www.cdf1.com 800.443.1920

Presented by

Joseph Sullivan

Drum Liners for the Petroleum Industry

1

History of Drum Liners

Industrial drum liners as we know them today, evolved from what once was a

mandatory component of type 2U packages.

Type 2U packages were the package of choice prior to the development of the

plastic drum for certain chemicals and foodstuffs.

The liners were specified by the DOT to be a minimum of .020 thick as they

were the primary source of containing the product.

These open-head 2U liners were mostly vacuum-formed.

2

History of Drum Liners cont.

In the mid to late 70’s a problem/ opportunity arose. Many companies that were

filling adhesives, paints and other products that were hard to clean out began

having trouble getting rid of their drums.

There was also an opportunity to help companies re-use their drums internally.

It was the combination of the technology used to make the 2U liners and these

new opportunities that spawned the lighter weight industrial liners that are used

fairly extensively today.

3

Benefits of Using Drum Liners

Provides product protection for new and reconditioned drums

Offers source and waste reduction

Reduces time and expense of cleaning and/or replacing drums

Promotes reuse of your drum internally, which keeps drums out of the waste stream

The above two reduces use of fuel and greenhouse gas emissions

Provides an after market value to either reconditioning network or recyclers for steel drums

Recyclable – most liners are HDPE 2 and LDPE 4

Ships flat or nested for economical storage and shipping

4

Typical Drum Liner Markets

Chemical (petroleum related products, adhesives, automotive, coatings,

detergent, ink, paint, sealants, soap)

Cosmetic (conditioner, cream, liquid makeup, lotion, shampoo)

Food & Beverage (dairy, flavoring, fats, oils, spices)

Pharmaceutical

Powder

5

Styles of Drum Liners

Flat Seamed

Round Bottom

Straight-Sided

Accordion

Combination

Vented

Anti-stat

6

Flat Seamed Drum Bags

Flat seamed bags are an economical solution, however they are not

recommended when mixing blades or follower plates are used.

7

Round Bottom Drum Liners

Liners provide an economic solution for protecting your products. These liners are

designed for easy installation and can be simply twisted and tied off to protect

contents.

8

Straight-Sided Drum Liners

Liners fit smoothly into new drums and are ideal when using a follower plate.

9

Accordion Drum Liners

Liners have flexible, pleated, side walls originally designed to accommodate

variations in reconditioned drum heights and also ship economically .

10

Combination Drum Liners

Liners combine a straight-sided design with a band of accordion pleats to

accommodate both drum height variations and follower-plate use.

11

Vented Drum Liners

Liners have four holes near the top to vent trapped air during a fill, allowing drums

to be filled with the lid on. Only recommended for high viscosity products.

12

Anti-stat Drum Liners

Anti-stat acts as a dissipater of an electrical charge.

Anti-stat liners have an anti-static additive made of low-

molecular-weight materials that attract water from the

environment, forming a thin film on the surface of the

plastic. The anti-stat additive continuously blooms to the

surface with a typical shelf life of 12 months. Typical industry

standards meet NFPA-99 and MIL-B-81705C.

Anti-stat liners should not be used as the sole means to

dissipate any charge. They only act to reduce the charge in

the polyethylene liner itself. 13

Anti-stat Industry Standards

MIL-B-81705C standards require static decay and surface resistivity testing

as follows: first the material must be conditioned for 24 hours at 12% +/- 3%

relative humidity. The material must meet the 2.0 seconds or less static

decay time at 12 +/- 3% relative humidity at a temperature of 73°F +/- 5°F

and a surface resistivity of 1012 or less according to ASTM D257.

NFPA-99 (National Fire Protection Association) standards require the

material to be conditioned for 24 hours at 50% +/- 2% relative humidity prior

to testing and then must meet the static decay time of 0.50 seconds or less

at 50% +/- 2% relative humidity at a temperature of 23+/- 1°C./p>.

14

Drum Liner Technical Considerations

15

Typical Manufacturing Processes

Blown Film

Thermoforming

Blow Molding

16

Blown Film Liners

Inexpensive

Least rugged

Very thin- typically 3, 4, 8 & 10 mil

Seams

Barrier films can be used (high

temperature above 180ºF, oxygen and

moisture barrier commonly used)

Folds

Typically not recommended when

follower plates, mixing blades and fill

and dispense wands are used.

17

Heat Sealing

Heat Seal technology is used to produce flat seam and round bottom liners.

Films that can be heat sealed:

Polyethylene (LDPE & HDPE)

Metallized polyester and foil laminates for moisture protection

Conductive laminates and anti-static films for volatile materials

Nylon and co-extruded films for chemical resistance

Polypropylene for high-temperature requirements

18

How Heat Sealing Works

In heat sealing, a thin clear thermoplastic film is bonded by heat, time and

pressure to form a closure.

Heat sealing technology is simple in concept and provides cost-effective products,

but the process is not trivial. Tight tolerances, proven materials, precise timing and

temperature control all play key roles in providing products that meet demanding

customer requirements.

19

Thermoformed Liners

No seams

Uniformity of wall thickness

Flexibility vs. Strength vs. Price

Straight side or Accordion

Vented

20

Thermoforming

Thermoforming or vacuum forming, produces strong, semi-flexible, seamless

(leak-proof) liners in a range of thicknesses designed to withstand the rigors of

most demanding applications.

In deep-draw thermoforming liners up to 40" deep can be produced in a variety of

shapes (cylindrical, tapered or rectangular).

Can be run with multi-cavity tools.

21

How Thermoforming Works

In thermoforming, extruded sheets of plastic are carefully heated to soften the

material. The sheets are then pressed into a mold and a vacuum is drawn to force

the plastic into the shape of the mold. It is critical to maintain an even distribution of

material during this process.

Sheets that can be thermoformed:

LDPE

HDPE

Polypropylene for high temperature resistance

Anti-static polyethylene for use with volatile materials

EVOH for oxygen resistance

22

Thermoforming Animation

23

Thin and Thick Gauge Thermoforming

There are two general thermoforming process categories. Sheet thicknesses less

than 0.038 inches are usually delivered to the thermoforming press in rolls. Sheet

thicknesses from 0.038 inches through 0.120 inches typically come in sheets cut

to final dimensions and stacked on pallets. These thin-gauge thermoforming

applications are dominated by rigid or semi-rigid disposable packaging. Sheet

thicknesses greater than 0.120 inches are considered heavy- or thick-gauge, cut

sheet thermoforming applications, which are primarily used as permanent

structural components.

24

Blow Molded Liners

No seams

Very rugged

Very precise gauge control

Thinner lip

Used with mixer, follower plate

Agitator

Typically produced one at a time

25

Blow Molding

Blow molding technology provides extra performance in maintaining package

integrity and durability. Wall thickness and lip design can be carefully controlled.

With this technology drum liners are typically cylindrical, but square or rectangular

shapes can be made.

26

How Extrusion Blow Molding Works

In Extrusion Blow Molding (EBM), plastic is melted and extruded into a hollow tube

(a parison). This parison is then captured by closing it into a cooled metal mold. Air

is then blown into the parison, inflating it into the shape of the hollow bottle,

container or part. After the plastic has cooled sufficiently, the mold is opened and the

part is ejected. EBM processes may be either continuous (constant extrusion of the

parison) or intermittent.

Compared to injection molding, blow molding is a low pressure process, with

typical blow air pressures of 25 to 150 psi. This low pressure process allows the

production of economical low-force clamping stations, while parts can still be

produced with textured surface finishes. The resulting low stresses in the molded

parts also help make the containers resistant to strain and environmental stress

cracking.

27

www.fluent.com/software/ polyflow/blow.htm

Extrusion Blow Molding Animation

28

Injection Molding

Although Injection Molding is probably the most popular form of plastics processing, it is

not conducive to liner manufacturing. In order to form a part as tall as a drum, the walls

would have to be much thicker than is needed in thermoforming or blow molding, which

would increase the part cost. Thicker parts also mean longer cycle times, also

increasing costs. Injection molds are also typically more expensive and generally need

more taper than thermoforming molds, so the liner will not fit the drum as well.

There are some technical issues with injection molding related to liners. There are

inherent stress points at the sprue and gate (injection points), which may cause a

fracture point and consequently a leak point.

29

Injection Molding Animation

30

Questions

Liner Markets

Styles of Drum Liners

Flat Seamed, Round Bottom, Straight-sided, Accordion,

Combination, Vented, Anti-stat

Manufacturing Processes

Blown Film, Thermoforming, Blow Molding, Injection Molding

31