What does "BDM" stand for ?

Mr Bercovitz was an industrialist who employed Dr Doelter to lead a team to develop the mass production of a zipper designed by Mr Mulka

So you have the B-D-M zipper, with a history going back to 1952. The name commemorates 3 men who struggled against great odds to make a sealed zipper.

What's the difference between PVC, PU, and PE - they're all "plastics"?

PVC and PE have much narrower temperature ranges than PU. PVC and PE become brittle in Arctic waters and therefore are not recommended for survival suits. PVC is fine for surface watersports suits in temperate climates, and in chemical suits in some environments. PE may prove to be an excellent chemical suit material, but we await the results of tests and trials so we do not offer the PE for anything other than packaging at present. PU is also much stronger than PVC or PE and our latest PU development has the same base fabric as the Neoprene and is replacing Neoprene zippers in some areas.

What's the difference between PU and Neoprene (CR) ?

In performance terms very little following our development work with Mann (now Highland) Industries in the USA. However suit assembly may be by way of High Frequency welding when the suit is PU as well as the zipper. CR must be mounted by an adhesive system or by sewing and taping. Many clients are moving on to PU to reduce the HSE problems experienced with solvent based adhesives. However, only CR is recommended by BDM for Diving Drysuits, though we have clients using PU in diving suits for certain applications...

What do the "Pitch" numbers mean ?

The New Zipper Company is an old established English company and therefore all the development work was done in inches and parts of an inch. The zippers were given sizes according to the number of outer elements per inch, ten, eight, or six. We are now metric of course, but the pitch sizes remain. Order zippers in in whole centimetres please. For example: 08RS/CR44/PHB/95cm is an 8 Pitch zipper on Neoprene tape, with an overall length of 95cm. There's more on:

When did YKK come in to the picture ?

The YKK group purchased the NZCo in 1983, and completely re-engineered the factory at the time of moving to the Banbury Avenue address in 1989. YKK's experience in conventional zipper manufacture has assisted the NZCo in upgrading the product in several areas in recent years. NZCo's experience in dry zippers has assisted YKK in other semi-dry projects.. The New Zipper factory is considered to be the hub of the sealed zipper world. We were first to make a sealed both ends zipper suitable for divers, first into space with a NASA project, first to achieve ISO9000, first on the Web, first into PE development, first into PU development... All this from a small company (30 staff) in Slough ! We now have 50% of the total World Market serviced from Slough.In 2005 we moved to larger premises in Deal Avenue.

How do I select the correct zipper for my project ?

FIRST OF ALL - Take into account the environment in which the zipper will be used, and THE END USERS, the suit material you have chosen, and the assembly method you would prefer. If you are still unsure contact us direct for Technical Advice, preferably by fax or by e-mail. We even advise on WHERE to fit the zipper on new projects, especially non-clothing applications. Our advice is extremely confidential, with only two people at NZCo involved. We cannot accept responsibility for your incorrect use of our zippers ! Use this service !

IF you can determine the performance levels you are seeking we have the Specifications (short form) for each zipper here:

How should I store dry zippers ?

In pre-production stores in a factory, the BDM Zipper should be stored OPEN, in a cool dark place, away from ozone emissions and draughts. Keep them in the box we supply them in BUT open them fully... This is a good form of "Goods Inwards" inspection - open every zipper. See they run smoothly.Any problems can then be reported immediately to us.

Once in a suit, the zipper should be open and waxed when not in use, and in a cool dark place also. However you may have a bag for the suit... Please roll the suit up from the feet and fold the zipper around the outside of the suit bundle to give a gentle curve to the zipper. See the CARE page for more on this. Do not fold tight or put other things on top of the suit. Hang the suit up if there is no bag. As a PADI Instructor who dives UK waters all year round, I hang my dry suit up om a shoulder-=saver hanger, with the zipper open, to ensure it dries and "airs" before my next use. There is no strain on the open zipper this way.

How should I maintain my dry zipper ? Read this page:

• Suits for Commercial and Sports Divers,

• Suits for Petro-chemical working environments,

• Sealed covers for the Petro-chemical industries,

• Low pressure medical re-compression chambers,

• Sealed covers for food and water storage,

• Sealed covers for vehicles in storage,

• Escape hatches in military vehicles used in amphibious landings

• Sealed covers on compartments in ships, aircraft, helicopters, rail tunnels,

• Barriers in sewers and tunnels,

• Doors to rubber and plastic dry-storage buildings,

• Fitted covers on military vehicles and aircraft,

• Fitted covers with quick release on missile systems,

• Camera covers for large video and cine cameras,

• Gas welding containments,

• Conveyer belt jointing,

• Filter assembly supports, in Sulphuric acid baths.

• Seals on Foil packaging containers for international shipping (Foil with PVC or PE inner skin)

Even Here: