determined by TMA measurement being not lower than 90° C. and not higher than 115° C. The difference between piezoelectric constants d31 measured before and after heating the piezoelectric body film at 100° C. for 24 hours relative to the piezoelectric constant d31 before the heating for 24 hours is 20% or less.

Disclosed are a graphite sheet formed from a polyimide film having a molecular orientation ratio of at least about 1.25, and a method for producing the same.

Disclosed are a graphite sheet formed from a polyimide film having a molecular orientation ratio of at least about 1.25, and a method for producing the same.

The present invention relates to a prestretched polyethylene film having a longitudinal stretch ratio of from about 1:2 to about 1:4 and having a longitudinal elongation capability of at least 170%, said elongation capability comprising an elastic component. The invention also relates to a method for producing said film and to a method of wrapping compressed bulk material such as a round bale using said film, the method comprising further stretching the prestretched film and applying the film around the compressed bulk material in direct contact therewith. The film according to the invention may be used as a net replacement film and allows increasing the efficiency and the economics in the baling process by allowing faster baling, use of a lesser amount of wrapping film and/or improved protection of the product.

The present invention relates to a prestretched polyethylene film having a longitudinal stretch ratio of from about 1:2 to about 1:4 and having a longitudinal elongation capability of at least 170%, said elongation capability comprising an elastic component. The invention also relates to a method for producing said film and to a method of wrapping compressed bulk material such as a round bale using said film, the method comprising further stretching the prestretched film and applying the film around the compressed bulk material in direct contact therewith. The film according to the invention may be used as a net replacement film and allows increasing the efficiency and the economics in the baling process by allowing faster baling, use of a lesser amount of wrapping film and/or improved protection of the product.