The phrase "a plastic pack" is correct and usable in written English.
It can be used to refer to a packaging item made of plastic, often used for containing or storing products.
Example: "I bought a sandwich that came in a plastic pack for convenience."
Alternatives: "a plastic pouch" or "a plastic bag".
He had found a plastic pack of crackers; he chewed them slowly, almost thoughtfully.
In her wire basket she had sausages and eggs and tins of baked beans and a plastic pack of four jam doughnuts, one each (she had another brother, James, fourteen): she'd put on weight since she'd been home, not much, but enough to make her aware of some new soft fat around her waistline and cushioning her chin.
In glass display cases at his exhibition were Paula Abdul's "Spellbound" CD in the shell of a giant metal compact case; a Slayer single in a squishy plastic pack full of skulls floating around in fake red blood; and a beautiful wooden-looking radio replica that held a multi-disc set of blues and jazz from Mercury Records.
Usually the concentrate is supplied in a squeeze-and-pour plastic pack with a graduated small dispensing chamber, so that you can squeeze up the required amount into this measuring chamber and then apply it to the animal.
This was the magical French way of making everyone the culinary equal of the great chef Alain Ducasse: Simply put, the food would be prepared and then sealed in a specially designed plastic pack, with some of the air taken out.
I tie a plastic ice pack around my face and commence with the morning's stretching exercises.
And there are some items which are cheaper at supermarkets: a plastic value pack of peppers, for example, is always cheaper than individually priced peppers at markets.
I opened the plastic pack.
The plastic pack looks like two plastic cream dispensers joined on one edge.
I'll never buy another plastic pack of supermarket Edam again.
(The watery effect is made possible by a web of plastic packing tape, one of Mr. Hirschhorn's signature materials).
