Wa `alaykum As-Salamu waRahmatullahi wa Barakatuh.
In the Name of Allah, Most Gracious, Most Merciful.
All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.
Dear questioner, we would like to thank you for the great confidence you place in us, and we implore Allah Almighty to help us serve His cause and render our work for His Sake.
In his response to your question, Sheikh Ahmad Kutty, a senior lecturer and an Islamic scholar at the Islamic Institute of Toronto, Ontario, Canada, states:
If your clothes have visible impurities on them, then it would be highly desirable to scrap them off before dumping them into the washing machine with other clothes.
If, however, you did not do so, they would still be considered as pure once washed in the machine so long as there are no visible traces of impurities.
Machine washing is hardly different from hand-washing. The water runs in the machine in cycles: the entire process has been described thus: “After the machine fills the tub with water, and then stirs the clothes around using an agitator; after some time agitating, the washer drains the water and then spins the clothes to remove most of the water. Then, it refills, and agitates the clothes some more to rinse out the soap. Then it drains and spins again.”
It is clear from the above, that machine washing after all is not at all different from hand washing; hence there is no reason to consider the clothes thus washed as other than pure.
Allah Almighty knows best.