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Extensive Molding Facilities
Precision Paper Tube Company has developed an extensive fabricated molded bobbin production capacity including the latest multi-cavity injection molding equipment (up to 475 tons pressure - 42oz. capacity). Due to the high output of this equipment, large quantities can be produced at very low cost. Accuracy is extremely uniform because of precise die tolerances and tooling. A wide variety of thermoplastic materials is available to provide desired electrical and mechanical properties coupled with cost factors. Any practical size molding bobbin, or IF and RF coil form, may be produced.

Molded Material Choices
Name Tensile Strength Deflection Temp °F(264 Lb/In2) Dielectric Strength (V/Mil)
6/6 Nylon
6/6 Nylon - Flame Retardant
6/6 Nylon - Glass Filled
Phenylene Oxide (Noryl®)
Polycarbibate (Lexan®)
Thermoplastic Polyester 20% G.F.
Thermoplastic Polyester 20% G.F, F.R.
Polyethylene Terephthalate (Rynite®)
Polyphenylene Sulfide (Ryton®)
Polyphenylene - Flame Retardant
® Registered trademarks of General Electric, Phillips Petroleum, DuPont.  
Fabricated Bobbin Core Material
Name Dielectric Strength (VPM) Temperature Class °C Specific Gravity
165 90 (O) .77
300 105 (A) 1.15
260 105 (A) 1.24
250 105 (A)
7,000 150 (B+) 1.39
720 220 (H+) .91
® Registered trademarks DuPont.
Detailed Information

Heat Resistant Qualities:
Fabricated molded bobbins exhibit unexcelled heat resistant properties. They can be used in applications where plastic bobbins are not satisfactory. The heat resistance of low cost dielectric Kraft is 200 degrees and bobbins made of Nomex are in excess of 570 degrees. Fabricated bobbins are also available in flame retardant materials.

Variety: An extremely wide range of materials is available for farbicated molded bobbins. These materials are kept in stock for prompt production of your orders. Materials can also be combined for unique specifications.

Stock Flanges: We have over 1500 stock dies for fabricated bobbin flanges. No tooling charge is involved for bobbins made to these sizes. Samples and prototypes are therefore readily available at nominal cost, (request catalog #B-328). Flanges are available in ROUND & SQUARE or RECTANGULAR.

Terminations: Complete facilities for attaching terminals to bobbin flanges are available, or holes may be pre-punched at the time flanges are made for insertion of your own terminals. Tie-offs and other configurations can also be punched out of the flange itself.

Washers: Washers and spacers can be applied to fabricated bobbins. They can be attached to the core according to specifications or place on the core free to move. These can be die cut to your requirements and can be punched for terminals or terminals can be attached at our factory.

"Plastilokt": This is a method that has been patented by Precision, for positively affixing and positioning flanges to the bobbin core. It assures that flanges, and any terminals on these flanges, will stay in position. It also prevents rotational movement in round bobbins and thus reduces labor costs in your plant.

Coatings: Fabricated bobbins are available coated with special varnishes to increase strength and to reduce moisture absorption.

Patented* Anti-Slip Surface: Mat finish surfaces are available for superior winding and taping characteristics. This surface can be obtained either on the core alone, on the core and inside surface of the flange or on all surfaces of the bobbin depending on the design. (* US Patent 3,460,246)

Tooling: Precision has one of the most modern tooling facilites in the industry. We make accurate dies from your prints or provide you with prints for your approval upon receipt of specifications. Tooling costs are kept as low as possible consistent with the making of a top quality product.

Terminals: A variety of holes and lead slots can be molded into the bobbin according to application. Printed circuit terminals or tie-off lugs, square or round wire terminals and snap-on or quick disconnect lugs can also be incorporated into the bobbin at our plant. Machines are available for terminalling in your plant.

Pre-Production Samples: Prototype work can often be done with fabricated bobbins, and sample production problems ironed out, before molded bobbins are tooled and produced. Precision has a wealth of tooling for fabricated parts at modest cost. These dual production facilites can save valuable time in preparing your prducts for market. Contact us for full details.

Friction Resistant Cores: In order to make solenoid bobbins more abrasion and friction resistant, we have developed a bobbin whose core is in line with "Mylar". The dielectric strength of this core is increased considerably with this lining.
Bobbin Mesaurement Specifications