Process for preparing polyethylene terephthalate useful for beve

Details Process for preparing polyethylene terephthalate useful for beve Process for preparing polyethylene terephthalate useful for beve

1978-05-16

1980-09-16

Taylor, Hosea E.

Synthetic resins or natural rubbers -- part of the class 520 ser

Synthetic resins

Treating polymer containing material or treating a solid...

528309, 528503, C08G 6322

Patent

active

042231280

ABSTRACT:
There is disclosed a process for reducing the acetaldehyde content and the generation rate of acetaldehyde of polyethylene terephthalate chip which has a crystallinity of at least about 30% in order to render the polyethylene terephthalate suitable for making containers which are useful in the carbonated beverage industry. This process comprises stabilizing the polyethylene terephthalate by heating it at an elevated temperature in air and maintaining an air to chip ratio at a predetermined value of at least about 0.8 standard cubic foot of air per minute/pound of resin per hour and at a vapor velocity of at least about 0.5 foot per second. The air used in the stabilization process has a dew point of less than about -30.degree. C.
The stabilized polyethylene terephthalate produced by this process has an acetaldehyde level of less than about 2.5 parts per million, a generation rate of acetaldehyde of less than about 3.0 parts per million per minute and an intrinsic viscosity of from about 0.60 to about 0.95 deciliters per gram.
There is also disclosed a process for molding a polyethylene terephthalate preform comprising melting the above described polymer, forming it into the desired preform shape, and cooling the molten polymer. This preform may then be reheated above its glass transition temperature and molded into the desired container shape.

REFERENCES:
patent: 2503251 (1950-04-01), Edwards et al.
patent: 2912457 (1959-11-01), Blaser et al.
patent: 3075952 (1963-01-01), Coover, Jr. et al.
patent: 3305532 (1967-02-01), Middleburg et al.
patent: 3349499 (1967-03-01), Katano
patent: 3544525 (1968-03-01), Balint et al.
patent: 3547890 (1970-12-01), Yamada et al.
patent: 3728309 (1973-04-01), Maxion et al.
patent: 4064112 (1977-12-01), Rothe et al.
patent: 4069194 (1978-01-01), Gey et al.
patent: 4069278 (1978-01-01), Borman et al.
Whitehead, "The Crystallization and Drying of Polyethylene Terephthalate", 16 Ind. Eng. Chem., Process Des. Dev. (No. 3), 341 (1977).
Perry's Chemical Engineers' Handbook, 5th Ed., McGraw-Hill, 1973, Section 22, pp. 52-54.
Buyers' Guide Issue of Chemical Engineering, Feb. 17, 1978.
Panametrics, Inc. of Waltham, MA, Data Sheet & Operating Manual for Model 600 Hygrometer.

Affiliated with

Also associated with

Rating

Process for preparing polyethylene terephthalate useful for beve does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Process for preparing polyethylene terephthalate useful for beve, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Process for preparing polyethylene terephthalate useful for beve will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-541501