Editing Sand casting (section)

===Fast mold making processes===
With the fast development of the car and machine building industry the casting consuming areas called for steady higher [[productivity]]. The basic process stages of the mechanical molding and casting process are similar to those described under the manual sand casting process. The technical and mental development however was so rapid and profound that the character of the sand casting process changed radically.

====Mechanized sand molding====
The first mechanized molding lines consisted of [[Sand slinger|sand slingers]] and/or jolt-squeeze devices that compacted the sand in the flasks. Subsequent mold handling was mechanical using cranes, hoists and straps. After core setting the copes and drags were coupled using guide pins and clamped for closer accuracy. The molds were manually pushed off on a roller [[conveyor]] for casting and cooling.

====Automatic high pressure sand molding lines====
Increasing quality requirements made it necessary to increase the mold stability by applying steadily higher squeeze pressure and modern compaction methods for the sand in the flasks. In early fifties the [[high pressure]] molding was developed and applied in mechanical and later automatic flask lines. The first lines were using jolting and vibrations to pre-compact the sand in the flasks and [[compressed air]] powered pistons to compact the molds.

=====Horizontal sand flask molding=====
In the first automatic horizontal flask lines the sand was shot or slung down on the pattern in a flask and squeezed with hydraulic pressure of up to 140 [[Bar (unit)|bars]]. The subsequent mold handling including turn-over, assembling, pushing-out on a conveyor were accomplished either manually or automatically. In the late fifties [[hydraulics|hydraulically]] powered pistons or multi-piston systems were used for the sand compaction in the flasks. This method produced much more stable and accurate molds than it was possible manually or [[pneumatics|pneumatically]]. In the late sixties mold compaction by fast air pressure or [[gas pressure]] drop over the pre-compacted sand mold was developed (sand-impulse and gas-impact). The general working principle for most of the horizontal flask line systems is shown on the sketch below.

Today there are many manufacturers of the automatic horizontal flask molding lines. The major disadvantages of these systems is high spare parts consumption due to multitude of movable parts, need of storing, transporting and maintaining the flasks and productivity limited to approximately 90–120&nbsp;molds per hour.

{{wide image|Horizflask.png|600px}}

=====Vertical sand flaskless molding=====
In 1962, Dansk Industri Syndikat A/S (DISA-[[DISAMATIC]]) invented a flask-less molding process by using vertically parted and poured molds. The first line could produce up to 240 complete sand molds per hour. Today molding lines can achieve a molding rate of 550 sand molds per hour and requires only one monitoring operator. Maximum mismatch of two mold halves is {{convert|0.1|mm|in|abbr=on}}. Although very fast, vertically parted molds are not typically used by jobbing foundries due to the specialized tooling needed to run on these machines. Cores need to be set with a core mask as opposed to by hand and must hang in the mold as opposed to being set on parting surface.

{{wide image|disa.jpg|600px}}

=====Matchplate sand molding=====
The principle of the matchplate, meaning pattern plates with two patterns on each side of the same plate, was developed and patented in 1910, fostering the perspectives for future sand molding improvements. However, first in the early sixties the American company Hunter Automated Machinery Corporation launched its first automatic flaskless, horizontal molding line applying the matchplate technology.

The method alike to the DISA's (DISAMATIC) vertical molding is flaskless, however horizontal. The matchplate molding technology is today used widely. Its great advantage is inexpensive pattern tooling, easiness of changing the molding tooling, thus suitability for manufacturing castings in short series so typical for the jobbing foundries. Modern matchplate molding machine is capable of high molding quality, less casting shift due to machine-mold mismatch (in some cases less than {{convert|0.15|mm|in|abbr=on}}), consistently stable molds for less grinding and improved parting line definition. In addition, the machines are enclosed for a cleaner, quieter working environment with reduced operator exposure to safety risks or service-related problems.

[[File:match-de.png|center|700px]]

=====Safety standards=====
With automated mold manufacturing came additional workplace safety requirements. Different [[Technical standard|voluntary technical standards]] apply depending on the geopolitical jurisdiction where the machinery is to be used.

======Canada======
Canada does not have a machine-specific voluntary technical standard for sand-mold making machinery. This type of machinery is covered by:

[https://store.csagroup.org/ccrz__ProductDetails?viewState=DetailView&cartID=&portalUser=&store=&cclcl=en_US&sku=Z432-16 Safeguarding of machinery, CSA Z432. Canadian Standards Association. 2016.]

In addition, the electrical safety requirements are covered by:

[https://store.csagroup.org/ccrz__ProductDetails?viewState=DetailView&cartID=&portalUser=&store=&cclcl=en_US&sku=C22.2%20NO.%20301-16 Industrial Electrical Machinery, CSA C22.2 No. 301. 2016.]

======European Union======
The primary standard for sand-mold manufacturing equipment in the EU is:
[https://standards.cen.eu/dyn/www/f?p=204:110:0::::FSP_PROJECT,FSP_ORG_ID:38822,6183&cs=187F082E35537138F42BC892EB6E6F41B Safety requirements for foundry moulding and coremaking machinery and plant associated equipment, EN 710. European Committee for Standardization (CEN).]

EN 710 will need to be used in conjunction with [https://www.cenelec.eu/dyn/www/f?p=104:110:1254549426375101::::FSP_ORG_ID,FSP_PROJECT,FSP_LANG_ID:1257239,58483,25 EN 60204-1] for electrical safety, and [https://standards.cen.eu/dyn/www/f?p=204:110:0::::FSP_PROJECT,FSP_ORG_ID:39285,6096&cs=1269268F03116BF7319D76D5A120E771A EN ISO 13849-1] and [https://standards.cen.eu/dyn/www/f?p=204:110:0::::FSP_PROJECT,FSP_ORG_ID:32684,6096&cs=14A2AF9B02A956FEEFFE273E56BFE6C04 EN ISO 13849-2] or [https://www.cenelec.eu/dyn/www/f?p=104:110:476494116260901::::FSP_ORG_ID,FSP_PROJECT,FSP_LANG_ID:1257239,58972,25 EN 62061] for functional safety. Additional type C standards may also be necessary for conveyors, robotics or other equipment that may be needed to support the operation of the mold-making equipment.

======United States======
There is no machine-specific standard for sand-mold manufacturing equipment. The ANSI B11 family of standards includes some generic machine-tool standards that could be applied to this type of machinery, including:

* Safety of Machinery, ANSI B11.0. American National Standards Institute (ANSI). 2020.<ref>[https://www.b11standards.org/standards B11 Standards]</ref>
* Performance Requirements for Risk Reduction Measures: Safeguarding and other Means of Reducing Risk, ANSI B11.19. American National Standards Institute (ANSI). 2019.
* Safety Requirements for the Integration of Machinery into a System, ANSI B11.20. American National Standards Institute (ANSI). 2017.
* Safety Requirements for Transfer Machines, ANSI B11.24. American National Standards Institute (ANSI). 2002 (R2020).
* Functional Safety for Equipment (Electrical/Fluid Power Control Systems) General Principles for the Design of Safety Control Systems Using ISO 13849-1, ANSI B11.26. American National Standards Institute (ANSI). 2018.
* Sound Level Measurement Guidelines, ANSI B11.TR5. American National Standards Institute (ANSI). 2006 (R2017).