Once a judgement has been rendered by the judge can a company ask for interest?

Yes.  A Judgment, once entered, automatically earns interest at the rate of 9% a year.

Once a judgment is entered, it automatically draws interest, at a rate that is set by law (and right now, is 9 % per year).  In some cases, pre-judgment interest can be sought, as part of the damages in the lawsuit, but those can't be added after the judgment has been entered, unless the court grants a motion to amend the judgment.  If you're the judgment debtor, you have a right to oppose that motion.

Typically, pre-judgment interest is awarded where the debt was clearly owed and was subject to interest charges in the original contract, to cover the time from when the complaint was filed until the judgment is awarded.  If it wasn't asked for in the complaint, I'd argue that the plaintiff shouldn't have it for that reason.