Christopher Wright, 57, from Oswestry, already has some movement back in his fingers and thumb just over a week after the accident.
He said all those who saved his hand, from ambulance staff to the surgeons were absolutely amazing.
Mr Wright, whose own training as a first aid responder helped him, was at the factory he works at in Wrexham when the injury happened.
WATCH: Video shows Christopher Wright wiggling his fingers
“Whilst working on a cardboard cartons machine, the chains grabbed my overalls and pulled my hand in to the machine. I heard a snap noise and at that moment I knew I had lost my hand," he said.
“After going on a first aid responder course a couple of years back, my training from then instantly kicked in. I grabbed my arm out of the machine, squeezed it and called for help. I called for a first aider who then called for an ambulance. I remained conscious for the whole time that this was happening.”
Mr Wright was taken to University Hospitals of North Midlands Major Trauma Centre by ambulance - his hand sitting next to him in a secure medical bag. From there he was transferred to the Royal Derby Hospital Pulvertaft Hand Centre by North Wales Air Ambulance where he was greeted by Mary O’Brien, consultant hand and plastic surgeon, and the rest of her team.
The Hand Centre team then performed an eleven-and-a-half hour operation which saw Mr Wright's hand reattached to his forearm.
Surgeons said he lost his little finger and also just over two inches from his arm where it had to be cut to create a smooth surface for the reattachment.
But Mr Wright said that just seven days on from the accident, he had some movement in his fingers and thumb.
“The work the surgeons and staff have done is absolutely amazing – they are unbelievable people," he said.
"There are no words that can express how thankful I am to all of the teams that have cared for me. Everyone has been amazing, and so kind – not just to me, they have been so supportive to my wife back at home too."
He said his wife, Elaine, couldn’t visit him in hospital due to the on-going pandemic, but they have kept in touch through regular calls on FaceTime.
Mary O’Brien said: “Mr Wright is an incredibly inspirational patient. He has a very positive outlook and is motivated in the face of what has been a life-changing industrial injury.
“The operation on Mr Wright’s hand was the result of a highly coordinated response from so many professionals working efficiently together. This included the ambulance and helicopter crew who brought Mr Wright to the emergency department, the theatre team which performed the surgery, supported by anaesthetic colleagues and nursing and therapy staff.
“This was an extremely complex procedure which involved five Consultant Surgeons as well as a wider multi-disciplinary team."
“Although we look after many patients with a range of different types of injury, it is very unusual to replant a whole hand. This is not just a physical injury but has a huge psychological impact on a patient and it is vital that mixed skill sets are involved to support patients with these injuries both immediately and in the months to follow to achieve a good outcome."