Webs is a good possibility if you're willing to accept you might be wrong about the time period, since it was released in 2003 according to IMDB.
Four electricians, Dean, Junior, Ray and Shelly, are sent to cut off the power in a condemned building before it's torn down. They notice there's a difference between the floor plans and the actual size of the building. Upon breaking down a door they discover an old laboratory, which encloses an atomic pile (vintage nuclear reactor) powering a weird machine in the floor. They unwillingly set off an alarm and then boot up the device. Dean falls through a dimensional portal that's created and Junior goes after him, while Ray and Shelly read a journal left behind by the scientists. Dean and Junior appear outside in a deserted and web covered Chicago. Dean goes off to have a look around, while Junior waits for the others. Shelly, by reading the journal, realizes that the researchers were attempting to make a gateway to a parallel universe and he and Ray decide to step through the portal.
Finding no one on the other side of the dimensional portal, Ray and Shelly set off and get a fright when Junior leaps out. Junior leads them to a broken-down security van, with much money in the back. Junior, Ray and Shelly start celebrating, while Dean comes running back armed with a block of wood. Junior suddenly says "Guys" and steps forward with a claw in his stomach. Junior dies, and more creatures (spider people) attack the others. A group of humans save the electricians and kill the creatures. They fight more of the creatures, and head back to the portal, Dean stops to help a survivor and the portal closes leaving him trapped. On Shelly's and Ray's side, the atomic pile shorts the portal. Shelly starts trying to fix it, while Ray goes off to call for help.
The survivors bring Dean into their hideout where they meet Crane. A female survivor, Elayna, insists that Dean come with them to see "The Old Man". She blindfolds him and they set out for the base. Meanwhile, Ray comes back saying that everyone thinks he's insane and refused to send anyone. He did however come back with a small arsenal of guns. Dean meets the Old Man, who is revealed to be Dr. Richard Moreli, the inventor of the portal who got stranded here 30 years ago. Dean tells him his friends are on the other side and trying to fix it. Dr. Moreli tells him when he opened the portal 30 years ago, it let in the giant Spider Queen, who set out to enslave or eat most of humankind.
Elayna says the "soldiers" (the spider people) used to be normal people, but the Spider Queen's venom makes them completely under her control. Any survivors are made to show the soldiers where their base camp is, when the others go out and find the camps they are empty and bloodstained. They leave the base, to find the Spider Queen has been watching, they hear gunshots and find Shelly and Ray. The survivors bring them back to the base, and Shelly and Moreli begin to build a new portal. ....
It's not exactly zombies, but the people enslaved by the Spider Queen act like zombies.
Here is a clip from the film showing the blond woman being eaten:
If the video isn't working, here's a screencap from the scene: