In general, you cannot sue your employer if you were injured while at work under the Workers' Compensation Law. However, in New Jersey, an injured worker can sue his/her employer under the "intentional wrong" exception. There is an intentional wrong when an employer commits an intentional act and knows that the act is substantially certain to result in harm to a worker.
For example, if an employer knows that a guard needed to be on the machine to protect the operators from amputation risks but removed the guard anyway to improve production time, then it can be argued that the employer committed an intentional wrong.
I don't know the circumstances and details of your accident to determine whether an intentional wrong occurred. Therefore, if is important that you talk to an experienced industrial machinery accident lawyer in New Jersey to discuss your accident. You may be able to recover from your employer as well as file a workers' compensation claim.