FACTS Tech Blog

A General List of Extrusion parameters to Control or Monitor

mttorley — Sun, 21 Sep 2008 02:08:05 +0000

In developing control systems, FACTS monitors and controls various parameters in the extrusion process. Below is a starter list. Feed System blending ratios of multiple ingredients extruder throughput in lbs/hour or lbs/ft Extruder barrel temperature zones – These are usually have heating & cooling Tooling temperature zones – These are usually heat only Die temperature zones – These are [...]

Extrusion Control - Automated Solutions Answer Problems left by Numerous Discrete Controls

mttorley — Tue, 16 Sep 2008 02:38:06 +0000

The control system is an integral part of the extrusion machinery and extrusion process. It has a very large impact on the productivity, quality, uniformity, and cost per production unit for the extruder and overall extrusion process. This post answers what benefits a computer has over operator/discrete controls. Operator vs. Computer Regardless of the technology that [...]

Factory Information Architecture from the Bottom Up, NOT the top down

mttorley — Sat, 13 Sep 2008 18:42:44 +0000

Historically, management information systems in the factory have been driven from the top down, with suppliers of MRP and ERP systems adding terminals and forms to capture manufacturing data from the factory floor. This approach is expensive, inefficient, and the data accuracy is generally poor. The additional work load for the operators is also [...]

Calender Fabric Issues Affecting overall Calendered Rubber Gauge

mttorley — Wed, 10 Sep 2008 02:01:07 +0000

The following relates to fabric calenders, both textile and steel cord only. Localized cord disturbance in cord distribution does not usually affect fabric weight, whereas overall cord distribution problems can affect fabric weight, sheet gauge, and quality. For example, an incorrect cord distribution that has a light weight center and heavy outer edges is due to: reduced average [...]

A Consistent Mill Feed Will Substantially Reduce Gauge Variations

mttorley — Wed, 10 Sep 2008 00:58:01 +0000

A consistent feed to the calender will substantially reduce gauge variations. Consistent, uniform, dwell times on the break down and feed mills, as well as consistent bank size, will result in consistent stock temperatures, work history, and reduced variations in roll separating forces. The stock temperatures, bank sizes, and work history all directly influence roll-separating forces. Minimizing [...]

Calender Speed Changes Result in Undesirable Gum Wall Thickness Changes

mttorley — Tue, 09 Sep 2008 02:51:34 +0000

When the calender is running there are forces generated that try to separate the rolls. These separating forces are proportional to calender speed, although the relationship is not linear. The hardness of the rubber stock and bank temperature determines the magnitude of separating forces. The thickness of the gum wall being calendered also affects the [...]

Minimize Temperature Rate of Change on Calendar Rolls

mttorley — Tue, 09 Sep 2008 02:42:58 +0000

Limit the temperature rate of change at all times to a maximum of 3 degrees per minute F. Faster rates can damage or warp the rolls. The control system on the TCU should limit the rate of temperature change for each roll water loop to 3 degrees per minute. Faster rates of change do not allow [...]

Increase Roll Temperature when the Calender is Stopped

mttorley — Tue, 09 Sep 2008 02:38:31 +0000

Increase the temperature by 20 to 40 degrees F when the rolls are stopped to maintain a more uniform roll surface temperature. The TCU (Temperature Control Unit) controls the temperature of the water exiting the calender not the roll surface temperature. This is an important distinction. When the calender is not actively processing rubber, i.e. [...]

Keep your Calender Running During Warm-Up and Cool Down

mttorley — Tue, 09 Sep 2008 02:32:12 +0000

Severe thermal run-out can be introduced during warm-up of the calender if it is not kept running. Remember that the calender gap will be reduced as the rolls grow (get larger) as their temperature increases. Good practice is to open the calender at least 100 mils (0.10”) before starting to increase the roll temperature above [...]

Limit Force Induced Gauge - Keep the Calender Running

mttorley — Mon, 08 Sep 2008 03:18:13 +0000

Keep the calender running – stops cause the rolls to become egg shaped and introduce significant gauge thickness variation. When the calender is stopped, roll heat loss is not uniform around the roll. Heat loss along the circumference near adjacent rolls is minimal while heat loss in other areas is much higher. This leads to different [...]